text:
What will be the best way to remove pla from a volcano nozzle?
My print popped out from the bed and glued to the nozzle. As the printer was printing next hour or so, a lot of pla was extruded and formed on the nozzle.
I'm wondering what will be the best way to remove pla from the nozzle without overheating wires?
a remark: was trying to heat the nozzle over 180, but I am getting a thermal runout. The pla is hard, I don't want to broke the throat.

If it doesn't heat up to printing temperature, will it when you removed all the goo? Personally I bought several heating blocks, throats, thermistors and heater elements. When I see this I instantly replace the extruder.

If you grab the blob with a pliers and twist, all or most of it may pop off.  If not,  heat the extruder up perhaps 10 degrees higher than usual, and wait for the external gunk to soften up and then pull it off.
edit :
Well, if it won't get hot enough, then try using an external source such as a soldering iron tip to cut off most of the mess, then it may be time for exacto knife blades and small files to remove the remainder.
Unless you're a clean freak :-) a little residue around the nozzle doesn't matter - it won't touch your prints and at some time in the future it'll be "cooked" enough to fall off.

thanks for that, but I was unable to heat it over 170... and more fun is that this is a volcano nozzle.

@profesor79 Disconnect your heater from the main board then apply 12V to make it work alone and wait the result that Carl describes.

@FernandoBaltazar that will fry the inner layers and could burst as per Horitsu answer

@profesor79 No my friend, nothing will be fried. The iron technique will be a little smoky, but the heater will be disconected from your board, so applying 12v will make to heat your melted pla like normally does, but this way you can reach a higher temperature that your board allows. If you doubt about 12V then just apply 10 or 9v but it will heat slower. This disconnection it will be like you are changing the whole E3D V6.

I would suggests to use a heat gun and carefully warm up the PLA to be soft and remove it carefully like a big piece of Play-Doh.
Using the extruder to heat up the PLA don't sound like the best idea, for me, because the inner PLA will be fluid and it could be a bigger mess than it is up to now.

that was said in Carl's answer as external heat source

He suggests a soldering iron tip, which I don't think to be a good idea, because you probably ruin the soldering iron, produces maybe toxic smoke/gases and would only heat up small parts at once. I instead mean to head up the whole blob to a soft enough point to be similar to play-doh.

So let see that from other perspective: soldering iron is external or internal heat source?

I never said, that a soldering iron is not an external heat source... Pls don't be rude, I just want to help you by making a suggestion.
I explained my idea and explained why I think the other (specific) one is not a good idea in my opinion.

Thanks for your response - I rather want to be on the same level of understanding, so most people when they imagine soldering iron, they see the small device used to join electronics components - but this is a wider area of devices. Using a heat gun will add a lot of risk to get a burn or to fry a closed object.


text:
Only generate supports between object and bed (for a brain model)
I would like to print a model of my brain (figure 1), it requires supports (figure 2). The supports also get generated between the brain folds/wrinkles of the brain by Slic3r. I only want the supports to be generated between the bed an the object, not within the object itself. I thought of writing a script to edit the g-code, is there an easier way out?
Figure 1:

Figure 2:

Within Slic3r, there are settings for support, which can be enabled to create support only from the build plate. This would still generate supports under the brain, but not within the hollow sections.

This worked, I had to install the latest version to get that option (cloned from github)

You could check meshmixer, the tree supports are pretty neat for complex models. You can edit the auto generated supports and when you are happy with the result it gets embedded in the 3d model.

source: Stack Exchange

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

sort: votes


text:
Finding a shredder for my failed prints
I would love to re-use my failed prints by re-extruding the plastic to be used in the 3D printer once again. One thing that stands in my way is finding an effective way to shred the plastic into smaller bits for the extrude to use. What is a good thing to look for to accomplish this? Maybe a really big 'paper' shredder?

LMGTFY produces several pages selling shredders and tools which re-extrude filament.

form what i've seen in youtube/forums it's not worth it. Making filament is hard because you have to nail the temp, extrusion pressure+speed, support the soft hot wet filament without drooping (which warps it) or sliding (which flattens it). Any variations in temp or speed will screw up the diameter. Any variations in scrap density will affect the temp and pressure. It's as complicated as nailing prints. Then you need to consider the effect that skin grease, dust, and other debris has on layer adhesion and uniformity. All in all it's not worth the time, equipment, or labor, at least not yet.

@dandavis You have a vary valid point, which is why I am still looking at doing this. I just watched some videos myself and it is indeed difficult from what I have seen. I just can't wait for something to come out that is simple to use and produces usable filament. I just hate not being able to re-use failed prints and knowing I could turn soda bottles into usually filament sounds great, but like you said its costly, time consuming, and difficult.

there is a project called precious plastic and there is a plastic shredder, but it is a rather expensive solution.
As I am waiting for parts for my Lyman extruder, my plan is to hammer the parts and then process in old kitchen robot with steel working area, an example here
The paper shredder will be ok as long as you can feed it with plastic.

I looked at the plastic shredder and darn it is rather pricey, but does look effective. I might do something similar to what your talking otherwise, for I don't make enough waste plastic to justify buying such a tool. But thank you for sharing that with me for it is a neat product.

The "plastic shredder" link is dead now.

I'm in the same boat as you, was contemplating spending $2000 on a shredder, and I was inspired by this RepRap article "Plastic Shredder using Kitchen Blender".
In which someone cleverly reminds us that thermoplastics melt. Put them on a baking tray on baking paper:

Melt them in the oven at a high temperature until they're pancakes:

The link puts them in a kitchen blender, but I've had success with a $70 micro-cut paper shredder from a local office supply store. The plastic puddles have a thin edge, which helps them fit into a shredder rated for "5 sheets of A4 at a time" (suggesting 0.3 mm max) but can process about 2 mm thick plastic if it gets a good lead-in.
The micro-cut particles it puts out are smaller than the PLA beads. I do mix recycled and virgin plastic together in varying ratios but mixing them evenly (especially with the dye beads) is tricky - it's very hard to get precise even colouring.
At 1.25 g/cc, 1 kg of PLA in an oven dish ~A4 sized is about 1.4 cm thick. So, aiming for about 100 g of plastic per dish will get you blobs averaging 1.4 mm. That fits through the shredder fine. 10 blobs make 1 kg of filament.
The only issue I have with the cheap office shredder is when you feed something slightly too thick in, occasionally the teeth deform the plastic into a chunk too big to fit into the shredder for a second pass, so that piece needs to go back into the melt queue.

Are there any issues with fumes from doing this?

@RockPaperLz-MaskitorCasket: PLA should not have any fumes issues whatsoever, but of course a lot of PLA is not actually PLA but some mystery blend. At least there are pigments (except in translucent natural color) but most "PLA" seems to contain at least some small part ABS or other acetone-soluble material, judging from what happens if you try putting acetone in a vessel made of printed "PLA"...

Have you checked the power cost?  Might be interesting to see the cost of power for all this.

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


text:
Problem with swapping E0 for E1 (TEVO TARANTULA MARLIN 1.1.x)
Looking at the following code, from Line 139, pins_RAMPS.h

Here is the actual code:
#if ENABLED(EXTRUDER_USE_E1)
  #define E0_STEP_PIN        36
  #define E0_DIR_PIN         34
  #define E0_ENABLE_PIN      30
  #ifndef E0_CS_PIN
    #define E0_CS_PIN        44
  #endif
#else
  #define E0_STEP_PIN        26
  #define E0_DIR_PIN         28
  #define E0_ENABLE_PIN      24
  #ifndef E0_CS_PIN
  #define E0_CS_PIN        42
  #endif
#endif

#if DISABLED(X_AXIS_USE_E1) && DISABLED(Y_AXIS_USE_E1) && DISABLED(Z_AXIS_USE_E1) && DISABLED(EXTRUDER_USE_E1)
  #define E1_STEP_PIN        36
  #define E1_DIR_PIN         34
  #define E1_ENABLE_PIN      30
  #ifndef E1_CS_PIN
  #define E1_CS_PIN        44
  #endif
#endif

I've already tried everything that the online community tells me to do to solve this problem, but that all doesn't help me. Almost everyone is saying that I just have to swap these lines of code and it will work, but it's not working. Any ideas ?
By the way E0 is not working because I've burnt a pot on it :)

Possible duplicate of How to change E0 to E1 on Marlin 1.1?

No, my question is different. I have lines of code changed, but it's not working while on the other post there were no such lines at all

please check this one and let me know if that helps: https://3dprinting.stackexchange.com/a/5916/9730

@IlyaSmirnoff the linked topic describes what you need to do to change the pin layout to swap E0 for E1, so that will work if you alter the pins in the correct pin layout file for your motherboard. Where is the snippet you posted taken from? I cannot find this in default Marlin.

Hi, as you say that 0scar's and Professor's proposed solutions didn't work for you, I was wondering whether you ever fixed your problem and found a solution? If so, could you post it..?

At first it was unclear from where the snippet you posted is taken from as it was not stated in the question (this has now been addressed by a moderator edit).
Depending on the value of EXTRUDER_USE_E1 (and where and how it is set) the underlying code of the if statement will be carried out. Albeit said, swapping lines will not work, if you want to use the E1 connector of your motherboard, you have to make the printer think that it is using the E0 while it is redirecting to E1! This implies that you need to assign the pins of the E1 to the E0 extruder (so swap the pins, not the lines). This has been explained before in this topic by editing the correct pin layout file of the Marlin firmware.

EDIT : Further investigation shows that you have a custom Marlin for the TEVO Tarantula and are using the fork of Marlin maintained by JimBrown (this is essential information for your question). I have looked into the files, the only thing you would need to do is define the constant EXTRUDER_USE_E1 in your configuration.h file:
//#define EXTRUDER_USE_E1

to:
#define EXTRUDER_USE_E1

So do not swap anything. Once this constant is defined, the pin re-allocation is done for you automatically! (see the pins_RAMPS.h file)
Basically, this is exactly the same as is explained in topic How to change E0 to E1 on Marlin 1.1? and hence a duplicate. ;)

I simply swapped the pins
#define E1_STEP_PIN        26  //swapping to E1 FRED
#define E1_DIR_PIN         28
#define E1_ENABLE_PIN      24
#ifndef E1_CS_PIN
  #define E1_CS_PIN        42
#endif

#define E0_STEP_PIN        36  //swapping to E0 FRED
#define E0_DIR_PIN         34
#define E0_ENABLE_PIN      30
#ifndef E0_CS_PIN
  #define E0_CS_PIN        44
#endif

Which worked for the basic operation, however now that I've tried to add Autoleveling it stopped moving E1 motor. My configuration.h file does not have:
#define EXTRUDER_USE_E1
 apparently as its an older version also, just like RAMPS.h doesn't have those conditional statements.

