Ultimaker 3 Extended prints pores in walls We have a fairly new Ultimaker 3 Extended.

When printing ABS with the AA0.8 nozzle and the recommended settings (up-to-date CURA) we receive a very poor wall quality that exposes some kind of pores. I've attached an image of those pores.

I assume those pores are dragged by the nozzle when it moves inwards to print the infill.

I already tried to increase the wall thickness or increase the layer height to 0.3 mm. Are there other settings I might be able to tweak to eliminate those pores?

While no expert, I'm wondering if you're going the wrong way with tweaking your parameters.

If I'm reading your question correct, you have a fairly large nozzle (it's a 0.8 mm?) and then you're using ABS which requires more heat (230 °C nozzle temp) than say PLA does (typically 190 °C). Along with that you are using a fairly thick print layer of 0.3 mm, where I've normally only used a 0.1 mm layer height. You add all this stuff up and it seems to me the nozzle temps are probably not keeping up with the amount of filament you are trying to extrude, and due to these things, you're seeing the gaps in the print.

My thinking on this to fix your issue is to do a couple of things. You can slow down your print speed to allow the heating element to keep up. Secondly, use a smaller layer height. Both of these things should help, but will increase print times dramatically. You could also go to a smaller print orifice. Lowering the orifice size to 0.4 mm would again, increase print time, but would mean less filament extrusion and the chance for the nozzle temps to keep up with extrusion needs.


What solvents are appropriate for smoothing/finishing ASA? When I print parts in ABS, acetone vapour smoothing is a good technique to get a smooth finish. Is there an equivalent solvent or process for parts printed in ASA? Ideally I'm looking for something as easy to obtain as acetone, and not so awful a chemical that I wouldn't want to work with it, but I'd still be curious to learn about less friendly solvents.

ASA is Acrylonitrile styrene acrylate. According to Wikipedia:

ASA can be solvent-welded, using e.g. cyclohexane, 1,2-dichloroethane, methylene chloride, or 2-butanone. Such solvents can also join ASA with ABS and SAN. Solutions of ASA in these solvents can also be used as adhesives.
Staff, PDL (1997). Handbook of Plastics Joining: A Practical Guide. Elsevier Science. p. 515.

Solvent-welding means that the material is at least somewhat easily soluble in these fluids (they dissolve the material at the interface and as they evaporate, the former interface layers bond as if molded or welded), and the fact that the material can become an adhesive means that it is somewhat good soluble in these.
The least dangerous (and thus most advised from my side) of these 4 is 2-butanone, the others are listed as carcinogenic, and in the case of 1,2-dichloroethane, also toxic.
If these solvents can be used as a smoother similar to acetone with ABS would need testing, but a short exposition to their vapors should suffice to test this.
Addendum:
These four solvents also are able to solve Acrylonitrile butadiene styrene (ABS), which is a quite similar plastic in regards to its contents (butadiene instead of acrylate).

The acrylate rubber differs from the butadiene based rubber by absence of double bonds, which gives the material about ten times the weathering resistance and resistance to ultraviolet radiation of ABS, higher long-term heat resistance, and better chemical resistance. Wikipedia

Acetone might prove to be also a possible option, but results might differ from those on ABS.


How long are the carbon fibre rods for a Travelling Kossel? TL;DR - For a given Kossel frame size (w.r.t. the vertical and horizontal frame lengths of the aluminium extrusion), what would the length of the carbon fibre rods be?

A case in point, from RepRapWiki - Kossel, there is an intriguing note about a scaled down Kossel:

  Optionally scale down to a Traveling RepRap that fits within IATA hand
  luggage size limit (see transportation):

  Frame height: 550 mm.
  Footprint: triangle, 270 mm width, 250 mm across (210 mm 15 x 15 mm aluminium extrusion like OpenBeam + printed corners).

However, there is no mention of the length of the carbon fibre rods (carbon tubes).

Now, as per my previous question, For a larger build volume, what lengths of 2020 aluminium do I need?, is there a formula or ratio by which one needs to abide? Whereas in my previous question, the answer was along the lines of: Not really, you can use any lengths, within reason, and account for it later in the firmware, I would imagine that the Delta aspect of the printer is somewhat more exacting.

I have tried googling for further information on this Travelling Kossel, but found nothing, except for the information of RepRapWiki.

Looking at the corresponding lengths (vertical/horizontal) of the aluminium versus those of the carbon fibre rods for the Mini and XL:

600/240 mm versus 180 mm
750/360 mm versus 300 mm

I really can not see what the (trigonometric) relationship is, and therefore can not deduce the lengths of the carbon rods for the Travelling Kossel.

Unless it is simply that the carbon rods are 60 mm shorter than the aluminium horizontals? Is it really as simple as that, or is this just a coincidence? In which case, would the carbon rods be (210 - 60 =) 150 mm?

By extension, imagine if you wanted to build a Kossel XXXL, with a horizontal aluminium extrusion length of, let's say, 1000 mm, would the length of the carbon rods be 940 mm?

Any ideas?

Most information I was able to find was the arms are 80% the length of the horizontal structure.  I did find a copy of the original Google Sheets that everyone used a few years ago here.  The source of that link did mention that there may have been some issues with it but all of those links were dead ends.

Some things to note:

The height doesn't matter, it has no relationship with the arms other than you are losing approximately the arm length from the height when figuring print area as some arms will approach vertical when reaching the outsides of your print area.

The arm length isn't terribly important from what I could find.  Longer arms = less travel of the carriages and possibly lower resolution.  Shorter arms = more travel of the carriages and possibly lower print speed due to required movement.


Surface Tension Support for FDM Printers I've been thinking about alternatives to support materials for FDM printers, such as multi axis printers, dual head with soluble support material or printing in a gel/liquid which traps the material in place. Then it occurred to me that it might be possible to use the surface tension of a liquid to act as support material, same way small objects an insect can float on water even though they are heavier than water. This would also work great for cooling the extruded material. NOTE, we are still using a base plate like any other FDM printer, the only difference is that we have a water surface on the build plate which act as support material for large overhangs/steep angles. Everything is still attached to the build plate itself. We are not just printing stand alone parts on the surface of the water.

After some highly scientific testing (Dropping an extruded string of PLA and placing a thin printed PLA part on the top of water) I've concluded that it is very feasible to float PLA on the surface tension of water. See picture for refence:

As you can see the floating structure is not at all trivial, it has both smooth round shapes and many sharp corners and holes in it, it was still extremely simple to get floating (I could drop it in from a height of 5 cm and it would still not break the surface tension).
I also tried my best to investigate the effects of having structures underneath which might mess up the surface tension by placing larger PLA parts under the floating ring and trying to sink the ring by touching the underside and corners without any success at sinking the floating part. The only way I could get this part to sink was to push it down under water. Even if the surface tension was only broken half way along the ring the ring would still float. If you are thinking that the ring acted as a boat, that is not the case. I made sure to fill the small indents with water so that there were no pockets of air keeping it afloat.

An even more encouraging result was another ring which was much thicker than it was wide. It still managed to float from the surface tension on the top side of the structure while the rest of it was submerged, accurately mimicking how the structure would actually be in the water during printing. See picture:

While this ring much easier to sink it was very resistant to being moved around. Again, basically the only way to sink it was to push it down under water, though as soon as the surface tension was broken on one side the whole ring quickly sank.

All this leads me to my question: Does anyone know of a 3D printer which uses the surface tension of water as support material?

I've searched around some on the web and I have not really found anything at all on the matter. I can foresee many potential problems (such as the extruder moving unsupported lines to the side when changing direction, layer adhesion, enclosed areas not filling with water etc) but the potential to print without support and only have to worry about keeping the newly extruded material in place could open up a lot of potential.

UPDATE: I also tried 60 degree Celsius water (In case you need hot water to help with layer adhesion) and the surface tension still was able to float the thicker ring piece, though it felt like the surface tension was weaker.

It's not feasible as described with normal FDM technology.
FDM bases on depositing material in a single path. This needs the deposited material to stay at the same XY coordinates for subsequent paths. And exactly here is where a floating piece fails: a free-floating piece is by its very definition unrestricted in XY, and would move to follow the nozzle.
There are is also a whole plethora of factors that make this idea not feasible with the standard technology, meaning you'll have to develop the whole process, not just recombine two ideas. This means, you need to solve the following issues:
Heatsink Water
The extruded plastic needs to stay close to the melting point for some time, so it can fuse and bond with the lines next to them. However, water is known to be a very good method to get the heat away from items, as each liter of water can take about 4.1 MJ and only heat by one Kelvin. PLA on the other hand only stores about 1.8 MJ per Kilogram and Kelvin.
As a back of the envelope calculation, the temperature differential between room temperature and printing temperature PLA is about 180 Kelvin. Each gram of PLA is equivalent to 319.8 mm of filament (assuming a density of 1.3 g/cm³) or an extruded line of 9.6 kilometer length of 0.4 mm width and 0.2 mm height! That one gram contains about 324 Joules of energy that will be dispersed to the room temperature as it cools down. The water vat would not even get measurably warmer from sucking those few joules from a whole print!
While this could be, in the right setup, be used to rapidly cool the print and solidify it in shape, the result of the rapid healing will most likely also impact print quality negatively, as cross-layer bonding is reduced.
Separator water
It is a well-known trick in creating polymer fibers to extrude underwater, as the water not only cools (see above) but also acts as a separator between the fibers, for the very short timeframe they are still malleable. This would also strike when printing into the water - there'll be a water layer in between the deposited filament, which would need to either get pressed out or cooked out before any cross-extrusion bonding can occur. As a result, just extruding into the water should result in a print that has almost no sturdiness, and might fall apart on touch.
Floating
Water has a density of 1 g/cm³. PLA has a density of 1.3 g/cm³. So a solid chunk of PLA sinks. But we don't print solid, we include air. Not just a few percent but infill is usually below 20 %. I have just printed a cube. After smoothing the surface by sanding, the cube is 29,7x29.9x29.9 mm. It has 3 parameters, 20% infill, 5 top and bottom layers with 0.2 mm layer height and comes to 11 grams. 11 g/26.55 cm³=0.41 g/cm³. Or in other words: the cube would float, about 40 % under the water surface, 60 % above the surface. The print would be, as a result, quickly break the water surface and get no support from the water at all.
Submerging the bed?
The main issue of a free-floating object (position) might be mitigated if there was a bed that would be submerged, but one would open a new can of worms, that might be even worse: the volume of the print and the accuracy of pumps.
As the print goes on - quality be dammed - the print grows in volume. However, it doesn't grow entirely linear, depending on two factors:

Is the print happening on/below the water surface? Then we will include water in the print. The volumetric growth of the print is in this case just the deposited filament. You'll need an overflow to compensate for the print growing and keep the water level in position.
Is the print happening just above the surface of the water? then the displaced volume grows according to the depth of the print in the water. This would mitigate most of the problems from water preventing cross-bonding and causing floating, and even use the heatsink properties more beneficial, as any filament starting to sag will be stopped. It also would prevent water from being encased in the print. However, it does not use surface tension. Also, you'll need an overflow system to keep the water level steady.


