One Extruder Motor for two filaments

mcole

We have a 10 year old Stratasys printer here, and one of the many boards in the back has died - probably the main power board. With the cost of someone coming out to repair it, we might as well replace it with something new, (and the trade in value was minimal) so a hobby printer it has become.

I want to convert it to be Duet controlled like all my other printers, and the thought of 110VDC for the heaters scares me, so a retrofit of just the control board does not make sense.

Happy to design and fabricate a new print head, but want to keep the clever mechanism for swapping print nozzles. At the moment they use a single DC motor and encoder for driving both material and support. I would like to swap that to be a stepper, but am not sure how to configure that in software.

Is it even possible? One motor to rotate clockwise for main material, and anti-clockwise for support?

TIA.

sebkritikel

@mcole Which Stratasys model? 1200, 768, uprint, etc? I have a 1200es BST I've been mulling over retrofiting using the info below.

Check out these posts by @Archeantus , they were able to do a fully reversible retrofit on a uprint, using the original tool head parts, steppers, etc, bypassing the original Stratasys electornics boards.

https://forum.duet3d.com/topic/12647/another-stratasys-uprint-retrofit/42

Wiring diagrams, Duet configuration files and whatnot on Hackaday
https://hackaday.io/project/186419-dueprint

For the extruder motor, if I recall correctly, the direction switches on tool changes, and the motor itself is contolled by a Geckodrive G320x via the Duet 2 board. Something similar could likely be done with a Duet 3 (I think the Mini can send step/dir, otherwise a 1XD board should work).

deckingman

@mcole said in One Extruder Motor for two filaments:

Is it even possible? One motor to rotate clockwise for main material, and anti-clockwise for support?

Well changing the motor direction is certainly doable. It's the "S" parameter in M569. So you could use M569 Pn S0 in one tool change macro (say tpost0.g), and M569 Pn S1 in the other tool change macro (say tpost1.g).

mcole

@sebkritikel said in One Extruder Motor for two filaments:

Which Stratasys model? 1200, 768, uprint, etc? I have a 1200es BST I've been mulling over retrofiting using the info below.

It's a Fortus 250MC, about 9 years old. It's been a workhorse for us and produced prints almost every day for all that time, so it certainly doesn't owe anyone anything, but the motion system is so nice I want it to live again.

@sebkritikel said in One Extruder Motor for two filaments:

Check out these posts by @Archeantus , they were able to do a fully reversible retrofit on a uprint, using the original tool head parts, steppers, etc, bypassing the original Stratasys electornics boards.

I've been searching through here (before posting, as I'm sure I'm not the first person to try this), but I think it's our PDB that has blown. Hard to be sure as there is a lot going on in there. The 5V PSU wasn't working, so I replaced that, but not sure if it was a symptom or the problem, as now the SBC in there continually beeps.

@deckingman said in One Extruder Motor for two filaments:

Well changing the motor direction is certainly doable. It's the "S" parameter in M569. So you could use M569 Pn S0 in one tool change macro (say tpost0.g), and M569 Pn S1 in the other tool change macro (say tpost1.g).

Rebuilding the head at the moment to take Revo hot ends, but will try that - thank you.