Basically this is a similar answer as the one linked in this answer. Why not post your own question on the auto bed levelling so that others may help you! Please note that #define EXTRUDER_USE_E1 is something specific for the JimBrown fork of Marlin. And last but not least: "Welcome to 3D Printing.SE!"

Hi and welcome to SE.3DP! Unfortunately, your answer does not really answer the question. StackExchange is a Q&A site, and not a forum of threaded messages. The reason for this is to aid the search for answers to issues, and provide it in a structured Q&A way. Can you repost your question using the Ask Question link at the top of the page? When you repost your new question, add the Marlin version, refer back to this original question using the URL (seeing as it is the reason why you posted in the first place) and delete this answer. Thank you.


text:
Nozzle heats while autoleveling (or before)
When I'm auto-leveling my Anet A8 with Marlin firmware, the nozzle heats to 195°C during the leveling process, which leaves drops of filament. I checked the resulting G-code but makes no sense to me:
M107
M190 S55 ; set bed temperature and wait for it to be reached
M117 Homing Axes
G28                          ; Home axis
M117 Autoleveling
G29
M117 Cleaning Nozzle    ; Indicate nozzle clean in progress on LCD
M109 S200       ; Uncomment to set your own temp run warmer to clean out nozzle
M107                ; Turn layer fan off
G21             ; Set to metric change to G20 if you want Imperial
G90                          ; Force coordinates to be absolute relative to the origin
G0 X10 Y0 Z0.15 F9000         ; Move in 1mm from edge and up z 0.15mm
G92 E0                       ; Set extruder to 0 zero
G1 Y190 E50 F500             ; Extrude 100mm filiment along Y axis 190mm long to prime and clean the nozzle
G92 E0                       ; Reset extruder to 0 zero end of cleaning run
G1 E-3 F500                  ; Retract filiment by 3 mm to reduce string effect
G1 X3 Y190 Z15 F9000        ; Move over and rise to safe Z height
G1 X3 Y0 Z15 F9000      ; Move back to front of bed at safe Z height to shear strings

My printer heats the bed, then homes axes while setting the nozzle temperature to 195°C.
Then autolevels and finally M109 S200 does its job.
How can I prevent the nozzle from heating when there is no G-code for it (except the M109 S200)?

According your code the nozzle will heat after autoleveling, M104 S210 will set the temperature you need during process and M104 S0 will turn off your extruder heater.

Which firmware and or printer are you using? Please update that into your question.

@FernandoBaltazar  I know right? but it heats before G29 at 195ºC then executes G29.

@0scar Anet A8 with Marlin.

Very strange, like @FernandoBaltazar mentioned, the heating is not instructed by the code before the leveling process has ended. Is the snippet taken from a g-code file from a product. Please re-slice and add the resulting g-code up to the point it starts printing. Also post your start g-code from your slicer. You are also sure that you did not accidentally preheat the nozzle through the menu?

I kinda off solved it with M109 S50 before G29 G28  M109 S50 M117 Autoleveling G29 M117 Cleaning Nozzle    M109 S200
I have to check marlin config files. Could be a firmware thing

I agree that it's possible the Autolevel command is interpreted on your control board firmware as initiating nozzle heating while levelling, to save time.  But really: a couple bits of pre-extruded material is not a big deal.

Besides, you should ideally preheat the nozzle and test the bed level with a heated bed and heated nozzle. Testing cold or hot may lead to different bed mesh values. Leaking filament can be fought by retracting the filament after a successful print or prior to G29 on temp.

Probe is far away from nozzle to not be influenced by it. Adding M109 S50 to force a temp before G29 did the trick and I had the best prints ive had in a long time. I consider that a solution

@0scar M109 is for waiting to a temperature can be reached, then execute the next code (extrusion). M104 is to set the temperature while execute the following codes this way you can change temperatures during extrusion where the temperature is too high and the area is too small like pivots.

@PetarPetrov   I'm using this lines after G28. G29 ; Autonivel M190 S38 ; set bed Temperature G1 Z4 F240 ; lift nozzle (to clean nozzle if material inside) M109 S195 ; wait for temperature to be reached then starts to print.

@SeanHoulihane It´s a solution that works to me, but not sure if it is THE solution. But its logical if the filament oozes while autoleveling because the nozzle its heated up, then before G29 i heat it to a point but not to the melting point that oozes G28 M109 S50 then after G29  wait for desired print temp to be reached and start to print.

I am using CURA as my slicer, and it sets the bed and nozzle temp before printer start code is executed.
You can easily check that by opening a file in a notepad and see, that there will be a few lines describing the job, nozzle and bed setting temperature and the user code that is inserted in printer properties screen.
To change that behavior - you need to open the file and move the M commands down after leveling is executed.
;FLAVOR:Marlin
;TIME:45
;Filament used: 0.0187665m
;Layer height: 0.2
;Generated with Cura_SteamEngine 3.3.1
M190 S60
M104 S200
M109 S200M82 ;absolute extrusion mode

lines above are added by slicer so temperature is set before instritions from START G-Code section:
G21 ;metric values
G90 ;absolute positioning
M82 ;set extruder to absolute mode
M107 ;start with the fan off
G28;
G92 E0 ;zero the extruded length
G1 F20 E3 ;extrude 3mm of feed stock
G92 E0 ;zero the extruded length again


text:
How to add "skin" to a Voronoi shape?
Suppose I'm given a shape with a Voronoi pattern, such as this lamp.  I'd like to be able to add a "skin" which covers the complete shape on the inner surface so I could print it with translucent material to produce a more-or-less uniform glow.  Here's an example of what I'd like to end up with: tea lamp shade.  Any ideas on how to reverse-engineer a Voronoi object?

I will rather ask on blender forum or pure 3dGraphics, as this is a very hard question - there are a few google responses when you search for 'reverse voronoi' , but I am not so deep it 3d modeling to suggest anythig.

I think blender might be the best application to accomplish your objective. With my limited knowledge of the software, I can only envision manually skinning each hole, but there has to be an easier way to accomplish your task than that.

@carl-witthoft With any program  than can edit your STL file and adding a mesh to the inner surface. Few years ago (18) I was using 3Dmax to create some models and adding meshes to create skins or textures, you can find any tutorial to use it easily.

@FernandoBaltazar thanks for the pointer.  If you could post up a simple example or "steps to follow" as an answer, I'll accept it.

I posted this to an Autodesk forum, and a fellow named "MagWeb" proposed the following solution.  I have not tried it yet.

A possible workflow depends much on the overall shape of the voronoi
  object:
  If it's convex  all over (like an egg) or convex and planar (like a
  cylinder) e.g:

SelectAll (Ctrl+A or Cmd+A on MAC)
Run Edit/FitPrimitive and set its PrimitiveType to ConvexHull (CreateNewObjects checked)
Run MakeSolid on this hull object and set its SolidType to Accurate. Accurate enables the OffsetDistance slider. Pull it down a bit and hit
  update. You want to get a result intersecting but showing the voronoi
  object. If needed adjust the offset. Finally accept.
Now activate both the voronoi and the MakeSolid result and run BooleanUnion
Show the FitPrimitive object again (MakeSolid did hide it before) and run MakeSolid again in Accurate mode. Now set a slightly bigger
  offset as you did before. The difference will determine the "lining's"
  thickness. Accept
Activate the BoolleanUnion result first and the last MakeSolid result and run BooleanDifference to get a hollow object. You might use
  another intersecting object to bool-off an opening the bottom.

Harder but doable with a different workflow on an voronoi object
  owning concave regions...

edit
Having run some trials, I can confirm this works for simple convex objects. If there are concavities, most likely the source shape needs to be chopped into sections each of which can be treated as convex.
 I played around with Meshmixer's "apply pattern" functions with limited success.  I could get a form-fitting pattern shape but with a rather uneven surface. Some fine-tuning of the pattern parameters may help. Note that the new shape tends to be as thick as the original voronoi object, so it may well be better to do something like the following:
1) create a duplicate of the original
2) shrink the duplicate by a few percent
3) align the two objects to a common origin and take the boolean difference to create a thin-wall version of the original.
4) Build the pattern object based on that thinwall object.
edit number 2
I succeeded!  For those who care, I took an open Voronoi glasses case and put a skin inside to protect your glasses.  See this Thingiverse item

The thing you linked shows up empty, no preview :(

@0scar  Yeah, I don't know what Thingiverse did wrong. I've tried to edit but the STL images don't show.  I'll add an actual photo one of these days.

@Trish  Amazingly enough, I found the forum page - now linked in my answer.


text:
Extruder prints fine up until further down the print
So I recently installed a genuine E3D V6 (direct) on my AM8 (Anet a8 with upgraded frame). I have already been able to fix most of the print quality problems. But the last one is a hard one for me.
It prints super fine up until a certain height. Then the extruder starts slipping and starts making weird noises like its clogged but I will be able to push through filament properly after cancelling the print. I thought it was heat creep but when touching the spiral heat break it is just a tad warm. I can comfortably put my finger on it and keep it there.
I also tried two different brands of filament and it seems to happen roughly at the same spot.
I tried PID tuning (the temps are literally perfect and super straight with no fluctuations), I tried cleaning the extruder gear and checked if it was worn or anything. Then I tightened everything on the extruder, making sure everything was nice and snug.
I am not exactly a newbie when it comes to fixing my own printer and troubleshooting the problems but this one I have never seen or had before.
Do you guys have any tips for me to point me in the right direction?
Running Marlin 1.1.8. I have a BLTouch on it and an AnyCubic UltraBase.

do you have the filament feed in a teflon tube to extruder? maybe it bends extensively and extruder has trouble to pull?

Is your extruder stepper getting really hot?

