lead screw settings
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Hello Everyone,
I've replaced a lerge x board with a duet2 ethernet on a Two Trees sapphire s.
So far I've got all axes homing correctly and the end stops set up.
X and Y moves the right amount but Z moves a lot more than requested.
I can't remember what I've entered in the reprap configurator for Z but I need to figure out how to change it.
As far as I know, I have a T8 leadscrew with 2mm pitch (hard to find the specs for it).
I would like to know how to figure out how to measure correctly and make the changes in the config file.Thank You
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Look up the motors, they'd be 200steps/rev and 1.8 degree or 400 steps/rev and 0.9degree.
Rotate the screw by hand 1 rotation; and measure how far the carriage moves.
Take the steps/rev*microstepping and divide by the movement (screw lead).
If you have 2mm lead*, 200 steps/rev and 16 microsteps (200*16)/2=1600 steps/mm.
*) if you have a multistart screw lead and pitch will not be the same, you want the lead - i.e how much travel does one rotation produce.
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Thanks.
I found Usongshine 17HS4401 has 200 steps/rev and 1.8°
I measured 8mm travel per rev.
I couldn't find the micosteps. -
@duettomio said in lead screw settings:
I couldn't find the micosteps.
its part of your config, most likely 16. look at your M305 line(s).
https://duet3d.dozuki.com/Wiki/Gcode#Section_M350_Set_microstepping_mode -
M350 Z16
So (200*16)/8=400
How do I set this in config?
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update the M92 line
https://duet3d.dozuki.com/Wiki/Gcode#Section_M92_Set_axis_steps_per_unit -
Right on. Z now moves exactly the requested amount.
Thank You!My next step is to mount the carriage with the E3d hot end.
So far I've used a dummy carriage holding a sharpie to simulate it.
I know I have to set the end stop again.
What is a good procedure to get it close to the bed and where should it stop?
All I know is to use the bed level screws to set the distance, but where is the starting point?Cheers
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not sure if this is the most applicable to your hardware, but I'd put the endstop at z-max, jog the z to be at the bed and run
G1 Z400 H3making sure the Z value is greater than the possible travel.https://duet3d.dozuki.com/Wiki/Gcode#Section_G0_G1_Move
H3 terminate the move when the endstop switch is triggered and set the axis limit to the current position, overriding the value that was set by M208.
maybe someone else will have another approach though.
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Thank you bearer for your help and pointing me in the right directions !
