XY Axis Test calibration failing
Hello,
I am having a problem with calibration in the XY direction. Starting from powered-off state, I turn on the printer, and it tells me I need to complete a "Calibration & Tests" before I do any prints (this is expected due to prior calibration fails). I acknowledge and then go to Control --> Calibration & Tests --> 2 XY Axis Test. It does a Z-axis calibration, which seems to be successful. It then tries (and eventually fails) the X-axis calibration. In the X-axis calibration, it first repeatedly bumps the print head against the left side of its range (around 0mm X). Then it begins to move the head a bit to the right (a few cm from the left side of its range). Then it moves the print head all the way to the right end of its range, and the displayed X-value increases to around 212mm, but then it suddenly changes back to near-zero as the print head is on the right. So, then the head is on the right side of its X range, but the X-value is reading close to 0mm. It proceeds to bump the head against the right-hand side for a while, then apparently decides that it has failed the X calibration test. It then conducts and passes the Y calibration test. What is going on? Initially the system displays a reasonably large and positive X-value as it moves the head to the right. But, then it just abruptly changes to near-zero. So, the head is all the way to the right - repeatedly bumping against the right-hand side of its range - and the display shows an X-value close to zero - as if the head were on the other side.
What causes this? The printer is almost new. I purchased it a few weeks ago, but have not been using it until the day before yesterday. That is, I took it out of the box and set it up Saturday. The calibration went fine then. Over Saturday and Sunday I did several prints (maybe 4 or 5). Then, Sunday night, it produced an error as it prepared for another print, so I power-cycled and did this calibration test. There does not appear to be any debris on the belt or rail, and the belt tension seems fine. Today is Monday.
I recorded a video that shows this entire test:
https://drive.google.com/file/d/1wQDtCR9nZWcYA1l2GpQXB-GnfyHCUwUL/view?usp=drive_web
RE: XY Axis Test calibration failing
at least yours will do the Z axis. Mine passes the X axis test, starts the Y axis, then brings the bed forward and just stops. It fails the Y and never starts the Z axis test. Factory built...
RE: XY Axis Test calibration failing
I wouldn't expect it to be an issue with a factory built MK4, but you could check the tie wraps on the cable bundle behind the extruder to make sure they don't hit the steel frame.
would probably contact Prusa support for help with this calibration failure.
RE: XY Axis Test calibration failing
Hello and thanks for the reply.
Indeed this is a factory-built Mk4. I did check to see if those zip-ties had begun to hit the printer frame - they don't.
What is really odd is how the position that the printer thinks the head is at gets reset to zero when the head is on the right side - I tried to make the video so that this was visible. It is as if the head was hitting a barrier going left when it is on the right side.
I'm not sure how these motors work - but I imagine there is a sensor in the motor that detects when torque is applied, yet the shaft fails to rotate, which would indicate that a barrier was being hit. If that sensor was faulty, that could explain what is going on. However, that sensor might be less of a object in the motor, and more like an algorithm in the firmware.
So, how does the system detect a barrier being hit?
Could it be a line to the motor that changes logic state?
Could it be that the motor reports rotation - when the controller tells the motor to apply torque, but then sees zero reported rotation it reports a barrier hit?
RE: XY Axis Test calibration failing
I just tried to edit my above post, but apparently some timer expired while I was editing it, causing my changes to not be made, and for me to loose those changes. So, now I have to re-write those changes. This is an extremely poor configuration of the posting-system - it can cause a poster to loose their work - it needs to be fixed.
Repeating what was lost in my attempt to edit the above:
I also opened the box containing the primary electronics board for the printer, and verified that the cable to the X-axis motor is properly connected.
I would like to know the manufacturer & model of the X-axis motor, and where I can get a pin-out & tech specs for it.
RE: XY Axis Test calibration failing
Good morning Gregory,
due to the actions of Spammers, Prusa have minimised the editing time to reduce spamming opportunities.
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: XY Axis Test calibration failing
Hey
You really need to fix your damn system.
If it does not post someone's post, it needs to give them a change to COPY it for future trying again.
I just solved my problem, spent 30min typing out a long explanation of what was wrong and how I fixed it.
Then I hit post.
Apparently the system did not consider me logged in anymore, so I get this error message "something is wrong with your data". BUT, I LOST EVERYTHING I TYPED. DAMN IT, I"M NOT TYPING ALL OF THAT AGAIN.
RE: XY Axis Test calibration failing
If you are going to post a long post then I recommend typing it into something like Notepad first so if something goes wrong you have a copy. Alternatively, after typing the post on here, but before hitting Add Reply, copy it to the clipboard of your system.