Voron 2.4 Layer Shifting

[dim furnace]

Hey I have a formlabs voron 2.4 that I built a year ago and tuned but it hasn't been entirely reliable yet. I've been having some issues with later shifting on longer prints and I've been having a rough time figuring out why? These 2 prints both failed at the same place. The second one I was able to stop when it shifted but I don't feel any blobs or anything that the nozzle would have crashed into but I definitely heard the belt slip when it happened.

[main mason]

Please check if belts are routed correctly, especially around motors.

check motor run_current in printer.cfg if you are using klipper

[dim furnace]

Motor current is at 0.8 in printer.cfg

[haughty hollow]

Hey, I have the same problem. After I recognized the shift, the felt the temperature of the Motors A and B. The one that had to stop to cause the shift in this direction was way hotter then the other one.

Maybe the motor is Brocken or the driver ? I will change the drivers from A to B and B to A. If the shift direction changes, the driver is down or overheats at some point. If the direction is the same, it musst be the motor.

[dim furnace]

Let me know what you find out. I upped my motor amps up to 1.0 but haven't had a chance to test it yet and see if it helps

[haughty hollow]

It happened again in the same direction. But the motors temperature is equal (Tested by touching :D) . So the drivers are fine. I think I have to reassemble the gantry and check everything 😦

[undone patrol]

Check chains they are not being caught by gantry moving

[haughty hollow]

The cable chains ?

[undone patrol]

Yes

Also check that rails are not moving around. Maybe they got loose over time from heat

[haughty hollow]

I thought about the same, because it’s only happening with higher chamber temperature. While printing pla with open doors, everything is fine.

Cable chains a fine an the rails are running smooth without the belts. Everything was tightened well. Maybe the belts or motionsystem. I will check this now

[undone patrol]

Was about to ask if your extruder gear that sits on shaft didnt go loose also (grub screw) but ith as nothing to do with Y axis shift

have you taken rails off and see if they slide on their own with no binding?

[haughty hollow]

I have removed the gantry from the frame and checked everything. The rails are moving smoothly. The bearings and pulleys are fine. I don’t know. I have switched the motors. Maybe the direction of the shift will change now, then it must be the motor.

[undone patrol]

Yea could be motors maybe dying if they are old running at high voltages

[simple silo]

Do you have sufficient electronics bay cooling? When I was bring up my v2.4 it would stall mid print due to the fact that I hadn't connected my electronics bay cooling fans and the drivers were over heating. Maybe your Klipper logs correlate with something when the layer shift occurs - worth a check.

[haughty hollow]

Yeah the electronics are well cooled. I have an thermistor down there. Not directly at the drivers, but near to the board. I reassembled the gantry today. I increased the motor current a bit. Tomorrow or on Sunday I will rerun the print.

[main mason]

hmm, Try increase Motor Current to 1.4. If this don't help that motor/s or Main Board is dying like @undone patrol mentioned.

or some motor cables are loose on connector

[haughty hollow]

I increased the currents up to 1.2 amps. Till now everything is fine. I will start longer prints now

[dim furnace]

Good to hear. I didn't want to really print anything until you had some positive news on your machine. Thanks

[crude wigeon]

You need to install some directly cooling on the drivers, electronics bay fan does very little effects on the drivers, try to visualize the driver temp, when they went up to 70°C with longer prints it's likely why the layer shift happens in my experience

If the current is too low the step motor could get over heat as well but high current would makes the drivers over heat, my 2240 with 1.2 current easily went to 80°c plus without cooling, print a fan support for your board and even zip tie some fans blowing air directly to the driver would help, a easy drop of 10-20°c

Driver temp are usually way hotter than the motors.... At least thats my case

[haughty hollow]

😄 yeah let that random dude on the internet crash his Maschine first und profit from the results 😄 just joking. I discovered a little gantry racking during the process. But not that much to cause such a shift. 2-3 mm. I will start a longer print today. Maybe you should wait for the results 👍🏻

[haughty hollow]

I have heat sinks on the drivers and the board is next to the electronic bay fans. That isn’t enough cooling ?

[haughty hollow]

I also had an issue with my Z endstop. The soldering connection on the switch was not well done by me 😄 it was actually not connected anymore. But the wire touched the connector, that’s way homing works in 8 from 10 times. But it failed more often at higher chamber temperatures. Maybe due to some bending of the materials. Could a randomly triggered z endstop during the print cause such a shift ? I mean I could test it, just have to trigger the z endstop during a print. But I don’t want to 😄.

[haughty hollow]

Nvm z endstop was not the problem. I triggered it during a print and nothing happened.

[haughty hollow]

So after 6 hours in total, everything worked well. Not the prettiest print but it finished 😊 I increased the currents and activated z hop for movements. I also re tightened everything on the gantry and the belts as well. And also Removed the little racking. I don’t now what was the reason for the shift. But for now it’s gone.

[dim furnace]

Glad its working better for you. I'm gonna try another 12 hr print tmw and see if it pushes past the failure point or not

[crude wigeon]

Not really if ur printing long time with higher run currents

Putting a fan on the xy driver would cost like $5, its totally worth it