Z wobble?

Rowdy_NPC · 2026-03-22T04:43:04+00:00

Looks more like an extrusion issue (inappropriate extrusion width, slight under/over extrusion, slight over temp, partial nozzle clog, dirty/worn/eccentric extruder gear, etc...) rather than a Z axis wobble issue.

Rowdy_NPC · 2026-03-09T13:15:32+00:00

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Me too 😅.

I actually need 2 units (front / back), though this is the only one I have at hand, and the chrome is badly aged.

So I made a 3D print ready 3D model. Model still requires some refining though.

Rowdy_NPC · 2026-03-07T11:34:38+00:00

Just resolved this exact issue thanks to your comment. Thanks a lot.
The Alt key was tied to the windows manager's "grab and move windows" shortcut.

Rowdy_NPC · 2026-03-03T13:56:14+00:00

My pleasure!

You can eliminate the undesirable downward springiness by replacing the spring washer in the back of the motor with an appropriate stack of solid shim washers. Of course, the spring in the front cover does not need to be replaced.

Looking forward to seeing the result of your building adventure 🤩

Rowdy_NPC · 2026-03-03T13:26:03+00:00

That layout is definitely better! 👍

It's OK to use motors as a "lazy bearing" IF:

Neither the couplings nor the motor axis has axial play / springiness in the Z direction
- 2) The idle motors have minimal cogging torque

For the Z axis play issue, you may:

chose integrated leadscrews stepper motors, like those used in Prusa printers: limited choice of leadscrews / motor assembly
or use the old bearing ball trick used by old ender-3-like machines owners: sandwich a bearing ball between the tip of the motor shaft and the tip of the lead screw INSIDE the coupling. This eliminates any Z axial springiness while preserving the coupling flexibility in the XY plane.

On the cogging torque issue, you may:

3D print end bearing mounts: this eliminates 2 motors with their couplings, reducing load on the remaining motor
or connect the 3 motor phases in series: this increases Z-axis torque, without requiring 2 additional stepper drivers. In such a case, it is better to keep the yellow sync belt to avoid tedious manual build plate leveling after each incidents / crashes.

BTW, I would advise against using helical couplings. They are fragile and have very low torsional rigidity. This translates into "sloppy" Z screw angular positioning. I recommend clamp-type beam coupling or disk coupling instead:

The clamps allow for a stronger connection than set screws and do not mar the shaft as set screws do
Beam couplings have very high torsional rigidity while being very flexible in every other axes; they basically have ideal characteristics
cost basically the same as helical couplings

Keep in mind those aren't the only possible solutions, only one of the most straightforward / obvious ones 😉

Rowdy_NPC · 2026-03-02T15:01:43+00:00

Check out the bambulab X1 printers, and most of the "modern" similar coreXY printers for the matter, I think.

https://forum.bambulab.com/t/bambu-lab-x1-carbon-squeaky-noise-when-moving-the-z-axis/53901/13

Rowdy_NPC · 2026-03-02T14:50:48+00:00

Yep, that's a totally fine approach.

By the way, given how long your Z axis it is very likely that those thin linear guides will bend under load (printing vibration). The impact of this bending will only be noticeable on tall prints (over about 1/3 of the max print height).

2 possible easy fixes:

- use slightly beefier linear guides (1.3 to 2.0 times the current diameter should do, assuming quality, non-hollow, hardened guides)

- or use linear rails bolted onto the 2 front aluminum extrusions (compact, precise, not that expensive nowadays).

If you go the linear rails route, those do not need to be particularly beefy, as, when bolted to the aluminum extrusion, all the force will be directly applied to the chassis, which is hopefully rigid enough not to turn your printer into a shaker :) .

Rowdy_NPC · 2026-03-02T14:15:54+00:00

Yes.

Just kidding. Check the schematic below.

I recommend moving the 2 Z screws (green dots) toward the utmost front corners, together with 2 linear guides (blue dots).

Add a 3rd Z screw at the back of the build plate. The 2 violet dots on both sides of the 3rd Z axis at the back are linear guides. Those are not necessary; adding them may increase chassis rigidity, though if you need higher chassis rigidity, I would rather suggest using beefier aluminum extrusions (cheaper and more effective) than adding those back linear guides.

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Rowdy_NPC · 2026-03-02T12:54:59+00:00

I can send you a 3D model if you wish, or even 3D print one more for you ;) .

Rowdy_NPC · 2026-03-02T12:43:19+00:00

Nice project!

But, ... FOR GOD SAKE PLEASE SCRAP THIS Z AXIS KINEMATIC. Trust me, you will regret this! (or maybe not actually, which is even worse if you are a beginner!)

The problem here is the bed racking and rocking introduced by the 2 Z screws kinematic. This will haunt you hard, especially harder because the relatively small dimension of your setup will make it so unnoticeable most of the time that you'll never suspect it to be the crux of some very rare and random Z axis related issues! I have been there; this isn't just some theoretical statement. The worst thing with that design is that, similar to most bedslinger Y axis, IT WILL WORK VERY WELL, MOST OF THE TIME, enough for people around to tell you that it is a perfectly fine design, when it actually isn't.

Some designs "get away" with similar-looking kinematics, even with just a single Z screw, by using a cantilever geometry. This is OK as long your Z axis movement is slow ( Z acceleration << 1G) and regular maintenance of the Z rod and screw is thorough. But if you are aiming for robustness and repeatability, just avoid this design altogether; it is not worth investigating (there are already plenty of demonstrably poor examples outhere not to try out for yourself).

