Best material for compression? I'm designing a mount for a cylindrical speaker to attach to my bicycle. It will mount on the bottle cages. I've printed a few iterations with various infill settings (using PLA) and the weak point is always the bolts holding the entire mount to the bike. They can't handle the compression needed to secure it properly. I had thought about using an imbedded metal part to distribute the load, but it's not easily replicable and I want to make the design public and fairly accessible to others with the same speaker. I currently have PETG and ABS, would one of those perform better or should I order a specialty high strength polymer?

Infill has minimal effect on the strength of printed parts, so I would expect the part to break in the same spot regardless of what infill percentage you used.
PLA is especially poor in this exact application, and it undergoes significant creep/cold flow under mechanical compression over time, so even if achieved the necessary strength by changing settings (which you can), it would require that you periodically tighten the bolts more and more, as the PLA would slowly deform under the mounting pressure.

Perimeter width and number of perimeters are what primarily influence the strength of a printed object, infill has very little impact on strength in comparison, and unless you're using an exotic pattern like gyroid, what impact it does have is not even close to isotropic (will add strength in some directions while doing nothing in others).  But even then, infill only really has an effect when we are talking about forces that are spread evenly over the entire object, not concentrated strength of a specific spot of the part.  And that effect is always much weaker than what perimeter count or width will have.

Just bump up your perimeters to 4 or even more and that should make a huge difference.

And also, don't use PLA.  I think PETG is a much better choice in this situation.  It is more ductile only slightly less rigid than PLA, making it much more durable overall than PLA, and less prone to cracking under compressive forces.  PLA theoretically has higher tensile strength, but that often doesn't mean much.

I would not recommend ABS, it tends to have similar issues with brittleness and is one of the weaker materials one can 3D print.

It terms of ordering a special high strength polymer.... unless printer and hotend is rated for in excess of 400°C, no such 'high strength polymer' exists, at least not that you can print.  PLA and PETG are close to the best you can get, with Polycarbonate inching out ahead but not by a huge amount (~20%).  Despite what filament companies would like you to believe, carbon fiber reduces the strength of PLA, ABS, PETG, PC, and probably nylon, and instead simply makes those polymers more rigid and increases dimensional stability.  The only filaments that would actually be made stronger with added fibers short enough for filament manufacturing processes are ones with glass fiber.  But you don't want to print those filaments, trust me.  They will dull the teeth on your hobbed gear(s), even if made from steel, and will just ruin all but ruby nozzles very very quickly.  And they still wear out ruby nozzles even then.

There are exotic polymers, but none of them print at less than ~350°C, and are generally exceedingly expensive.  All the polymers that can be used at normal printing temperatures are all fairly similar to each other in terms of tensile strength at least.


Material for printing orthotics I noticed foot arches are already digitized, but custom arch supports are usually expensive.  PLA and ABS aren't the best material for printing arch supports, especially if they replace the shoe's innersole.

Is there a more flexible material for 3D printing that could be used for making custom orthotics?

The standard choice for this would be TPU, thermoplastic polyurethane.

TPU is a common filament material for use in fused filament fabrication 3D printing due to the fact that it is an elastic thermoplastic which makes it ideal for printing objects that need to be flexible and elastic.
...
Properties of commercially available TPU include:

high abrasion resistance
low-temperature performance
high shear strength
high elasticity
transparency
oil and grease resistance

In addition to TPU, there are plasticizer-modified PLA filaments with similar flexibility, but not necessarily with the other nice properties like abrasion resistance. I've printed with one from 3D Solutech and had good results, after figuring out what to do about stringing.
Also, it's possible to achieve a decent degree of flexibility merely with printed geometry, rather than special materials. It's possible that PETG with an appropriate geometry could work for your application.


Object's height not a multiple of layer height This basic question has been bothering me for a while.

Let's say I'm printing an object of height 20.1 mm with 0.2 mm layers. What will the slicer do? in other words, how will it print the last layer? Since I'm printing with 0.2 mm layers, my object will be printed in 11 layers, but the last one would make my object 20.2 mm high. Is there some sort of compensation (in Slic3r or Cura for example), or will I just get an inaccurate object?

Slicers will round off to the next nearest layer, so 20.2 mm in your case. However, you can get to 20.1 mm if you use a 0.3 mm first layer.


Sunken and rough bottom layer Most of my part is printing very well, but I have problems in the bottom layer and in layers that are the first layers, but not necessarily layer 0.

Looking at the print quality troubleshooting, I can't find a problem that fits my needs. Using the terms over there, I would describe it as "gaps in bottom layer".

Photo from part A (RPi case top piece):

Photos from part B (RPi case bottom):

There is a really ugly screwhole (sorry for the blurry picture):

But in the same part, there's an almost perfect much better screwhole:

For the location on the print bed, it's here (both parts):

I have seen the question First bottom layer has gaps, where the OP has already tried a lot.

My thoughts so far:

I don't want to generally lower the Z height, since it prints fine over a large area with a really flat and smooth surface.
I'm not sure I should change the temperature settings. I use the i3 MK3 printer and I use Prusa PLA filament with Slic3r Prusa PLA filament settings.
I don't understand many of the extrusion width / extrusion multiplier options of that question.
I thought I might have had a fingerprint on the print plate. I typically avoid that by wearing gloves and cleaning the print bed with alcohol every fifth print or so. However, I didn't clean before any of the two parts. (I cleaned now)

Given the description and the pictures, can you name the problem and suggest the most likely solution?

Printer and filament details:

Prusa i3 MK3
Prusa PLA filament 1.75 mm, pearl blue
0.20 mm SPEED setting
20% infill
5mm Brim
215°C first layer, 210°C other layers
60°C bed temperature
Prusa PLA default filament settings

I use a Prusa spring steel print bed. No special adhesion, tape or anything. Closest I could find in the shop is smooth PEI, but mine looks more golden.

I know you said you don't want to change the Z height, but it does look like you're printing a bit too far from the plate. I would recommend adjusting your Z-offset if you can, or adjusting the limit switch (or whatever your Z-homing mechanism is)


What is the best 3D modeling software for a beginner on a 3D printed mini barrel project? My goal is to 3D print a 5 liter miniature barrel with a side stand, similar to this wooden one on Amazon. I want it to have a removable top so that a boxed wine bladder may be put inside, and there should be a hole on the top as well so that the spigot may stick out and be used. I have no experience with 3D modeling or printing, but I have access to a public 3D printer at my local library. I know you can print parts individually (ex. curved wood-colored sides with staves and holes to interlock and make up the body of the barrel, the metal-colored hoops to go around the barrel). I don't know what software to use, though. I was thinking of starting to learn Blender? Would that be effective for this project?

Your question begins in an inappropriate format for StackExchange, but you've ended it with one more appropriate by asking if Blender would work.
If you are willing to take the time to learn Blender, you are certain to discover that it will do as you require, and much much more. Your referenced model could be created using engineering-type design software such as Fusion 360 or SolidWorks or many of the free packages, but the free-form aspect is more suited to the flexibility of Blender.

2020 UPDATE: Fusion 360 now supports a sculpt feature, which combines organic modeling with the engineering-type for which it is previously known.

Even though Blender is not an engineering-type program, it has internal support for precise modeling. Should you learn to use those features, you get the best of both types of software.
If you construct your model in the software in segments/pieces as you suggest, your result will have greater flexibility at the printing stage, specifically with respect to color and filament choices. Instead of wood-colored sides, you can use wood-simulated PLA filament! Depending on the printer at the library, you could also use filamet, a filament containing 88 percent metal for the hoops.
I use Blender for some aspects of modeling, often importing the STL into Meshmixer to address things I've not yet learned in Blender.
I hope your reference to 5 liter is the original size and that your model will be a miniature of it. A 3d printer with 5 liter capacity would be a wonderful asset at the public library!


BLTouch does not compensate for differences in bed level Printer: Ender 3
Bed: Creality Glass
ABL: BLTouch
Everything else: Stock
Few weeks ago I had a meltdown during a failed ABS print. My hotend was completely wrapped in plastic and trying to remove said plastic I snagged the termistor. Anyway I had to replace the nozzle, hotend and thermistor. Everything on here. I went ahead and measured the Nozzle BLTouch needle offsets and re-flashed my Ender 3 with TH3D Firmware and configured BLTouch. After which I adjusted the Z offset again.
All good here. BLTouch appears to work, well at least it appears so.
I started printing and I see that my bed always hangs lower on the right side and BLTouch does not compensate for this difference.

Manual leveling (with a heated bed, also tried without)

Auto home
Move Z axis from 5 to 0
Move the head to each corner of the bed
Adjust the corner hight using the paper method (repeat 2x for each corner)
Auto home
Move Z axis from 5 to 0
Go to Z offset, and move it until it tugs on the paper.
Save and Auto home

But this did not solve the issue. When I move the head to Z0 (with the offset) in the centre it's perfect. Moving it to left gets close to the board, right goes way away from the board.
Belts & screws
Went and tightened all the belts and all the screws.
X Axis alignment
I set the Z axis to the max 250. And measure the distance from top of the X axis to top of the frame. There is no difference in the left, right or centre of x axis to the top of the printer. Same for distance from bottom part of the frame.
I cleaned the belts and the wheels with a soft brush. Not sure what else to do. I'm giving up on Creality/Ender :(

The issue was BLTouch i'm not sure what use is this thing if it cannot compensate for differences in bed or frame.
I'm not sure why but the probing seems to be bad. I tried everything clean TH3D install and config, pitch perfect alignment of everything frame, bed, mounts everything. Perfectly calibrated Z offset at the centre of bed. I triple checked the belts. Checked if X axis was off or if any screw was lose, checked wheels to make sure everything was snugg.
Anyhow in the end the issue was with bad BLTouch probing not sure why. I gave up and went and disconneced BLTouch did manual bed leveling with the paper method. Press print and I got a perfect print. Like literally perfect. Even extrusion everywhere.
BLTouch seems to have probed the distance at the centre of bed, I set the offset for it. Than when it went and probed other corners before the print it seems to have read the values wrong.


