MK4 startup home Y axis intermittently fails
I performed a forum search and could not find that this has been discussed previously. I've had my factory assembled MK4 for about a month now. It is unmodified, completely factory stock.
When a new print job starts the Nextruder homes by moving left on the X axis until it reaches the end, then is backs off and taps a couple of times. This looks fine.
Next the print bed moves rearward along the Y axis until it reaches the limit and then retracts and taps. This tapping motion can occur 2, 3 times, or more than 20 times. The test/check is usually successful and the MK4 continues on processing and printing the job.
However this Y axis check occasionally fails. The microcontroller appears to reboot and a code appears on the screen indicating an obstruction exists on the Y axis movement and caused the failure. Rebooting the microcontroller and restarting the print job has always been successful without this Y axis check failing twice sequentially.
I cannot find any obstructions inhibiting print bed movement. There appeared to be excess grease pushed to the back of the Y axis guide rods and I wiped that off, but nothing else is visible that could be obstructing movement.
Has anyone else experienced this? I have not yet contacted Prusa support because the failure has only occurred three times and I never know if or when it might happen again.
Thanks
RE:
have you already performed a firmware update? possibly on the alpha to test whether it is better there.... and I would do the test again... are the plastic threads in the z axis tight? take it out and see if the spindle is in the middle of the hole if not mediate on the motor using the 4 screws. Look into kit assembly manual z spindle...for me it was the y axis but the belt was loose...
RE:
@Atilla thank you for your reply and advice. I was on firmware 4.6.2 and have since updated to 4.6.4.
After the update I ran the XYZ axis self tests which passed fine (it had also passed on the 4.6.2 firmware earlier today). I then launched a test job three different times. During the startup of each job the X and Y axis movement / taps occurred one twice for each. This is clearly an immediate improvement.
I'm suspicious there may have been a bug or issue in firmware 4.6.2. I'll continue to be vigilant during print job starts and repost if the failure reoccurs.
As a side question, how to I get auto-notifications when new firmware is released?
Thank you!
Jake
RE: MK4 startup home Y axis intermittently fails
Actually this has been seen with 4.6.2, 4.6.4 and the 5.0 alpha firmwares. More user experiences are in the Input Shaper section,
RE: MK4 startup home Y axis intermittently fails
Thank you! I'll check that out.
Actually this has been seen with 4.6.2, 4.6.4 and the 5.0 alpha firmwares. More user experiences are in the Input Shaper section,
RE: MK4 startup home Y axis intermittently fails
Hi guys,
I have a similar problem. I have finished building my MK4 kit and started the printer. In the setup wizard, the Y axis always fails and I have already checked everything (Belt tension, installation of the servo, all screws, the bed and bearings, etc.). Do you think that may have to do with there being a software problem with the Y axis in general? Have any of you already found a solution?
RE: MK4 startup home Y axis intermittently fails
I'm having this, but mostly with X axis. CS says its likely bad motor related, so I'll wait and see if it improves when replacement motor arrives.
I'm also wondering if its firmware related eg. its expecting WAY too much accuracy when homing.
RE: MK4 startup home Y axis intermittently fails
Replacement x axis motor arrived (due to resonance issues, new motor is MUCH quieter), which seems to have reduced the amount of failures on x axis - however, sometimes it still bashes 8-10 times before it finally homes. I have checked belt tension since installing new motor - belt tension app says its at the correct tension.
Now the motor is ruled out, I'm leaning more on firmware being an issue, or potentially a motor driver issue.