RE: Y Axis now bashing repeatedly during homing
I had the loose belt too. It fixed it for a day or two but then returned, while Y belt kept the same tension.
Don’t worry about the resonance going 180Hz, it’s a multiply and that’s a wave, so if your belt home (eheh) at 90 Hz after going to 180 Hz you’re likely fine with it.
RE: Y Axis now bashing repeatedly during homing
I've had the Y axis bashing problem on my factory assembled MK4 which is about one month old now. It has only occurred 3 or 4 times. Sometimes it will bash 20 or more times before failing.
Until today I was on firmware 4.6.2 and have since updated to 4.6.4. After the update both the X and Y home tests "tap" only twice and then succeed. I thought the 4.6.4 update was my fix but after reading this thread I'm not so sure now.
I'll check my Y axis belt tension after the currently running print job completes.
Has anyone from Prusa made an official comment or acknowledged this issue?
Thanks
RE:
I built mine as a kit and it came with 4.6.4 pre-installed on it and still had the issue after a few days (only built the kit about a week ago since they just started shipping). It has been a few days now since I adjusted my belt tension with fairly regular printing, and so far the problem has not returned for me... 🤷🏼♂️
RE: Y Axis now bashing repeatedly during homing
I'm having this issue, but mostly with the X axis. On 4.6.4, haven't touched alpha firmware.
CS mentions it likely is related to the motor being from a bad batch, but I'm also thinking its firmware related.
RE: Y Axis now bashing repeatedly during homing
I have this problem too. Exactly like everyone else has described it. Hope it's fixed soon. I will contact support soon because it seems to be getting worse. The only thing that seems to help is if I put a bit of pressure on the y-axis belt while its doing the homing sequence. That usually makes it succeed after only a few bumps.
RE: Y Axis now bashing repeatedly during homing
I don't want to talk too soon, but this is exactly how I might have fixed it for myself, but when then printer was off.
Just bashed myself the plate to the back (not to strong to damage anything, but firmly for sure) and since then, no homing error anymore.
I'm thinking the main issue is on the pulley grub screw preventing a microstep, but I'm not sure.
RE: Y Axis now bashing repeatedly during homing
I've put the issue on github if people want to raise the issue there:
RE: Y Axis now bashing repeatedly during homing
I've put the issue on github if people want to raise the issue there:
Test 4.7.0
they changed something about it (homimg)
RE: Y Axis now bashing repeatedly during homing
I just noticed. I'll update and test.
RE: Y Axis now bashing repeatedly during homing
I just updated to firmware 4.7.0 and the Y axis bashing issue still exists for me.
On my first attempt to print the bed tapped the rear of the Y travel limit 31 times, failed, the microcontroller rebooted and the QR code for failed to home was displayed.
On second attempt the bed tapped the rearward Y axis travel limit 8 times, succeeded and started the print job.
RE:
(continued from above)
Third print job attempt the heated made 2 taps / attempts and succeeded.
Fourth print job it made 8 taps / attempts and succeeded.
RE: Y Axis now bashing repeatedly during homing
was yours a kit or a preassembled, I haven't experienced more than 6 on the input shaping, albeit more than the 2 on the stock firmware 4.6.4
(continued from above)
Third print job attempt the heated made 2 taps / attempts and succeeded.
Fourth print job it made 8 taps / attempts and succeeded.
RE:
My MK4 was factory assembled and is about one month old now. This Y axis homing issue started within a week of receiving it.
was yours a kit or a preassembled, I haven't experienced more than 6 on the input shaping, albeit more than the 2 on the stock firmware 4.6.4
(continued from above)
Third print job attempt the heated made 2 taps / attempts and succeeded.
Fourth print job it made 8 taps / attempts and succeeded.
RE:
When Y taps more than 4 times, it gives an error on the screen - not yet a crash so in most cases it can proceed if it homes correctly, but you can clearly read “Y axis homing error - retrying”.
That’s not normal, so if it bashes 6/8/10/12 times and the error appears, you too suffer from that, don’t ignore the problem!
The correct amount of tapping is 2. 4 is acceptable somehow because no errors are shown.
RE: Y Axis now bashing repeatedly during homing
I checked and adjusted the Y axis belt tension according to these instructions from Prusa.
I ran four prints to test. One of the four prints started after the Y axis tapped rear 2 times. The other three jobs tapped 8, 10 and 12 times, but eventually succeeded and ran. No complete failures or reboot of the microcontroller.
RE: Y Axis now bashing repeatedly during homing
Updated to 4.7.0. It still sometimes fails, maybe less than usual though? X axis will bash 8-10 times and then home.
Y axis sometimes does this too, but it never fails.
RE: Y Axis now bashing repeatedly during homing
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.
RE: Y Axis now bashing repeatedly during homing
I think its a firmware issue I get 4-6 on my y axis on 4.7 more consistently now
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.
RE:
I think I agree. Things were alright on 4.6.4 for me, hadn’t had more than two bashes since I adjusted my Y belt, and any issue was always on the Y axis. Upgraded to 4.7.0 yesterday, and ran some auto homes (i think 5 times, maybe 6) to see what would happen. All of a sudden X axis bashed a dozen times on every zero, and a couple times bashed until the whole machine rebooted (that has never happened before). Y axis, my previous problem child, was never more than two bashes.
RE: Y Axis now bashing repeatedly during homing
Despite printing fine, my factory assembled MK4 has this issue, but installing 4.6.4 seemed to miss the homing. If i run the Homing self test, it comes up with passes. The belt tensions seem fine using the App. I too think its a firmware problem perhaps. My first large print had a line from left to right. Looking at it i found when moving the bed by hand towards the back, there was a bump. I found that the bed frame underneath rubbed on the Y axis bracket. Filled it down and it was fine. Feel that more pre shipping checks ought to be carried out.