Homing takes a lot of time solution
Hello all,
Before each print, the printer would take a really long time (6-7 minutes at best) doing what it called 'Readjusting home'. It would also throw the occasional 'crash detected' and 'measuring axes failed'. Lastly, it would stop, reset, and throw a nice red screen where it told me it wasn't happy with my setup.
I would reduse this problem by re-tuning the belts but inevitably it would come back.
I contacted support and it appears I missed this step. The front right corner had quite a bit of play, and by experimenting I managed to remove said play from the axes and now homing takes mere settings.
Also, for anyone out there that wants to tune the belts, don't use the prusa app or the website, because they are too slow to respond. Instead use a sound analyser app (I use Spectroid) to reach that 85 Hz goal.
RE: Homing takes a lot of time solution
Thanks @avarice - I did two PLA prints this morning. First one did the homing/head-crash dance for about 6 minutes before it decided to start the actual print (well the probing bit of it). The second one - 10 minutes later - kept the banging going for just over 10 minutes. And here's me thinking "this damned thing is going to break itself". Reading your post though: (a) makes me happy that it's not just my printer being a "lemon" and (b) gives me some hope that maybe the process you've outlined will help my orange-and-black monster.
Really hope so because I did a PETG print the other day - 25 minutes of head banging, z alignment failures and nozzle clean failures before the print actually started. Although I've since stripped off the 0.6mm ObXidian I've got and cleaned it carefully/thoroughly.
Again, thanks for the helpful post!!
RE: Homing takes a lot of time solution
Thanks @avarice - I did two PLA prints this morning. First one did the homing/head-crash dance for about 6 minutes before it decided to start the actual print (well the probing bit of it). The second one - 10 minutes later - kept the banging going for just over 10 minutes. And here's me thinking "this damned thing is going to break itself". Reading your post though: (a) makes me happy that it's not just my printer being a "lemon" and (b) gives me some hope that maybe the process you've outlined will help my orange-and-black monster.
Really hope so because I did a PETG print the other day - 25 minutes of head banging, z alignment failures and nozzle clean failures before the print actually started. Although I've since stripped off the 0.6mm ObXidian I've got and cleaned it carefully/thoroughly.
Again, thanks for the helpful post!!
Hey, hope that the procedure works for you!
RE: Homing takes a lot of time solution
There's some important parts of this process that bear emphasizing:
- Make sure your adjusters are able to move freely. I had one that was binding, where loosening the screw didn't have the adjuster part that has the bearing move properly. They should be free to move front and back. Start with loosening the belts and checking that motion.
- With the belts loose, verify that the gantry hits both front stops simultaneously. Bend the gantry slightly to get them into alignment.
- Slowly tighten the belts, trying for equal turns on each side.
- Get them as close as you can to the same tension.
- Check the gantry again. It should not have shifted if your belt tensions are the same.
With that, I have no more incessant knocking when homing.
RE: Homing takes a lot of time solution
There's some important parts of this process that bear emphasizing:
- Make sure your adjusters are able to move freely. I had one that was binding, where loosening the screw didn't have the adjuster part that has the bearing move properly. They should be free to move front and back. Start with loosening the belts and checking that motion.
- With the belts loose, verify that the gantry hits both front stops simultaneously. Bend the gantry slightly to get them into alignment.
- Slowly tighten the belts, trying for equal turns on each side.
- Get them as close as you can to the same tension.
- Check the gantry again. It should not have shifted if your belt tensions are the same.
With that, I have no more incessant knocking when homing.
And if you still experience too many knocks, slightly tension the right side a little bit more until the knocking is normal.
RE: Homing takes a lot of time solution
There's some important parts of this process that bear emphasizing:
- Make sure your adjusters are able to move freely. I had one that was binding, where loosening the screw didn't have the adjuster part that has the bearing move properly. They should be free to move front and back. Start with loosening the belts and checking that motion.
- With the belts loose, verify that the gantry hits both front stops simultaneously. Bend the gantry slightly to get them into alignment.
- Slowly tighten the belts, trying for equal turns on each side.
- Get them as close as you can to the same tension.
- Check the gantry again. It should not have shifted if your belt tensions are the same.
With that, I have no more incessant knocking when homing.
Thanks, at this stage I'm delighted to take all the "words of sage wisdom" that I can get (and not forgetting your contribution @sgtcaffran).
I've got a lot of IT knowledge (back to when 8K was megaRAM), can build my own PCs - but all the engineering smarts I obviously need for 3D printing is a challenge, albeit a fascinating one.
Great maker bless everyone here! 😀
RE:
There are plenty of other posts on this topic.
1. CHECK THE PULLEYS ON THE MOTORS. IF THEY ARE MOUNTED WRONG it cant work.
Anyhow, if it doesnt finish after 20sec something is not right, or maybe 30 in caliration mode. you can just turn it off right away.
Follow the Prusa Belt Tension Procedure. Make sure the while the belt is untensioned your Gantry is properly squards. Means wenn you pull it to the front there are no gaps left and right. If there are gaps > 0.5mm fix that first by applying the proper bending technique. use a machinists square or any other perfectly rectangular piece of measuring equipment.
Make sure both sides have 90° on the angle brakets. After that you shoud have the gantry squared.
you dont really need to continue if there are gaps.
After all thas is perfect and just then tension the belts. Make sure there is no gap after tensioning.
If it still does not home you have an issue with your sensor.
RE: Homing takes a lot of time solution
Okay, I finally managed to get around to tuning my XY belt - they were about 10Hz too low. First print post tuning gave me about 20s of banging then gave me message something like "Axes alignment failed" and started the print. Second print (not long after) was 120s of banging (with an "Axes alignment failed" message in the middle of it) then it started printing.
Think I need to double check with Prusa support...
PS interesting observation - printing is quieter with the tuned belts, not sure why this should be the case, but it's welcome (not that the Core One has been particularly noisy - except when head aligning)