Print failing when connecting mains loads I am running the SeeMeCNC customized version of Repetier on a Rostock Max V2. I have experienced this problem with both the stock configuration along with an E3D The Chimera. Sometimes, when I am printing and connect a mains device, my printer will fail in some way. The first time this happened I was printing with ABS, so I connected my fume sucker (A ~25-50W fan) to an outlet. However, when I connected it, the LCD showed garbled characters and my software (MatterControl) reported an error. Restarting the printer returned it to the previous state. I had a ~15 foot (coiled) extension cord connected to a 3-way splitter.

Today, I connected a hot glue gun, and MatterControl reported that Repetier had switched to "Printer set into dry run mode until restart!" (no heat or extrusions). Looking at the firmware, this seems to be caused by a thermistor failure. I had everything plugged into the same setup as before, except for a surge protector at the end. The circuit that it is connected to has a 20A circuit breaker, with probably ~3A of it constantly used.

My theory for this is that an additional device causes a slight fluctuation in the thermistor wires, causing an error to occur. However, the Rostock Max is designed so that wires are inside of aluminum tubes, which I think would provide EMF protection. The power supply is a generic 12V 30A power supply that was included in the kit, usually seen in LED strips. Both of these occurred while printing. I have ordered a UPS for the printer: would its under/over-voltage detection help? Are there any other solutions for this?

I have had the same Issue with my Maker select prusa printer, the way I found that best combats this is to attach the printer to a UPS and avoid attaching any High draw devices from the same circuit. Every Time i'd switch something on, My TV, my lights, etc. The same would happen. Hope this helps!


I've exported 3D models from the game, can I print them? Assuming I've extracted 3D models from a game which I legally bought (such as StarCraft). I am allowed to 3D print them for personal use or give it to close friends?

Is there any general rule, or this suppose to be specified in the license? If so, which section/clause potentially can prevent me from doing that? Or I need to contact the company who owns the game to obtain the permission?

No. Such figures are generally covered by copyright, which means that nobody but the copyright holder is allowed to (re-)produce copies of the work. Copyright also covers personal use. In the US there are limited fair use exceptions but they do not apply here.

The only way to do this legally is if it is specifically authorized in a license or if you get permission.


Can 3D printer work with enamel paints (or paints generally)? Are such printers available? There are lot of advices on the web how to paint the 3D printed objects, but generally they are advices for manual painting and this required special skills, especially if the object is small. My guess is that maybe 3D printer can lay the color layers as well? I am especially interested in the layering of enamel paints (which can be transparent and which can required high temperature heating afterwards). Medieval art has fine examples how detailed enamel art was created on the metal. Maybe something like this can be achieved with 3D printers as well?
If 3D priner with the paint-printing capability is not available generally then what are the prospects when such printer can be available? Maybe there are some early, experimental efforts to create such printer and maybe test devices are available?

So, there's not really anything like a 3D painting machine/robot like I think you're looking for, but there are printers that do fine detail with actual paint, usually oils, but not on 3D materials.
I found a thread that talks about canvas printing about 8 years ago, along with a couple of videos that show current machines doing just that, but that's still not what I think you're looking for.
There are also CNC machines that print with enamel paints, but these are usually for 2D again, and not very precise, as they are used for lapel pins that have cavities to hole the paint while it dries. I'm sure something like this could be used without the cavities, but you'd have to do a lot of testing to make sure the paint stays put or mixes as you want it.
Just like the oil printers, these enamel printers are likely very large and costly.
Alternatively
What might work for you is hydrodipping. There's a variety of methods to this, but one company has done a bunch of research on this and can do extremely accurate detail printing to "paint" 3D objects. The below video shows a variety of these hydrodipping techniques, but I've skipped to the most relevant part.

Here's the original video of what I think you're most interested in. It's not 3D printing in the way most of us think, but it's definitely a fantastic outcome.

To explain, if these videos are ever deleted: detailed prints are made of a 3D model to color it exactly the way it needs to be, sometimes using multiple steps and computer positioning to get the object colored/"painted" correctly and seamlessly. One part of the video shows how the software can accurately make straight lines on a human-contoured face mask, while another part shows how a blank, fully 3D cat model can have spots or stripes added in 3 steps with the seams being completely invisible as well as it detailed enough to be mistaken for a real housecat beyond first glance.
As it turns out, you can do (some of) this yourself. After doing some research, I've found that you can actually get blank (instead of pre-printed) films and use an off the shelf printer, as long as it meets certain requirements. (I'm not recommending a site, brand, or anything else, this is just the first/only option I can find. If you do more research, I'm sure there's more options out there.)
https://www.tsautop.com/blank-hydrographic-film/
https://www.tsautop.com/blank-hydrographic-water-transfer-printing-inkjet-printer-6-color-inks/


Does the Creality Ender 3 allow variable layer thickness? I'm new to the 3D printing world but I've been using some of the 3D printers at my local library, and am now interested in purchasing my own! One thing that's important for my projects is being able to use variable layer thickness (for example, the first 50 layers are 0.3 mm, the next 50 are 0.1 mm, and the last 50 layers are 0.3 mm).
I know the Prusa printers can do this, but I've been trying to understand whether the Creality Ender 3 allows you to use variable layer thickness. Unfortunately, I can't seem to find this information online so I would like to ask here!

Variable layer height is a setting of the slicer, not an ability of the printer itself.
However, the printer must be able to print at such layer heights. Any FDM (Fused deposition modeling
) or FFF (fused filament fabrication) printer, which is the type you describe in the question, is able to print at 0.1 to 0.3 mm with at least a 0.4 mm nozzle diameter.
There is also notion of optimal layer heights. Optimal hight depend on full steps of Z motor correlated with a leadscrew type. It is especially important when microstepping for Z is disabled or when printer disconnects a Z motor during long printing of single layer, otherwise positioning may get imprecise. Prusa calculator helps to determine these values. For 8 mm/revolution lead of screw (standard T8 in Ender 3) the step for optimal heights would be 0.04 mm.


Bed probing feed rates I was watching a friend's Prusa run the bed-probe routine and I realized how pathetically slow mine is and takes forever. I want to speed it up.
What parameters in Marlin's Configuration.h do I modify? Also, it seems to retract for the second "accurate" probe by like 10 mm which could be reduced by 8 mm or so. Where is that one? I looked through but can't be sure. Also, could I just change the feedrate in the pre-script?
#define DEFAULT_MAX_FEEDRATE { 300, 300, 8, 50 }    // was { 400, 400, 8, 50 }

To speed up the probing for a touch sensor, a "High Speed" option is available in Configuration_adv.h which is by default disabled (//#define BLTOUCH_HS_MODE) as not all printers/sensors are able to use this.
You can also increase the homing speeds in your Configuration.h file.
// Homing speeds (mm/min)
#define HOMING_FEEDRATE_XY (50*60)
#define HOMING_FEEDRATE_Z  (4*60)

.
..
...
..
.
// Feedrate (mm/min) for the first approach when double-probing (MULTIPLE_PROBING == 2)
#define Z_PROBE_SPEED_FAST HOMING_FEEDRATE_Z

// Feedrate (mm/min) for the "accurate" probe of each point
#define Z_PROBE_SPEED_SLOW (Z_PROBE_SPEED_FAST / 2)

However, you can simply speed up the movement between probe locations by setting the movement speed directly through G-code. The G29 code, used for automatic probing of the bed surface is described in "G29 Auto Bed Leveling (Marlin - MK4duo)". The S parameter in G29 can be used to set the movement speed between probes, where the units are specified in "units/min", e.g. mm/min.
Note that you potentially can change the Z-height for deployment:
/**
 * Z probes require clearance when deploying, stowing, and moving between
 * probe points to avoid hitting the bed and other hardware.
 * Servo-mounted probes require extra space for the arm to rotate.
 * Inductive probes need space to keep from triggering early.
 *
 * Use these settings to specify the distance (mm) to raise the probe (or
 * lower the bed). The values set here apply over and above any (negative)
 * probe Z Offset set with NOZZLE_TO_PROBE_OFFSET, M851, or the LCD.
 * Only integer values >= 1 are valid here.
 *
 * Example: `M851 Z-5` with a CLEARANCE of 4  =>  9mm from bed to nozzle.
 *     But: `M851 Z+1` with a CLEARANCE of 2  =>  2mm from bed to nozzle.
 */
#define Z_CLEARANCE_DEPLOY_PROBE   10 // Z Clearance for Deploy/Stow
#define Z_CLEARANCE_BETWEEN_PROBES  5 // Z Clearance between probe points
#define Z_CLEARANCE_MULTI_PROBE     5 // Z Clearance between multiple probes
//#define Z_AFTER_PROBING           5 // Z position after probing is done


Print sketchup files (STL) on makerbot One of the local libraries has a new small Makerbot 3D printer. I have been submitting Sketchup files converted to STL files for printing.

The tech guy who runs the printer for patrons is having trouble getting a project of mine to come out to be the right size. I need this item go be 2 inches wide. The tech guy sizes the item on the screen to 2 inches. I watched him do it. But, the item is printed with a base of 2 inches, and the item itself comes out smaller.

Does anyone have suggestions about this? I can get more info if someone can give me the right questions to ask. The tech is open to taking suggestions. He wants to get the printer running smoothly for patrons.

I submitted a file with my own base with supports made in Sketchup. But, the tech guy said he needs to set the printer to create it's own base and supports.

Additional info:

When I printed it by letting Makerbot create the base and supports, it came out to be 1 3/4" as shown here:
https://flic.kr/p/EashnD

Printer: Makerbot Replicator with Smart Extruder (not Plus).
(I am now at the library with the technician.)

Here is a screenshot of what I am trying to print. It is a replacement clip for a messenger bag. So, it has to be 2 inches across.
https://flic.kr/p/EtdM6s

Here is the printer:
https://flic.kr/p/E5F1M6

I used a website to convert the DAE file exported from Sketchup to an STL file. It was GreenToken.com.

If I open the object's STL file in Tinkercad, the object appears two inches wide. And, if I open the file in one of the 3D printer websites in Tinkercad, the object appears two inches wide (in cm).

The security on the library's computers do not allow me to apply plug-ins to Sketchup. The library's Tech staff is going to eventually put the plug-in in there.

If it is resized to 2 inches wide in the MakerBot software to be sent to the printer, why is it printing the generated base 2 inches wide and not the object? Are there some settings the tech guy in the library is missing in this set up window?

