david.t11
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MK3 Self Test Fails - X Axis Length

Sun Feb 18, 2018 2:51 am

Hello,

I just finished building the MK3 kit and the self test is failing with a "X Axis Length" error. During the test, the extruder carriage just jitters a tiny amount in both directions, but the stepper motor doesn't even make a full rotation and the carriage stays in the center of the printer. If I go to the settings and try to jog the x-axis in one direction, it does the same thing and the carriage and motor both just jitter slightly back and forth.

With the printer turned off, I verified that I could move the extruder carriage left and right with my hands just fine and the belt moves freely and smoothly. I tried completely unscrewing the x-axis stepper motor and laying it down next to the printer so that there was absolutely no load/belt on it. Even then, when I try to jog the x-axis, the stepper motor just jitters back and forth and the shaft doesn't make a full rotation.

Does anyone have an idea of what might be going on?

Thanks!

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joan.t
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Re: MK3 Self Test Fails - X Axis Length

Sun Feb 18, 2018 8:40 am

Hi David,

there are no end stops on the mk3... it uses motor current to detect an obstruction to identify the extremes of motion, perhaps you have too much drag on the assembly
with the power switched off, try lubricating the rails and moving the X carriage from side to side to distribute the lubricant and retest, if this doesn't work,

try removing the X motor and see if it runs without the belt fitted, if this doesn't work,

try swapping the X and Y motor connections on your einsy, if the same motor is faulty on both controllers, it could be a motor fault
if the fault moves to the other motor, it could be an einsy controller fault,

if the fault disappears, it could be a poorly seated connector... regards Joan
I try to make suggestions that I believe to be well founded and safe,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.

david.t11
Posts: 6
Joined: Wed Feb 15, 2017 4:12 pm
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Re: MK3 Self Test Fails - X Axis Length

Sun Feb 18, 2018 9:48 pm

Joan,

Thanks so much for the reply and advice! It's interesting, I first tried to remove and reinsert the x-axis motor connector to confirm it was seated well and I ran into the same problem. I then swapped the X and Y-axis motor connectors and both motors then worked. I then swapped them back to the normal positions and then both continued to work. The printer is up and running now and test prints are working!

I'm assuming that the x-axis motor connector was just seated poorly, although I'm still not clear why it required two tries to get it seated properly. I'll have to keep a close eye on it, but it appears to be working right now.

Thanks again!

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