I had a similar issue, but probably not your issue. Either way, in case it is, I would check the wiring for the extruder. Maybe when it reaches a certain height, a fault in the wire itself causes disconnects and hence a extruder stopping/being weak. I tested by pulling/dancing the wires as I manually set extrusion. Seemed to stop when wires were stretched. Sounds weird but I redid my wiring and the extruder wouldn't start acting up halfway through anymore. Let us know if you figure it out. Good luck.

@profesor79 I have a small guide tube going into the E3D up until the bottom bit of the extruder stepper. I doubt it will be bending because the spool is literally above it. Also why would it bend on roughly the same spot everytime? Not that its not possible ill check for it anyway.

@0scar I am not sure, ill have to check that tonight.

@AthanasiosKaragiannis Ill check that tonight. But the extruder is defenitely not weak when this happends, it twists and bends my whole mount with it. But I do have the wires ziptied to the frame, maybe in a wrong way. Thanks :)

@0scar So i just made a test print. The stepper reaches a max temp of around 35 degrees. Which I do not believe is too hot.

@Granny, nope that is very cool!

@Granny according the noise and slips I'm sure that the spiral heatbreak is the problem because that part need to be cold not warm, the cooling fan must be active all time at 100%.

@FernandoBaltazar Maybe my wording was a bit wrong. It is as good as cold but I can feel a slight warmth. Its not hot its not super warm, i would say roughly around the 20/30 degrees.

@Granny Can you upload an image to see how is installed your E3DV6? every thing close to the motor extruder.

@FernandoBaltazar I currently do not have a photo of anything. But I did however solve my problem. The heatbreak was a all-metal variant. For some odd reason my printer did not like this one bit. I solved it by using one with PTFE tube inside the heatbreak.

@Granny Is nice to know that you solved your problem. I'm will add this kind of problem on the troubleshooting as well.

I used a different heat break with a PFTE lining inside. After that it ran smoothly.
Probably what was happening was that my filament was getting too hot and started to stick on the full metal heat break.

I have had some similar problems as you describe with my custom build CoreXY printer. I used an all-metal heat break for my 2.85 mm diameter filament. The heat break clogged up. I found that the inner diameter of the heatbreak, although specifically designed for 3 mm filament, narrowed down having a ledge inside. I replaced the heat break with a spare with a teflon tube inside, and never had any problems again.
Since then I scoured the internet to find some proper all metal heat breaks and order a few that do not seem to have that deficiency. I have not tried these (while hot, but when cold the filament also moves better through it and does not get stuck on a ledge like the first one), but will when I print POM and ColorFabb PA-CF Low Warp with my soon to arrive Olsson Ruby nozzle.


text:
Getting bumps/warts on surface, Cura doesn't want to comb?
I have not been able to print smooth and round shapes using Cura 3.3.1 (or earlier) without bumps. I think they are seams? The filament is PLA.
Combing is enabled, which I thought makes it so that the nozzle travels over already printed areas, instead of flying over the air...right?
I have been able to keep the seems hidden for the most part when there are sharp corners. Sometimes cura hides the seems properly...sometimes it doesn't.
Here is an example shape I have tried printing with several different settings:

The object above was printed using "random" seam corner preference. If I had chosen "sharpest corner", the bumps would all just stack up in one place, but still stick out.

Just look at the travel lines below! Why is it jumping all over the place?

I have tried "Avoid printed parts when traveling" enabled and disabled, doesn't seem to make much difference.
I feel that there should be a configuration that results in the nozzle not jumping through the air like that, but I can't find it. Perhaps that's not related to the bumps?
The printer is a MonoPrice Mini Delta.

Do you print one part a time?

What is the nozzle temperature?

One part at a time. The temp is 195.

You may want to look in the coasting option, this option tunes the pressure in the nozzle chamber by reducing filament extrusion before the move, thus preventing those blobs.

Possible duplicate of What do you call this effect in 3D printing and how can I remove it?

@0scar - Can my Q be considered a duplicate if I asked mine first? Because then mine is at risk of being closed.

Your topic was not very active any more. Please look into the linked topic and report back. It's now active ! :)

@0scar, Bort does have a point :-) Don't worry, we'll sort this out if it all goes wrong. I've made it a favourite and will keep an eye on it.

Following on from Toon's answer, here is a run down of Thomas Sanladerer's excellent
 video: 3D printing guides: Calibration and why you might be doing it wrong.
However, this may not be a definitive answer to the actual question about warts and bumps...

0:08 - A step back
Back in time - when the RepRap project (and the hobby grade 3D printing market) was new territory - it was seen to be a doable technology, with no restrictions imposed by patents. The new printers created and developed included Darwin, Sells Mendel and Prusa Mendel. These often produced unusable parts.
However, impromptu solutions, or kludges led to poor quality fixes giving poor quality prints, by today's standards. However, people (today) believe that because they worked back then,. that they must still be valid solutions today. However this is not necessarily the case.
The common misconception is that it is necessary to calibrate the esteps per mm for all axes other than extruder - adjusting the x, y and z esteps per mm until the 10 mm cube measures exactly 10x10x10 mm, even if that means squeezing the callipers.

1:25 - Car analogy
You find that your car pulls to the left, when going in a straight
  line, so you adjust the steering. However, then in hard corners and
  the rain the car handles poorly.
Upon closer inspection, it then turns out that the car had a flat
  tyre. You wouldn't compensate for having a flat tyre by adjusting the
  steering, now would you?

In order to get that 10 mm cube precise, it is usual to calibrate for the filament diameter, and extrusion multiplier (most straightforward option), but some printers aren't even that precise in the first place.
Mechanical, ripple, slaw, blacklash, can throw you off by 0.1 mm.  Compensation for this 0.1 mm is certainly possible and achievable. However, then for a larger print, say 100 mm, then these overcompensation will become more evident, and you will be one entire milimeter off the desired dimensions.
So, use the ideal calculated esteps per mm. Timing belts and threaded rods are made to tight tolerances. therefore the worst case of ideal step per mm setting is an inaccuracy of 0.5%.
So, to find the ideal calculated steps use Prusa's calculator which is very good indeed.
If you are not using belts, or very large printer, then it is worth recalibrating the steps per mm for x and y, as 0.5%  will make a noticeable difference in larger parts.
Use the files and instructions for these Calibration sticks on Youmagine, for proper recalibrating without results slewed by the extrusion multiplier being off by a bit.
3:45 - So what do I need to do?
What do you need to empirically calibrate your printer?  In actual fact, not all that much:

extruder steps per mm setting
extrusion multiplier (see video link - Extruder calibration)
print speed, jerk and acceleration settings - These depend upon how much quality you want to sacrifice for increased speed.
Pro-tip: slow your printing down. For example, try printing at half speed. Quality may be improved, and even if it isn't you will be able to observe more clearly what is happening, and going wrong.
(see video link - Super Fast Guide:Tuning Speeds)

4:30 - Other than that?
There is not much else needs calibrating, per se.
With regards to slicer software, there are only a certain range of settings make sense, but this isn't printer calibration. You simply learn the slicer software and, with familiarity, see how far you can go.
These days any well maintained and well built and solid printer will produce good prints.
Most slicers give you decent prints without tweaking or calibrating, other than the basic settings about your printer and deciding how the part should be printed.
What about print temp and retract settings? Well, just use the default settings, or settings which depend upon the type of filament.  So, no calibration is required there, as it is a property of the filament.
5:24 - Summing up
Don't try to calibrate everything
The technology, in particular the software, i.e. slicers, is still developing and improving. Slic3r's prototpye beta (in Nov 2014) has added compensation for fitting errors(?) without messing other things up, which is essentially what the cube calibration tries to do, but in the correct way.

Have you correctly calibrated your steps per mm a.k.a. esteps? Tom made a great video about it:
3D printing guides: Calibration and why you might be doing it wrong

Toon thanks for answering this open question that has gotten out of view. However, your answer is more or less a comment. If Tom's link dies there is not much to go on. I hope the OP tries your suggestion and reports back. In  the mean time you can edit your answer to a more proper SE answer describing at least the basics of how to calibrate the extruder.

Hi Toon, can you expand upon this answer? The best thing would be to take the main points made in the video, and note them in your post (if that is possible), or that if the link dies the information isn't lost. Else I will convert your post to a comment.

Following a written procedure is much, much more difficult to understand compared to watching the video. So i prefer not to write it out. There are already some great written instruction on the reprap wiki about about this subject. @Greenonline if it's more appropriate you can convert this post to a comment.

I understand completely. Some things just need to be watched rather than read :-) I will leave your answer as it is.


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What is wrong with my "disable sensor" gcode?
I have a spool of translucent PLA filament that doesn't work well with the filament sensor on my Prusa i3 MK3. The translucency trips up the sensor, making it think the filament ran out. I thought I'd create a filament profile in Slic3r and disable the sensor in the "Start G-code" block that gets inserted at the beginning of the exported gcode file.
I've got the following code:
M900 K{if printer_notes=~/.*PRINTER_HAS_BOWDEN.*/}200{else}30{endif}; Filament gcode
M406 ; Disable filament sensor
M117 Filament sensor OFF

The first line is provided by Prusa's default PLA profile. The second line should disable the sensor, and the third line should print the "Filament sensor OFF" message. If I look in the gcode, it's there:
G92 E0.0
M221 S95
M900 K30; Filament gcode
M406 ; Disable filament sensor
M117 Filament sensor OFF
G21 ; set units to millimeters
G90 ; use absolute coordinates
M83 ; use relative distances for extrusion
;BEFORE_LAYER_CHANGE

But if I print this gcode file, I see no message, and when checking the sensor in the "Tune" menu while printing, the sensor is still on.
I thought I might have a problem with line endings, but looking at the file in a hex editor, all the lines seem to end with a 0A line feed character, including mine.
Why isn't my printer doing anything with the M406 and M117 messages? Full gcode file here.

When you download the latest version of your firmware you find the implementation of all the codes in Marlin_main.cpp. Here you see that the M406 is not implemented! Hence it does not work.

this is original Prusa - so marlin is not used!