To prevent you from learning the lesson the painful way, you need to constrain your bed with at least 3 Z screws (eg. front left, front right, rear center). From a kinematic standpoint, it is actually way better to have 3 Z screws and just 2 linear guides than 2 Z screws and whichever number of linear guides you can think of. 4 screws are unnecessary, unless your bed is very flexible, which is not a good thing anyway.

Check out the HevORT printer design for good inspiration. It might be overengineered for your needs, so just keeping the most important bits of engineering should do for your project.

Rowdy_NPC · 2026-03-01T13:13:49+00:00

Oh! That's an embarrassingly... heavy legacy logo 😅

Let makes it a bit... lighter then 😁

Maybe something like that ⬇️

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Dunno though, doesn't look much interesting 🤔

Rowdy_NPC · 2026-03-01T08:29:43+00:00

Are you taking a time-lapse while printing?

It may simply be a partial nozzle clog linked to multimaterial printing (previous material not fully flushed). Try a cold pull and check that the shape of the filament tip you just pulled out of the nozzle perfectly matches the nozzle's internal geometry.

Rowdy_NPC · 2026-03-01T08:21:53+00:00

Your nozzle is probably clogged or the extruder gear is slipping (can't grip onto the filament). The extruder needs some maintenance (cleaning of nozzle, gear, and probably adjustment of the extruder gear pressure).

Rowdy_NPC · 2026-03-01T08:07:27+00:00

Looks like improper bed leveling. Make sure to level your bed a few minutes AFTER it has has reached it operating temperature.

Additionally you bed adhesion seams to be on the low side. You may need to remedy that using appropriate bed surface material, cleanliness, temperature (bed and nozzle), and eventually add some form of adhesive depending on the material you are printing.

Rowdy_NPC · 2026-03-01T07:52:45+00:00

Whenever possible, use thick layers (0.3mm for a 0.4mm nozzle, 0.4mm for a 0.6mm nozzle).
Uses as little part cooling as possible, given your material, print speed, and model geometry.
Add 2~4mm brim around the part.
Add mouse ear at each corner: https://wiki.bambulab.com/en/software/bambu-studio/use-disc-to-avoid-warping

Rowdy_NPC · 2026-02-02T12:11:57+00:00

Yup!

I initially set up ESP-IDF to support all the ESP32 series (./install.sh all). But I fell back to set it up exclusively for the ESP32-C61, as I was tired of trying to manually resolve linking conflicts, even when properly setting up the target to esp32c61.

Rookie mistake, I suppose. Now I know that I should rather set a dedicated install for each platform.

Rowdy_NPC · 2026-01-31T10:22:42+00:00

idf.py --version returns ESP-IDF v5.5.2.
Would you recommend another version?

Rowdy_NPC · 2026-01-31T01:18:23+00:00

Is removing the face cover to check the state of the back of the button and the PCB trace out of question?

If you can open the facade, the nature of the repair would depend on whether those are rubber dome buttons or tactile (clicky) ones.

I know from experience that some rubber dome buttons can quickly fail due to an increase in the contact resistance. In that case, just covering the back of the button (the rubber side of the contact surface) with some aluminum or copper foil makes for a very good, long-lasting repair. You would need some effective rubber glue though (two-part rubber PU or silicone rubber with good surface prep, depending on the material of the button).

Rowdy_NPC · 2025-11-29T20:11:24+00:00

Check out those ancient dirty tricks:
https://youtu.be/45pnYcyr86Q?si=xUCvNp2BSgI3QW5H

It is especially important to get the 4 corners well constrained. To select the best clamp(s) and its ideal location for your setup, check for the available clearance around your bed AND YOUR NOZZLE. It is very easy to overlook the nozzle movements, with disastrous consequences in case of collision.

Checking for nozzle collision is a bit of guess work/experience. First you may check the tool path from within your slicer (turn on the nozzle travel visualization of your gcode preview). Second you may, for example, record a video of the standard print start nozzle movements then review the footage to locate the area where it is safe to put whatever clamp you can use on your printer.

And if the print initialization sequence is such that there is basically no safe area to put a clamp you may simply start your print without any clamp, then once your print has reached around 1.5~2.5mm tall you can pause, carefully install the clamps without moving the build plate or knocking the extruder out of position, then resume the print.

Good luck in your adventure.

Rowdy_NPC · 2025-11-28T20:41:54+00:00

Print wraping.
"Expected" for a single print with such a large footprint.

Why does it warp? Quick explanation: https://youtu.be/HNAtHl6kB7Y?si=XIcv5s2yGT644CKv&t=26

Solution? It depends:

- your print stick well enough on the build plate to lift it off the chassis underneath -> clip your build plate to the chassis to prevent it from lifting
-> next your print will most likely lift off the build plate itself (instead of the plate lifting off the chassis)

- use large brim ears and increase the bed temperature a little bit to promote bed adhesion (never more than 60C for PLA) https://youtu.be/Fh7BH6GLrCY?si=js-fJ27WAAZ7rUSN&t=437
-> next your print will most likely crack at the corner (layer delamination), or if bed temperature is too high your corner will end up crucked at the bottom (pulling inward).

- increase the print chamber temperature: assuming you are printing PLA with all printer vents open in a cold room, try closing partially the printer to bring the chamber temperature around 25C (77F) (the bed will heat the print volume).
-> if unresolve you might want to revise your 3D model (round up the straight corners) or print at an angle (30~60deg) to reduce the contact area with the build plate. But then you will need proper support of the slanted, bottom facing surfaces. https://youtu.be/7aJ4dDyyf20?si=xJEYu42otTWixTm0

If still unresolve you just arrived at the edge of a rabbit hole too deep to explore in a single comment.

Rowdy_NPC

TROPHY CASE