Do the TW, THW and THHN or THWN wire insulation types matter in terms of powering RAMPS 1.4 or the MK2a Heat Bed? I'm still looking at wires for my Prusa i3, to go between the power supply and RAMPS 1.4, and the power supply and the MK2a Heatbed.

I also recently found a 400 ft. Wire Storehouse that I bought from Harbor Freight which has wire sizes in it from AWG 10 through AWG 22 (and additionally speaker wire, Zip Cord and Bell).

I also bought some reading material, I picked up Wiring Simplified 44th edition, and in it on page 28, Table 4-1, there is a table with information about the Ampacity of copper wires including their maximum temp (C), and maximum carrying current (Amps) based on their insulation types.

Unfortunately, the 400 ft. Wire Storehouse does not provide any information in regards to the insulation type or quality and this makes it difficult for one to choose the correct wire based on the specification in the table.

Given that the thing only cost $30 for 400 Ft. of wire, it would lead me to believe that the cheapest grade of insulation was used; as I understand it, the TW type wire.

I also read a forum somewhere in which people were complaining about the cheapness of the wire in this kit, stating that one ought to wear gloves when working with it as there is probably lead in the insulation as well as the wire.

The largest copper wire I have found in the table that I have (AWG 10) says that it is rated at 30 AMP regardless of which type of insulation it has, should I be using the speakerwire instead?  That isn't listed in the table.  Also it should be noted that though the ratings for the Ampacity are 30 AMPs, the max temperatures are different; with the TW being at 60 C.

As far as I can tell if I use the AWG 10 (TW?) to connect everything it won't matter, but I just thought I'd check here to be sure first since my power supply is rated at 30 AMPs and that's probably the same as the wire....

THHN wire is thermoplastic high heat-resistant nylon coated wire.
THWN is thermoplastic heat- and moisture-resistant nylon coated wire.

"T" stands for thermoplastic insulation covering the wire itself.
"H" stands for a heat resistance of the insulation max 167°F.
"HH" stands for a heat resistance, but increased max 194°F.
"W" is for moisture resistant.
"N" is for a nylon coating make the insulation oil and gas resistant.

In my opinion the Wire Storehouse is good for simple stuff, but I would not use it for something I consider important.   It's quality is poor on the insulation rating and the number of strands is low.  Higher strands number allows for more flexible wire.

If you get high end audiophile type speaker wire it could be considered as you can find high strand number with good quality insulation properties in heavier gauges.

Or your local auto parts store will carry 8 and 6 gauge wire with better insulation properties.


Printer thermistors read completely wrong after changing firmware I recently installed Marlin 1.1.9.1 onto my Creality CR-10S. After doing so, the temperatures for both the bed and hotend now read -14 °C. I have changed the setting in the Marlin configurations.h to several different thermistors, and it either reads 0 or -14 °C.
I have now installed several different versions of Marlin and with each one I experience the same problem.
Is there some tuning setting that I am missing or has installing the firmware somehow fried something on my board?

Okay, to anyone who is looking at this post, I am an idiot. I have spent the last 4 or more hours sifting through youtube videos and forum posts to figure out this problem. I have reinstalled firmware modifications dozens of times. All of this, to just now discover that I never had the bed or hotend cables connected. That's right, I never even considered the fact that I had yet to plug in those cables after transporting my printer to a new location.
Don't be like me. Check the simplest solutions first.


G-code (M-code?) for Get Bed Temperature I'm familiar with 3D printing, and the G-code concept. I'm also comfortable with programming.

Can anyone give me the G-code (or probably the M-code, actually) to read the bed temperature?

Is there an equivalent of M105 (Get Extruder Temperature)?

M105 should give you the bed temperature.

For future reference you can find a general list of G/M codes here - RepRap Wiki - G-code.

Most firmware files include a list, Marlin has it in Marlin_main.  I have no idea how often the list is updated but they don't change often.


OpenSCAD / FreeCAD splitting, hollowing and threading model I had a thought the other day that it's 100 % waste to have either a solid or hollow 3D-printed model in relation to utilizing the space inside of it for different modules, e.g. secret compartments, modules like salt/pepper shakers, etc.
So I thought the best way of achieving this in a streamlined semi-automated manner is creating a simple script in OpenSCAD / FreeCAD and I would love some professional input on how to achieve this exact process:

Split any given model at X height with Y angle Z times (eg. slicing a model in half & keeping both parts separate)

Make a hollow compartment inside the model with working 3D-printable threads sticking out from one part fitting into the other with definable shape, tolerance & size in relation to the parts size (eg. a cylindrical hidden compartment or a space where specific user-made modules fits into)

I'm thinking a few simple yet potent lines of OpenSCAD code or a FreeCAD script should do the trick but my knowledge is limited in this field at the moment so any input is highly appreciated.

OpenSCAD lacks any facilities to perform computations on the resulting geometry (derived from CSG or directly imported). It has a decent functional language for expressing geometry in terms of parameters and functions/modules, but the road is one way; geometry is an output only and doesn't loop back into input. So automation of this entirely in OpenSCAD is really not an option.
On the other hand, doing it manually is rather easy. You can use CSG operations (intersection or difference) to cut the model, cut a compartment out of it, cut threads in it, etc. as well as (union) attaching external threads. You just have to decide how to size and position them for your model yourself.
Note that there's no canonical module for doing threads in OpenSCAD. You can either derive the cross section for your thread profile (can be done with OpenSCAD code) then linear_extrude it with twist (needs really fine division to be accurate though) or skin a polyhedron for the thread. There are a few published modules for the latter and I have an unpublished one I prefer.


Ultimaker Cura 3.6 choosing to fill in narrow walls with diagonal striping I'm playing with printing some Lego-like bricks. I'm using brick models where the wall thicknesses are aligned to match an exact multiple of my printer nozzle (.4 mm nozzle = 1.2 mm brick walls, vs the standard 1.4 mm), with other adjustments to the interior ridges of the brick so they should still fit with real Legos.

I'm seeing an odd effect when slicing in Ultimaker Cura 3.6. My settings for Wall Thickness/Wall Line Count are 1.2 mm/3 lines. And yet, in the layer view, I see one wall line, with diagonal striping between those walls:

Part of it could be the interior ridges creating some thicker walls in places, but if you look at the piece on the left, there are no ridges (it will be a plate, rather than a brick, and Lego plates don't use ridges). Yet it still has the striping. I re-measured the STL in 3 different modelling programs (Meshmixer, 3D Builder, Tinkercad) and all show the walls as exactly 1.2 mm thick.

I then noticed I can remove this by putting something small (even .001 mm is enough) in the "Horizontal Expansion" setting:

This is more what I wanted, and it cuts the print time almost in half. I can also fix this by setting enough bottom or top layers to handle the whole piece with a wall thickness of 1 line...

... but why was it necessary? What is going on here?

All slicers have their own peculiarities, and one of Cura's peccadilloes seems to be that It likes to generate an even number of shells for narrow structures, even if an odd number of shells would work nicely. Slic3r and Simplify3D have no problem with this, and will automatically generate an odd number of shells if they will fit the model.

Cura, on the other hand, will reduce the number of shells and generate infill. If you have set the infill percentage to less than 100%, it will try its best to fulfil that requirement, and in your case, generate zigzag infill. However, if you set the infill to 100%, it will, in effect, create an additional shell, although it is really infill that follows the direction of the walls as far as Cura is concerned, since there is no space to generate the specified infill pattern pattern.


How do I update my firmware after installing a 400XL kit on my Ender 3 I've updated my Ender 3 with V4.2.7 mainboard, BLTouch and 400XL kit (extends the capabilities of your Creality Ender 3 3D Printer to a 400 mm X, 400 mm Y and a 500 mm Z printing platform). Now I need to update the firmware. YouTube did not provide any help: i.e.: out of date, so cryptic as to be unusable. Marlin & Creality had overly complicated, for what I need, solutions. Trying these led only to frustrations! Any ideas?

Without knowing exactly which Youtube videos you've looked at, I think where I would start is by downloading the latest Marlin Fimrware and configuration files for the Ender 3 with 4.2.7 board:
Latest Release of Marlin Firmware on Github
Configuration File Repository on Github
Microsoft visual Studio
PlatormIO
If I were doing your upgrade in your place, I would refer to this video for how to compile the firmware for the correct board. I've had to compile firmware for my Ender 3 a few times and I sometimes forget a step. This video is the best that I've found for showing/reminding me of each step.
Essentially, what I think you need to do is compile your firmware as if it were a stock Ender 3 V2 using the settings files I linked above but then change your print area the configuration.h file to match the X400 x Y400 x Z500 print bed area.
Look for the following:
// The size of the print bed
#define X_BED_SIZE 200
#define Y_BED_SIZE 200

Change to the following:
// The size of the print bed
#define X_BED_SIZE 400
#define Y_BED_SIZE 400

And then look for
#define Z_MAX_POS 200

and change to:
#define Z_MAX_POS 500

There are other changes you'd need to make to the settings file (refer to the video for those). I haven't done your particular upgrade on my machine, so I'm just guessing those extra couple of changes would work for you.