@profesor79 Download the software from Prusa itself and you will see that it does have the Marlin_main.cpp file! https://github.com/prusa3d/Prusa-Firmware/blob/MK3/Firmware/Marlin_main.cpp

ok got that, another bit it the puzzles sorted :)

@profesor79 Always glad to teach the professor ;)

Interesting. So why doesn't M117 work either?

@Bas I can't tell for sure, Prusa has implemented M117 differently (with a higher priority?). Maybe this does not work flawlessly.

As per github PR this is not implemented - see this PR for details
Please check if your printer is processing M406 by issuing it manually.
In meantime, a sticker on the sensor will help you to print :)

Professor79 Could you give a little more detail on how to use a sticker to stop the filament sensor issue? Maybe a photograph or specific placement advice? Left to my own devices I will continue to avoid the issue by printing my shiny filaments in total darkness. There has to be a better way. Thanks, from the peanut gallery

@Winky42 that depends if you have a mechanical or optical sensor. if is optical then just cover the lenses, if is mechanical put down the lever.


text:
Subdivision surface for STL files
How much should I subdivide a surface in preparation for 3D printing?
For computer graphics, I know that I need to balance the smoothness and the rendering time, but for printing, I'd like it to be completely smooth. Are there any reasons why I shouldn't subdivide a lot (e.g. 7x) in preparation for 3D printing?

Subdividing an existing mesh further won't do anything because you're not adding additional detail, just representing the same thing with more triangles. Subdividing as "preparation" doesn't make much sense. You should make sure the mesh is created with sufficient detail while modelling.
A mesh created for 3d printing should generally have a lot more triangles than one created for use in rendering, but within reason. It doesn't make sense to make the mesh (much) more detailed than the printer can print, and similarly having lots of triangles can make the slicer slow or unreliable. As a very rough guideline, I would say that 10.000-100.000 triangles per model is reasonable (but this obviously depends on the size and level of detail).
Some slicers may output G-code that will have segments corresponding to each and every triangle in the model, even if these segments are very tiny. This may cause the printer to slow down a lot while printing, but most slicers take care of this by merging small segments into larger ones. Depending on your slicer, you might have to watch out for not having the triangles be so tiny that the number of segments created becomes a problem.

When possible, you might compare the max dimension of triangles to the layer height or X-Y positioning limit of the printer.


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Configuring BLTouch with Marlin firmware
Has anyone configured BLTouch with Marlin firmware?
I could only find videos about older firmware version. I followed this document. To avoid causing any damage to the printer, I removed all connections, took the board out and connected a stepper to Z-axis terminal and BLTouch to Z-min and servo 1. All other axes are not connected. X-min and Y-min end stops were shorted using jumper (Mine is NC configuration).
After updating the firmware, I can move the X and Y steppers, but not Z stepper. There's a blue light glowing inside BLTouch, which turns off if I remove Servo connections.
The M119 command shows all end stops are open.
Do I have to change pull up settings of end stop?
I cuurently have:

Marlin 1.1.6
BLTouch Classic

Here's my configuration file

I connected jumper between Vcc and 5V, BL touch is powered up. Now it's the issue with firmware

For security reasons, you cannot move Z until home position is applied to X, Y and Z.
With the level sensor attached, we need to home X and Y, and then Z will be homed in the middle of the bed (as configured). Execute G28 to home all axis and then you shall be able to run 'Z'.
To test that, you can unplug just steppers (with power switched off to prevent damaging the stepper drivers) and move X and Y manually to home position, then just give a touch to the BL sensor (when servo/pin) is deployed to confirm home position.

That was the issue. I didn't home X and Y. Before enabling BL touch feature in firmware, Safe homing function was disabled. I didn't know I have to home X and Y before Z. I didn't read comments in that section of firmware. Seems like it's working now. I can touch BLTouch during homing and it works as a limit switch. I used separate stepper for Z axis not the one in my printer to avoid accidental crashing

Edit: The answer below reflected the original question and upload of the configuration that was incorrectly configured. The value of this answer can be found in checking your configuration thoroughly before you post a question. It also answers the question whether pull-up resistors need to be set for the end stops.

Basically you need to follow the instructions of the manual/sheet you mention in your question. Be sure to get all the changes correct in your configuration.h file!
E.g. in your configuration
//#define NUM_SERVOS 3 // Servo index starts with 0 for M280 command

should be
#define NUM_SERVOS 3 // Servo index starts with 0 for M280 command

So no servo was defined (the servo pulls up the pin of the BLTouch sensor)! Also your BLTouch delay is 375 while 100 is prescribed. Please check that you managed to get all the proposed changes in the configuration file (as I stopped comparing for you after finding 2 errors in your configuration!) as I believe that you have not updated your configuration correctly as described. There should be no differences in setup for Marlin 1.1.6 or 1.1.8.
To answer your question: No, you do not need to change pull-up settings.


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Would a really short melt-zone be beneficial
IANAE (I am not an engineer), but I've been wondering: wouldn't it make more sense to limit the length of the melt-zone and hot-end as much as possible? I've been having a lot of problems with nylon causing jams inside the heat-block, this being the region where the filament is no longer rigid, but becomes squishy then liquid as it is heated.
In my extruder (E3d v6) there is a cold section, then a heat-break then about 20mm of hot-end.

If the heating of the filament took place at the last possible moment, say the last couple of mm before the orifice, wouldn't this not only alleviate jamming problems caused by soft filament deforming, but also allow for much more precision with extrusion - less hysteresis due to the reduced volume of semi-liquid material.

I'd imagine that this would work by having a heated nozzle tip, say a nichrome ring around the nozzle orifice, and as the filament hits the inside of the bottom of the nozzle it melts and is forced out the hole.

We have a higher-level extrusion printer in our office which, instead of retracting, closes off the output by moving a "shutter" across the nozzle outlet.

There is a trade-off between the length of the melt zone and the speed at which you can print. The filament itself is somewhat of an insulator, so as the outside of the filament is heated up by being in contact with the melt zone, the inside stays cold. Therefore, the filament needs a certain amount of time inside the melt zone for the inside to fully melt. If you have a shorter melt zone, you need to print more slowly to give the filament enough time to melt. This is precisely the reason why the E3D volcano exists. It has a longer melt zone, so you can print more quickly.
You can partially compensate for a shorter melt zone by heating the nozzle up more, but there is an upper limit to how hot you can go (you don't want the outside of the filament to burn before the inside is melted).


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Dual extruder unused nozzle is breaking prints
So I got my first 3d printer, with 2 nozzles. I thought why not, I may want to print 2 colours, dissolvable supports etc in future. But for now, only using one.
I've had good success on small items so far, but when I try to print something that's a big on the bigger side, my "spare" nozzle seems to crash into the side of the print - either snapping a bit off if it's delicate, or losing bed adhesion.
What could be the possible cause of this? I've levelled and re-levelled the bed, but I am losing the heart to keep trying. I have more half-printed broken bits now that successful parts...
Not sure of the relevance, but I'm printing in PLA

When you "bed level", is it clear that both nozzles are "exactly" the same height from the bed everywhere on the bed?

I started this as a comment, but it got too long. I have been working for much too long on a multi-extruder printer, and so I understand that the fixed, dual-head designs are somewhat fraught with problems.
I am assuming that this is a mechanism in which the two nozzles are inline in the X-axis, the Y-axis is parallel to the bed and normal to the line between the two nozzles, and the Z-axis is normal to both X and Y (and usually vertical).
When you "bed level", is it clear that both nozzles are "exactly" the same height from the bed everywhere on the bed?  If there is anything non-parallel about the movement plane and the bed, it can cause one head to dip lower than the other when over the same position on the bed.
Is twist along the Y-axis of the heads possible?  A twist could be because of either looseness or compliance (springiness) in the X-axis.  The twist could be induced either through acceleration or by a nozzle being pushed up in reaction to the plastic extrusion against the object.
Is the printing from the active nozzle properly flat, or does it produce verticle bumps?  Any vertical ripples will cause any head passing over them to bump against them.  Something will need to comply with the force.  Either the head will melt through the bump and smear it out a bit, the bed will be pushed downward, or the nozzle pushed upward.  If the passive nozzle hits a bump, that compliance will be conveyed to the active nozzle, creating another defect.
Is the passive nozzle cold or hot?  It may help to heat the unused nozzle so that it can melt the plastic it touches rather than pushing against it.  If this helps at all, it may be necessary to slow down printing so that the passive nozzle has more time to melt through the obstacle.
If you find that the problem is bump defects from the active nozzle, it might help to remove the passive nozzle completely and focus on printing a smooth, even surface with the active nozzle.  Debugging that would be easier without the passive nozzle compounding the problem.

Yes, that's the setup I have. I don't have a flatness guage to check, but there don't seem to be any ripples/bumps from the active nozzle  - I'm away this weekend but when I'm back I will check the nozzle heights. It didn't even occur to me they could have been factory fitted not level to each other, nothing in the setup manual! Passive nozzle is cold for now, Ideally the solution wouldn't involve heating it as in future I will want this using a different material


text:
Can you put PLA parts in your car (in the sun)?
I'm in the process of building my own head unit / stereo prototype for a car, which will have a 3D-printed enclosure.
My concern is that cars can get quite hot in the sun, and even more so if you live in hot climates. Some estimations put the interior of cars getting up to 50-60 °C, sometimes even in only 20 °C weather due to the 'greenhouse' effect created in the car. I live in a fairly temperate climate, but the summers can still get up to 20-29 °C (80-85 °F), and my car might get up to 60 °C/150 °F on a hot day.
The part won't be exposed directly to the sun, but will obviously be exposed to heat both from the interior of the car when in the sun, and potentially from the engine radiating heat through the firewall, though the latter factor will differ from car to car.
Should I be concerned using PLA for my part? If not, what material, if any, would be better suited for these possible temperatures (other than metal)?

Please see, https://3dprinting.stackexchange.com/questions/2952/pla-use-outdoors/2982#2982, https://3dprinting.stackexchange.com/questions/4487/pla-continuous-operative-temperature/4502#4502, https://3dprinting.stackexchange.com/questions/3968/abs-or-pla-for-structural-printed-parts/3969#3969, https://3dprinting.stackexchange.com/questions/10/3d-printing-for-outdoor-use-what-types-of-filament-are-most-weather-resistant.
Also related, temperature wise, although not strictly in-car related:

https://3dprinting.stackexchange.com/questions/1128/travel-mug-woes/1134#1134

@Greenonline if you think any of those answers this question, please put in a "Close" request

@CarlWitthoft - I can certainly vote to close it if that is required. However, if I vote to close, then it will immediately close. It would be more democratic if the community votes to close it as a duplicate when it receives five votes. It doesn't seem to have received any votes as yet. I only raised awareness of the linked questions as I remember having read them over the past couple of years.