Additional notes:
The library now has the latest version of SketchUp on Macs. They are working on installing the STL plugin. (Security issues)

My process for producing an STL file to print is now this:

I create something in SU and export it as a DAE file.
I have found that meshconverter.com produces better STL files than greentoken.
I then upload/fix the STL file at the netFabb website.
I then import the STL file into TinkerCad to view it. If there are problems in the file, I can see them. And, I run it through netFabb again. I can also modify the file in TinkerCad. It is no where near as sophisticated as SketchUp. But, it doesn't claim to be.

I have found that there is a way to export the STL file to 3D printer hubs through TinkerCad. You can see the prices, the material available and the location of the company/person doing the printing. You can contact the printer ahead of time and they can look at your file to give you advice.

Update

I just wanted to add that the netFabb website does not export STL files after it fixes them. It now gives you a 3MF file format when you upload an STL file. I am not sure why this happens. But, this has put a big wrench in my process. I can no longer fix SketchUp STL files with netFabb. When I bring them into TinkerCad, I see errors in the object. It seems like there are issues with complex curves.

It appears that you have scaled the object after the raft and supports were added. As you can see in your photo of the raft, the clip is approximately 7/8ths (1.75/2) the size of the raft.

Edit: As a side note, STL files don't actually have a concept of units. Each axis is defined in arbitrary units. That's why when you export and import it you have to set the scale appropriately.


What ambient humidity should one target for filament storage? I live in an arid environment and have never worried about leaving filament out for an extended period of time. To reduce how frequently we receive static shocks I installed a whole house humidifier with a target humidity of 35 %. Is this enough humidity to warrant storing filament in a dry box? At what point does ambient humidity become a concern?

The closer to zero humidity the better.  Maybe a garage or some place protected from rare precipitation outside would be better.  If one room is considerably less humid than the others, you could use it.  Keep the bags and dry packs the filament comes in and put them back in when not in use.


Use Gcode Extrusion Speed in Calculations I have a Rostock Max V2, and I've added a second extruder going into a y-splitter into a single nozzle on my printer. I have both extruders working correctly, but I'm having trouble tuning the retraction settings to prevent stringing when I switch between extruders during a print.  My system is essentially identical to the setup seen here.  However, I can't get my printer to retract as cleanly as the one in the video

What I'm trying to avoid is the long, thin "tail" that forms when retracting the filament from the hot end. That "tail" binds the other filament during the switch and makes the extruder grind a hollow spot on the filament.

I've had limited success tuning my retraction settings, but I find that I need different settings for different extrusion speeds. For example, after an extrusion like G1 E20 F240 a 3mm retraction, 3mm extrusion, then a fast retraction creates a nice, clean break (this routine is recommended here by kraeger on the SeeMeCNC forums). However, after an extrusion like G1 E20 F900 I have to use longer  retractions to get a clean break.  I think this might have to do with the filament acting like a spring inside the bowden tube. It would make sense to me that the harder you push the filament, the more you need to pull back to compensate for the pent-up spring force.

Here's my question:  Is there a way to read the value of the extrusion speed, essentially the "F" term from the gcode commands, and change my retraction routine accordingly.

Example pseudocode:

If F value < 500 Then do short retraction
If F value > 500 AND F value < 1000 Then do medium retraction
If F value > 1000 Then do long retraction

I'm using the tool change script feature in Simplify3D to store the tool change code.

I don't think you're going to find either a firmware feature or a slicer feature that handles specifically what you want to do. The slicer would probably be the best place to put it, and I'd recommend maybe opening a feature request ticket with Ultimaker, because that sounds like an awesome feature.

That being said, there's nothing stopping you from post-processing your GCode file after it's been generated. If you're experienced with python at all, that's the place I'd recommend you start.

You'll probably want to do it via the following:

Find the first line number that does a retraction.
Sum up all the extrusion distances between that line and the starting point (the beginning of the file)
Replace the retraction distance and feedrate with whatever your short/medium/long retraction settings are
Store that line number as your new starting point
GOTO 1.

If you're using Slic3r, there's actually a post-processing script function built into the app itself, you just need to write the script and give it to the application to make the whole process hands-off. For other slicers you'll probably just have to run the script manually between slicing and printing.


Trouble printing perpendicular walls I'm trying to print the following model:

I'm using Simplify3d to print the model with the following settings on my Qidi X-pro:

Filament is ABS
Bed temp is 100 °C
Extruder temp is 230 °C
1 top layer
1 bottom layer
4 perimeter shells
The outside direction is 'outside in'.
Internal infill is triangular at 60 %.

I've tried numerous tweaks to the settings, but, I can't seem to get a perfect perpendicular exterior wall as seen in the photos. The print more resembles a trapezoid. It appears like the walls are bowing inward. This also seems to throw off the dimensions. They aren't consistent. For example, the height of the part is 6 mm, but, in measuring with a caliper it shows 5.8 mm to 6.2 mm.
Can anyone tell me how I can get my external walls perpendicular?

You may be getting shrinking due to cooling on the non-top and non-bottom layers. Sixty percent infill is rather substantial. I'm printing 20 hour pieces in ABS at 100 °C / 250 °C using ten percent infill and getting nothing like what your image shows.
Can you do with a lower infill? More isn't always stronger. Four perimeter shells may be a factor but you'll probably see a difference with a smaller percentage infill.


Irregular adhesion on Creality glass bed I have an Ender 5 pro and upgraded from the magnetic bed to the glass version. I print with Prusament PLA on 65 °C bed temp and 220 °C extruder temp. I measured that the glass surface has ~58 °C in the center and ~56 °C on the corners. That should be in the specs of the spool which has a printed recommendation of 50 +- 10 °C for bed and 215 +- 10 °C for extruder temps.
Now I also have a BLTouch and use the TH3D firmware so Z offsets should work correctly and are done with the Z offset wizard present (nozzle touching the bed).
The problem I currently have is that the first layers have "lifts" in them. Also, it seems that the layer itself is not 0.2 mm everywhere. It's close to 0.23 mm on the edges but on the inner there are variances up to 0.36 mm.
Currently, I slice with Cura 4.8.0 on Standard Quality 0.2 mm
How do I get rid of the lifts and irregularity in the layer? Is it a problem with the bed?

The only time I've seen lifting, away from the edges of the part like this, is when the bed is contaminated with something which will stop the print sticking, like fingerprints and such.
A thorough wipe-down with IPA on the heated bed is usually enough to stop it.


Extruder stepper motor problem, what can be wrong? I bought a self-made Reprap Prusa Mendel 3 printer, modified to be built from cheaper materials, and immediately after the deal I got various problems. I fixed the majority of them, but don't know what the reason of the strange extruder behavior is: The stepper motor is not rotating while extruding filament, it's moving back and forth with small steps instead. I made some footage, Reprap Prusa Mendel 3d printer extruder problem, hoping that someone has met a similar problem before.

If so, please tell me what to do to make it work as it should.

The obvious option while encountering this problem was to slacken the bolt which holds this parts together (in the left bottom corner of the video), but that did not help.

Any ideas are very welcomed. Thanks for your time. I hope this is an appropriate kind of question here.

Your controller board probably requires calibration.
It sounds like, maybe, the extruder's stepper motor is not receiving sufficient current, to make it turn. Or, somewhat confusingly, maybe the stepper is receiving too much current, and overheating.
You don't say which controller board you are using, but regardless, there should be an adjustable potentiometer on the board, next to each of the stepper drivers, or on the stepper driver daughter boards.  Like so,

This potentiomenter adjusts the reference voltage used to control the stepper motor. From this reference voltage, and the resistance of the stepper coils, one can determine the current, which is used to drive the stepper motor.
For the stepper driver of the extruder, you could try turning this adjustable potentiometer slightly, in order to provide more current to the stepper, in turn to provide sufficient torque such that the motor is able to turn. Or, less current to stop the stepper from overheating.
The adjustments can be made whilst the power is on, but a non-ferrous (i..e. plastic) screw driver should be used, so as to avoid short circuits. Also care needs to be taken, when turning the potentiometer, as they have been known to just fall apart whilst being turned. If you are paranoid, then make micro adjustments with the power turned off, and then turn back on to check the behaviour.
Note: it should go without saying that one should never disconnect a stepper whilst the power is on, as both the driver and the stepper motor may be irrevocably damaged.

The photo above is taken from POTs Calibration – RAMPS 1.4.

If a POT is set too high then the associated stepper driver will tend to overheat and go into over-temperature thermal shutdown (to prevent damage to its components). The first sign of overheating is erratic stepper motor behavior. Typically, this can be recognized by the sounds of the stepper motor suddenly losing power (thermal shutdown). If no load or movement is required of the motor, it is hard to detect whether it is over-powered as the driver is barely producing any heat.

and

Conversely, if the POT is set too low, the stepper motor can enter an underpowered state. This can be recognized by a lack of holding torque and a stepper motor that is skipping steps because the necessary movement  requires a higher power demand than the POT setting allows for.

Driver cooling
In addition to the possibility of the stepper motor over heating, it could be possible that the stepper driver is overheating, although the symptoms may be different, to those that you are experiencing. Regardless, you may still find it advantageous to cooler the controller/driver board with a fan that is always on (not temperature controlled).
Additional reading

RigidWiki - Stepper Driver Adjustment, which goes into further detail about the adjustment of the potentiometers, that I outlined above, as well as the reference voltage and the adjustment thereof.

RepRap Wiki - RepRapPro Setting Motor Currents describes a different controller to yours, but goes into the process of adjustment, and description of the reference voltage (which is applicable to all boards):

The wiper on each potentiometer generates a DC voltage that is sent to the chip. This is the reference voltage; it defines how much current the stepping motor driver chip supplies to the motor. The bigger the reference voltage (VREF), the higher the current (A) that the chip will send to the motor. For most NEMA14 motors, the current maximum is 1A, but this will generally cause it to get warm, so a setting of 750mA is recommended. For NEMA17 motors, depending on size, the limit on current is generally between 1.3A and 1.7A. If you drive stepper motors with more current than they were designed for, the motor will get hot, and may be damaged.

Pololu - A4988 Stepper Motor Driver Carrier with Voltage Regulators - this is a very common stepper driver.