How to improve very poor quality prints on my Ender 3 I get very poor quality prints from my Ender 3: The prints are weak, brittle , stringy and contain gaps.

Please help me sort this as I'm new to 3D printing and have no idea what the problem might be!

The prints look like this:

i would suggest to start with something simpler

there are many test objects to print and see the results
please take a look here

the idea is to recognise issues (one by one or at least the most basic) and point them and eliminate them directly

looking at your printout i could of course suggest many things
but it would be better to make this process more clear... for you

so you could manage it on your own

to be somehow constructive

i would say there are 3 main issues on the picture you've presented

HE temperature
printing speed
not-so-stiff printer construction (or belt tension)

print test cube and show your results so we can go further


Is there a technique for turning an image into a 2d model? The overall goal is to create a print of the liberty bell.  No clapper is needed.  The support beam is not needed.  I am just looking to mimic the outside shape of the bell.  After an application of Google-fu I found this image.  It has been cleaned up and cropped a bit.

In OpenScad the surface function was applied to the png to generate a height model.   I subtracted out a few cubes, and eventually got it down to a layer of about .1 height.

My Evil (pun intended) plan is to get it down to a 2d model.  Then by shifting a copy of model from itself, and subtracting the two.  That should leave just the curve.  Then rotate_extrude the curve to generate the actual bell at the desired thickness.

I see the problem coming. If the model is layered down to zero height it will vanish. Leaving me nothing to rotate.

So on to the question.

Is there any tool or technique to turn the image into a 2d openscad object or failing that is there another way to approach the problem?

The direction that fred pointed me at is viable. I didn't use the actual image shown here, but a manually generated one from OpenScad.  As a proof of concept the technique works well.

As you are already familiar with OpenSCAD, consider to use the projection() function to accomplish your goal.

If you allow for an interpretation that one can cast a shadow of the part on a surface below, it becomes a 2D representation of the part. This is effectively how projection works in OpenSCAD.

Note that the part image below is centered in x, y, z and the cut/projection action takes place at the z = 0 plane:

When the function is applied to this model, the result is a non-contiguous 2d image:

When the cut parameter is ignored or set to false, the image which results is effectively an orthogonal shadow of the entire object, rather than a selected slice:

It gets better, of course. In OpenSCAD, the translate, rotate and scale functions apply. One can tip a model over, resize it, spin it around, combine with the cut parameter and get any combination of 2d image from the original model:

It's important to note that OpenSCAD does provide non-zero thickness to these projections when rendered, or maybe when previewed. I always get those two swapped around. As your objective is a 2D result, you may be able to select from PNG (save as image) or Export as DXF or SVG.

Re-reading your post, I also missed part of a more useful answer. Once you have the profile you desire, you can use the rotate_extrude function on the profile you generate. Despite the non-zero thickness, it uses the zero-thickness aspect to create the model from that function.

That aspect of the answer is left as an exercise for the reader, as the options are many and results can be complex.


Can't level CR10 as nozzle is touching the glass I have a brand new Creality CR-10 S5. I'm new to printing.
I'm trying to level the print bed, but after using the Auto-Home function the nozzle is left touching the glass. I understand that to do the leveling, I must move the head manually to the four positions for adjusting. But I really don't want to do that because I don't want to damage the glass, nozzle, or both. From the explanations of leveling I've found, I think I should expect the nozzle to be too high if anything.
Am I conceptually wrong, or have I made some rookie mistake?

If the nozzle is touching the bed, you need to further screw down the bed. If the springs under the screws are already fully compressed, you cannot lower the bed further and you will need to move the Z-endstop up. Note that there are handy fine tuning aids you can print to help you with this, see e.g. this fine tune part for your printer. Note that this issue is not uncommon, I've read that more people encountered this.


Different infill in the same part I´ve have read an article to change different pattern depending on amount of layers, but my question is if is possible to have different infill in the same part? For example:

Base: has the infill of 25 % but the same base has some tabs for screws and mount the part for this area the infill need to be 40 % or greater.
The walls and forms: this has the same of the whole part and can be filled at 25 % but some areas need to be filled at 15 % or less.

Probably someone has seen or reviewed another software to achieve this, or I'm fooling myself.

This answer explains that you can have different infill within the same part. Firstly the implementation in Ultimaker Cura is described, secondly how you can do this in Slic3r.

Ultimaker Cura
I've used a feature in Ultimaker Cura that can be used to alter the infill density locally. What you need to do is load your model into Cura, then load other objects (models) at the size of the area/volume you want your infill differently and position those at the position you want a different infill. So basically, you use other models to intersect with your primary model to create intersections that can take a different infill percentage. This is extremely useful for lugs and brackets where you need some extra infill (e.g. extra stiffness for compression stresses) at the fastener holes. Note that this is an advanced feature which is not easy to use, but quite handy if you master it.
I could not find the video (on second thoughts, I think it was animated GIF) posted by Team Ultimaker, so I quote a section of one of their forum topics.
A short how-to: (italic font is not in the reference, but added to reflect recent version of Cura)

Unselect "keep models apart" (now called: "Ensure models are kept apart") and "drop models to build plate" (now called: "Automatically drop models to the build plate") in Cura preferences
Import a second object (for example a simple cube)
Put Cura in "custom mode"
Select the cube, and use the button "per object settings" on the left side
Select "Infill Mesh" (now called: "Modify settings for infill of other models") and enable that setting
The cube now turns transparent gray.
Position the cube to overlap part of your model. It should overlap with the section that you want to change the infill for.
Also with "per object settings" (now called: "Per model settings") select the option "infill density"
Set it to the desired value. All is more or less illustrated in the screenshot below
The picture shows a cube on the buildplate with infill 20 %. Locally, with a rotated 2nd cube, the infill % is raised to 100 %.
What happens is that the volume where the cube intersects with your object is locally sliced with different infill.

Please find below another example of a simple bracket that has extra cylindrical objects loaded to create the intersections with the bracket at the fastener holes. In the example, the infill at the fastener holes is set to 99 %.

After slicing, you will see that the infill at the intersections is adjusted accordingly.

Note: I've tested this in Ultimaker Cura 3.4.1, and confirm it works. I sliced a part with the inserts for fasteners and it actually is not very difficult, it just requires a little more work. You will have to make some STL's of cylinders and position them correctly. If you make your own 3D models it will be a very easy task to add extra components while you design, positioning will be a lot more easy then (as they align with your model). An example is the following linear Z rod bracket of a Hypercube Evolution CoreXY printer, this bracket requires local enforcements for the bolts clamping the bracket onto the aluminum extrusion profile:

Inserts are modeled together with the development of the bracket:

When combined, it looks like this:

Now the infill can be modified locally to 100 % to increase compression strength.
Note that this will also work if you want a different infill percentage at the first X layers, just use a large cube (larger than the model) and position it correctly. Note that Cura already has an option called "Gradual Infill Steps" to adjust the density at the top layers.

Slic3r
This reference describes how to do this for Slic3r in detail.
The blog describes the use of a simple volume (the green volume loaded from an STL file). After loading:

Right-clicking on the main part brought up the object settings menu.
From there, clicking "Load Modifier" and selecting the previously
saved model adds it to the part as a modifier.
The green "+" was selected and "Fill Density" was added to modifier
list and set to 100 %.

This shows that the functionality in Slic3r is very similar to the functionality in Ultimaker Cura.


M3D filament not extruding well (anymore) I use OctoPrint on an Ubuntu system with a M3D printer.

Midway through a recent print, the filament just stopped extruding although the motor-functions of the printer were proceeding fine. Since then, every print I attempt has trouble extruding proper amounts of filament. It's always not enough. The output is stringy and not cohesive.

I'm thinking there may simply be a clog in the extruder and wondering the safest way to remove it.

The weird thing, though, is that when I use manual control and extrude at, say, 220C, the filament comes out fine.

You can see the raft definitely isn't printing right. Way too little output:

Suggested remedies for 3-D printers which are not extruding required amount of filament:

First, check the temperature of the extruder. Try 220-225C to see if that improves the problem.
The second step is to increase the flow of the filament (increase mm/sec) for extruder speed.
A final step is to increase distance between extruder and base-plate. If the extruder is too close to the baseplate, there may not be enough space for the filament to begin the printing process.

Another possible source of lack of material extrusion is a clogged extruder. To solve this problem:

Retract filament using jog control in software
Heat extruder 20-30 degrees Celsius above normal extrusion temperature
Disassemble Extruder, use small thin wire to remove blockage (guitar wire as suggested below)


Odd dotting when printing a line I tried printing a "improved" calibration cube and noticed that the printer was laying down dots instead of a solid line. This was right after switching out my extruder motor and tweaking retraction settings. I believe my first setting was 0.3 mm, then I tried 0.1 mm. I didn't get a picture of the first setting, but shown below is when retraction was set to 0.1 mm. I think the print was at layer 3 roughly. The difference is 0.1 mm had a higher frequency of dotting, ie more dots that were closer together.

This was only present in the first couple of layers. The dots weren't occurring in the same spot so the picture shows dots overlapping each other making a sort of "twisted" or braided look. This also happened on both the x-axis movements and the right side of the y-axis movements. The rest of the cube came out relatively well.

Settings

Printer: Creality CR-10S
Temp: 205 °C at nozzle; 60 °C on bed
Retraction: 0.3 mm initially, 0.1 mm (pictured)
Bed Distance: ~0.1 mm
Nozzle Diameter: 0.4 mm
Layer Height: 0.2 mm. I usually do 0.4, but I was lazy with slicer presets (AstroPrint)
Hotend: e3D Hemera direct, e3D v6 heater and nozzle
Filament: Hatchbox PLA white

I never saw this issue before on my printer nor have I seen it mentioned in various articles/videos online.

I have seen this a lot of times on my tronXY-X1 with an e3d-v6 via Bowden tube. It is not related to retraction but a different settin: Your first layer is set too thin or not leveled to the right height.