No, PLA cannot be used in cars standing in the sun. Temperatures can locally get over 50 °C (122 °F).
I have printed sun visor hinge pins from PLA for a car (not exposed to direct sunlight either), but after one day in the sun (it usually doesn't get over 29 °C or about 85 ˚F here too) the pin deformed (only printed it for form fitting). The actual pin was eventually printed in PETG, and even with PETG the part deformed a little when it got really hot in the car.
Your part might not get that hot as it is lower in the car, but you could best print parts in Nylon (Polyamide, PA), ABS or any other high temperature resistant Co-Polymer (e.g. made from Amphora HT5300), there are lots to choose from nowadays.
If it is a non load bearing component that is not stressed (e.g. a cover or a bushing) it could be printed in PLA, but I would not take a change and would print it directly in a more temperature resistant material.

Downloading some of the technical data sheets from various filaments will give you for PLA:

Not suitable for long term outdoor usage or applications where the
printed part is exposed to temperatures higher than 50 °C (122 °F).

similar for Nylon:

Not suitable for applications where the printed part is exposed to
temperatures higher than 80 °C (176 °F).

To complete the overview, generally, materials should not be exposed prolonged periods of time above (give or take):

70 °C (158 °F) for basic Co-Polymers
85 °C (185 °F) for ABS
100 °C (212 °F) for enhanced Co-Polymers and ASA
105 °C (221 °F) for Polypropylene (PP)
110 °C (230 °F) for Polycarbonate (PC)

As an anecdote, I've printed parts for my car that go under the hood (not touching the engine) in nylon--no issues and it's been at least a year at this point.

A material that is used in automotive indurstry is ASA which can be printed at 240-265 °C (90-110 °C bed, enclosure recommended), and could withstand prolonged exposure to about 100 °C for a prolonged time. It has a tendency to warp for a price starting around 23€/kg. On the top end of the materials are iglidur-filaments, which are available with a sustainable temperature range of up to 180 °C at a price of 100€/kg upwards. Ceramic filaments like LayCeramic could get (after tempering in a kiln) sustain MUCH more, but cost upwards of 200€/kg

I have a PLA washer fluid coupling piece under-hood with no major problem.

As we discussed in chat, it may be worth mentioning CoPA by Polymaker, which is Nylon which holds up to 180°C (I'm not sure how to derate it when under stress)

If you put PLA parts in a sealed plastic bag (or two to keep it dry) and simmer in water (212 °F or  100 °C), the part "anneals". The time taken varies with the part shape, but for small parts should be about 15-30 minutes. You can simmer longer if unsure, but it provides no additional benefit once the part is annealed. When you remove and cool the annealed part, it will feel harder and more compact. You may also notice a slight hazing or color change.
Annealed parts become a bit more resistant to heat warp. The annealing process shrinks and hardens your part (I've annealed gears) so you need to account for the shrinkage by making the unannealed part slightly larger. I do this for stepper mounts or gears as needed. Putting your part in the passenger compartment of a car can work depending on your climate. My daughter-in-law has a camera mount on her dashboard showing significant warp, but she still uses it.
Here's more information and I'm sure you can find more...

The sun will rot most, if not all plastics, with PLA, ABS and PETG rotting to varying degrees and at differing rates. So, if even part of your enclosure, such as the edges, are visible, they will invariably be exposed to the sun at some point (although maybe not sufficiently enough)  which will make them brittle.
However, as you say, your main concern here is not direct sunlight, but heat. As this informative article, Using PLA for Long-Term Outdoor Applications, suggests:

PLA is great as the warping is less than with ABS.

Interestingly, it also notes (again related to sunlight, not a concern in your case):

As a side note, PLA is referenced as considerably UV resistant.

Similar Questions
Whilst your question is not a duplicate, as such, there are already a number of questions (and answers) on this topic, that I remember having seen and being relevant.
Whilst I have quoted some of the relevant parts below, it might also be worth taking a look at the other posts on these links:

PLA use outdoors?

Keep in mind that PLA has a much lower temperature point, where is starts getting flexible. I once had PLA-printed parts in my car in the summer for 3 hours and when I came back, they where bent.
I don't know about the weather conditions in your local environment, but if you experience hot temperatures and your sign is hanging in direct sunlight, I would suggest to make sure you secure the letters against bending (e.g. cover them with a coat of epoxy or something like this).

PLA continuous operative temperature

The property you're looking for in the thermoplastic (which will determine the continuous operating temperature) is glass transition temperature. This is the point at which the plastic begins to flow, and becomes deformable as EvilTeach described. PLA reaches this state at around 60 °C, whereas ABS is around 105°C, just suiting your specifications. To go a bit further, polycarbonate offers a glass transition temperature of around 150 °C, and Ultem at 217 °C.

ABS or PLA for structural printed parts?

50 °C is hot for you. PLA's glass transition temperature is 65 °C. A car in the mid-day sun can get very hot indeed.
... if the part is designed to be strong enough for its use in PLA, it will be no better in "stronger" ABS. If the PLA part will be "more precise" and "less warped" - that may well make it better for its use. Other than a widespread community dedication to self-replication, (or mostly self-replicating with some metal parts) there's plenty of arguments for making most printer parts out of machined metal, for that matter - much stronger than ABS or PLA.

3d printing for outdoor use: what types of filament are most weather resistant?

PLA also will slowly melt in direct sunlight. I have seen this one firsthand, having left a print on my windowsill and watching it slowly morph with the weight of objects on top of it.

Also related, temperature wise, although not strictly in-car related (although that is where you would most likely find a travel mug), is the most informative answer by Ryan Carlyle, which makes mention of annealing as suggested by OyaMist Aeroponics's answer:

Travel Mug Woes

It is possible to anneal PLA to survive higher temperatures, as this increases the crystallinity of the polymer and thus makes it more heat-stable. However, that is highly experimental and results will vary considerably with filament provider, color/pigment, and annealing process used.

Which is more durable to sunlight/weather - PLA, ABS or PETG

PLA would be a non-starter for outdoor use as it's biodegradable and can breakdown in sunlight. Albeit slowly, but won't be useful for long term project.

"Not an answer" flags on diamond-mod-answers are usually denied for natural reasons, but I really must point out that these types of answers are not a good fit for Stack Exchange. This should be a comment on the actual question. Your links will show up in the "linked" section on the post anyway. If you feel that those answers will also answer this question, you can copy the relevant portions to make this a freestanding answer.

@pipe - You are quite right, obviously. I apologise for setting a poor example and my rushed, link-only answer. I remember having seen similar questions to the OPs in the past, but did not wish to flag it as a duplicate, and so I started to make a comment, but then it did not fit within the character limit. It was very late and I didn't have time to complete the answer to a satisfactory standard (poor excuse I know). I will expand the post, quoting the relevant parts on the linked to questions now. :-)

@pipe - Updated somewhat. BTW, I really like your homepage's pet peeve about SI units. It also annoys the hell out of me, and I am forever editing and adding &nbsp between the amount and the units - much to some people's chagrin.

Just minutes ago, I took a PLA part from my car that is parked in the sun, it is warped and bloated. It was wrapped in a towel, not in direct sunlight. The temperature in the car was near 60°C. I would not recommend using PLA on parts that may be left in a vehicle.

Just for completeness sake, one can print a casting mould and then cast UV resilient resins from the mould.
The mould would be made of PLA. Because it is quite brittle, you would need to make a multi-part mould if you want it to be re-usable. Otherwise, if you are using something heat-resistant then you can melt or break the mould once you are done.


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Flashforge Dreamer not able to read Cura created G-code file
I'm using a second hand Flashforge Dreamer with ABS filament and Cura as slicer.
The Flashforge Dreamer cannot read the printing (G-code) file Cura creates, I think due to not knowing what the printer firmware is? I want to use some of the Cura features that the FlashPrint software does not have.
What firmware does Flashforge Dreamer use? I think I have to input to cura the machine details (name not listed on list of printers in the drop down menu) and even Google could not tell me, nor the Flashforge website.
Cura has a built-in list of printer specs, but no Flashforge, so even the name of a clone type of the Flashforge using the same type of firmware would help.

For the Flashforge Creator model an alternative firmware is available; Sailfish. However, Sailfish is not available for the Flashforge Dreamer. As a matter of fact, no alternative firmware is available for the Dreamer as a consequence of the Flashforge Dreamer being closed hardware and closed source.
Not knowing the flavor af firmware (as it is closed source and could well be using a custom firmware build) using Cura to slice models for G-code files gives no guarantee for successful printing.
To be able to use Cura you would have to switch the current board from the Flashforge Dreamer and replace it with a board that accepts Marlin Firmware. Note that there is no default configuration for this pronter available so this requires a little work from you to go through the Marlin configuration file and adjust various constants to make your printer work. [edit: As pointed out below in the comments, in the process you will lose some of the maximum speed the Dreamer is capable of!]
Another option is to buy a license of e.g. Simplify3D (note that I have no affiliation with Simplfy3D!) as they claim to support this printer. There could be other software suites that support your printer.

the one important thing with changing the board could be decreasing printing speeds (ff is able to go up to 200mm/s) and with Marlin on Arduino that is slightly lower. More here https://github.com/MarlinFirmware/Marlin/issues/1563


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Problem in X and Y-axis dimensions
3d printing is a fun hobby for me. The  problem that I face is deviation in X or Y axis dimensions. When I print something with specific dimensions there is 0.7 or 0.4 mm difference (smaller in X or Y dimension) when I compare it with the design. Even when I print a cylinder, it is oval. I don't have a problem with the Z-axis. My 3D printer is a Prusa i3.
How can I fix this problem?

Can I solve it it through the software?
Do I have to change something of the hardware of the printer?

