Big default "baby steps" - Duet

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wepollock
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Big default "baby steps" - Duet

Post by wepollock »

The Z baby stepping feature in Duet is set to .05mm+/- which seems to be a big default baby step for my purposes(a). I would like to have .01 or .02 baby steps. Where can that parameter be tuned?

Some more questions, notes;

1) Does it pay to add more test points in bed.g
2) Should you PID tune the bed? (how does the solid state relay come into play, cycles and pwm)
3) Should relative extrusion distances be checked in Simplify3d. (so far I am getting very good prints with a S3D I am tuning)
4) What should you lubricate the linear rails with (when needed)

I am currently printing a hard to print Octopus directly on a clean glass bed.
http://www.sublimelayers.com/2017/12/pr ... print.html
IMBoring25
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Re: Big default "baby steps" - Duet

Post by IMBoring25 »

Add M290 with your desired step in mm as an S parameter. http://reprap.org/wiki/G-code


I'll let someone who's with autolevel handle (1).

Some PID tune their beds. I've been happy with my results without even using PID. An SSR gets the high bed power currents off the circuit board and gives the option of using a separate power supply for it. RepRapFirmware now uses slow PWM on the bed circuit so it is theoretically compatible with an SSR, but again I've never seen the need for PID.

Your slicer and electronics should be configured the same way. I like relative extrusion coordinates myself and there have been some minor UI bugs in the past with absolute that may have been fixed by now.

I've always used 3in1 for my printer mechanisms and haven't had a problem.
dc42
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Re: Big default "baby steps" - Duet

Post by dc42 »

wepollock wrote:The Z baby stepping feature in Duet is set to .05mm+/- which seems to be a big default baby step for my purposes(a). I would like to have .01 or .02 baby steps. Where can that parameter be tuned?
0. I presume you are doing baby stepping in the web interface. Go to Settings -> User Interface and change "Z Distance per Babystep".

1. More probe points reduce the effect of a single point giving a bad reading. I use 16 points on my large Kossel.

2. Yes, otherwise it will use bang-bang control. Although with an AC mains powered bed heater, this is much less likely to cause Z banding.

3. We recommend relative extrusion, but you can use either. In your S3D start script, include M83 if using relative extrusion, or M82 if not.

4. I'm no expert on the finer points of lubrication, but I use white lithium grease.
wepollock
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Re: Big default "baby steps" - Duet

Post by wepollock »

Thanks DC.. modifying the interface was exactly what I was looking for because I wanted to fine-tune height in motion from the web interface.

I looked at the GCode generated by Simplify 3d and when you checkoff "relative extrusion" M83 is inserted into the instructions.
Also I have some number 2 white lithium grease, but I was thinking teflon, or silicon. I just looked at HIWIN and they have their own brand of NGLI 2. NGLI-2 it is.
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