Horrible print quality since upgrading
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If you use M350 to change microstepping after you have set the steps/mm with M92, the steps/mm will be adjusted automatically for you. Run M350 and M92 without parameters to check what the current microstepping and steps/mm are set to.
I am not familiar with the Flex3drive, but I spotted few things:
1. You have the motor current set very low. This suggests to me that you may have it set too low, or you may be using a high-inductance motor that can't reach the required speeds with the supply voltage you are using. See https://duet3d.com/wiki/Choosing_stepper_motors#How_to_work_out_the_power_supply_voltage_you_need.
2. You have quite a high maximum extruder speed (3000mm/min) in your M203 command. This may not be achievable.
3. You have very low extruder acceleration and extruder jerk set. These may adversely affect the quality when printing curves.
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What he said.
You an go higher with acceleration and much higher with jerk for extruder. Try 500ma current.
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They were the recommended settings by Jason who makes the flex3drive. Apparently lower current / jerk is better….
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Just for reference here is a 80mm box, you can clearly the diagonal lines. They are like little bulges (sorry - so hard to capture on camera clearly) It's a cyclic pattern.
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DjDemonD, you sent me these settings on another forum, let me give them a try…
[c]M92 E4130 ; 1.8 degree motor on 1/16th microstepping
M906 X1100 Y1100 Z1100 E800 I60 ;e motor current 800 (though I am lead to believe you can get away with as little as 500ma depending on the motor, lower is better I'm told)
M201 X3000 Y3000 Z200 E200 ;low E -accel to achieve faster reverses, go lower if your having stalling issues rather than upping the current
M203 X15000 Y15000 Z15000 E3600 ;max speed
M572 D0 S0 ; pressure advance off, although it might help to use a tiny bit like 0.025 to account for the twist in the drive cable but this is splitting hairs
M566 X1000 Y1000 Z1000 E100 ;low jerk value, higher than with nimble which I use 40 for, but then flex3drive is geared higher and therefore has needs less torque to start[/c]
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OK upped my acceleration and jerk to these below. Aside from the printer being a little noiser, not difference in quality
[c]M566 X1000 Y1000 Z1000 E100 ;low jerk value,
M203 X30000 Y30000 Z600 E3000 ; Set maximum speeds (mm/min)
M201 X500 Y500 Z100 E200 ; Set accelerations (mm/s^2)
M572 D0 S0 ;pressure advance off
M906 X800 Y800 Z600 E800 I60 ; Set motor currents (mA) and motor idle factor in per cent[/c]dc42 is the duet capable of 1/8 stepping?
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dc42 is the duet capable of 1/8 stepping?The gcode Wiki is always a good resource for these sorts of question - see here https://duet3d.com/wiki/G-code#M350:_Set_microstepping_mode
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I'm also had a similar issue. I think it's caused by the non-linearity of micro steps. From my calculation, the pattern is repeating every full step of the stepper motor. I also tried a 0.9 degree stepper motor instead of the 1.8 degree motor I was using, the length of the pattern halved. Stepper motor current does affect micro stepping linearity, you need to find the optimal value. You may also try replacing the extruder motor which worked for me.
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dc42 is the duet capable of 1/8 stepping?The gcode Wiki is always a good resource for these sorts of question - see here https://duet3d.com/wiki/G-code#M350:_Set_microstepping_mode
Ah so that's why even though I set 1/8 my steps didn't need to change. Thanks. Running a new test at 1/8….
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I'm also had a similar issue. I think it's caused by the non-linearity of micro steps. From my calculation, the pattern is repeating every full step of the stepper motor. I also tried a 0.9 degree stepper motor instead of the 1.8 degree motor I was using, the length of the pattern halved. Stepper motor current does affect micro stepping linearity, you need to find the optimal value. You may also try replacing the extruder motor which worked for me.
So are you saying it was the motor in the end that was causing the issue? Was it a failing motor?
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Just noticed this in the wiki
If using a highly-geared extruder (for example, an extruder that uses a flexible drive cable to transmit the torque from the motor to a worm reduction gear), use a short low-inductance 1.8deg/step motor to drive it.
I'm not too electrically minded, but this is my motor, is it suitable?
https://www.amazon.co.uk/gp/product/B01J3IKKHW/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
Size: 42*40mm
Weight: 279g
Voltage: 3.3V
Current: 1.5A
Power: 35W
Step Angle: 1.8°
Phases: 2
Resistance: 5.2Ω±10%
Inductance: 9.0mH±20%
Holding Torque: 4.0Kg ·cm
Detent Torque: 150g·cm
Insulation resistance: 500VDC 100MΩ
Insulation class: B
Rotor inertia: 57g ·cm² -
No. That motor is long and it has high inductance.
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I'm also had a similar issue. I think it's caused by the non-linearity of micro steps. From my calculation, the pattern is repeating every full step of the stepper motor. I also tried a 0.9 degree stepper motor instead of the 1.8 degree motor I was using, the length of the pattern halved. Stepper motor current does affect micro stepping linearity, you need to find the optimal value. You may also try replacing the extruder motor which worked for me.
So are you saying it was the motor in the end that was causing the issue? Was it a failing motor?
It's not failing, but it might not be the best option for your extruder.
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BTW, I reduced the steps to 1/8 but it made no difference. The diagonal lines had the same frequency
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Is there any way to revert to the original extruder setup, so that you can isolate the variables?
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Sure, i'll refit my old titan this evening and do some more test prints
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This type of motor works for me for both flex3drive/nimble and titan:
https://www.omc-stepperonline.com/hybrid-stepper-motor/nema-17-bipolar-18deg-13ncm-184ozin-1a-35v-42x42x20mm-4-wires-17hs08-1004s.htmlIts lightweight, and has enough torque to drive a geared extruder.
Long/large motors are needed when you need to achieve high holding torque, or to move a large heavy load such as a large 3 leadscrew bed etc.. for turning an extruder with gearing like 40:1 or 30:1 requires almost no torque at all. What more important is can you spin it up quickly and reverse it quickly.
The image with the cube above, does show what appears to be pulsing of the extruder, maybe this is the effect of the drive cable tightening and loosening as it turns. Grease it up and look at the path it takes to see if you can keep it from having to go around a tight radius.
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Yeah i'm not convinced I have the optimal route for the cable worked out yet. I've also noticed that the cable doesn't spin concentrically at the motor end. Not sure if this makes a difference or not or how I would fix this
https://photos.app.goo.gl/lTdTj8taKpn6q29Z2
The only other stepper I have kicking around is the one recommend for the titan
https://e3d-online.com/nema17-slimline-stepper-motor
but this is 0.9deg.
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I agree with bot, if its possible to split the issue to isolate the issue(s). I know people on this forum have had good success with flexible drives but minimising the number of variables changing at once can help to find the problem quicker.