Usually uneven dimensions in X and Y directions are a result of improper belt tension of one of your belts. With improper belt tension, the positioning of the printer head is less accurate and typically results in non-circular prints. You should check the belt tension and adjust the tension, not too sloppy, and not too much tension (as it stresses the stepper motor which can lead to missing micro steps).
Furthermore, the uneven dimensional differences you mention (are these values you mention for similar sized dimensions? e.g. is this measured on a test cube print), if they are smaller than the design, and if it is a complex design, can also be related to shrinkage, e.g. ABS is a well known material that shrinks. Plastic shrinkage is basically the same in all directions, but complex shapes could introduce stresses preventing even shrinkage in all directions. To counteract shrinkage, you should slice your model scaled, e.g. scale to 102% to counteract a 2% shrinkage.
If the belts check out right and you are printing in PLA, you may want to check the steps per mm value. This calibration is only useful when you print a test cube at e.g. 200%, the inaccuracies also increase with the same ratio. If not, than it is a positioning error, caused by some play in the machine. Please check the bearings.

Dear Oscar, Thanks for your answer, i think it is not caused by shrinkage, when i printed a cylinder, diameter in model was 5 mm, but in X axis,  Diameter of printed cylinder was 4.8 mm, but in Y axis it was 4.4 mm. i will check the belt and will adjust it again, hope to fix problem

@MahdiShakeri belts and play, are usually the culprits. My answer just mentions that there are more possibilities, if somebody else sees your question, his/her belt may be fine but may have problems with play or shrinkage, therefor we try to give the most elaborate answers. Please let us now how you solved it. If it is something different that you find than described above please add your different answer, you can even accept that answer (after 24 hours). This way more people learn from it. Good luck with trouble shooting. Note that a 0.05 to 0.2 tolerance is pretty acceptable.


text:
Extrusion stops during print
I changed the filament (PLA) in my Wanhao Duplicator I3+. I ended the first try to print when I saw that the 'lines' were too thin. I re-sliced with a higher temperature (195°C instead of 190°C). Now the print started without a problem but after about 25% no more filament came out of the extruder. What can be the reason and how can I resolve it?
The filament is from Vertex, grey. The object that I use to test is a 20 mm hollow cube from Thingiverse that I have used for the previous filament too.
I am not sure that this is a clogging problem since the print starts with no problems. It just stopped after 25%. When I started another print I was able to finish by increasing the temperature.

You are probably experiencing clogging. Note that there are a few topics on that subject here on 3D Printing SE. Your question is a possible duplicate of I'm getting a prusa i3, if I have a nozzle clog, can I easily get rid of it by simply replacing the nozzle?; the accepted answer may be of interest for you.

Can clogging happen during printing? The printed part is of good quality now that I use a higher temperature. It just stopped all of a sudden.

I redid the print in order to reply to some questions posed in the answer of @kdtop. The print started but the output was not consistent and sometimes stopped. The temperature is 195°C and sometimes 'drop' to 194°C. First I pushed the new real so that the extruder did not need to pull so much. When this did not solve the problem I changed the temperature to 200°C. Now the output became consistent and my print finished. It was not as good as the one that I did with my previous filament. The top was not as neatly closed. Only the last 2 layers covered more or less for 100% the surface (perhaps 200°C is too high for this?).
For me the solution is to higher the temperature to 200°C (or perhaps 205°C).

I have a Lutzbot Mini and use Cura. I noticed that my nozzle clogs if each layer is too small. If your cube is 20mm with thin walls, then I agree with you that the retraction may cause the feed to overheat, soften and clog. If you don't want to print at the higher temp, you can try printing with more detail. Sometimes that works. In general I also try to avoid small layers by printing multiple objects at once even though I'm sure I could tune the printer better.

My slicer (Cura-lulzbot) has a setting for initial printing temp, and then printing temp after the first few layers.  Is it possible that your temp is initially OK, but then drops too low?  Does your printer have a readout that shows the current temp?  Is the temp still OK when it stops?
It sounds like you are printing a sample cube, so I assume not too large.  Could you simulate this by just directly command your printer to extrude 500 mm of filament, or longer?  Then see if it clogs.  That would tell you if it was a physical problem with your printer instead of some change specified by the G-code for a sliced print.

I will do a test with another object. The gcode is the same as before when the print finished correct.


text:
On a LENS printer, does the head move, or is it table that moves when printing?
I'm wanting to know how a LENS printer moves to create 3D prints.

Whilst this is not a definitive answer, if you watch the video on their website, LENS 450 Systems, it is the bed that moves in the X and Y axes - the head remains static. The bed also appears to move in the Z axis, after each layer (as there is noticeable bed wobble).
However, the head is on an armature so it could be that which moves - it is not entirely clear.
LENS 450 System for 3D Printed Metals
Note that the MR-7 system appears to be similar to the 450, with its "3 Axis CNC Control System". However, the 850-R differs, inasmuch that it has:

5 Axis CNC Control System
XYZ gantry + tilt-rotate table

which are not mentioned in the specifications of the 450 and MR-7, so the 850-R could well differ from the video.


text:
Can't print anything, clicking and low extrusion
I am the owner of a pretty Anycubic Mega I3 and it was very cool to own it.
However, now I have several problems when printing with it. It clicks all along, at high or low temperature, at 5 mm above the plate, and the result is very disgusting. It is the same with the basic black PLA, or with other PLA from ICE-Filaments but I can't do anything.
I use Cura and I've reset it several times, using the defaults options or not.
Here are two examples of some prints (normal cube):
example 1

and Example 2

Clogged hot-end or too low temperature will cause this.

I had a similar issue after installing an E3D V6 using a Bowden extruder.
PLA needs a heat break that has a PTFE liner, since with all metal heat breaks, it's probable that the filament will reach glass transition temperature in the heat break and stop flowing properly.
Also, I had filament that was 1.86 mm instead of 1.75 mm, which caused it to bind inside the PTFE tube.
Before correcting these issues, I was able to temporarily fix the issue by doing a cold pull to unclog the extruder, and was able to print around 10 cm in height of a 20x20x20 mm cube.
To do a cold pull, heat your extruder between 80-100°C, and then pull out the filament. If successful, the tip of the filament will be shaped as the inside of the nozzle. If needed, heat the extruder to 200°C and manually push the filament to fill up the nozzle and heat brake, then let it cool down to the above temps and do the pull.

The "click of death" is the feed bolt skipping as it chews a bite out of your filament. Your filament feed is encountering resistance and the feed bolt is slipping. I've seen that sad spaghetti so many times. After unclogging your head with a cold pull and cutting off the mangled filament, you'll have some things to try:
I had a Lulzbot with the older Bowden extruder and learned to prevent spaghetti air prints by: 1) replacing PTFE liners periodically, and 2) increasing temperature for certain colors. My black PLA required +5C over my natural PLA, which was a total surprise.
Now I have a new Lultzbot with the metal extruder and life is good. All metal hot-ends are so much nicer.


text:
What is retract speed & length?
On a 3D XYZ printer extruder, I found two terms I have no idea about:

retract speed
retract length

What are these and why/how should they be set?

Hi KD and welcome to SE.3D Printing..! Do you mean do these terms mean, or what are the actual settings required?

Hi KD, did my answer help you at all? If so, please mark your question as answered, by clicking on the accept answer icon (green tick). Doing that will also remove your question from the unanswered list. If your question is still uinanswered, then maybe you could refine your question a little, in order to get a better answer. Thanks

Retraction is the reversal of the direction of the filament and is generally used when moving from one non-contiguous point of the print to another, in order to prevent stringing and oozing of the filament. If retraction is not employed then the filament still coming out of the nozzle, after the last point was printed (and paused), will stretch, thus creating a fine string, as the print head is moved to the next position where printing is to recommence.

The retraction speed is the speed at which the filament is retracted, or pulled back (by the extruder stepper), and the retraction length is the amount that is pulled back.
These settings are dealt with in the XYZware User manual, on page 43, section 11.5 Retraction

11.5 Retraction

11.5.1 Retract Length
In printing object, before large movement of print module, print
filament will be drawn back, such that slight negative  pressure
occurs  in  print  nozzle,  preventing  material  from  adhering  to
the  object  while  moving, improving surface quality of print object
11.5.2 Activate Threshold
Such  setting  will  allow  users  to  set  up  retraction  mechanism
activation  style.  For  setup  mode,  users  usually specify the
minimal print module movement distance for retraction mechanism
activation
11.5.3 Lifting height for extruder withdrawal
After retraction, the print module will be elevated slightly with such
setup value. Such action prevents material from adhering to the
object, and makes a more orderly final print stop point. However, it
should be noted that excessively large elevation will extend print
preparation time for the next print layer, and portions of angles may
results cooling and difficult to bond conditions between layers
11.5.4 Add Extra Filament after Travel < Retraction
Material  compensation  may  be  used  to  improve  upon  holes  or
poor  extrusion  due  to  excessive  extruder withdrawal

Retraction speed isn't dealt with in the above section though. In section 3.3, of the XYZware Pro. User Manual, it is mentioned:

Retract Speed
The speed for pulling filament backwards. Refer to the function introduction in the next chapter for more about retraction.
Hint:
Cooperation of retraction speed and other print speeds will affect feeding stability directly in printing. A print speed slightly faster than the retraction speed would prevent material squeeze from interrupt.

However, the manual doesn't then go on to give any setting. However, the default settings should suffice, unless you are experiencing issues with stringing and/or oozing.
A further explanation can be found here, Stringing and oozing:

Reason 2: Retraction Length
The retraction function includes two setting options. One is
retraction length and the other is retraction speed. The retraction
length determines how much melted filament will be pulled out of the
nozzle. In general, the more plastic that is retracted from the
nozzle, the less likely the nozzle is to ooze while moving. As for the
issue, the default setting in the expert mode is enough for you to
solve the problem. If you encounter stringing with your print job, you
can increase the retraction length slightly to test again to see if
the performance improves.
Reason 3: Retraction Speed
The retraction speed determines how fast the filament is retracted
from the nozzle. If the speed is too low, it will make no difference
to your print job., the melted filament will still drop down through
the nozzle and leave on the model. On the contrary, if the speed is
too fast, the filament will be back to the nozzle and cannot be
extruded out in the next movement of printing. As for the retraction
speed setting, users can reserve the default setting which is perfect
for almost every models.