MyHomeFab - DRV8825 Adjust Stepper Current goes into the adjustment of the reference voltage, for the commonly used DRV8825, which is an alternative to the popular A4988.

This thread, about non-actuating steppers, may also be useful, Motors, which mentions setting the trimpots and points the OP to RepRap Wiki - Pololu stepper driver board, which, in turn, refers to this thread, Strange stepper behavior and this video, video-2012-02-02-16-37-26.mp4, which describes a jitter in the stepper behaviour.


Adhesion problem when printing calibration test Here is my first attempt at printing a "Bed Leveling Calibration test".

It obviously didn't come out as I would have hoped, but what can you say just looking at this picture?

Is it possible to tell from this calibration print which corners are not leveled? Or is this just a general lack of stickiness issue (e.g. i need glue)?

I leveled this thing with paper several times, but honestly, I'm terrible at leveling. I just got this new piece of glass and there's nothing on it. The glue residue is actually on the sheet beneath.

What are some tips for printing on glass? I hear some people say use glue, others say never use glue. Should I increase or lower the temp?

I'm printing Dikale PLA on Monoprice Select V2, extruder temp 200 °C and bed temp 70 °C. Initial layer speed is 30 mm/s (print speed is 60 mm/s but I don't think this print goes that far).

What can you say just looking at this picture?

->There are 2 obvious observations that can be drawn from your image.

First, the bed does not seem to be levelled correctly, the right side (especially the front right corner) is closer to the nozzle than the left and left-back side.

  Is it possible to tell from this calibration print which corners are
  not leveled?

-> Yes, the front right corner is higher. The filament is much thinner there, it is more transparent than the rest of the lines.

Second, you have glass mounted onto an adhesion sheet similar to BuildTak. Note that such adhesion sheets are rough (to create more surface area for the filament to grip on), placing a sheet of glass on top of such a sheet will create small air pockets (less contact surface area to the glass plate as that is perfectly flat by its production process) and thus an unsatisfactory heat transfer process. Glass directly onto the Aluminium will have a higher temperature than with an insulator (BuildTak sheet) in between it, it is far more difficult to determine the bed temperature that way. For printing on glass, you could also raise the temperature compared to direct printing onto the metal bed.

  Should I increase or lower the temp?

-> When using glass on top of the heated bed, you should raise the temperature a few degrees.

You should remove the BuildTak sheet and put the glass directly onto the Aluminium heat bed or remove the glass plate and print on the BuildTak sheet directly, level the bed better or consider installing an auto-level (touch) sensor if your printer electronics board supports that.

  What are some tips for printing on glass?

Furthermore, use some PVA based spray (e.g. certain hairspray brands or specific print adhesion spray) or Polyvinylpyrrolidone based glues (certain glue sticks, white wood glue, etc.) to create a sticky surface for the filament to adhere to. I have great experience with PVA based sprays like 3DLAC, but there are great alternatives found in common household hairspray cans as well, as long as it contains PVA.

  Or is this just a general lack of stickiness issue (e.g. i need glue)?

-> Yes, Polyvinylpyrrolidone/PVA based glue/spray will result in better adhesion.

A general remark is that you could listen at what others have tried, but you need to find out yourself what works best for you. In order to get the print to stick to the glass, you should use every trick there is to get good adhesion. If PVA based sprays or Polyvinylpyrrolidone based glues work for you, use it, if not, print on bare glass, use tape, BuilTak, elevate bed temperature, overextrude first layer, use brims/mouse ears, etc..


How can I decrease the thickness of a wall in an STL file? There seem to be a lot of search results answering the question of how to increase wall thickness, but how can I decrease wall thickness? I have an STL model of a mechanical keyboard key where the outside dimensions are correct, but the walls are slightly too thick so the key gets stuck in the down position. I'd like to shave some of the thickness off of the inside of the walls to better match the original key I'm replacing, while leaving the rest of the model dimensions as-is. How can I go about doing this? I consider myself technical in general, though I'm a novice at 3d modeling software.

The process is rather simple:

import your model into either a modeling software (e.g. Blender et al.) or a CAD-program (e.g. fusion360, Design Spark Mechanical et al.) that can import and export STL.

if needed, convert the STL into a useable model with your chosen program's functions or switch to edit mode.

select inner walls and extrude them the desired amount.
export as STL again.


FDM layer bonding strength I'm looking for some advice, rules of thumb, or models for how to design parts for layer bonding strength.

As an example part, lets assume a circular beam in bending (tall cylinder). Depending on how the part is setup on the build platform (tube axis aligned parallel to Z, or setup to lay in the X-Y plane) the layers and internal structure will then be different depending on the orientation chosen at the time of building. Does/has anyone done any investigation to what roles these factors will play on simple shapes like a solid cylinder?

Ideally, with a CNC'd, injection molded part the total strength of a solid part is quite easy to model (mathematically) for strength and flexibility. However, with a 3D printed part the orientation makes the isotropic material properties effectively anisotropic, as layers don't bond perfectly, different cooling rates, and a host of other reasons.

Ideally I'd love to find a 'simplified' model that can be applied to hand-calculations to come up with rough approximations to part strength and bending. My guess is that these parts would be modeled something similar to an ABD matrix, similar to composite materials, but that's just a guess.

I have not been able to find a simple model for FDM part strength.  FDM parts are pretty complicated as they have a LOT more things that affect their strength than just layer adhesion.  Since any "solid" part will have infill, the part can't really be modeled as a laminant.  There are so many settings you can play with in the slicer that effects part strength, the model would have to have tens (if not hundreds) of parameters.  Also, you would likely have to establish them for your own printer since lots of things can affect them (like room temp, ventilation, humidity, material, material storage, ...)

One empirical example discussing the affects of FDM choices on part strength is a video done by Angus at Marker's Muse.  In the video he discussed how orientation and wall thickness affects strength.  Angus is not a math/ME guy (by his own admission).  FEA or other modeling would not be his approach; but, you can get some insight from his experience.

On the modeling front, I have seen one company that did create an FEA model to test whether their product would be strong enough if they produced it using FDM.  Here is the publication they wrote showing their analysis approach.  It will give you some insight on how they approached what I think you want to do.

Note: They do offer a service where you can pay to have your part analyzed for a considerable amount of money.  I have no idea how much money; but, based on jobs I have quoted in the past, I would expect it would be a least a few hundreds dollars.

As for me, I really enjoy basing my decisions on models and understanding how a part/process works. In this case; however, an empirical/experimental approach might be more cost effective.  If you really want to take an analytical approach (and have the time to spend doing it), I would recommend choosing several key parameters and run an analysis using DOE (Design of Experiments).

If you come up with something, I would love to see it posted here.

Good luck and happy printing.


How can I print to my FLSUN QQ over WIFI I want to be able to control my FLSUN QQ over wifi, and don't have octoprint or a raspberry pi to run it on.

Assuming you use Ultimaker Cura to slice, there is a MKS plugin that allows connecting to the MKS WiFi module that comes with the QQ. Just follow these steps:

Install the MKS WiFi Plugin

Open Cura
Click "Marketplace" in top right
Select "Plugins"
Scroll down to find the "MKS WiFi Plugin"
Click on the plugin.
Click "Install"
Restart Cura (quit and reopen)

Configure WiFi

Turn on your QQ
Tap Settings
Tap WiFi
Enable WiFi
Note the IP address and network name
Connect your computer to the printers network
Open your browser
type the IP address of your printer into the address bar
hit enter
Scroll down to "WIFI Configuration"
Select STA
Enter your home network SSID into the field labeled "WIFI"
Enter the password into the field labeled "KEY"
Click configure and reboot

Setup your printer in Cura

Open Cura
Open settings > Printer > Manage Printers...
Click "MKS Wifi"
Click "Add"
Enter the new IP address of your printer (can be found by opening WiFi settings on the printer)
Click Ok
7, Click connect.

Now you should be connected to your printer. After slicing you should have the option to "Print over FLSUN..." In the Monitor interface you should have some other options such as sending commands to the printer, and printing any files already on the SD card, as well as uploading gcode files to the SD card.

Happy Printing


Layer bending with first layer not sticking I'm pretty new to 3D printing, so I'm looking for some tips with following problem I have.
I'm trying to print following model https://www.thingiverse.com/thing:4671256 on my Ender 3 v2.
But as soon as the print reaches the body and the first layer parts are attached, the print comes loose from the bed and the print will be dragged by the nozzle.
If you look at the picture you can see the bending of the front paws of the sculpture. So they don't stay sticked onto the bed.
I have changed the model to be 80 % in size, but also upped the bed temperature from 50 to 75 °C.
Running at 50 °C was even worse...
My printed 20x20x20 mm test cube was flawless by the way.

Try a Brim (the model is rather tricky on FDM), which can help with bad adhesion.
Your first laser appears coarse and not "smooched" as it should. This hints that you leveled either high, or you hit the portal off-angle. If it is just high leveling, a tiny turn "up" can help a lot.
The model has some rather flat overhangs, like the mouth, chin, under the tails and lower body. I suggest printing that with support turned on.
For PLA Filament, I use 200°C nozzle with 60°C bed, so unless you go far beyond that, your print should work.
Last words: that the model you chose was made with resin printing in mind, so you will use some details.


Using a Full Spool of Filament, Read as "Empty" I have a cheaper consumer-grade printer that I've owned for a couple of years now. It is an XYZ da Vinci Mini W and it seems to recuperate its incurred losses from selling a cheaper printer by jacking up the prices on their filaments. I don't have much of a problem with this (and I'm not asking to "hack" the chips to let me use cheaper filaments), but I went to switch out my filament with a full one I had laying around and I noticed the chip case it contained was a chip (probably removed by somebody for some odd reason). I used a chip that I had laying around, but the printer read the full spool of filament as "empty" because of the old chip. Because of this, I was wondering if there was a way to force the printer to keep printing when the spool is "empty" or if I can somehow reset the chip.

From what is read online, it depends on the firmware version your printer has. It seems that later versions keep track of tag serials and reports tampered tags as non-genuine tags. The best and most recent reference found is from 2018 which describes you should be creating new tags instead of resetting existing tags. This involves installing an Android App from unverified source and new "paper" NFC213 tags.


