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Auto calibration failing  

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 none
(@none)
New Member
Auto calibration failing

MK3 kit, just finished assembly, first printer, no idea what to expect. Powered on, and couldn't get through the self test. Downloaded and applied latest firmware, self test passes fine.

When the XYZ calibration routine runs, it tests the four corners of the board (as it tells you it will) at the last corner, the lcd goes back to "testing point 1 of 4" but it stays in position 4, it then moves to position 3 and says "testing point 2 of 4", then it tries to move the sheet BACK (which it can't do, because it never moved forward from point 4 to 1 ) and "fails to find test point".

I don't think there's anything I can calibrate, this looks like a straight up programming error of the calibration routine. Has anyone else run into this?

Posted : 28/03/2018 4:15 am
Martin Stoufer
(@martin-stoufer)
Estimable Member
Re: Auto calibration failing

Ian, does the bed make any attempt to move forward for the next pass? I'm wondering if it got physically stuck somehow and the motor can't move it. I assume you can move it by hand w/o the y-axis motor energized.

I'm using 3.1.3 as the firmware and just ran a Self-test tonight to re-measure belt tightness.

Posted : 28/03/2018 5:11 am
Kwaad2
(@kwaad2)
Honorable Member
Re: Auto calibration failing

During the first 4 points, before it returns to point 1 of 4... does the bed move "quietly" and not "poppy" I have no idea how to describe the sensation, but it should be smooth. (I mean it's got a stepper motor, and it's jerky... but it shouldn't seem to bind) Is the nozzle hitting the heat bed? Are there any wires that might be catching on something? before you plugged the stepper motor into the board, did the print bed slide ANNOYINGLY free end to end? (seriously, that's the most annoying part of assembly, that blasted bed was ALWAYS in the way).

Hi, I'm Sean. I used to work on CNC machines.
I try to not make mistakes, but the decision is YOURS.
Please feel free to donate to my filament/maintance fund.

Posted : 28/03/2018 5:52 am
Olef
 Olef
(@olef)
Prominent Member
Re: Auto calibration failing

Sounds like an assembly issue, perhaps the bed is getting stuck when fully forward. Keep in mind that this printer does not use endstops - it tells if the bed is at the end of its travel by feedback from the motors.

It sounds like your calibration runs fine from points 1 to 4, then the machine issues the command to move the bed backwards. It is stuck or binding in the forward position, it cannot move so the printer reads this as "bed has reached end of travel" and believes the bed is in the right position to carry on calibration at point one when in fact it never moved from point four.

I have seen this in action myself. Check your bed can move smoothly and freely along the full length of its travel, especially when it is fully forwards.

Posted : 28/03/2018 7:50 am
beau.m
(@beau-m)
Trusted Member
Re: Auto calibration failing

Last night my printer threw itself out of alignment so bad it's driving the extruder into the bed super hard upon doing a "Z calibration"

So my latest issue is fixing my axis I suppose, which I tried but could not find any issues.

Posting mostly to see replies to possible fixes.

Posted : 28/03/2018 4:49 pm
none
 none
(@none)
New Member
Topic starter answered:
Re: Auto calibration failing

It doesn't try to move the bed forward at all, it just starts running the "point 1" routine while still sitting at point 4, then moves over to run the "point 2" routine while physically located at point 3, then it tries to move the bed back (lots of noise from the stepper motor for a few seconds) then it throws the error message.

I do not believe the issue is mechanical, as I can literally reach over, acknowledge the message, restart and the machine immediately homes all three axes without issue, and runs through the exact same calibration routine to fault at the same point. It seems like it is missing the command to return to position 1.

Posted : 29/03/2018 3:22 am
Kwaad2
(@kwaad2)
Honorable Member
Re: Auto calibration failing


It doesn't try to move the bed forward at all, it just starts running the "point 1" routine while still sitting at point 4, then moves over to run the "point 2" routine while physically located at point 3, then it tries to move the bed back (lots of noise from the stepper motor for a few seconds) then it throws the error message.

I do not believe the issue is mechanical, as I can literally reach over, acknowledge the message, restart and the machine immediately homes all three axes without issue, and runs through the exact same calibration routine to fault at the same point. It seems like it is missing the command to return to position 1.

So if you place your hand on the print bed, it has no humm, when it "should" be going to "step 1"?

Try to re-flash the firmware on your printer. I highly doubt a bit was corrupted when the printer was "flashed", but honestly, if what you are saying is true, that it is NOT trying to bring the print to where it should be at all, it could be possible.

Hi, I'm Sean. I used to work on CNC machines.
I try to not make mistakes, but the decision is YOURS.
Please feel free to donate to my filament/maintance fund.

Posted : 29/03/2018 3:45 am
none
 none
(@none)
New Member
Topic starter answered:
Re: Auto calibration failing

Yeah, that's all I can think to do at the moment. Have to wait till friday to do it though.

Posted : 29/03/2018 3:58 am
RH_Dreambox
(@rh_dreambox)
Prominent Member
Re: Auto calibration failing

It doesn't try to move the bed forward at all, it just starts running the "point 1" routine while still sitting at point 4, then moves over to run the "point 2" routine while physically located at point 3, then it tries to move the bed back (lots of noise from the stepper motor for a few seconds) then it throws the error message.

Your Y-belt is badly tensioned. This causes the drive wheel to slip over and can not pull the bed to the next position.
Then tension the belt one step on the belt bracket and calibrate again.
If you hear noise from the Z engine again, tighten the belt one step more.

Bear MK3 with Bondtech extruder

Posted : 29/03/2018 11:30 am
david.w5
(@david-w5)
Eminent Member
Re: Auto calibration failing


Your Z-belt is badly tensioned.

Z-belt?

Posted : 29/03/2018 11:45 am
RH_Dreambox
(@rh_dreambox)
Prominent Member
Re: Auto calibration failing

Y, I wrote wrong letter 🙂

Bear MK3 with Bondtech extruder

Posted : 29/03/2018 11:47 am
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