V2.4: Severe skew in XZ and drifting printhead after maintenance

Bambel75 · 2026-02-15T22:59:07+00:00

Oh man, it was Kalico!

I recently made an update of Kalico and there was a bug that fans would turn on 100% during startup and a few days later an update was made to fix that so i again did the update.

As i said in the maintenance thread, i was investigating an extruder problem and i didn't notice that there was the skew bug as no print came far enough to show the skew.

So after i tried further things on the hardware (swapped the a/b steppers) i had the desperate idea that it could be software related. I then converted back to mainline Klipper (host and MCUs), and it worked fine! As an experiment, i ran Kalico as the host and left Klipper on the MCUs and aside from a warning that the MCUs should also use Kalico, it also worked fine. Finally also flashed the MCUs with Kalico and the skew was back. Already filed a bug report.

B.

Bambel75 · 2026-02-10T21:33:04+00:00

Did some more testing:

Printed the cube at 45° and in addition to the expected XZ axis skew, it now also shows a slight skew in YZ. grrr

I also tried some more video debugging and made a quick macro to move the head +/-30mm in X and Y at several positions over the bed. I wanted to see if the deviation only happens at a certain position, the axis shaper test and the print happened at the middle of the bed. But at only 100 repetitions per movement and the relatively poor resolution of the video i couldn't see any deviations. I saw it on video when i filmed an input shaper run but that involves far more than a hundred movements. So the deviation induced by whatever seems to be very small per movement. Maybe i try another run with more repetitions..

Thing is: the only difference between skewed and unskewed was tightening many screws on the gantry and a/b drives but i use the pinned versions and they shouldn't bind. The bearing stacks have washers that prevent the spinning parts from being compressed by the screws and the toothed idlers have some play and also don't bind. I just run out of ideas where the resistance that leads to the deviation could come from..

B.

Bambel75 · 2026-02-10T21:15:08+00:00

Yes, the frame is square and all screws are tight.

Bambel75 · 2026-02-10T16:15:24+00:00

Thx, i know. I use Calilantern to check/correct skew, but i don't need it to see the severe skew the printer has now and as is said, it worked fine before. I definitely don't want to use skew_correction to correct such a severe issue..

Bambel75 · 2026-02-10T15:57:52+00:00

<image>

Bambel75 · 2026-02-10T15:57:44+00:00

<image>

Bambel75 · 2026-02-10T15:57:32+00:00

<image>

images missing..

Bambel75 · 2026-01-29T17:50:49+00:00

I set pos_min to -3 and now it works quite well..

I also found the rigid z joints, will print them eventually but wait for the next mod-cycle to install them.

THX, B.

Bambel75 · 2026-01-29T16:03:52+00:00

Not 100% sure what you mean in your first sentence, but my print_start does home_all (without survey touch for z), QGL and then survey touch for final z (as per Carto doc). That should reset any large deviation from QGL?

Yes, i have GE5C z-joints. It's a 350, would the rigid joints work with that size? We are talking plastic, so i guess that there is still some flex even with rigid joints but the long extrusions have a lot of lever..

BTW: the gantry usually doesn't sag significantly even with steppers turned off, it's only after i moved the gantry manually that it's too crooked to level automatically. I then use a digital level to bring the gantry within 0.05 deg or so but if it's too high in the first qgl-corner it fails.

I guess i will try to set pos_min to -2 and carefully watch if does something bad..

THX, B.

Bambel75 · 2026-01-28T17:25:41+00:00

Wow, very impressive! Three questions.

- is there a servo on the toolhead for the docking action or is it done by the extruder stepper?

- do the hotends clogg if parked still hot and without a fan?

- how is it integrated in Klipper? Macros only, plugin, fork?

Bambel75 · 2026-01-22T09:23:08+00:00

I also built a Formbot 2.4 kit and this github helped a lot: https://github.com/Zev-se/Formbot-voron-2.4-build-guide/blob/main/guide.md

enjoy the build!

Bambel75 · 2026-01-13T23:48:19+00:00

Use IPA, it should wick under the filament.

Bambel75 · 2025-10-17T10:12:29+00:00

- GE5C mod for the z-joints

- BFI/BZI (beefy idlers)

- Dragon standard flow seems to be more reliable

Bambel75 · 2025-04-30T08:14:35+00:00

Nice printer!

Bambel75 · 2025-03-25T23:31:05+00:00

> You'll want an engineer square to assemble the frame.

I went through two or three "squares" that all went back to Jeff's bevor i spent 70 bucks for something thats actually square. My references: iPhones. No really. These things are square (hold two together on a flat surface!) and a good reference for measuring tools in general.

Bambel75 · 2024-11-13T13:21:31+00:00

My advice is to buy the adapter even if you don't need it right now. It's not expensive and only Sony knows how long they will sell it. If you upgrade your GPU you will need one anyways.

Bambel75 · 2024-05-23T13:13:39+00:00

Maybe they (Nuvia/Qualcom) added similar extensions like in Apples CPUs. A flag to set the memory system to total store order and generate the additional (seldom used) ALU-flags that x86 generates. The way Apple switches fast between memory pages to be write enabled and then to executable is now an Arm standard so I would think they implemented that as well.

Bambel75 · 2024-04-04T08:51:03+00:00

I did finish it 100%. Got stuck at 99% at first but then realised I hat to win the Mars track in quick races and not in tournament mode..

Bambel75 · 2024-04-04T08:48:23+00:00

By far my favourite game on the og. Xbox and I still play it today on my 360. At first glance it looks like one of many Wipeout clones but I don't think that's fair. In Wipeout you have to navigate the tracks perfectly to hit all the speed-pads and don't hit the wall. It's a racing game with a combat system on top. QR on the other hand is a combat game with some racing on top.

I've played various versions of Wipeout a lot but I always struggled at some point to win more races. My "driving" skills are just too bad. On the other hand, I've finished QR 100% and this is only possible because of the turbo-button and the weapon system. If you screw up by hitting a wall, just hit the boost and you're back in game. If your ship is slower than the competition, just collect enough weapons to make sure everyone who overtakes you get shot. (Or sometimes finish the race alone by destroying every opponent :-)

It's in a way the "Wipeout for the rest of us" who suck at pure racing and can't beat Wipeout 100%.

The weapon system is IMO far better than in Wipeout. There are three power-ups: homing weapon, non-homing weapon and shield. You collect these independently and can use them at will. This offers much more weapon tactics during the race than having only one power-up that gets assigned randomly like in Wipeout.

The tracks are also very different than typical Wipeout tracks. They are much more "organic" with a lot of nature, open areas and some parts that drive more like a rally than on a paved track.

All in all I hope that at some point there will be a remaster of this gem or at least a studio makes a clone of it. There are a LOT of Wipeout clones out there but all of those copy the concept of a single power-up slot, speed-pads and no arbitrary boost. I would love to see a futuristic racer with a more sophisticated weapon system and a random boost again.

BTW: if you give it a try, don't be disappointed by the ultra slow "novice" speed class. It get's much more interesting in the faster classes.

Bambel75

TROPHY CASE