Are there multi-filament hardened nozzles or equivalent systems? I discovered "diamond" nozzles (name of the design, not the use of diamond material), which have multiple filament inputs (designs for 3 or 5) and a single output nozzle, see figure.

They look like a very good and compact solution to avoid or significantly reduce purge towers, where filament is wasted until the channel is primed, and to avoid a second hot end, which takes space and which could be oozing when unused, but I could find them only made of brass.

Are there hardened diamond nozzles, or equivalent systems which are lightweight and can avoid a second hot end, to print composite or abrasive materials?

Yes, but there is no hardened version of the "Diamond" nozzle design. Basically when you want to use a hardened nozzle, or a Ruby nozzle in combination with color mixing (I specifically refer to mixing solutions as the melting chamber is smaller than filament changing solutions and your request for none or minimal purging towers) you need to order a design that accommodates the replacement of the nozzle. In such a case you can remove the standard nozzle to replace it for a hardened version.

There are a few 2 and 3 filament input designs that are offered on typical auction and Chinese selling sites. Below is an example for the Zonestar M3 mixing color hotend with a replaceable nozzle.


Can the `render` function be used to speed up rendering? I am designing a moderately complicated piece in OpenScad.

It renders fast enough in preview mode (1s).
But when i do a full render so I can export to STL,
it takes ages (In the 10s of minutes)

I have read that sometimes the function render is useful to speed up overall rendering.

Is this correct, or have I misunderstood?

If I have misunderstood, what is the render function useful for?

How does this work?
In what circumstances can I apply it?

First a disclaimer: I am far from an expert on the subject, I'm just a regular Joe who happens to use OpenSCAD and have done some experimentation with it.  I believe the answer below to be correct, but I will be very grateful if errors or misconceptions were brought to my attention in the comments. :)

  I have read that sometimes the function render is useful to speed up overall rendering.  Is this correct, or have I misunderstood?

I'm unaware if it is possible to use render() to speed up the "overall rendering", but I'm rather confident that the intended purpose of render() is to simplify the in-memory representation of the model and thus the responsiveness of the preview window, rather than speed-up its final rendering.

  How does this work?

In order to understand how this work, one has to understand how Constructive Solid Geometry (CSG) works.

The entire premise of CSG is that using boolean operations between primitive solid shapes, it is possible to represent complex shapes.

However, while the human operator may see subtractive operations like difference and intersection as something that makes the model smaller in volume and thus possibly easier to handle, the computer sees each and every operation as adding geometry and complexity to the part, as the following image aptly illustrates:

When manipulating the model in the CAD viewer, OpenSCAD is in the preview mode and all that "invisible geometry" needs to be processed for each adjustment of the viewport. It is easy to reach a level at which the OpenSCAD viewer will become jittery or unresponsive.

What the render() function does, is telling OpenSCAD to compute the mesh resulting from the boolean operations enclosed in the render() call, and use that single mesh instead of the underlying boolean-combined primitives when handling the model in the viewer.  Meshes are what is normally used in the render mode of OpenSCAD (F6) rather than in the preview one, but here their advantage is not better visual quality, but the fact that OpenSCAD needs to handle a lot less geometry.

  In what circumstances can I apply it?

You can apply it any time you like, really, but it is a trade-off: a model that uses the render() function internally, will take longer to display its initial preview (because generating the mesh is an expensive operation) but it will behave very well in the viewer.  Conversely, a large model that does not leverage render() will be jittery to handle in the viewer, but it will render to screen in a fraction of the time.  It has to be noted that OpenSCAD make heavy use of caching, so the first preview is the one that will take the longest, while successive ones may be a lot faster.

For reference, the code at the bottom of this answer (which generates the image above) behaved like this:

With render(): 15s for the preview, 1m29s more for the proper rendering (TOTAL: 1m44s).
Without render(): 0s for the preview, 1m45s more for the proper rendering (TOTAL: 1m45s).

I don't know if the fact that the totals resemble each other is a coincidence peculiar to my model or a general rule of thumb (the render() function effectively creating part of the final rendering during preview), but you are free to play with the code and if you find out a pattern, please leave a comment.

In the following code, you may need to increase the grid size to 20x20 if you want to see the difference in responsiveness between vanilla code and render() function.

Also remember to close and reopen OpenSCAD between tests, in order to flush the cache.

$fn = 30;

module shape() {
    render() difference() {
        sphere();
        cylinder(r=0.3, h=3, center=true);
        rotate([90, 0, 0]) cylinder(r=0.3, h=3, center=true);
        rotate([0, 90, 0]) cylinder(r=0.3, h=3, center=true);
        rotate([45, 0, 0]) cylinder(r=0.3, h=3, center=true);
        rotate([-45, 0, 0]) cylinder(r=0.3, h=3, center=true);
        rotate([0, 45, 0]) cylinder(r=0.3, h=3, center=true);
        rotate([0, -45, 0]) cylinder(r=0.3, h=3, center=true);
        rotate([90, 0, 45]) cylinder(r=0.3, h=3, center=true);
        rotate([90, 0, -45]) cylinder(r=0.3, h=3, center=true);
    }
}

module line(x, y) {
    translate([x * 2, y, 0]) shape();
    if (x > 0) line(x - 1, y);
}

module grid(x, y) {
    line(x, y * 2);
    if (y > 0) grid(x, y - 1);
}

grid(3, 3);


First layer looks weird and print fails Update below
Printed 650 of these tokens, no problem. Then all of a sudden I can't get them to stick and the first layer looks wavy and weird.

After a few tokens it knocks one loose and the whole print fails.
Did try to recalibrate the z-height. Should it be even closer? The test pattern for first layer height looks good.
Removed the nozzle to inspect if it's damaged but it looks fine to me...

Any help is much appreciated.
Update - Dec 29th 2019
With the new nozzle and recalibration I managed to get one more print to stick as in my answer below. Then back to not sticking.
I did order a textured plate from Prusa. Recalibrated the XYZ. That did not help.
I have played around with the first layer calibration.
In the video below the setting of -0.900 is fixed the whole time.
The lines look good and healthy but then lifts on the right side of the bed.
Video of first layer calibration
I then moved the nozzle even closer and REALLY smash it into the bed @ -1.050
It still lifts on the right side and a little bit in the corners. The first purge plastic that is output to the bottom left usually does not stick at all.
Untouched with nozzle closer
Things I have done:

Recalibrated the XY & Z axis from scratch.
Did two cold pulls of the filament (link) to make sure the extruder is not clogged. The pulled filament looked nice and clean.
Switched to new textured bed sheet
Switched to a new 0.4mm nozzle (E3D V6)
Tried different filaments (only PLA though)
Lubricated moving parts
Checked heat bed to make sure screws are tight and the bed sits snuggly

Two ideas now:
Can it be the mesh leveling that is acting up? How do I check that?
The heat bed feels differently warm in different places. Is the heat bed constructed with different zones where one can fail and the rest keep working? Do not have access to a heat camera to check.
Any suggestions would be much appreciated!
EDIT:
Thanks @Paulster2! It's good to find this community!
I've been using several different PLA filaments since this started happening. Before, they all stuck to the printing bed like champions, now none of them do. Pictured is som generic white, but getting the same result with Prusament PLA. Nozzle 215°C, Bed 60°C. As I wrote above, I did check the nozzle and it LOOKS fine. It's very small though and I have ordered new nozzles. If no one has any other suggestions I will post more when I have tried the new nozzle.
Also thanks to @Greenonline for correcting spelling and layout. Cheers!

A new day, a new nozzle, an old result!

EDIT

The success was a one off. The problem remains!
Heat on the heated bed seems to differ a lot in different areas. Just using my hands to feel it since I have no IR-camera.


Is hot glue suitable for FDM printing? Is hot glue suitable for FDM printing, or some process similar to it?

I think it has all of the required properties, and could produce a flexible transluscent print.  It's cheap, hotends are cheap, and the technology has been around for a while.

I couldn't find any examples or anyone talking about such a material for use, on here or the general Internet.  I wonder if there are tradeoffs or challenges that make it not worth pursuing.

You could mount a hot glue gun to a 3D positioning frame, but you would immediately notice the following:

Hot glue sticks are fat, so you lose a lot of precision for each feed/retract increment. I.e., it's a lot harder to get precise feeds with a fat stick because the stick size is so much larger than the nozzle.
Hot glue sticks are short, so you would to create a filament to spool the stuff or come up with a glue stick feeder.
Hot glue melts at 120 °C and common plastics such as nylon melt at much higher temperatures. So hot glue would make an AWFUL structural part like a stepper mount. Even PLA barely deals with stepper temperatures. Note that temperature tolerance is irrelevant for costume parts.
Hot glue is soft, which makes it a great glue, but not very stiff for, say, making parts for a 3D printer. However, the parts might be fine for  use only in costumes, etc.

But, if you then used your 3D glue printer to dispense glue for gluing stuff together, well...that might be valuable. :D


What is a w/t ratio? I have seen a few guides mentioning w/t ratio but I can't find anything which defines it.

I am using Simplify3D with a Wanhao i3.

It appears to refer to calibration factor called Width over Thickness.

From Calibrate your 3D printer to print parts to fit

  Here is the list of necessary variables for this calibration to work,

  Carve/Extra Decimal Places (float) : change to 5
  Carve/Edge Width over Height (ratio) : nozzle diameter/layer height
  Inset/Infill Width over Thickness (ratio) : nozzle diameter/layer height (initially)
  Dimension/Filament Packing Density (ratio) : needs calibration (equivalent to the reciprocal of the extrusion multiplier in Slic3r)
  Scale/XY Plane Scale (ratio) : needs calibration


Marlin's bed leveling Mesh Validation Pattern ignoring home offset I'm using a Prusa clone with Ramps 1.4, Marlin 1.1.5 and an inductive proximity sensor Z-probe. Due to the design of the printer, the X and Y end-stops and the Z-probe are not exactly aligned with the heated bed, so I must use Marlin's Home Offset feature to align the coordinate space to the print area, using the G-code command M206 X-18.5 Y-2.5 Z1.1.

I am now attempting to use Marlin's Unified Bed Leveling feature to compensate for a slight but significant curvature of the bed.

