just installed duet and no good joy for me

Printer was printing fine with ultimaker arduino combo but I wanted "modern electronics"... So i upgraded to duet and dc42 firmware and spent two solid days trying to get a print. Travles are nice and smooth, endstops correctly set. Motor current set at 650. Belts tight everything normal but the layers are aweful and look like my prusa when it skips and shifts the layers.

Printing 20x20x20 cube the corner where it layer shifts is really bad.

Also uploading large file is hopeless. The upload speed is pathetic. Any suggestions?

Edited 1 time(s). Last edit at 09/18/2015 09:06PM by thetazzbot.

Quote
thetazzbot
Printer was printing fine with ultimaker arduino combo but I wanted "modern electronics"... So i upgraded to duet and dc42 firmware and spent two solid days trying to get a print. Travles are nice and smooth, endstops correctly set. Motor current set at 650. Belts tight everything normal but the layers are aweful and look like my prusa when it skips and shifts the layers.

Printing 20x20x20 cube the corner where it layer shifts is really bad.

Also uploading large file is hopeless. The upload speed is pathetic. Any suggestions?

What upload speed do you get?

I get between 200-300kb/s, mostly ~220kb/s.

Could you provide a picture on the printed part and maybe you config.g?

650mA sounds rather low. What motors are you using, and what sort of extruder do you have? What motor currents were you using with the old electronics?

Edited 1 time(s). Last edit at 09/19/2015 03:12AM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

If you are getting layer shifts, make sure your end stop cabling is separate from your stepper cabling.

If not, stepper signals can crosstalk onto the endstop wiring, causing false endstop events during the print.

3v duet signaling is much more susceptible to this than 5v arduino signaling.

Quote
Ezrec
If you are getting layer shifts, make sure your end stop cabling is separate from your stepper cabling.

If not, stepper signals can crosstalk onto the endstop wiring, causing false endstop events during the print.

3v duet signaling is much more susceptible to this than 5v arduino signaling.

Not true. Like most other firmwares,RepRapFirmware uses the endstop switches (which are better referred to as homing switches) for homing the printer only. So noise on the switch wiring cannot cause layer shifts. I have never heard of anyone getting false endstop triggering using a Duet. The Duet is a lot less susceptible to noise on the endstop wiring than Arduino/RAMPS, because it has filter capacitors on those connections whereas RAMPS has none..

The usual reason for layer shifts on a delta printer is that the nozzle has hit a blob or bump, and this has caused a motor to skip steps. This is particularly likely if the motor current is too low. Which is why I asked what motors the OP is using, so we can tell whether 650mA current is too low.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Thanks for the correction about the Duet signaling - I was not aware of the filer capacitors on the endstop lines, and was going only by my prior experience with 3v electronics and crosstalk.

Yes, with endstops no longer in the picture, blob jams seem most likely.

Quote
Ezrec
Thanks for the correction about the Duet signaling - I was not aware of the filer capacitors on the endstop lines, and was going only by my prior experience with 3v electronics and crosstalk.

Yes, with endstops no longer in the picture, blob jams seem most likely.

To expand: there are two types of crosstalk that could affect endstop signalling.

Capacitive crosstalk could cause a switch to read closed when it is open if the homing switch wires are routed near the stepper motor wires.. This is one reason why it is a bad idea to use normally-open homing switches with RAMPS, because it could indicate that a switch has been triggered when it hasn't, thereby causing a homing move to terminate prematurely. Capacitive crosstalk can be reduced by using shielded cable.

Inductive crosstalk is unlikely to be a problem in RepRaps. If it was really bad then it could cause a closed switch to read open. It can be reduced by using twisted pairs for the stepper motor and/or homing switch cables.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Inductive crosstalk was an issue with my Geeetech (whee!!) Delta - the endstop signals were untwisted and in the assembly manual are pictured as routed with the extruder steppers.

And normally open to boot!

Just the absolute worst possible config.

On a lark, and since I was working on an assembly tips page, tried it out "as specified in the manual".

As expected on RAMPS, layer shifting everywhere.

My setup is now twisted pair, normally closed, routed separately from the extruder steppers, as is common and sane practice.

No more layer shifting, even with Repetier set to constantly monitor the endstops.

its not hitting a blob. it was just shifting entirely on one axis... if looking at the printer, X tower on left, Y on right, Z at the back, the layers shifted to the back.

The current setting is about 50% of the motor's rated. figured it was a good starting point. i'm printing in white otherwise would take a picture. White is very hard to photograph

Please print in a different colour that you can photograph then. Also confirm which firmware version you are using.

You still haven't told us the motor type you are using. Half the rated current may be enough for long high-torque motors, but not for shorter motors.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

I have just released new firmware version 1.09k-dc42. It's just possible that one of the fixes in it may relate to your layer shifting problem, if you are using absolute extruder coordinates and are currently running version 1.09j-dc42. So I suggest you upgrade to 1.09k. But I still suspect that you have your motor currents set too low.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Up to 1.4a

[vi.raptor.ebaydesc.com]

Quote
thetazzbot
Up to 1.4a

[vi.raptor.ebaydesc.com]

For those motors, I suggest you use between 800mA and 1A.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].