Testing your settings
As 0scar has reminded me, there are a good number of retraction test prints available (cubes, towers, bridges), which will help you check that your settings are adequate. These prints provide models that have a lot of print breaks (points between which printing is paused and then resumed), which can cause stringing to be exhibited. See RepRap Wiki - Oozebane:

Oozebane
Objective: stop material oozing out of the nozzle during
'non-printing' moves.
Many extruders will emit (ooze) plastic even when the extruder motor
is not turning. To overcome this your slicing software needs to
'retract' the print medium during head movement when not printing. The
retraction creates negative pressure within the hot end heating
chamber which effectively sucks the print medium back up through the
nozzle, stopping it from oozing.
Calibration Object: oozebane-test.stl
The calibration object prints two towers about 30 mm apart. The head
must move between each of the towers at each layer. If your printer is
not set correctly then you will see many fine filaments (or strings)
between the two towers. You can eliminate these filaments by
eliminating ooze.
Calibration Object 2 (Variable sized towers for testing ooze): variable_size_ooze_test_nobase.stl
This is a simple model to help tune reversal parameters for a stepper
extruder (using much less filament before actually testing the
ooziness). It consists of a number of towers with different
thicknesses, with different spacing between each tower. A well-tuned
bot should be able to produce even the smallest towers.

A simple google search, thingiverse retraction, shows up a lot of examples, such as:

10 Minute Mini Calibration Test for Oozing/Retraction at Different Distances
4 Cube Retraction Calibration
Retraction Tower Test or String retraction tower test

Check out the following (suspiciously similar) tags1, for even more examples:

retraction_test
retraction-test
retraction

Additional note for Bowden setups
As Trish notes in the comments:

According to my experience2 it is generally a good idea to add 2 to 4 mm of retraction to a bowden setup in comparison to a direct drive when dialing in the perfect retraction. This is, because some distance is "eaten" by the flex of the Bowden tube.

1 It seems as if Thingiverse could benefit from tag synonyms
2 and Thomas Sanladerer's advice during a stream

You may consider adding (to complete the answer) a hint to printing retraction calibration tower that are readily available, e.g. from Thingiverse.

@0scar - Ah, very good point. I'd forgotten about that. Will do so now. Cheers! :-)


text:
Anet A6 printer power on/off
Just built my new Anet A6 and not seeing a power off button.
How do I power it down safely?
Am I missing something?

Thank you very much for your quick reply.  The power strip seems to be the simplest alternative here.

The Anet A6 does not have a power switch. To power the printer you need to put the power cord into the socket. To "safely power off" the printer you need to pull the plug from the socket. You can even pull the plug during usage when it appears to go wrong (e.g. when the nozzle is digging into the bed). The printer runs a continuous running program/instructions that can be interrupted at any time, it does not have to be shut down according to a certain procedure like computer operating systems that use a proper file system.
You can insert a power button in the power cord yourself for ease of use.
Furthermore, it is pretty common to replace the power cord for a computer power cord with a C13 plug and connect a C14 socket with power button (and an optional fuse) to the power supply unit:

Please note that it is very dangerous to mess with the mains voltage, so please be sure what you do or get help from someone that does. Use proper tools to crimp wire correctors to the leads.
If you are not able to do the rewiring of cables to put in a switch, plug the printer into a power strip with an integrated switch button.

It would be helpful to clarify that "pulling the plug" to power off the printer isn't unsafe. With e.g. computers, you shouldn't just "pull the plug" because this might corrupt the file system if the system is shut down suddenly. For a printer such as the A6, there is no file system, so nothing to get corrupted (apart from the printer reading from the SD card, but since there's no writing hopefully nothing will get corrupted). In any case, pulling the plug isn't any less safe than any other option (including using a switch as you mentioned).

I think that reset button shall do the work

@profesor79 With the reset button you can only interrupt and reset the program/instruction set, power will remain on the printer.

that is enough to stop head failing into build plate when leveling

@profesor79 Totally true, but not the answer to the question to power it down completely. Also, the reset button is very inconveniently located on the Anet printer board, and totally inaccessible when you have put the board in a case (unless the case has some pin extension integrated in the lid of the casing).


text:
How long can you leave filament in the extruder
Just one quick question about the filament.
Can I leave the filament in the extruder for a prolonged period of time while the printer is off?

Keep in mind that merely removing the feed line doesn't clear out the nozzle.  But that's a matter of cleaning or reheating ahead of next print, not preserving the reel of filament itself.

Most filaments you can leave in the extruder indefinitely without any ill effects.
There are some filaments that need to be stored away from moisture, particularly Nylon, because they absorb moisture from the air and don't print well if they contain a lot of absorbed moisture. However, this isn't an inherent issue with having the filaments in the extruder (if you had some setup that protected the filament from moisture while in the extruder, that would be fine as well - but in most cases it is more practical to store such filament in an airtight box).
Most commodity filaments (ABS/PLA/PETG) don't suffer from this as much (PLA supposedly also absorbs moisture but I haven't noticed this to be a problem, perhaps it depends on the conditions of the room in which your printer is kept) so they're fine to leave in the extruder.

What about the wood filaments?   Same moisture considerations?

Most specialty filaments (wood, metal, etc...) are basically just PLA.

PVA should also be stored in an airtight container.

If you "planing" to leave the filament there for months, then it would be a good idea to store it away, but for most filaments it is not a big deal to be stay loaded... provided that the humidity is not high (e.g. a shower or kitchen next to it would be not so good).
My experiences with "moistured" filament is that they get brittle, but only breaks when I don't print something. And it is a pain in the a** to get out the last part of the filament that broke right at the entrance... so store it away is always a good idea, if you are not too lazy ;)

A pain in the neck, because you try to see where is the rest of the broken filament.


text:
Creality Ender 4 extruder problem
I cannot get my extruder to work on my Creality Ender-4 printer. I have heated the nozzle but the extruder does not move.
I tested the motor and cable on another system and they work just fine.
Could it be the board or what could it be?

Apparently your 3D printer runs Marlin firmware. Marlin firmware default code has build in protection against extrusion below a certain temperature (usually 170°C) as defined in the printer configuration:
// *** IT IS HIGHLY RECOMMENDED TO LEAVE THIS OPTION ENABLED! ***
#define PREVENT_COLD_EXTRUSION
#define EXTRUDE_MINTEMP 170

Are you sure that it heats up above this temperature? Please check the connections of the thermistor and the heater cartridge.
Marlin firmware code supports disabling the cold extrusion safety measure by setting:
M302 S0    ; Allow extrusion at any temperature

(save this line in a file with extension gcode and load and run it from an SD card or alternatively hook up your computer over USB to the printer and use an application like Pronterface, Repetier-Host, etc. to upload the command to the printer)
If cold extrusion safety is turned off, you should try to extrude (without loading filament) to test if the extruder works.
To revert use the following code:
M302 S170  ; Allow extrusion above 170

I change the stepper driver and that helped.
One of the stepper driver was faulty.

Jens, may I ask what stepper driver you used as a replacement for your faulty driver module? What is the chip part number, or module name?

Please mark your answer as the accepted answer, that way your question will no longer be in the unanswered list. Also, please use the [edit] link to fix errors in your answers, rather than adding the correction in the comments.


text:
Heated Bed not heating on original Prusa i3. Using a Ramps 1.4 EFB
So as the title said my heated bed stopped heating mid print.
I'm pretty confident the bed itself is not the problem as I've ran continuity tests from the wires and a resistance check (which showed a total resistance of about 1.5 ohms, which is where it should be). I've done voltage checks across the input terminals which showed a successful output of 12 V.
Finally I did a voltage test across the output terminal at D8 where the heated bed should be outputted to. The result came up with nearly 0 V. I then noticed that the LED that usually lights up for D8 was turned off. The weird thing is, I unplugged the wires from D8 and this time the LED lit up like it was supposed to. Due to this, I believe the problem to be with the MOSFET attached to D8.
My proposed solution would be to move the heated bed terminal to D9 instead of D8. I wish to this because despite the firmware set up for a fan, I do not have a fan attached to D9. This leaves this terminal open and with a potentially unharmed MOSFET. Despite this I have found no information on how to go about accomplishing this.
What do you guys think? Is that even a good idea or should the component (or board be replaced)? Any help would be greatly appreciated.

You absolutely sure your gcode doesn't turn off the heat?  Might be worth checking for existence of heater commands mid-file.

First you should check if the bed still works when applying 12V directly. You can then also check the voltage over the 12V output terminals to measure the power supply unit while it is powering the bed. It is unclear whether you measured the voltage of the PSU while it was powering a large load.
It is also a good idea to get the external MOSFET board out of the equation (the less components you have, the less you need to troubleshoot).
From the post can be concluded that you are using the so-called RAMPS EFB setup, e.g. in Marlin firmware defined by constant IS_RAMPS_EFB in your firmware printer setup (Extruder on pin 10, fan on pin 9 and bed on pin 8).
In the pin configuration file pins_RAMPS.h you can find the following lines:
#define FAN_PIN        RAMPS_D9_PIN
#define HEATER_BED_PIN RAMPS_D8_PIN

To change the pin layout, switch the values of the constants.

you can swap pins in Marlin firmware.
When you download it from GitHub, there is a file called pins.h (please be aware that this file is an example), and you can play with your setup to skip the broken mosfet.
Sometimes, it could be easier and faster to desolder and swap elements directly on the board - that depends on the skill set we have


text:
Printer Enclosure Material Selection
Im planning on building an enclosure for my CR-10S and am debating whether to use MDF walls lined with an insulation foam that reduces noise and keeps the heat in or going with double pane glass walls.
My main concern is not necessarily keeping the enclosure hot as it is for noise reduction. Obviously the wood with insulation will give better sounds dampening, but I am wondering if anyone has tried both or at least heard a printer before and after with both and if the glass alone had a significant effect on the sounds reduction.

To reduce the noise, you could replace the metal linear bearings for plastic ones. This reduces the produced noise considerably from experience. Also, put the printer on damping rubber feet.
Enclosing the printer should be done with care, completely boxing the printer up could lead to increased temperatures of your board electronics, steppers and cold end cooling. Make sure to vent some air. How you box up does not matter, although double glass window panes does seem a bit of an expensive solution.