Having the first layer too thin, means that with a tiny error, the calculated correct extrusion becomes either a massive overextrusion or a barely sticking underextrusion. For example, the repeatability of the probing is the biggest error source. A well calibrated probing might varry about 0.05 mm between extremes, so would be written as (layer thickness)+-0.025 mm. On a 0.1 mm layer, that is a 25 % over- or underextrusion; overextrusion of that degree is well known to create such ripples.

Setting it to 0.2 mm for the first layer in Cura, Slic3r and PrusaSlic3r (look in your advanced settings!) did eliminate such rippling for me. My understanding is, that the extra distance gives the filament better ability to flow and stick on this first layer. Also, remember to set your line width to ca. 10 % wider than the nozzle - 0.45 mm is my typical setting.


SLA printers: safety with resin contaminated disposals I've purchased an Elegoo Mars Pro recently, and I've been watching hundreds of video of all kind of processes, and everyone tells the same: resin is toxic, so you should cure it before throwing it to the trash, otherwise it must be treated as toxic waste.
But I've not been able to find anything with "things that are contaminated with it". For example, if I touch with some paper the resin, I guess that I should let it cure in the sun (like putting it in a plastic box and let it cure, maybe?).
But how about the IPA? How do I treat the rests of IPA contaminated with uncured resin? I don't think leaving something flammable into the sunlight during some hours is the best I can do (maybe I'm wrong and it's totally safe?).
Also, are resins water-washable (like this one from Elegoo) as toxic as the rest? Can I wash them in the faucet, or should I use a plastic recipient with just water and wash them there? What do I do with it once I finish? May I throw it into the bath, or let it cure into the sunlight, or...?
Hope this helps me and some others to treat resin disposals as they should be! Thank you!

The IPA with the resin in it is a chemical waste and toxic to nature. As such, it needs to be given to a chemical waste handler. But those handlers do charge by volume, so you need to find a way to handle volumes reasonably. On the one hand, this means to not use huge volumes for washing the prints but reasonably small batches, and on the other hand to try to saturate them as much as possible before giving them to disposal.
It is not safe to leave the IPA in the sun or close to a source of flame, and it would certainly be not a good idea to try to torch the IPA to try to reduce the volume, but you might manage to try to concentrate the toxic waste if you might have access to a vacuum distillation apparatus - the IPA would be able to be distilled over to be reused while the original material would end concentrated.
At the moment I am waiting for an MSDS of eSun's Water-Washable resin, but the Eleegoo one is available, and it reads that it is classed as "Aquatic Chronic Class 2" - that's better than the Class 4 which IPA-washing resins have, but it is still not Sewer-safe: Do not allow product to reach sewage system or any water source. However, water is much less of a dangerous base for the waste than IPA, making it easier to handle. This mixture too needs to go to a chemical waste handler or be made inert but the waste also can be concentrated with less danger than IPA using a similar apparatus (cold distilling out water) or even a dedicated waste cookpot/evaporation vat that is exposed to heat - though you clearly should do this in a chemical-grade air filtration unit to mitigate the chance of resin fumes escaping into the atmosphere or your work environment if you heat it more than some. The dissolved resin might not be able to cure anymore as the photoinitiator might be used up during it evaporating.


How to transport a 3D printer? Dismount needed? I need to transport my FDM 3D Printer because I am moving.

What are the precautions that one should take? Should I dismount the motors and axes? I would definitively unplug the electronics as far as reasonable and fix the motors to the frame so they don't slide during transport. Should I have a housing to avoid dust and other mechanical issues?

Yes, fix the motors and any other loose/movable parts. Remove the bowden tube if it's there, and any other parts that are sticking out. Put the whole thing in a a bag to protect from dust, and put the bag in a box to protect it from getting beat up. Remember to calibrate it when you're ready to set it up again.


How may I identify the firmware in use on my 3D printer? I have a generic printer with no support documentation.

How do I determine what firmware is in use so that I can research how to make the print run?

Send M115 to the printer. This command is

  Request the Firmware Version and Capabilities of the current microcontroller.

Response example:

  ok PROTOCOL_VERSION:0.1 FIRMWARE_NAME:FiveD FIRMWARE_URL:http%3A//reprap.org MACHINE_TYPE:Mendel EXTRUDER_COUNT:1

For more info see here, RepRapWiki- G-code - M115: Get Firmware Version and Capabilities.

Of course, this isn't guaranteed to tell the truth, just whatever your generic clone firmware had in its source code.


Removed Nozzle, Plastic Still Backed Up after Cold Pull on Ender 3 I am still very much a novice and learning so here is the situation:

Filament was not extruding from nozzle. Checked the filament feeder (worked fine, filament was being squeezed through) and tried to push filament through hot nozzle to see if anything came out. Nothing did.
Did a cold pull, got a little bit of gunk out. Second cold pull didn't work out like the first one, and the glob of PLA that I fed into the nozzle remained stuck there.
I heated and removed the nozzle properly. I am going to soak it in acetone to get rid of the gunk inside. However, when I tried to install my other nozzle, it would take in the threads, and I see now that a little bit of the plastic from the last cold pull melted and trickled down.

What can I do to clean this out and install the nozzle? It is on an Ender 3 Pro.

I have encountered this many times. This is how I solved it:
Sadly you have to disassemble the entire hotend. Remove the nozzle, remove the heatbreak and heatsink leaving the heater block in place, it does not need to be cleaned (unless I am mistaken). If there are any plastic pieces in those parts, remove them as well.
Now for the cleaning. Use hot air gun to heat the nozzle/heatbreak/heatsink hot enough so the filament starts to melt. Then you can use a thin screwdriver (or metal wire) to push the stuck filament out.
Alternatively, you can use blow torch (or gas soldering iron with the soldering tip removed) to melt and burn away the stuck plastic. However, when the plastic burns it transforms into a solid dirt which you have to manually remove. But it does not stick as well as the original filament.
I advise against using q-tips because they are made out of plastic which can stick to the surface as well. Instead, use a piece of old cotton cloth (old sock or t-shirt will do) to wipe the surface or threads after heating the part.
When doing so, use needle nose pliers to hold the part in one hand, with the other hand use hot air gun or blow torch to head it up. Then remove the source of heat and with the same hand use screw driver or piece of cloth to clean the part to your liking.
It is ugly and messy and you will most likely burn yourself several times. But it solves the problem quite reliably, unlike cold-pulls and other methods (at least in my experience).
Bathing the parts in acetone will most likely do nothing (unless the stuck filament is ABS) because most filaments in use are resistant against dissolving in acetone. If you need to remove filament from anywhere, use heat not chemicals. It is easier and works almost 100% time.
Good luck.
Note: The solution above for heatbreaks and heatsinks concerns only full metal hotends. Hotends with PTFE lining (such as on Ender 3 Pro - I do not own one, cannot confirm) need to wory about filament being stuck in the nozzle and/or in the PTFE tube, not in the heatbreak and/or heatsink.


Nozzle rubs on previous layers I'm having a frustrating problem with my recent built custom 3D printer
so every single print I made, from the third layer, the nozzle is "rubbing" on the already placed filament.  This results in a complete mess, melting the previous layers with the nozzle / new extrusions coming, getting malformed and out of precision forms, if I leave this happening, my Y-axis motor (bed) start to jump steps (by the force of nozzle friction to cold material). To stop that symptom, at the beginning of this, I have to raise the Z-axis by hand turning about 1/8 rotation of T8 fuse. By doing this, every rest of my printing runs peaceful, nicely, and beautiful.
I'm using Marlin firmware, the most recent version, and Ultimaker Cura. My nozzle size is 0.5 and I'm using Ultimaker Cura's Fine Preset (0.1 mm height)
My stepper motors axis are very well calibrated (X, Y, Z and Extruder). I tried:

lowering and raising the print bed to get spaced or shrunken first layers to see if something helps,
tried to change Z home offset on display,
tried the M206 command to change the print zone of the Z-axis,
tried to change the first layer height on Ultimaker Cura,

but nothing seems to solve my problems.
Due to my lack of experience, I don't know what I could try to solve this frustrating issue. I already check and rechecked my mechanical structure and everything was fine solid and very well balanced and square.

From comment:

Printing speed are 40 mm/s,
Temps:
Hotend: 220 °C;
Hot Bed: 120 °C;
I have also tried 110 °C,
My Z-axis uses 800 steps per mm (1/32 micro stepping on DRV8825 at RAMPS).

I'm thinking about over extrusion but I have fine tuned my stepper, checked and rechecked for it and seems normal

I have made some learning on mechanical setup and discovered some issues on my printer, there are few:

Bed warped, even with glass (thin thickness), making BAL confused with Z-movement over the bed.
Overextrusion making layer oversized in terms of thickness.
Some of missing mechanical fine adjustments.

The main reason for this symptom was the overextrusion (that made my X and Y axis jump some steps when hotend collapses in the already-printed materials on their movements).

I hope this helps some of those who have this similar problem!


Is it possible in any 3D printing software to create a coiled tube? I've gone on quite a few sites (thingiverse, grabcad, etc) in search for a coiled tube, but I have yet to find anything suitable. There are a few coils ("springs") but no coiled tubes (i.e. the springs are hollow). Maybe my searching hasn't been good enough! But I was wondering if this is a limitation to 3D printing models?

I managed to do it in the end using AutoDesk 123D.

Did it by making two coils of differing radius, then subtracting the smaller from the larger. I made each coil using the instructions found here:

So there we go...

Printed it out just now without supports - in the orientation shown - and it came out fine. Used a brim, though (don't want it rolling away!)


