Calibration difficulties

[L Steyn]

Hi all. I have been struggling the past week with trying to get my Morgan calibrated. When moving, it doesnt seem like its going where its supposed to be going. It doesnt move in a straight line either. It almost appears as if one of the x/y motors is rotating more/ less than it is supposed to, causing the issue of not being able to move in only the x or y direction. If anyone experienced similar issues or know what the cause might be, please comment. Any help will be greatly appreciated.
L Steyn

[Quentin Harley]

Does not seem normal…

Please post the output of M503 here.

[L Steyn]

This is what I get:
>>>m503
SENDING:M503
echo:Steps per unit:
echo: M92 X430.00 Y430.00 Z100.00 E450.00
echo:Scaling factors:
echo: M365 X1.00 Y1.00 Z1.00
echo:Maximum feedrates (mm/s):
echo: M203 X300.00 Y300.00 Z300.00 E45.00
echo:Maximum Acceleration (mm/s2):
echo: M201 X400 Y400 Z400 E8000
echo:Acceleration: S=acceleration, T=retract acceleration
echo: M204 S9000.00 T3000.00
echo:Advanced variables: S=Min feedrate (mm/s), T=Min travel feedrate (mm/s), B=minimum segment time (ms), X=maximum xY jerk (mm/s), Z=maximum Z jerk (mm/s)
echo: M205 S0.00 T0.00 B20000 X10.00 Z10.00 E5.00
echo:Home offset (mm):
echo: M206 X0.00 Y0.00 Z0.00
echo:PID settings:
echo: M301 P22.20 I1.08 D114.00

I am unable to set the x offset after m360 because the arms are far from where they should be (the hotend is almost at the middle of the build surface) and i hit the build plate limitation before theta is parrallel to the platform.

Thanks for the help.
L Steyn

[Quentin Harley]

Does it not move far enough to reach it? You could increase the steps/mm somewhat. Try M92 x500 y500

[L Steyn]

Increasing the steps/mm doesnt solve the problem of it not moving in a straight line. I am able to reach a position where theta is parrallel though. When I try to get it to a 90deg position with m361 (the arms are olso far from where they are supposed to be), the value of theta stepcal decreases dramatically as I jog it towards the 90deg position. Just before stepcal reaches 0deg (still not in position), the arms start to rotate fast in a clockwise direction and I have to hit the reset button on the ramps to protect the printer from itself. Then I have to start all over again.

[Quentin Harley]

Can you come to h4h tomorrow night?

[L Steyn]

See you there!
Thanks a lot

[FuzzyFish]

I had the exact same issue, getting absurd calibration numbers. Seemingly random movements, sudden reversing, X/Y coordinates that made no sense etc.

Turned out the firmware provided, combined with the first RAMPS 1.4 wiring diagram I found on Google was moving the motors backwards in my case. Flipping the connectors around on both X and Y motors, and resetting everything back to defaults solved this. Next attempt at calibration was simple with no issues.

[Quentin Harley]

This is what I suspect. Only one way to find out…

[L Steyn]

Just an update. All of the problems in my case was caused by me forgetting to compensate for using pulleys with a much smaller diameter than those recommended. I tried calibrating the printer with initial steps per angle at 430 each which didn’t work at all. currently it is calibrated at 736 steps per angle and its working beautifully! Remember to adapt your software if you adapt the hardware!

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