Problems with sensorless homing
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; homeall.g
; called to home all axes
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; generated by RepRapFirmware Configuration Tool v3.1.4 on Sat Sep 26 2020 16:50:18 GMT-0600 (Mountain Daylight Time)
M400
M913 X70 Y80 ; drop motor current %
M400 G91; relative positioning
G1 H2 Z5 F12000 ; lift Z relative to current position
G1 H1 X-305 F6000 ; move quickly to X and Y axis endstops and stop there (first pass)
G1 H2 X5 F6000 ; go back a few mm
G1 H1 X-305 F3600 ; move slowly to X and Y axis endstops once more (second pass)
G1 H1 Y-305 F6000 ; move quickly to X and Y axis endstops and stop there (first pass)
G1 H2 Y5 F6000 ; go back a few mm
G1 H1 Y-305 F3600 ; move slowly to X and Y axis endstops once more (second pass)
G90 ; absolute positioning
M400
M913 X100 Y100 ; return current to 100%
M400
G1 X130 Y150 F6000 ; go to first bed probe point and home Z
G30 ; home Z by probing the bed; Uncomment the following lines to lift Z after probing
;G91 ; relative positioning
;G1 Z5 F100 ; lift Z relative to current position
;G90 ; absolute positioning -
; homey.g
; called to home the Y axis
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; generated by RepRapFirmware Configuration Tool v3.1.4 on Sat Sep 26 2020 16:50:19 GMT-0600 (Mountain Daylight Time)
M400
M913 Y90 ; drop motor current to 90%
M400 G91; relative positioning
G1 H2 Z5 F6000 ; lift Z relative to current position
G1 H1 Y-305 F6000 ; move quickly to Y axis endstop and stop there (first pass)
G1 H2 Y5 F6000 ; go back a few mm
G1 H1 Y-305 F3600 ; move slowly to Y axis endstop once more (second pass)
G1 H2 Z-5 F6000 ; lower Z again
G90 ; absolute positioning
M400
M913 Y100 ; return current to 100%
M400 -
Thanks. Can you also send M115 and confirm your firmware version?
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It’s a completely new setup, I deleted the old files and did a restore to 3.1.1 for my initial setup then used the web configuration tool to generate the setup and then made the changes I needed.
Date Event
2020-10-25, 2:29:19 PM M115
FIRMWARE_NAME: RepRapFirmware for Duet 2 WiFi/Ethernet FIRMWARE_VERSION: 3.1.1 ELECTRONICS: Duet WiFi 1.02 or later + DueX5 FIRMWARE_DATE: 2020-05-19b2 -
@c-bldwn said in Problems with sensorless homing:
M913 X70 Y80 ; drop motor current %
@c-bldwn said in Problems with sensorless homing:
G1 H1 X-305 F3600 ; move slowly to X and Y axis endstops once more (second pass)
@c-bldwn said in Problems with sensorless homing:
M913 Y90 ; drop motor current to 90%
First. The motor current you're dropping down to is inconsistent. You will need to find the absolute lowest current you can use and still get reliable motion. Having low current is critical to getting a reliable stall.
Second. Don't do multiple passes when using stall detection homing. The stall is going to be most reliable on a fast pass. Once it hits and you back off slightly and then slowly try to stall again it's never going to work as well as the first fast pass. There is no accuracy gain here as there might be from multiple slower passes on an endstop. The stall is going to snap to the nearest motor full step.
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Maybe that’s something that should be also changed in the web configuration tool as that is not something I added. I had my concerns about that as I know you don’t generally want it and I had removed it on my other printer still running marlin but left it in as I figured maybe duet had a reason for it. How can I find out the best current setting, I’ve tried between 40% and 90% in increments of 10 already and didn’t have any luck. Here are my motor specs.
Motor Model 42HS1411-20B19
Step Angle(°) 1.8
Holding torque(mN.m) 280
Rated current(A) 1.5
Rated Voltage(V) 3
Resistance per phase(Ω) 2.1±10%(20℃)
Inductance per phase(mH) 2.5±20%
Mass 0.2kg
Rotor inertia(g.cm²) 45
Insulation Class: B
Ambient Working Temperature Range(℃) " -20 to + 60℃ "
"Temperature rise MAX (rated current, 2 phase on) (℃)" 80℃ -
@c-bldwn said in Problems with sensorless homing:
How can I find out the best current setting
For normal operation to recommendation is to use 60-85% of the rated max current for the motor.
So 1500 max * 60% = 900
or 1500 max * 85% = 1300And in your config you have 1000ma, which is fine.
To find the lowest current for reliable movement, simply use M913 to lower it down to the lowest you can still get movement.
Try M913 X10 and try to move the X axis around with the jog buttons. Try blocking it with your hand. If it sometimes stalls without any effort on your part, increase it to X20. etc.
Do the same for the Y axis.
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Oh I forgot to mention before switching to duet, on the factory arduino 2560 mega board with tmc2209 drivers I was running the Y axis at 1000ma normal and 50% of that for homing and didn’t have any issues before.
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Doesn't really matter. Once you drop the current and do a single fast homing move stall detection should improve.
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Ok so I tested as you reccomended, got best results with X60 and Y90. I ended up bumping The current up for the Y from 1000 to 1200 and tested again and found Y80 to work well. I then had to up the Y threshold to 5 to get it to move and seems to work as expected when it hits the home. However I’m still having issues with the y axis wanting to go the wrong direction sometimes. I bumped the threshold up to 7 and seems to be more reliable. I’ll test this out a bit and let you know if I’m still getting the problem or not.
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This post is deleted! -
Ok so after testing for a bit last night and today my problem seems to be fixed. Thanks for the help!!