File size limit in 3D printing software Odd question for everyone, hope it has a distinct answer.   I'm often printing bone models derived from CT scans (I work in a hospital) and they often have something on the order of 5 million faces +/-.  Now, I know from experience that I can decimate them down to 10-20 % of the original faces and they still pretty much look the same, so I often do that to help my computer run faster.  I also know that "GrabCad" (the software for my j750) can handle these face counts and the limiting factor is more so the actual physical print resolution.  But it got me curious:
Lets say I was using other software.  Lets say more universally available software such as PrusaSlicer or Cura.  Now obviously if I'm printing on a Prusa I probably don't need to worry about capturing all the detail from 5 million faces because I doubt I can print that intricately, but lets take the actual printing out of it (and I guess even before it gets to the G-code stage).
Can Cura/PrusaSlicer handle that many faces?  Is there a limit?  Do files get "dumbed down" at all when they come in?  What I'm trying to ask exactly is outside of the G-code and actual printing step, can the software side of things handle something with 10 million faces? 20 million? Is there a limit?

As a software developer and 3D printing enthousiast I can tell you that indeed, like Trish said, the limit is your memory (RAM) and loading/slicing time depends on the cpu power.
RAM: keep an eye on the memory usage in the task manager/performance/memory tab. When it reaches the top of the graph, the application will suddenly crash and disappear.
CPU: The application (cura/slicer/prusaslicer) can become "not responsive". This does not always mean that the process hangs. It just means that the cpu is very busy and the program is not reporting the progress to windows. Most probably the application will recover from this if you just choose to wait.
Files do not get dumbed down when imported afaik in cura. They are shown exactly like in the STL. Don't know about other software though, but I doubt this happens.
Like you noted, this has nothing to do with Gcode, which is loaded serially.


How to use E1 as E0? Like many people, I have burnt the pins in the micro-controller connected to the E0 motor - the E0 motor is not working anymore and I need to print tomorrow! I need to control the extruder motor with the working E1 pins. How do I change this in firmware?

I tried to change to the pins in `pins_RAMPS.h" but it was a complete fail, the motors that i tried to change didn't move.

I have a Arduino Mega + Ramps 1.3 in "Extruder Fan Bed" configuration, I use Repetier-Host as host and Marlin as firmware.

I would change the pin assignments by swapping E0 and E1 in pins_RAMPS.h.


Can I replace a damaged firmware of a 3D printer based on Arduino Mega? I have acquired a second hand 3D printer, the GEEETECH I3 Pro B. The previous owner tried to change the firmware but he made a mistake and he bricked the board.

I want to substitute the firmware of the board (which is an Arduino Mega 2560 based board). Do you think is possible if the board doesn't respond to the controls?

I have inquired and found an open source software called Marlin I want to use to restore the printer.

If you have an advice or you think that I can do it in any ways tell me.

It is hard to diagnose the board without hands on experience. It is even more difficult if you get a board that has been "updated/upgraded" by a previous owner leaving it not in working condition.

But, there are at least 2 solutions.

You could buy a new printer controller board, upload new firmware and connect all connectors.
You could try to burn a new bootloader onto your current board and upload a new version of the firmware.


My 3D printing part starts to bending after about 1 cm height and blue tape separates from bed I use a Prusa i3, and this is ABS printed part with 225/90°C. Why did this happen?

I tried to print this part again with new settings on Slic3r (I used Cura for previous print), but I got the same result. I found that the problem is because the model starts to bend after about 1 cm height. Also the blue tape starts to separate from the bed.

I don't use the fan for printing part (although the MK8 extruder's fan works all the time), and the temperature for the new part was (225/85°C first layer and 220/80°C for other layers). Also I must say that the adhesion of the model sticks to the bed is very good and strong, but it is bent!

Multiple problems here. Let's try to isolate them.

Blue tape. Good for PLA, not suitable for ABS. ABS works fine with kapton tape, glue stick, hair spray, ABS juice over glass, aluminum or PCB epoxy composite board.
Always use at least brim feature to ensure good adhesion along the edges (your last photos have none). For parts with small hotbed contact area use raft.
Hotbed temperature should be 100°C+, because at 80°C adhesion is weaker. If you can't raise hotbed temperature to 100°C, think about thermal insulation.
Layers of plastic don't stick to each other. Either plastic comes from extruder being already cold (check that there are no draughts of cold air nearby), or you're printing too fast (50 mm/s should generally work, if not try 30 mm/s).
No infill between walls. Either it is set to 0 or optimized out by some option.
Round walls aren't round. Either printing speed problem, or your belts are loose.
Underextrusion. Bottom of your first print looks like mesh rather than solid surface. Check that plastic flow is around 100%.

Also check that your thermoresistor measures the actual temperature of the extruder (i.e. is in direct contact with it). Otherwise you will get overheated plastic extrusion, which looks like your first photos.

Also, print a 1 cm cube first. Don't do anything complex, just cube.


Should I vary the first layer height Up till now, I've tended to scale my first layer according to the print quality, so a 0.12 mm first layer for a 0.08 mm print, and 0.28 mm for a 0.2 mm print.

After changing to a PLA which isn't sticking well, I'm wondering if the first layer is best determined by the printer/tolerance/material, rather than the overall print quality settings. Am I going to get more predictable results if I stick to a 0.12 mm first layer regardless? This is with a 0.4 mm nozzle on an Anet-A8.

Default settings for first layer height in Slic3r Prusa Edition print profiles regardless layer height is 0.2 mm.

If you need to improve bed adhesion then try tips from this video 3D Prints not sticking anymore? Watch this! 3DP101 by Maker's Muse. It's about using glue stick and spreading it using paper towel and isopropyl alcohol.

There are other possibilities how to improve bed adhesion, e.g. Ultem sheet or other printing surface like BuildTak.


Tuning line width and flow compensation in Cura I'm currently in the process of fine-tuning my cheap CTC i3 clone. I'm using Cura 3.1 for slicing.

After calibrating the extruder steps, I wanted to optimize the line width and flow compensation parameters. I am using a 0.4 mm nozzle and therefore set the line width parameter to 0.4 mm in Cura. I then printed a cube with 0% infill, 1 wall line and no top layers (basically an open cube with 4 bottom layers). The wall width I measured on the printed result is 0.52 mm. To correct for the difference I set the flow compensation to 80% and repeated the print. The wall width I got from this was 0.45 mm, which is much better than before. There is only one problem: the parallel lines in the four bottom layers do not touch, so the print is not watertight. Up to now I assumed that Cura would calculate the distance between the lines from the line width setting. So with 0.45 mm lines and line width set to 0.4 mm there should even be some overlap.

Why am I seeing this effect? Am I getting something fundamentally wrong here?

That is very bizarre.  Since GCODE describe each movement of the printing head (so, the printer does not get to decide anything in terms of printing strategy, it just executes), I can only see three possibilities that would explain what's going on.

The print is being scaled up at printer level.  This could for example be due to your firmware having your steppers improperly calibrated and moving them too much for a given unit of measure (say you say 1mm, they move 1.5mm instead).  This is easy to check: if this is the case, your cube will be scaled up (so - using the example above - if your cube is 10x10x10 it will come out 15x15x15).

You are printing with a raft.  Then there is no problem with your set-up, the first layer(s) of a raft are not solid, but intentionally "grated".  Check your settings to verify.

Cura is producing the "wrong" gcode.  This could be really wrong (as in "you found a bug", in which case you should report it on their github), or just look wrong (as in "you found a weird combination of setting producing that gcode", in which case you should reset the settings to their default and see the problem disappear).  Either way, if the gcode is "wrong", you should notice the gaps in the gcode preview mode in Cura.


Why do I have to lower my Z axis steps per mm? First, X and Y axis works perfectly, I measured well. I have plugged all jumpers, and use a very standard ramps 1.4 setup with standard Nema 17 200rev 1.8 motors and A4988 drivers.

For Z axis, I have leadscrew with 8mm diameter and 2mm pitch.

I calculated it should be 1600 steps per mm.
Problem is when I call G1 Z5 it goes to 2 cm. So I lowered my setting to 400 steps per mm and problem solved.

I don't understand what I'm missing here. I have used this calculator to find 1600.

Where I'm wrong on the math then?

Your leadscrew probably is a 2 mm pitch, 4-start leadscrew. This means that there are actually 4 separate grooves on the leadscrew, each with a pitch of 8 mm. Confusingly, this makes the total pitch 2 mm, since the distance from one groove to the next is 8mm divided by 4 grooves. However, one revolution of the leadscrew will still move the nut by 8 mm. Thus, in the Prusa calculator, you should enter a pitch of 8 mm/revolution. Since you entered a pitch of 2 mm, you ended up with a figure that is 4 times too large.

The reason leadscrews are made like this is that if you just had a single groove with an 8 mm pitch, the nut would need to be made very long to enable it to make contact with a sufficiently long portion of thread. By increasing the number of grooves, you can get away with a shorter nut. With lower pitch (lead-)screws you don't need multiple starts, since the lower pitch means the same length of nut is in contact with more thread.

For the relative advantages and disadvantages of the various leads (8/4/2 mm), as opposed to pitches, see also Would using a leadscrew with 1 or 2 mm lead, en lieu of 8 mm, result in a better printer?


Can I mix TMC drivers with A4988 on the same RAMPS board? The closest thing I can find is this wiki page that state DRV8825 and A4988 can be mixed. However, the TMCs seem different, requiring more connections and offer more features, so I wonder if they can be used on the same RAMPS board with A4988, particularly for X and Y axis.

Yes you can mix different drivers, including the TMC drivers (e.g. using for X and Y only).
How you do that is described in this instructable.

Please do note that, from observations, the 8-bit based Arduino boards and shields such as the RAMPS are becoming more or less obsolete; the 32-bit based controller boards are becoming mainstream. Such boards have a lot more potential in execution speed, memory and more available options for peripherals.


What causes "ghosting"? I am printing some minion chess pieces for my teacher at school and on every model I have found something called "ghosting", or at least I heard that is what it is called. For example there is a strap on the model for the pants. And going left and right there is very shallow "straps" or something happening.

I am interested to know what causes this to happen and how to fix it. It is not super bad, but would be nice to fix.

Ghosting is an artefact in the print due to the vibrations in the printer that are induced by rapid changes of direction.  It is important not to confuse them with inherent vibrations in the printer due for example to the belts being loose or the bearings not being in perfect order.

The good news is that it is relatively easy to tell them apart: ghosting (also known as "ringing" or "ripples" or "waves" or a number of other names...) is always downstream of a change of direction, and fades rapidly.