Unfortunately, it appears that the Mesh Validation Pattern command (G26) is not taking the Home Offset into account when printing a test pattern. The printed pattern hangs off the left side of the bed and the center printed circle is clearly misaligned with the center of the print bed by the bed offset amount.

Does this suggest that my firmware is misconfigured? Or is there an alternative method for aligning the mesh validation test pattern with an offset print bed?

A Marlin developer confirmed that bed-leveling and probing are now performed entirely in the machine coordinate space.

To clarify further, if one has a non-zero home offset enabled, the following commands refer to different physical locations despite the supplied parameters being the same:

M206  X10  Y10 ;  Set a home offset in X and Y
G30  X100 Y100 ;  Probe (100, 100) in machine space
G0   X100 Y100 ;  Move to (100, 100) in print space, ie. (90, 90) in machine coordinate space

I was able to correctly align the bed-leveling grid by altering header files in the source code. I defined the XY offset using two new macros BED_OFFSET_X and BED_OFFSET_Y in Configuraion.h and altered the following lines in Conditionals_post.h.

#define X_CENTER ((X_BED_SIZE) / 2) + BED_OFFSET_X
#define Y_CENTER ((Y_BED_SIZE) / 2) + BED_OFFSET_Y

The mesh is now physically aligned with the bed and I have not observed any adverse effects.


Can't print the top part of a circle I'm trying to print the painter's tripod from this tutorial:

I can't get it to finish the print. It always fails towards the top when it's closing the circles. I've tried brims and even glue for adhesion, and different settings for inlays, perimeters, etc... my bed levelling is correct and my first layer is perfect. The prints come out beautiful, but they always fail there. I have a theory but since I don't have a camera set up I can't confirm, but I feel like the nozzle gets stuck against the previous layer, as if when it's coming from the other side of the "bridge" completing the upper layers of the circle, it get's to the other side of the gap and it finds that the filament has hardened just a bit higher than when it's going to print, and therefore knocks the piece to the side (despite using glue!!), and from that point on, obviously, total mess and I have to cancel. Just a theory though. Any ideas of what else could this be or what to do about it?

Printer is a Prusa i3 Mark3S

You are trying to print an unsupported edge up there - the top edge has nothing to rest on and thus sags down. As a result, the print failed.

To remedy this, activate printing with support. With a support angle of 80° or tree support, you could minimize the needed material.


How do I modify Cura's code generation? Cura is generating temperature commands in the wrong order.  I need to swap lines 6 and 7 below so that both the printhead and bed can begin to heat at the same time.

Is this code generation configurable in Cura?

5 ;Generated with Cura_SteamEngine 2.5.0
6 M190 S60    ; set bed and block
7 M104 S215   ; set printhead, don't block
8 M109 S215   ; set printhead, block

You can do so by placing this at the top of the start code under machine settings (tested on 2.6.1).

M104 S{material_print_temperature}
M190 S{material_bed_temperature}


How to add tolerances/gaps in 123d Design? When I design parts that must fit in each other, I usually keep in mind that prints are 0.2-0.5 mm wider than expected (depending on material) and I size the parts accordingly.

However, sometimes I design the whole part and then I slice it with planes or lines. In these cases I need to push/pull afterwards each contact surface manually by the same amount (0.2-0.5 mm) and that is a time consuming task. Another option is to use a cutter to remove the outer surface layer (basically I remove the rigged surface, making it smooth again) but it's not safe and even more time consuming.

How can I quickly generate said controlled gaps on the contact surfaces between two objects, but not on the rest of the object? to make it everywhere I could use shells, I guess, but I don't need that on the whole object.

Unfortunately, 123D Design doesn't have such a feature.

You could select multiple surfaces and push/pull them all at the same time though.

Remember, your 3D Printer's slicer should have an option to undersize or oversize holes and walls, to help reduce/remove the effect you talk about.
It's called size correction, I think? Simplify3D Has it, atleast.
You might have to tweak this for every filament type, though.


How can I stop my print bed tape from sticking to the filament? I made a test print for a small gear (~ 1.5 inches in diameter) a few months ago, with a hole through the center. On the first try, the filament (ABS) fused to the print bed, meaning that I had to spend ten minutes scraping off material to loosen it. One solution to this is to use painter's tape spread across the print bed.

This yielded a good print during the next run. The problem with this method was that some of the tape subsequently fused to the backside of the gear; it was so tight that I had to discard the prototype. Multiple varieties of tape made no difference.

Is there a way to continue using this tape without having it fuse to the filament?

This can highly depend on the slicer you are using. Some software such as Makerware and Slic3r allow you to adjust the settings for the first raft/part layers. I might suggest adjusting this "Z0" point to about 1/4-1/2 of your layer height. Essentially the first layer (or two) will not adhere as well.

This is just one suggestion of many solutions. Here are some other variables I could think of off-hand:

Type of build plate tape (ie masking, painters, kapton, etc.)
Type of material. I've noticed that PLA is very stubborn if you let the part completely cool after printing and that it's much easier to remove the part from the build plate/raft right after it's complete.
Type of build plate. Are you applying too much heat (if you have a heated bp) for the material such as PLA?
Try lowering your layer height. This will ensure that each strand does not have too much surface area and therefore less chance that it will create a vacuum affect with the build plate. This can, however, result in a worse surface finish.


LCD full graphic smart controller, no character display and screen blinking After uncommenting the REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER, the display is blinking and no characters are shown on the screen, I have already switched the cables between EXP1 and EXP2, but it did not succeed.

this problem can be solved by turning the slots on the display, as in the image below. Some Chinese displays are inverted from factory.


Z Offset on autoleveling sensor setup How does Z offset (M851) work with an auto leveling sensor? Does it add the Z offset to the offset of the G29 mesh? or the G29 value replaces the M851?
My printer is an Anet A8 with Marlin firmware, I was having issues with the autoleveling sensor and reset the Z offset to 0 and let G29 get the mesh offsets and its working good now.
I was looking through Marlin G-code page but couldn't figure out how G29 affects M851 or vice-versa.
My setup with level issues:
M851 Z0
G28
M211 S0 ;turned endstops off and got a paper to find the zoffset
M851 Z-0.59
M500
M211 S1

And G29 before printing.

G28 instructs the printer to home itself to the X an Y endstops and the Z sensor determines the homing of the Z axis; i.e. when the sensor triggers, this is not necessarily (and most commonly) not the position where the nozzle is at Z=0.
G29 determines the shape of the bed by probing the bed. This will set the shape of the bed with respect to the sensor trigger point as described earlier. The Z-offset (set by M851 Z-x.xx is needed to set the offset between the nozzle and the sensor trigger point (to the bed).
The sequence to determine the offset is:
M851 Z0; // Set the Z offset to zero height
G28;     // Home Z in the middle of the bed
G1 Z0;   // This will move the head to zero height;
M211 S0; // This will disable the end stops so that you
         // will be able to proceed lower than Z=0

Now adjust Z height to fit a piece of paper and note the negative Z height (either through the LCD or through an application or console/terminal over USB)
M851 Z-1.23; // Define the Z offset
M500;        // Store the settings
M211 S1;     // Enable the end stops again

Please note that -1.23 is a fictive value that should be replaced by your own value.
To explicitly answer the raised question, the G29 probes the bed by scanning the surface geometry and the M851 adds an offset for the sensor trigger to the nozzle (at the center). The offset is required to let the firmware know where the nozzle is with respect to the trigger point. The offset therefor lowers the scanned G29 surface, no replacement is taking place. The sketches below illustrate this:

note that the bottom line of the "M851 Z offset" denotes the G29 scanned surface


Regular over-extrusion..? Can anyone explain to me why I'm getting regular over-extrusion patterns on this extrusion calibration cube?

Just upgraded the extruder from stock to Flexion HT on my Balco Touch (Wanhao i3 plus) and now I'm getting a strange pattern on my prints.

The photos below show me trying to calibrate the extrusion multiplier after completing the extruder install.  The first is with a factor of 1 and the second with an adjusted factor of 0.86 (which I suspect is the reason for the change in pattern?).

I guess this is some kind of mechanical issue causing the over-extrusion?  Any ideas?

Note: during the second print (below) I was playing with the Flexion extruder's Cam set screw hence why it stopped extruding all together.  I tried it set tight and loose and other than when really tight and stopping the extrusion there was no real difference in the pattern when extruding.

Help..!

Mine is a shot in the dark, but the fact the overextrusion is so regular let me think it is due to something rotating going around in cycles.

The fact that the pattern changes with the flow parameter make me think the culprit is the stepper motor pushing the filament (as different flow means different number of rotations for the same lenght of printed wall).

A possibility could be an irregularity in the cobbed wheel biting it the filament: a longer tooth would push more filament into the hot end, for example.

Another cause could be a problem in the actual stepper motor, in which a failure in the coils causes it to move to steps instead of one, at some point.

There are possibly other suspects in firmware settings and stepper dirivers, but that's not the area of 3D printing I am most expert in.

Much more unlikely, it could be a defect in the filament, but that's easy to test: just swap it for another one!


How is the print time of an object to be printed estimated? I am curious about the algorithm/principles behind the estimates that the slicing softwares provide. Is there a standard technique behind this and how accurate is it ?

Much of the software used in 3D printing is open-source, and so are some slicers. Cura, for instance, does (or did, this source code is from an older branch) its print time estimation in gcodeInterpreter.py.

The relevant portion of the source code is (simplified and with many lines removed for clarity):

    totalMoveTimeMinute = 0.0
    pos = util3d.Vector3()

    for line in gcodeFile:
        G = self.getCodeInt(line, 'G')
        if G is not None:
            if G == 0 or G == 1:    #Move
                x = self.getCodeFloat(line, 'X')
                y = self.getCodeFloat(line, 'Y')
                z = self.getCodeFloat(line, 'Z')
                e = self.getCodeFloat(line, 'E')
                f = self.getCodeFloat(line, 'F')
                oldPos = pos.copy()
                pos.x = x
                pos.y = y
                pos.z = z
                feedrate = f
                currentE = e

                totalMoveTimeMinute += (oldPos - pos).vsize() / feedRate

As you can see, (this version of) Cura simply:

Loops over all the G-code instructions,
Computes the length of each move (in X/Y/Z) and divides that by the feedrate to get the time that move will take,
Sums this up over all the moves.

and does not take into account:

Acceleration or deceleration. It assumes the printer is always operating at the maximum feedrate,
The length of filament extruded. The feedrate is the speed for the move in (X,Y,Z,E), but Cura only looks at (X,Y,Z).
The time it takes to heat up the print bed/hotend or homing/autoleveling,
The effects of the printer slowing down if moves can not be read (from USB/SD-card) sufficiently fast (though this would be rather hard to include in any estimate).

