X and Y are moving simultaneously when homing and first print test was slanted.

[FernandoT]

Printer Model

Voron 0.2 Formbot kit

Extruder Type

Other

Cooling Type

Stealthburner

Hi everybody,

I have built my Voron 0.2 Formbot kit and it was very satisfying.
Board is a SKR Pico and the SBC is a BTT Pi v1.2
After watching allot of videos and especially the ones from Ballistictech (which has built the exact same kit) I went through all the calibration steps etc. (stepper buzz, PID, e-steps, z-offset, 3 bed screws callibration etc.).
Sensorless homing tunning etc.
Printer homes correctly (or so I thought) and axis moved fine.
After a while I thought I was finished and just tried to print a Benchy but then things went wrong, The start of the printer after homing the axis moved to the front and jammed into the front and later to the side (like it did not sense the endstop which it did with homing) and then it started printing. But I noticed right aways that the print was slanted/skewed.

Then I got on discord and asked some questions and posted a video of the printer homing and someone noticed that while homing each axis the other axis also moves slightly, which is obviously not good.
The problem is that I don't know what is causing it.
The movements on the printer do not have any bindings or grinding. Belts (most issues here on the forum the resemble mine are belt coming off pulleys related) seem to be routed fine and run on the pulleys.
Belt tension is 110hz
When I do the stepper Buzz on the X only one pulley turns when I do it on the other it looks that way but when you look really closely you can see a very slight nudge in the pulley that should not move.
I made lines with a fine liner to see if the shaft moves inside the pulley but that is not the case (used threadlocker on all grubscrews).
Sensorless homing seems to finish fine.
I did the setting of the current in the printer CFG (my motors are the same as ballistictech's and I am using his printer.cfg with some adjustments).

So I am kind off clueless where to look next.

Here is a movie of the printer homing which looks fine and the second I move the axis by sending 100 mm movement and then 2x 10 mm. In the movie it is really clear to see that both axis move.

Homing:

Moving the axis with the jog in klipper dashboard:

Stepper Buzz:

My Printer.CFG is attached.

Info on my MOONS motors.

 

[transonic_gecko]

Why is your rotation_distance set to 33 for the y stepper? It should be set at 40, just like it is for the x stepper.

 

[claudermilk]

The homing video and it doesn't look ok to me. You can see Y is moving slightly during the X home. In the videos of moving X you can see Y is moving. I haven't run across that myself, so I don't have a ready answer. But there is definitely something amiss that is connecting X movement to a bit of Y movement. In the one where it's grinding, that indicates to me the printer isn't homed right (been there, done that).

 

[FernandoT]

Why is your rotation_distance set to 33 for the y stepper? It should be set at 40, just like it is for the x stepper.

Because I am a moron, I took a premade cfg and used it without checking very thing 100 times and making sure to understand what all the options do. Now with your help I adjusted that value did the sensorless home tunning again and now it homes and the axis move as supposed. Thank you very much, I was banging my head against the wall. Everybody was telling me I had to take the complete printer apart etc. but I had a feeling it was cfg settings related, but could not find it.

 

[BallisticTech]

Because I am a moron, I took a premade cfg and used it without checking very thing 100 times and making sure to understand what all the options do. Now with your help I adjusted that value did the sensorless home tunning again and now it homes and the axis move as supposed. Thank you very much, I was banging my head against the wall. Everybody was telling me I had to take the complete printer apart etc. but I had a feeling it was cfg settings related, but could not find it.

It wasn't the premade cfg from my github was it?

 

[transonic_gecko]

It wasn't the premade cfg from my github was it?

It doesn't appear so. The one here https://github.com/SrgntBallistic/Formbot-V0/blob/v0.2/Firmware/bigtreetech-skr-pico-v1.0.cfg doesn't have the same error.

 

[FernandoT]

It wasn't the premade cfg from my github was it?

It was the one from your github but I already changed and added parts to it. It is working fine now, the issue was the rotation_distance mismatch as transonic_gecko mentioned.
I must have made a stupid mistake miself (probably during the e-steps calibration). Your github example I used as a starting point has the correct values.

 

[FernandoT]

Now I need to find out how to get this adxl attached to my toohead to do the inputshaper config:

BIGTREETECH ADXL345/S2DW Accelerometer Board for Running Klipper

The S2DW V1.0/ADXL345 V2.0 is an accelerometer module that helps reduce vibrations and improve print quality in 3D printers. It can be easily connected via USB and attached to either the printer's nozzle or the Voron StealthBurner. Whether you are new to 3D printing or have experience, this...

biqu.equipment

Does anybody have a good mount?

 

[claudermilk]

From the shape of the board it looks to me like it is meant to use the extruder motor mounts. You would just need long screws and a couple of standoffs. Look at the V0 umbilical mod here. The STL might work for you.

 

[ChrisA]

Now I need to find out how to get this adxl attached to my toohead to do the inputshaper config:

BIGTREETECH ADXL345/S2DW Accelerometer Board for Running Klipper

The S2DW V1.0/ADXL345 V2.0 is an accelerometer module that helps reduce vibrations and improve print quality in 3D printers. It can be easily connected via USB and attached to either the printer's nozzle or the Voron StealthBurner. Whether you are new to 3D printing or have experience, this...

biqu.equipment

Does anybody have a good mount?

It looks to me like it does not need a printed mount. It says "For 36 stepper motor". allowing for poor Chinese to English translation it seems to be saying it uses the mounting screws on a 36mm motor.

I hope that PCB is REALLY stiff or it would add its own resonance. The LAST thing you want is to mount the accelerometer on a spring or something that acts like a spring.