Inherent vibrations - on the other hand - tend to be consistently present when printing along a given direction, and do not fade.

Mechanically, ghosting works like this:

The moving part is travelling along - for example - the x-axis, when suddenly the direction of movement becomes the y-axis.
At that moment, the stepper motor of the x-axis stop rotating, but the momentum of the moving part stretches the belt even so slightly past the intended stop point.
At this moment the belt becomes like a rubber bend / spring, absorbs the kinetic energy of the moving mass and releases it by "throwing" it past the intended stop point in the other direction.
This keeps on repeating a number of times, but at each pass, some of the energy is dissipated, and the moving mass moves less end less away from the ideal stopping point.
While all of the above is happening, the object has also begun to move along the y-axis, so the extruded plastic looks "weavey" along the y-axis.

Understanding how this process works, makes it possible to understan why the three main factors affecting ghosting are:

The amount of mass being moved
The speed, acceleration and jerk settings
The elasticity of the mechanical components

Namely, mass and speed are important because their product is the momentum.  That in turn means that diminishing either one of the two will reduce the amount of "overshooting" past the stopping point.

Elasticity of the mechanical components is important as the more flex/stretch the part can take for a given amount of force, the more overshooting a given momentum will result in.

Finally, acceleration and jerk are important because - simplifying things a bit - the faster the change of direction happens, the less time the system has to adjust without vibrating.

So, concretely... what can you do to fix/reduce ghosting?  Three things, of course! :)

Reduce the mass being moved.  Depending on the geometry of your printer, the mass being moved could be the bed+print, the printing head, or an entire gantry.  These are normally considerations done when designing the printer itself, and engineers normally mitigate problems by using lighter materials (plastic over metal, aluminium or carbon fiber over steel, etc...), or adopting different designs (like using a Bowden extruder instead of a direct one, to save the weight of the stepper motor).
Reduce speed, acceleration and/or jerk.  Speed is normally the safest bet, as - besides your prints taking longer - there is really no penalty for it.  Acceleration and jerk - on the other hand - can cause overestrusion at sharp corners.
Reduce the elasticity of the system.  This is commonly achieved by tightening the belts and eventually switching to more rigid rods / tracks / rails.

A couple of resources that may come in handy for you to understand and solve the problem better:

A really nice article with illustrations (two of which I "stole" for this post)
A test model specifically designed to highlight any possible ringing problem with the printer.
A video showing lots of different test prints done with various settings (very useful to understand how changing the above parameters affects the print).


3D print a paint roller I was thinking about this question and thought of maybe printing a pattern-drawing roller painter.
The question is: is it possible to print with an ink absorbing material that could make a paint roller possible?
P.S: I don't own a 3D printer, nor have I any deep knowledge in this matter. I simply want to know if this is feasible, so I can start looking for someone to 3D print this for me. If it's not, knowing beforehand could spare me a lot of time.

While printing a roller stamp or rubber-roll from a flexible material such as [hard]TPU, [softer] TPE, or even a [super soft] foaming flexible filament is certainly possible. In any case, this would create soft, somewhat squishy prints. These prints will work quite easily as a stamp or woodblock printing stock, transferring ink from a pad to paper. The print pattern will depend a lot on how soft the stamp is: the harder, the sharper it will print. A massive roll of this material can behave akin to a rubber roll as one uses it in linoleum printing.
A foaming filament might be able to take a little paint in its airgaps, but it will never be as soft and contain as much paint as a foam lacquer roll - making it at best an improvised tool, or one that is chosen for a specific artistic purpose. It behaves more akin to closed-cell foam, while foam brushes and rolls from artist supply are typically open-cell ones. So if you go for a roller-stamp, you'll need to have an ink reservoir in the shape of a soaky-roller that isn't printed.
To top it off, it is nearly impossible to print a hairy wall painting roller: the hairs used in them can't be achieved with common print materials and slicers at the time. Even if stringing creates hair of similar dimensions, they are not affixed well enough to not get lost in the paint and can't be reliably created on demand.
Notes on pricing: One of the few options for foaming print materials is colorFabb, who was the first to offer such. Most of their foaming filaments cost around 50 €/kg, their flexible NinjaFlex costs about 80 €/kg.


How do I know when filament is getting old, and what things can I do to correct for it? I've heard I should store filament in sealed container, preferably with a desiccant.

But let's say I let a spool get a little old on the printer, or I purchased a filament spool that was old or improperly packaged. How would I know? How would this impact prints (what kind of symptoms would I see)? What things could I do (perhaps in the slicer) to correct for this and prolong the life of marginal filament?

And the corollary... in a typical environment, how long can filament be left out without suffering from the exposure?

I'm thinking mainly about PLA, but responses for ABS and other materials are useful, too.

The primary issue with long-term exposure of filament to the environment is that it will absorb water moisture from the air. When a filament that has absorbed water is passing though the hot end of a printer, the water will turn to steam and cause problems with extrusion:

Small bubbles of steam can form, causing extrusion to sputter - you might hear a sizzling noise and have poor consistency.
Large steam bubbles can cause significant oozing followed by no extrusion.
Extreme cases can cause mysterious jams that seem to clear themselves (the extruder cannot overcome the steam pressure).

In short, this will cause terrible print quality and failed prints. As the effects are not consistent, there is nothing that can be done by slicer settings to "recalibrate" for filament that has absorbed water.

This can be avoided by storing filament in an air-tight container with desiccant to ensure low humidity. Some people use "dry boxes" that allow the spool to be mounted inside while filament can be passed to the printer, so there is minimal exposure even while the spool is in use.

If you do suspect that your filament has absorbed moisture, you can dry it out, by placing the spool in a warm oven or in a food dehydrator for a few hours. If you weight it before and after, you should find that it weighs several grams less afterwards. WARNING: It is important that the temperature does not soften the plastic at all, or it can become distorted or bind on the spool. Most ovens will peak well above the set temperature as the thermostat cycles. Of course, fully melting a roll of filament could destroy your oven or cause a fire.

It's hard to say how much environmental exposure is too much, as every filament and environment is different. When I started out, I had several spools of PLA that I stored in the open for months. I didn't think I was having any problems, but I was also learning much and improving my printer settings at the same time. After getting PETG, it became unusable with oozing and jams after about two weeks but a few hours in my oven was a miracle cure! I then dried some PLA as well, and I found that print quality did improve, but not amazingly so. I have not used ABS, but in theory it is less hygroscopic than PLA, so it is probably not very sensitive to exposure.

I set up a dry storage box, and I am careful to always store PETG or my "good" PLA when I'm not actively using it. I have a couple rolls of PLA that I don't like as much anyway and generally just use for draft prints, and I don't really worry about it that much.

Note: An object that has been printed will also absorb moisture, but in general this isn't a problem.


Accidentally printed a chocolate mold instead of the object itself This is my first time printing 3D of any kind.
I'm not 100% sure what happened.  The quality of some of these first printouts has ranged between 'not great' and 'unrecognizabe glop'.
I'm testing with a Wiiboox Sweetin.
So far the quality of the printed items, using the demo designs and the company-included sample dark an white chocolate is a little underwhelming: The details are crude (rough edges / lack of detail) and the speed is slow (about 20 minutes to print something the size of your thumb).
Also tried to print a word created Blender (MacOS), exported to STL, imported to Ultimaker Cura where it was sized and positioned, sliced and exported to a .gcode file.  That printout seemed to be a mold of the object as opposed to the object itself.
Attached are two images, the 1st shows what was intended to print.  The 2nd shows what actually printed.

If you can see past the globs and blobs, and look closely, you might be able to make out why it looks to me like a mold instead of the intended item.
Side note I noticed that when the printer stopped printing (to move w/o printing), the extruder screw pulled back 10 - 20 mm, which seems excessive.
So some first timer questions:

What 3D printing controls might affect rough edges?

What 3D printing controls would have an impact on a speed of completion.  I know there's arm speed, but perhaps detail, maybe something else?

Is there some control -- something along the lines of 'invert' -- that would explain why I seemed to have gotten a cast instead of the printed object?

Is there a setting that controls how far back the extruder arm retracts when it moves?

Is it necessary to install a printer to compatible with Wiibox Sweetin in Cura?  Wiiboox isn't an option, but perhaps there's something compatible.  The printer comes with a CuraWindows.exe app (I'm on MacOS using Ultimaker Cura v4.8.0); there are two .ini files that come with that: 60ml0.6.ini & 60ml0.84.ini.

Thanks for any and all advice.

Cura contains a few different so-called "special modes" which changes what the software does with your STL. One such special mode is Mold mode which, instead of recreating the object, creates a mold for the STL. It appears you may have that setting turned on, so disabling it will cause Cura to work as intended.
To answer your other questions:

Most settings affect "rough shape", properly slicing your STLs to fit your printer and printing material is an essential skill to master in 3D printing. So there is no magic setting to get it all working, you need to tune all your settings according to what you want to print.

Your speed sounds fine, I can't speak for this printer in particular but print jobs taking hours or even days is not out of the ordinary. 3D prints in general take quite some time to complete.

Yes, usually it's called Retraction Length.

Yes it is definitely necessary to set up Cura to your printer settings because Cura needs to know the build volume of your printer and what flavor of firmware is installed on it.


Marlin bed autoleveling confusion I've just added a Z-Probe sensor to my custom printer (Arduino - RAMPS 1.4 - Marlin 2 default disabled EEPROM) but now I'm confused. Printer seems to work but I cannot configure the right nozzle height.

I use Pronterface and before start printing I send G29 code. Printer succesfully ends bed calibration. At this point I start printing but the printer seems to ignore the calibration (no bed compensation).

Do I need to run other commands to tell printer to use the previous calibration?

When the printer ignores the scanned topology (grid) of the bed this means that the levelling is not active. G29 activates the M420 to enable the grid. A G28 after scanning the bed will reset this.

You need to make sure that the start G-code (this is an optional script that is pasted before the sliced object) contains both the G28 and the G29, where the G28 is placed above the G29 on separate lines.