There's a type of 1/2" insulation foam available in the US that my shop uses. Here's a link to it at Home Depot. It's pretty tough so long as you aren't hanging things off it, and you could build a frame out of 2"x4" beams to pressure fit squares in there. It's also massively sound dampening.


text:
What is the best way to dry filament?
I have some nylon that appears to have soaked up some moisture, the prints have the texture of rice bubbles. So I'm wondering what people suggest for drying.
My priorities are:

cheap
low energy use
safe
effective

I know you can put it in the oven for four hours, but that's going to chew up a lot of electricity.
I have been leaving the spool in front of a fan heater, since the heater is on anyway, it probably only gets to 40°-50°, but since my kids spend all day sitting in front of the heater I can leave it there for an extended amount of time. Anyone have success with this method?
I had considered putting it in my car. I know even on cool days it gets pretty warm in there, but I'm not sure whether that would translate to low humidity.

a freezer has a lot lower humidity than warm room air...

Good point. I know ice cubes disappear in my freezer, I might give it a try. The better half is going to love it when I start filling the fridge with spools of plastic.

word. just be sure to put an empty ziptop bag in there with it (not bagged), then bag it in-freezer before removing to prevent condensation from defeating the purpose...

If we think about drying as a process, then we need to consider some factors:

we need to get same humidity level on the spool
that will require a good stable temperature and an air rotation (fan)
then we need to store  spool in a dry area (a bag and silicone sachets will do the work)

As energy consumption by owen could be the case, if we will run it for 4h full steam, then considering that we shall have about 60 degC, will turn down the usage by at least 70%, so we could assume that 2kW heater will be on only 30% of the time (so it will be 2kw*0.3 = 0.6kW, multiply by 4h -> we have 2.4kWh, so that is about 50 cents).
If you consider the price of wasted filament - then adding 50 cents to the drying process is something that is cheap enough to save precious nylon.

So long as you have a kitchen oven which does not expose contents to direct flame or electric heating elements,  setting the oven to  50 C or so will work as well.  Presumably it'll use less total energy than a heating fan.

that is true, but the fan runs anyway as OP states :)


text:
Multipart 3mf file, need to extract one of those parts for printing.
I have a 3mf file that has 24 parts in it.  I want to extract one of those parts for printing.  I have Solid Works, Magics, and NetFabb.

welcome to 3d printing, could you tell us where is your problem exactly?

If your 3D file has separate objects and vertices and are just merged together then do the following:

Import into Magics;
Select part (in the part list menu).
Right click (in the part list menu) and select Shell to parts;
(Be very careful here) Select the area you want to isolate with the translate tool. If you don't know how to do this just left click hold and drag the mouse to select an area inside a box;
Use translate tool to move it a little ahead from the original grouped object (just drag on any axis);
Right click (in the part list menu) and select merge part.

Should work out fine. Tell me if you get stuck.
This can also be done on Netfabb. Not on SolidWorks.


text:
How to calculate the strength of a printed object?
If I'm working with standard PLA, and I want to print a box that I can stand on without any risk of it breaking, is there any good way to calculate the appropriate print settings?
I know that structural strength comes from the infill.  Knowing this, and knowing the dimensions of the box, the weight of my body, the surface area of my shoes, and the material I'm working with, is there any good way to determine the minimum infill percentage I'd want to use in order to safely bear my weight?

different print settings, different PLA, and even different environmental conditions can all affect strength, making calculation VERY complicated on an exacting basis.

this is a Structural engineering problem

Related https://3dprinting.stackexchange.com/questions/109/ (but not quite a duplicate)

Strictly speaking, it is difficult to do calculations on these materials, but not impossible (I've heard about a few commercial analysis tools that do that). The FDM process (Fused Deposition Modeling) creates a product based of fused slices of material causing an anisotropic material (this means that the properties of the material are different in different dimensions). Basically, your product will be quite strong and similar in the X and Y directions, but fragile in the Z direction (layering direction). You can imagine that every layer may be a seed for cracks to grow when you're pulling at the part.
When applying a compression load on a product like in your example, the walls need to be strong enough to hold the pressure (not all of the load as, based on the type of infill, the infill also can/should take part of the load!) and need to be of sufficiently high percentage, not only to take part of the load, but also support the walls to prevent buckling. I remember that stress calculations for buckling are difficult and require FEA (Finite Element Analysis) for more complex objects other than bars or beams.
I think it is difficult to determine or calculate the infill percentage based on the compression load beforehand as you do not know the exact material properties and the buckling behavior. You do know that a 100% infill will give you enough strength and support, you could try to print at a lower infill, e.g. 75%, and test if that works for you.

good answer, shall you include a dynamic aspect of load? Let say a man with 90kg steps on the stool with left foot, then raises other - will generate more pressure as the body will be moving to accommodate right foot movement and balance to stay on the stool....

@profesor79 No I won't as that is not necessary. Actually you are describing a static load that is gradually applied. Also the safety factors in place on mechanically engineered parts is generally very high opposed to safety factors used on aeronautically engineered parts. The latter are usually subjected to complicated calculations to take fatigue into account. The strange thing is that fatigue life calculations originated from the railways (axles) but are nowadays not a subject for them (as of increased safety factors), but it plays a major role in the aircraft (engine) design.

I would suggest doing some calibration runs - granted this'll use up a lot of time and filament.  But an infill of even 30 to 40%, plus a reasonably thick set of walls and top/bottom layers, should have almost the same strength as a 100% infill.   Look at the girders & beams on road bridges, for example.  As Oscar wrote, modelling with FEA tools is unreliable, more so because every extrusion printer is a little different.
Try printing a test box, say only 10 by 10 cm, same height, and see if you can stand on that, before printing the full-size item.

you mean test box not text am I right?

@profesor79  ooops.... tho' it would be pretty funny as a text box.

I just started my imagination here ... as a software developer :)

"Try printing a test box, say only 10 by 10 cm, same height, and see if you can stand on that, before printing the full-size item."  But how valuable would that be, when it's well known that things get less strong as they get larger?  (Square-cube law.)

@mason that's not applicable here, where we care only about crush-strength in one axis.

@CarlWitthoft To further build on your clear understanding of the drawbacks of these techniques (more so because every extrusion printer is a little different). Note that although the properties of the plastic may be known, due to these differences in printers or extruders it should not be taken for granted that the properties of the deposited plastic has similar properties. If you look closely there are local voids, under extrusions, separations, etc. This is especially a problem in metal powder laser printing. An even bigger problem is to certify components made by these techniques!

A fast way to do this is by using SolidWorks.
You can draw the box in it and run a simulation test with the max load expected.
Here is a link on how to make dynamic load simulations work in SolidWorks, How to apply dynamic load in solidworks simulation ?
The catch in the process is that SolidWorks takes cubes and most objects as complete solids, i.e. 100% infill in 3D printer terms.
You would have to actually design your infill pattern into the cube so as to get the best and most accurate result.

Just about every polymer has non linear mechanical properties, SolidWorks is notoriously bad at nonlinear FEA simulations, so not really a good way to calculate this for polymers


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StoneFlower3D - how to pause a print?
I've been trying to make a paste extruder and I came across StoneFlower3D. In their site, they mentioned about a feature called Infinite Printing. Please see page number 25 of this document.
They're only using Step, Dir, Enable and GND from main controller and there's not a serial connection with the controller.
Anyone have idea about how they're doing it?

Moving off-topic - back with a regular printer, you can insert PAUSE commands into a gcode file if you expect to run out of filament, or want to change color, etc.  It helps to be on-site to make the change quickly :-)

I read about that in Marlin git hub page. But I was wondering how they are doing it over StoneFlower3d without any command or communication with Main controller

@Athul The ceramic extruder is taking the signals before the a4988 to make a kind of bridge, so the white module has a new a4988 with a pulse generator to drive as standalone the A4988 so this way the extruder can be cleaned  without need of using the 3Dprinter driver; however this doesn't mean that can be paused the whole printer. :) This gave me the idea to extrude cement and adapt the cleaning process.

@FernandoBaltazar That means,there's a pulse generator inside this white control box. Which can give square pulses to the STEP pin of whatever driver the box contains. So when switch is toggled to KIT position, driver receives pulse from this generator and when in PRINTER position, receives signals from printer controller, Right???

@Athul yes, that`s right

The extruder is connected to 3d printer mainboard as a stepper driver.
That said it is not using standard stepper motor output, but it is fed directly from CPU digital pins.
Please see OP reference manual.
The extruder has theability to self-feed (load filament) - so that is the reason of kit/printer switches - see pic 1.
Then pausing a print to feed the clay tank need to be executed from printer (pause print) and then operated locally in the kit mode.

if get your comments well - pic below gives an overview how to connect it to rams - see manual for details

@CarlWitthoft it is in original OP LINK,, will fix that

OP reference manual?? Instead of using the driver in main control board, they've taken out the Step, Dir , Enable and GND pins which are feeding signal signals to the main driver, and use same signal to power two parallel connected stepper drivers. I know that. But how can they pause print with this connection but toggling a switch provide?

@Athul I'm confused as the extruder is part of the printer, so it is not a standalone unit, that means it is operated by printer interface (a screen or gcode)

as per their site, it can be used with any control board. In case smoothie board, there's provision for connecting header pins for Step, Enable, Dir, and GND pins, if anyone want to use another powerful driver instead of provided one. But in Ramps you have to remove plug in driver and identify pins.  In stone flower 3d there's an electronic box which comes with the kit(note that which can be used with any printer). It has two parallel connected driver, one for ram extruder and another for auger extruder. Both work from same step, enable, dir signals given by main controller.......

........which is given as the ONLY inputs to the electronics box. here's no other connection with the Main controller board(what ever that is, ramps, smoothie...). Also the PAUSE button is installed in the electronic box provided with the kit. It iss not connected to controller. That's what confuses me. If it is connected with micro controller, okay I can assume it's doing something to the controller to pause the execution of code. I've searched marlin page and feature requests. Only feature i could find was inserting M0 as mentioned by @CarlWitthoft. But it's not what they're doing

@professor79 signals this electronic box gets is one PWM, 3 digital signals not any gcode

@Athul please see my edit