The accuracy of this estimate can be arbitrarily bad if the feedrate is set to some unrealistic value.

Newer versions of Cura use a much more advanced time estimate method, and it can be found in timeEstimate.cpp.  It is much more complicated, and actually takes jerk/acceleration/deceleration into account. It is much more accurate.

We know exactly how 3D (open source) 3D printer firmwares work, so estimating print time is as easy as simulating execution of the G-code by your given firmware. There is no reason you can't get a really good estimation (if you take into account all of the intricacies of your given firmware's acceleration/deceleration techniques) but writing the code for it is rather involved.


Good Designing Software for cheap So I've seen some very good design software, but almost all of it is very expensive. I'm just wondering if there's a good cheap design software out there.

Try Fusion 360. It's free for educators, students, enthusiasts and start-ups. It's not 100% intuitive, but once you learn the basics, it probably has all the facilities that you will ever need for mechanical design.


CR6-SE fails to heat hotend to set point TL;DR - Please help me rebuild my CR-6 SE so that I can move on

Here's a link to the latest issue that I had to make proof of in a video: CR6-SE failed
Basically, it's failing to reach/maintain temperature (set point of 240 °C, fails to heat above 230 °C), issues start to happen at temps as low as 210 °C.
Creality support is evasive/dodgy. First, they want to see a video proof for the problem reported, and after a while and emails from me asking, suggested something obvious (set temp to 200 °C).
And without any video, they don't respond. Just like last time when I ran into the defective/burned power switch and failed bed leveling.
If you have some spare time, please quickly check the video and provide some feedback.
I already fixed the burned power switch and auto-leveling (Creality ignored me, so I got the parts from Amazon).
This is the last issue that I need to do a "mercy" fix, so that I can either repurpose it or, just give it away (but I still have to make it working again and safe!).
I already placed an order for an i3 MK3S+, should've bought this in the first place to help me study 3D modeling, not working my degree towards fixing Creality printer failures :)
Thanks in advance.
My troubleshooting steps so far after a screw fell off during print:

Disassembled the hotend: found heater block loose, screws were bent and somewhat stripped
Heater resistor has a bad crimp
Thermistor is reading temp, but I don't know if it's accurate (don't have a multimeter+thermocouple)

Ordered a hotend from AliExpress, hopefully, that's it

Perform PID calibration procedure for hotend using G-code 'M303' with nozzle fans turned off completely.
You may use detailed guidelines from AK Eric's blog, RepRap wiki or 3DMaker Engineering.
If this will improve or clearly change the situation, but you still observe some issues during or after tuning, review other posts for troubleshooting. For example: large initial overshoot, no oscillations, struggle to fit into functional range or narrowed down hardware issues of incorrect heating cartridges.
When succeeded, you should repeat the procedure with fans enabled at the regular speed you use during printing.
PID calibration can be performed from Marlin's LCD menu (Configuration > Advanced Settings > Temperature > PID Autotune E1). It will allow to select target temperature, but not number of tuning cycles. It is only accessible when PID_AUTOTUNE_MENU is enabled in firmware settings (Configuration.h):
//#define PID_EDIT_MENU         // Add PID editing to the "Advanced Settings" menu. (~700 bytes of PROGMEM)
#define PID_AUTOTUNE_MENU     // Add PID auto-tuning to the "Advanced Settings" menu. (~250 bytes of PROGMEM)


Spiral bevel gears in OpenSCAD I'm trying to design a "Lifting Table" in OpenSCAD which will consist of 2 concentric cylinders. On the inner cylinder I plan to mount 3 un-powered bevel gears vertically plus a 4th powered  one each at the proper location/angle to interface with external cylinder's spiral bevel gear and keep the external cylinder level.

OpenSCAD's involute_gears library makes a bevel gear pair that is close to what I need, but the bigger gear is flat instead of a spiral.  How can I get the bigger gear to be a spiral and more than one rotation (level) 720 degrees for example?

I read this question a few months ago, and thought I knew what you wanted.  Re-reading it now confuses me a little.
But, I think you may be asking for a large, flat surface with a spiral in it, like the tightening mechanism in a 3-jaw chuck.  In effect, are you using the large cylinder as a worm gear to drive four gears which ride on it?
I thought you wanted more general bevel gears, and today I found a package in OpenSCAD that looks quite good.  it is found at: https://github.com/dpellegr/PolyGear
If this is the answer you were looking for, great.  If not, please comment here and I will delete this answer.


Painting an STL file I have an STL file that I want to add a tribal tattoo to with the end goal of getting it printed in colour sandstone from Shapeways, or in full colour on an Mcor Arke at some point, but I'm not really sure where to go.

I've looked at Microsoft Paint 3D. It's ok, but I cannot get the paint job symmetric. It outputs the .3mf format which the Arke will eventually handle with their Orange software, but it won't export into anything Shapeways will accept.

I've looked at UV unwrapping in Blender, but it seems I have to create the image in another graphics program and then import it... but I can't really work out where the images will be applied to the object, and then when I'm done it seems I cannot export the bits I'm expecting. On the plus side I have the mirror function so I can just paint one side and it's symmetrical.

I've looked briefly at Maya and 3Ds Max, but they are eyewateringly expensive, way out of my league.

Blender with some form of layers for the image might be really useful so I can make the tattoo in bits and then apply them to parts. I've kind of seen how you can split the model into panels but my brain is struggling to get round this as it's really quite hit and miss... and exporting seems to be a problem, although DAE and the texture will go to Shapeways, assuming the DAE has the texture layout embedded. FBX seems to go into Paint 3D and then I can export it to 3MF for the Arke.

Has anyone got any helping pointers for this confused noob?

Thanks

It is indeed more related to the blender forum  than the 3d printing one.

You can start by looking at this post from blender.stackexchange.com which explain how to unwrap and paint on a 3d object. You can also paint the texture on a 2d software like Gimp and then put it in the UV Image editor of Blender. Then you should be able to export your project (with the texture) in a suitable format for 3d print.


Z axis not moving on Prusa i3v 8" I have a Maker Farm Prusa i3v 8" i just finished building.  Initially when i first homed it, it ran fine, it even ran a test g code for movement.  The problem is now the Z axis wont move anymore.  First i checked for physical issues such as binding or nuts coming out of traps, everything's OK there.  In Pronterface i can move x & y no problem, but Z will not move, there is no noise from the steppers.  Also unusual is the the Z axis is not on the endstop, its resting on its own in a spot (the hotend is about 2mm off the bed).  I ordered some new end stop switches to try on my Z axis....any thoughts?  I'll update after switch install.

If you are using Repetier the code to test the endstops is m119 I think. If your z stop is triggered, you may have to invert it in the config.h file. I had this same issue for days before i figured out the control board was reading the switch as normal close instead of normal open. Hope that helps!


Printing shells and pouring filler I had this idea for bulky parts for just printing the shell (PLA) then pouring in some kind of filler in to make up the bulk/strength.

Printing bulk .2mm at a time line by line is slow and subject to warping!

So I though precision print a shell and fill it with 'something' - has this been done by anyone? What is a good something to use?

Yours hopefully!

I've looked into doing something similar to this before and love the idea, never had the chance to follow  through on it yet. This is sort of a hybrid method between cast molding and 3D printing.

The accepted answer to a question I had a while back had some very good points by fred_dot_u

Post processing FDM for strengrh

Short version, Epoxy is a good option but you may have to consider heat generated from it. Urethane is another really good option (cast urethane is a pretty standard process). Chem-Eng isn't my area of expertise but there is a huge range of material options out there that can be mixed as two parts. I think there are enough options out there right now that you can choose your material properties you need and then select the material from there.

You  could also consider going the chopped-fiber composite route. (carbon, glass, etc) and then combine with whatever the appropriate resin is for those materials.

I see the most difficult part of this is getting the shells to print properly. When I had looked into doing this, I considered modeling my part then hollowing it out completely. Then going back into the hollow part and designing in minimal internal structures for the purpose of supporting the thin-walled shell model. Printing that, and then drilling and filling the part after the fact. This approach I see as being a good option however the location of the drill points would be critical otherwise you could get voids as your fill material is injected in. And, the additional modeling time wouldn't be insignificant, however the saving I expected would come from having a ridiculously strong part, with complex geometry and be significantly cheaper than even a cast-urethane part.

If you get some good results, please post a link to them! This is a huge interest of mine!


Monoprice select mini underextrusion? Can someone please review the picture and tell me things to try to fix, the threads are full of little gaps. The layers that are solid, below the threads have a tiny bit of space between them. Is it underextrusion, or a clog? The bottom layer seems good. Also I have taken a picture of grooves on the filament after the extruder. Is the the groove from the extruder normal?

The grooves (notches, more accurately) are acceptable and indicate that your hobbed gear has a good grip on the filament.

Many factors will cause your probably-correct diagnosis of under-extrusion. If you are confident that your extrusion settings are correct, you could have this problem from under-temperature on the nozzle.

One method to assess this is to increase the nozzle temperature by five degrees C and examine a test print. If the gaps are reduced but do not disappear, consider an additional step or two of five degrees.

If you are so inclined, locate one of the many temperature tower models and modify them accordingly for your printer. This will give you a good range of temperatures for best results.

Also note that different filaments will have different temperatures and the temperatures will vary between colors from the same manufacturer and between different manufacturers.


Is there a well-tested Ender 3 printer profile for PrusaSlicer available for download? I am very comfortable with using PrusaSlicer and having a hard time adapting Cura.
Is there any downloadable well-tested PrusaSlicer profile for some of the Creality printers?