For each slicer this is defined in different places, bit if you use Pronterface for slicing, a good chance is that it uses the Slic3r engine. If I open an STL for slicing in Pronterface, it starts loading Slic3r.exe; this brings up the GUI for Slic3r which has options to define/modify the start G-code.


What do I need to do to recalibrate my printer after updating the firmware? I just updated my Maker Select Plus from the stock (I believe RepRap-based) firmware to Advi3pp, which is Marlin based. The printer starts up and everything seems okay, but I haven't actually tried a print yet and there was a message during the upgrade about deleting incompatible settings.

What do I need to do to recalibrate the printer following the firmware upgrade?

If it is Marlin based or RepRap based, many parameters are stored in EEPROM memory. A G-code command M502: Read parameters from "configuration.h" would reset all parameters that can be changed to their default value as defined in your configuration file. Don't forget to follow the M502 command with a M500 command to store the loaded parameters to EEPROM. This would overwrite all previous settings.

From the linked source, M502:

  This command resets all tunable parameters to their default values, as set in the firmware. This doesn't reset any parameters stored in the EEPROM, so it must be followed with M500 if you want to do that.

You can send these commands over a terminal interface to the printer using applications such as Pronterface, OctoPrint, Repetier-Host, and probably many more, or store the commands in a G-code file (e.g. a text file with a .g extension) and print the file using an SD card.


tips for pinching down onto an object I was wondering if anyone could give me tips for designing a 3d printable structure that can "pinch" down onto a hockey puck shaped piece and hold it tightly.

I'd like for the structure to normally want to "pinch" two edges together, but I can pry/force them open when I shove the hockey puck into it. Once I let go, the two ends are now holding the puck fairly tightly.

My first thought was something like a potato chip bag clip, but that would require a couple pieces and a spring.

Is there a way to do something like this with one solid piece?

Here are first 3 the most simplified and generalized options you have:

All you need now is to give use more details about your needs. If you reveal more details we could help you to apply (and modify) one of these  options.

Each of above has its own pros and cons of course. You said you don't want to have spring... so maybe a rubber ;)
But in fact whole-red is one-piece-clip in which the force comes from material elesticity or stiffness.

Please tell me what is the application of such clip.


Resin burns to transparent sheet I recently bought a Kelant s400 LCD DLP 3D printer. I am using Wanhao resin (green) to print, using the recommended settings from Wanhao. I was printing a hollowed out cube as a test and it printed fairly ok, except one corner didn't print. Please see the attached photo. Turns out the corner stuck to the transparent sheet and not the rest of the print (base layers printed fine). Why would this happen and what can I do to prevent it?

Thanks

The first thing to check is the transparent sheet itself - are there any defects (rough patches, creases, grazes) in the area in which the print was stuck to the "transparent sheet"[1]. This will cause the newly cured layers to cling better to that sheet than they should in that area, and likely caused the failure.  If the sheet is marked in any way in that area, you likely need to replace it.

This kind of failure happens when the forces holding the newly cured layer to the transparent sheet are weaker than the forces holding the part together/to the build platform. These issues are usually to do with exposure settings - underexposed layers are less likely to bind together well and more likely to fail.

Since the majority of your part printed correctly, it looks as though your exposure settings are probably about right.  If there are no defects in your transparent film though, there may be unevenness to the spread of light across your LCD that means some areas on the build area cure less well than others. You don't mention what slicing software you are using, but many slicers allow for a 'greyscale mask' that can compensate for this by making the image displayed on the LCD screen less transparent in the areas that the UV output is stronger so that the weaker areas can catch up.  Note that after applying such a mask, you may need to alter your layer cure times to compensate.

[1] This transparent sheet is likely FEP film - essentially transparent flexible teflon,  though I can't actually find that specified in the product details for this model of printer


Has anyone applied four 200 x 200 mm PEI sheets to a 400 x 400 mm bed? Of course I'm referring to side by side and not stacking or overlapping.  200 x 200 mm PEI and Kapton sheets are more readily available than 400 x 400 sheets.  I'm wondering if anyone has tried this and if the edges of the sheets cause a problem.

I haven't tried such a thing, but a speculative answer covering the constraints and expected failure modes may suffice here.
Unless the sheets have squared (rather than rounded) corners, the corners will almost certainly be a problem. In particular you'd end up with a hole right at the middle of the bed.
If the sides aren't entirely square (perpendicular) with each other then you'll have large gaps at one end or another.
As Trish noted in a comment, it's also possible that you may hit problems due to mismatch in thickness between the different sheets, although I'd expect these are fairly well-controlled in the manufacturing process; otherwise I'd expect bed leveling issues even with just a single sheet. If you do hit this kind of issue, it may be possible to avoid it with shimming of some sort.
Assuming you can avoid all of the above potential problems, I would expect what you've proposed to work reasonably well, especially if you're ok with very minor surface defects at the seams.


How to test Arduino Mega, RAMPS 1.4 and Full Graphic Smart Controller LCD? Unfortunately, my extruder 8825 driver ended up fried. I guess this might have damaged the Arduino Mega and RAMPS Board.

I tested the Arduino Mega and I'm pretty sure that it is fried too, so I bought a new one. I thought the MOSFETs on the RAMPS are damaged, so I removed them and tested them. One of them was not working, so I bought a new RAMPS Board too

Now I have a new 8825 driver, a new Arduino Mega and a new RAMPS 1.4 but the LCD still doesn't show anything and it just lights up on power up.

So basically you just replaced everything except for the LCD (the LCD testing is described a little further). If the LCD is not working then, this could imply that either your LCD is broken, or one of the new parts is not functioning as expected, or you have not connected things correctly.

Are you sure the firmware flash went okay? You could test the Arduino Mega 2560 by connecting it over USB to e.g. Pronterface, you do not need the LCD for testing the Arduino Mega and the RAMPS.

The LCD could be tested separately by creating a sketch in Arduino IDE and connect the correct pins of the LCD cable to some pins of an Arduino device, e.g. load the the U8Glib example sketch "GraphicsTest" and add the following constructor:

U8GLIB_ST7920_128X64_1X u8g(6, 5, 4);  // SPI Com: SCK = en = 6, MOSI = rw = 5, CS = di = 4

This implies that you need to attach the correct pins on the Arduino (in my case to digital pins 6, 5 and 4 for respectively SCK, MOSI and CS to the respective EXP1 pins 5, 3 and 4):

Note that you see 5 pins attached, as the LCD needs to be powered (pin 10 on the EXP1 header) and grounded (pin 9 on the EXP1 header).

I wired this on an Arduino Uno clone and confirmed that 2 of the spare RepRapDiscount Full Graphic Smart Controller clones showed the test program.

PS, this is a simple wiring of the LCD, it displays the test in fade blue-ish, so not the bright colored white pixels, but that is normal!


What are the pros and cons of collecting parts yourself, versus getting a DIY kit and then modifying it? I'm thinking about buliding my own 3D printer from scratch.

Is it better to buy a starter DIY kit and try to build your printer around it, or to order separate parts for printer, and then to combine a printer?

From a general point of view, there are a few things to consider.

If you buy a kit:

Pros:

You get some insurance that you have all the parts that you need to get a functional printer - all the electronics, structure, bolts, nuts, screws, washers, wires and so on.
Most likely, all the parts you get are made to fit together.
You will (usually) get a manual, often a community that can help you out, and sometimes even technical support.
Sometimes, it can be cheaper than buying each part separately (but it can also be more expensive)

Cons:

You have limited/no options to customize your printer to your own preferences without purchasing additional parts.
Some kits can be difficult to upgrade later or may be locked to some configuration or software.

My opinion:

The way I look at it, the better option for you depends on how you want to spend your time. That is:

If you get a kit, you can spend more time building.
If you collect all the parts yourself, you will have to spend time planning, ordering parts (possibly multiple times) in addition to actually building the printer. A possible lack of manuals could also increase the building difficulty.

If you don't already own a 3D printer, I would recommend getting a kit, simply because struggling with trivial things like parts not fitting together can take away the fun for many people.


Why are skirts designed the way they are? I understand the purpose of printing with a skirt (or at least, I think I do): it gets the filament warmed up and flowing properly, in order to avoid extrusion problems while starting to print the first layer. (Perhaps it has other benefits as well? If so, I'd be interested to know what they are.)

However, what's not clear to me is why skirts are set up in exactly the way they are. In particular:

Why is the skirt drawn around the whole of the outside of the print, at a roughly constant distance from it, instead of (for example) just going round in a small circle in one corner of the print bed?
Why does a print with a larger first layer need a skirt that uses more material?

I ask partly out of curiosity, but also partly because I'm printing several small but awkwardly shaped parts, and using a skirt reduces the usable area of the build plate. If the skirt could just be put in one corner instead of going all the way around the edge I would be able to fit more parts on the build plate. This leads me to my final question:

In Cura, can I change the layout of the skirt, so that it gets drawn in a convenient part of the build platform, instead of going all the way around the edge of the print?

Skirt and Brim are not only nozzle prime operations. While Brim is intended to help in adhesion by increasing the area, Skirt is a method to test some things about the bed and positioning:

If the bed is unlevel, you can see this in the skirt before the print starts. This demands to go around all of the print.
If the bed is greasy, you'll see also before the actual print starts, as the extrusion does not stick well.
It provides a visual check if the slicing is positioned well on the printer. If you for example run printers of different dimensions, the skirt shows instantly, if you loaded G-code that is too large for the bed.

The effect to reduce airdraft to the first layer is sometimes brought up, but I don't think it is relevant. However, if one would pause between skirt and print, one could use the outline to put down glue or ABS-slurry for materials that need extra adhesion.

The use of the material in a skirt is directly proportial to the width (1 or 2 lines) and the area included (as circumference is proportional to area).

  In Cura, can I change the layout of the skirt, so that it gets drawn in a convenient part of the build platform, instead of going all the way around the edge of the print?

No. Skirt is, by definition always around the whole set of parts. Just turn off Skirt and use an alternate priming, if you don't think you'll need it or find it cumbersome. Instructions for example priming operations can be found in Writing G-code : swiping at start of print


Marlin Minimum X/Y Feedrate I'm in a situation where I'd like to move the XY axes on my printer extremely slowly (down to 0.05 mm/s = 3 mm/min). [I'm okay with 'smooth' motion not being possible].

First off, here's the (somewhat Frankensteined) setup I'm using:

I'm basically using the LulzBot TAZ 6 for motion control (XYZ, bed temp) with a custom extruder mounted in the place of the printhead. I've got a computer running a Perl script on Debian which sends synchronized commands to my extruder hardware and the board on the TAZ 6. So far I've only slightly modified the Marlin firmware to match the baud rate on my computer and shrink the motion command buffer.

Motion control for the TAZ 6 is accomplished by directly sending G-code line by line either from a terminal or from that Perl script.

What I've found is that while I can set arbitrarily slow speeds for the Z axis (lead screw), the X and Y (belts) won't go slower than about 15 mm/min. The printer will accept the e.g., G1 F0.1 X1 input, but will just move at the 15 mm/min.

Unfortunately, the experiment I'm trying is giving me good results at ~5 mm/min (on a commercial linear stage), so I'd like to resolve this.

I've tried setting the jerk to 0/low values via M205 S0 T0 X0 Y0, and the maximum acceleration lower as well (M203? I recall), but without resolution.

Is movement limited just by the type of actuator? It seems to work for the Z-axis but not the X/Y-axes, I think it might be some firmware setting.

Edit: I've attached an image of the default settings from an M503 call (acceleration, jerk, steps/unit, etc).

What I could suggest here is:

set the acceleration to 1 instead 0 so we have M201 X1 Y1
use G1 Xdest Ydest F3 - feed rate is given as an integer


What's the difference between "Initial Layer Width" and "Initial Layer Flow" in Cura? I'm trying to increase adhesion of the first layer (as well as to fill gaps for a more even surface) by squeezing more material against the bed. The obvious way of doing that in Cura is by increasing the "Initial Layer Flow", i.e. to make the printer push out slightly more material than it normally would.

But then there is also a setting called "Initial Layer Width" and according to the the Cura Settings Guide (see image below), increasing line width will make the nozzle

  extrude more material and that material has to flow wider outward. This causes the nozzle to press the material harder on the build plate (...) Not only will the lines be wider ... but they will also be farther apart ... by the same factor, so it would not produce overextrusion

This seems to imply that increasing the initial layer width will automatically also increase initial layer flow. If this is so, the question is: which setting is applied first?

In any case, it seems that the two settings should not be applied together, if they manipulate the same variable (but I have not seen this recommendation anywhere). Which leads me to my may question: what is the difference between the two settings? More specifically (based on my above reasoning): what else does "Initial Layer Width" manipulate, apart from the flow rate in the first layer? Just the distance between the lines so that increasing the setting will lead to fewer lines?

Cura option Initial Layer Width will cause lines to be further apart or closer together, based on the value you set with respect to the default. The required filament flow to produce these lines is calculated based on the width of the line and the overlap between lines (and layer height).

The Cura option Initial Layer Flow adjusts flow for the current line width with a multiplier, this means that the distance between lines stays the same. I.e. with this parameter you can overextrude to push more material to the build plate. Note that for a well calibrated machine this is not necessary. My printers use the paper method to determine the initial Z=0 for levelling and never use a wider initial line width or overextrusion of the first layer to get perfect filled mirror finish first layers on glass. However, if (paper) tape is used, the bed may be less flat and overextrusion might be beneficial for better adhesion.

The options can be used together, the multiplier will act upon the calculated flow.


What type is that glass? I own a Magic Build 3D Printer. I found out, that the glass is scratched like in the picture.
So, I'm looking for a replacement glass plane to put in front of the projector. Is this a special glass? What are the properties? Where can I find it?

This is a sheet of glass you'd most likely need to acquire as a replacement part for your printer's manufacturer:

The dimensions of the glass, especially with the rounded corners, are usually very odd and make buying a spare from a glassmaker really expensive.
Some printers like the Elegoo Mars have an LCD mounted as part of this sheet.
Printers also might have this plate coated for different properties, for example, to reduce reflectivity and refraction inside the printer.

In this case, we have a DLP setup that uses a projector. You best inquire at the manufacturer itself using their website, E-Mail or facebook about a few spare pieces - that will get you the same quality as the bed you already had (save for the scratches) and they usually have such items in stock.


Z-Axis does not appear to be working on Ender-3 Pro So, the wife got me a Creality Ender-3 Pro 3d Printer for Christmas.

Assembly was easy, axis movements are all solid... when I go to print the test-dog.gcode file provided with the machine, it comes out looking... flat.

Not kind of flat. TOTALLY flat.

The Z-Axis motor works - I can move it with the machine's control panel - and it moves on it's own for repositioning of the head for printing purposes, but it doesn't seem to be moving 'up' for each new layer.  Layer height is set for 0.1 mm, nozzle is .4 mm. No settings changed in the G-code, or on the machine (and I did a "reset to failsafe" before attempting to print anything).

I'm relatively new to additive manufacturing, can someone help out here?

It turned out that there's something wrong with the G-code file that came with my printer.

I downloaded a calibration cube from Thingiverse and printed it - while it wasn't 100%, it did print viable. Now I need to get into details as to quality, and I suspect that too will be a factor for the G-code used in the printer. I'm looking at "Ultimaker Cura" to figure out the changes in G-code based on option changes.


Thermal runaway triggers when raising temperature amid cooldown I've noticed an interesting behavior on my Ender 3 with SKR Mini E3 mainboard and Marlin 2.0.x bugfix firmware. (otherwise, all other hardware is entirely stock) After the hotend/bed are commanded to cool down, e.g. after a print completes, I have to wait until after they both cool down to ambient before commanding another temperature setpoint.

If I don't do this, the printer most often triggers thermal runaway protection. (usually citing the extruder, but also sometimes the bed) I think this might be due to the thermal inertia in the material between the heater and thermistors, causing a 5-10 second delay in sensed temperature rise. I don't see any reason why thermal runaway should trigger; the Octoprint temperature graph looks completely normal, with no perceptible anomalies.

Is there some way to tune parameters for thermal runaway protection to alleviate this false-positive situation?

Yes there are ways to tune false positives. For Marlin firmware you can find these option in the Configuration_adv.h file.

From the file itself you can read what you need to do:

 * If you get false positives for "Thermal Runaway", increase
 * THERMAL_PROTECTION_HYSTERESIS and/or THERMAL_PROTECTION_PERIOD
 */


How do the MAX endstops work? I’m building my new 3D printer and I have a doubt. I’m using limit switches on the 3 axes, but only the MIN switches. I also have another three switches which I want to use as MAX switches. How can I do that? I mean, if I insert a specific measure of the plate in Marlin and than the extruded stops before of the limit of the plate due to the MAX endstop what will happen? What should I do, upgrade to MIN and MAX endstops or only keep the MIN ones?

You should see MAX endstops similarly as MIN endstops, or as an additional option to protect the printer:

Similarly seen as MIN endstops, you would define in the firmware that you are using them to set a reference point at maximum values, your offsets and bed dimensions would be calculated from the MAX positions;
You can configure the MIN endstops and have additional MAX endstops set beyond the bed size dimensions. If the printer would encounter a layer shift causing the nozzle to go beyond the printer (MAX) boundaries, the printer shuts down when the MAX endstop is triggered.


Any experience with nylon drying on heated build platform and printing on paper? A while a go I thought that I could try printing in Nylon on my Wanhao Duplicator i3 with full metal hotend. Boy, was I wrong: The filament was not dry and popped like foam. The platform (Buildtak) was not sticking at all (at any temperature), I had the cooling fan at 100 %, so the bits that stuck to the platform warped like the Enterprise.
I learned that a filament dryer, an enclosure, Gaolite and PVA glue will be my friends, but I am determined to not spend a lot of money to printing something that I don't need often. (PLA works fine for me)

I am now at the point that I dry my filament by leaving a roll of nylon on the heated buildplatform at 90 °C. It stopped popping and hissing, so I guess that works. I learned that nylon sticks to cellulose, so without needing to recalibrate I can tape a piece of printer paper to the build platform and it sticks like crazy! Extra bonus is that if it warps, the paper curls up slightly and keeps the print from falling off. I have only printed a single test piece until now, so I can't really say if it's to be recommended.

Has anybody used these methods (drying nylon on heated build surface and printing nylon on paper) too and have you found any downsides?

To make this a worthy stackoverflow question: "Can I dry nylon on my heated build platform and print nylon on paper?"

Heating spools on the bed can be an option, but it seems inefficient to me: you lose a lot of heat and an oven would save quite some energy. Also, I wonder whether the open air will reduce the effectiveness even more, since the outer parts and the top of the spool will be colder.


What causes these round corners Nozzle diameter = .4
Extrusion multiplier = 1
Extrusion Width = .45    <-- I feel like this could be reduced to fix it?

Layer Height = .3

I'm using Simplify3D.

If it's on each corner, and not the layer change corner, it's a combination of overshoot and the short "pause" of the printer when it changes direction.

You can minimize it, but it won't go away 100% (due to overshoot from direction changes), usually models with a slight rounded corners work great.  If you, say, increase the jerk as an experiment and they get sharper (but you obviously have to deal with potential ringing artifacts) then it's due to that pause and acceleration after a direction change.

I would try lowering the temperature a bit to slow the flow/oozing of the nozzle and calibrate extrusion - just to keep the settings tight as possible to keep dimensional accuracy, but not under extrude obviously.

If it's where a layer change occurs, tweak and play with retraction settings - such as coasting and extra distance on restart (you can put negative values here). Once those are set, as an advanced tweak, try to max the z speed... Obviously this involves motor current, testing for skipped steps etc... but this would make the layer change a bit quicker, to further reduce oozing, due to the delay in layer changes if retraction settings don't fix it.

Usually, you can fix the corners with retraction settings but then it can mess up other parts of a model, since those settings are global... I wish slicers were more intelligent.