Open PrusaSlicer, go to Configuration -> Configuration wizard, then go to page named "Other Vendors", tick the checkbox next to the name "Creality", then click "Next" at the bottom right of the window. A page with a handful of Creality printers should appear including Ender 3. Tick the checkbox under Creality Ender 3. Then click "Finish" at the bottom right. The profile should appear in the selection.
It imports various print settings (from 0.3 mm to 0.08 mm I believe) as well as some basic material presets. You can import more materials by just going to the "Filaments" page in the Configuration wizard and ticking the desired options.
The profiles are tested by PrusaResearch themselves I believe and I think they are based on other profiles found online with some tweaks and adjustments to better fit to PrusaSlicer.
I am using PrusaSlicer 2.3.0
Here is an image, what it should look like. Your colors might be different, I asume you are using Windows, wheras I am using Linux Mint.


Dots in Cura on Prepare-mode When I load a figure in Cura 4.6.1 I get weird dots all over my figure in Prepare-mode.

How come, and can I turn it off?

It's on every model I load :( I am fairly sure the normals are facing the correct way as well.

Solution found!

If Display model errors is disabled, the dots appears.
Check the setting, hit OK, click on the box and they disappear.


Convert an STL model to a two-extruder model I have an STL file from thingiverse. The model is of a rectangular lid with an engraving. I would like to print it using two different colors, so that the engraving would be in a different color than the lid base. In the model description, the creator explained that he simply switched the material mid printing.

However, I have a two-extruder printer, and I'd like to utilize it for this printing. What's the easiest way (tool) to select a part of the model and define that it should be printed using a different color?

One method is to use meshmixer to select the faces to be created in the second color and "detach" them without removing them from the model. Keeping the detached faces in place provides the appropriate alignment when brought into the slicer. When exporting the model for printing, check your preferences to ensure both segments are exported at the same time. The preferences (file) default to separate exports based on selection.

Some manipulation will be required with the extracted segments, as typically one is removing a zero-thickness surface from a manifold object. The videos I've seen usually create an extrusion towards the inner body to create a dimensional model from the extracted skin.

Even if you are not familiar with Meshmixer, there are a number of videos and tutorials explaining this feature. If you use the terms "meshmixer dual extrusion" you'll get loads of links in return. I narrowed it by adding "Maker's Muse" to the search, as his explanations are clearer than others.

I know that Slic3r and Simplify3D will support the correct positioning when importing the model, other slicers may require additional research to accomplish this objective. My search also appears to indicate that Cura will support such processing.

The rabbit in this image was being prepared for two colors. I've seen the video but cannot recall why this image was presented, as the other pieces were eventually incorporated during one print. It's possible this image represents a single color print, based on the supports, but it is indicative of a partial process during the creation of a dual extrusion print.


Expansion in bottom skin after first layer I'm having an issue where prints with narrow tolerance come out fused. This makes it pretty much impossible to print anything with narrow parts. It seems to be mostly (maybe only) an issue in the bottom skin layers. Once it gets through those, the rest of the print goes smoothly and tight tolerances are not a problem.
Here's an example where I've tried to print some hinges:

It's a test print where each hinge has a different tolerance, so the left and right are expected to look different. Below each real image is a preview layer from Cura showing how it's supposed to look.
The first layer appears OK. The second layer looks a little messy, and the gap between inner and outer circles has shrunk. By the third layer the hinge on the right is completely fused.
The printer is an Ender 3 Pro with a glass bed (flat glass, no special surface), BLTouch, and Marlin 1.1.9. The slicer is Cura 4.6.1, and for this test print I used the default for "Super Quality - 0.12 mm" at 200 °C and 60 °C bed with no changes. The filament is Mika3D PLA.
Some things I've tried to fix this:

Calibrated e-steps (currently set at 95.88) - no noticeable difference
Calibrated flow rate (got 97.859 % but returned to 100 % for this test) - no noticeable difference
Varying temperatures from 190 to 230 °C by 5 °C increments - no improvement from 200 °C
Set "Initial Layer Horizontal Expansion" to -0.1 mm, -0.4 mm, and -1.0 mm in Cura. - no improvement.
Set "Initial Layer Flow" to 90 %. - no improvement.
Obsessively leveled and re-leveled the bed. - no improvement.
Moved the Z-offset up and down to get more or less squish on the first layer - no improvement.
Tried various brands and colors of PLA - problem is consistent.
Reduced build plate temperature to 45 °C after initial layer - no improvement.

What else is there to check?
Edit 2020-06-26:
At R.. GitHub STOP HELPING ICE's suggestion I returned the e-steps to default (93), re-leveled the bed, and adjusted the z-offset tighter. I made 10 attempts with varying z-offsets, and here's the best one:

The first layer looks better! But the second and third layers are just as bad as before, in fact maybe worse. The circle on the right completely fused on only the second layer. And the top surface is just as ripple-ey and messed up as before.
Here's a closeup of the fourth layer to show how bad it is:

So although the re-calibrated e-steps may have been a problem, that clearly wasn't the only problem. What else should I be looking at here?
Edit 2020-06-27:
At Davo's suggestion I double-checked all my slicer settings. Flow is set to 100% everywhere, wall thickness is 0.8 mm for two walls (so 0.4 mm each), and nozzle diameter is correct at 0.4 mm.
At R.. GitHub STOP HELPING ICEs suggestion I double-checked my filament diameter. It is set to 1.75 mm. On the actual filament, my digital caliper measures 1.74 to 1.76, within the expected tolerance. So that doesn't appear to be the issue.
At 0scar♦s suggestion I tried a print with 0.2 mm layer height. Here's the first layer:

Looks like the same over-extrusion.
Then I tried reducing the flow multiplier to 90% (for both "flow" and "initial layer flow") and printing at 0.2 mm layer height:

Better, but it still looks over-extruded!
I don't know what else to try.

OK, let's start with your pictures. Putting aside the expansion in the XY plane, layer 1 looks seriously underextruded (gaps between the lines, even) while layers 2 and 3 look severely overextruded. It would be possible to achieve this with a reduced first-layer flow setting, but you haven't indicated that, and moreover, in addition to looking underextruded, the first layer's lines don't look very flat - they look a lot thicker than 0.12 mm. I suspect if you can take a caliper with resolution greater than 0.1 mm and measure the thickness of the first layer, you'll find it's at least 0.2 mm thick, maybe more.
So, what's happening? You're overextruding by a lot, but have lowered your bed enough to (more than) compensate, giving the excess material in the first layer a whole 0.2 mm or more of vertical space to expand into, preventing it from being pressed against the bed and taking up the horizontal space it should. Now, as soon as you start the next layer, the big problems start. Since the nozzle has only moved up by 0.12 mm, you only have 0.12 mm of vertical space, and the overextruded material gets squeezed out horizontally. Some of it goes down into the gaps between the lines of the first layer. But by the time you get to layer 3, there are no gaps and things go really bad.
What's the source of the overextrusion? Your "esteps calibration". This is not a number you need to calibrate. It's a function of the extruder gear, and for the Ender 3's (including the Pro's) factory gear it's 93.0 (*).
After you fix the overextrusion by putting esteps back to the right value, you're going to need to re-level your bed. If you use the paper method, make sure there is significant tension on the paper and it does not slide freely under the nozzle at Z=0. If prefer using real metal feeler gauges and moving the nozzle to Z=0.1 to level. (You mentioned that you have BLtouch, which I'm not familiar with, but as I understand it you still need to calibrate it due to possible difference in sensor height and nozzle tip height.)

(*) Note that for compressible filaments like TPU and to a lesser extent PETG, compression of the filament in the gear will alter the effective steps per mm of (uncompressed) filament moved. However, rather than modifying your firmware esteps setting for this, it makes a lot more sense to model that as either a flow adjustment percentage or a narrower filament diameter (since essentially that's what it is -- the filament becomes narrower at the point of measurement), since slicing software supports adjustment of these per-material. So, don't touch esteps unless you replaced extruder hardware.


How to get less Z-seam? I printed this Curvy vase from Thingiverse and it came out pretty well on my Chiron.

However, I am not happy with the Z-seam that is very large. When I look at other people's problems with this, they often seem to have too little filament at the seam, but I have too much. What setting should I change to make it less visible?

Printer: Anycubic Chiron with Marlin 2.0.7
Material: PLA
Slicer: Cura 4.8.0.
Nozzle: 0.4 mm

All Cura settings are here (except that I lowered printing temperature to 200 ºC while printing).
All files used and some pictures are here.

2021-03-07 Addendum after I made 19 test-prints of a small portion of the vase's neck. Below are some of my notes:

Combing Mode=All is better than Off
Speed=60 is worse than 40
Retract Before Outer Wall=On is worse than Off
Outer Wall Line Width 0.45 to 0.35 gave a Z-seam on the outside with more build-up
Inner Wall(s) Line Width 0.45 to 0.35. Some places has less contact between layers, so less appealing and less robust. Also less material use.
Outer Wall Wipe Distance 2.0 spread ot the seam (too much), and also made a ditch before the Z-seam (on the outside of the ring).
Coasting tripled to Vol=0.588 and Wipe Distance 5.0 is more appealing. Two changes at once make it impossible to know which one helped. 5 mm is not enough to completely wipe.
50% printing speed improved Z-seam and surface smoothness

In the future I will use slower speed for Outer Walls, test Wipe distance=2*Line Width, use Combing (turned Off because of some advice to do so when LIN_ADVANCE is used) and experiment with faster retractions and Z-movement.
Pictures and complete notes are available here.

There is a Cura option to choose a random seam alignment in the shell menu:

Z-seam alignment
This setting allows you to choose where each new layer in the Z direction starts and affects where the seam of the model will be. This is useful for models with consecutive equal layers as the seam can be visible. By changing the Z-seam alignment you can decrease the visibility of the seam. The options available are:

User-specified: Set a coordinate for the X and Y direction of the Z-seam. This coordinate is absolute by default. Example: X 100, Y 200 will move the seam to the center back of the model.
Shortest: The next layer starts at the endpoint of the previous layer. This is the fastest way of printing, but also creates the most visible seam.
Random: The next layer starts at a random point of the previous layer, which eliminates the chance of a seam. Print time will increase due to the necessary travel moves.
Sharpest corner: This puts the seam in the sharpest inward or outward corner of the model, when available. This is the best method to completely hide the seam.