1LC gcode for stepper application
-
I’ll try and explain this the best I can…
I am looking at prototyping a 4 nozzle toolhead. It will not be extruder direct driven at the toolhead, but using Bowden tubes with 4 remotely placed filament extruders, driven from the main board.
I would like to use 4 1LC boards on this toolhead to run the 4 hot-ends. I would also like to use the 4 1LC boards stepper drivers to each momentarily drive a NEMA 8 stepper motor that physically repositions each hot-end when it is time for that hot-end to print, or finished printing.
Theoretically I know this should be possible through the g-code. Would there be any foreseeable issues using the 1LC boards for this purpose?
-
@br7408 that sounds workable. Of course a custom hot end board that can drive all four heaters and the associated fans would be preferable.
Duet WiFi hardware designer and firmware engineer
Please do not ask me for Duet support via PM or email, use the forum
http://www.escher3d.com, https://miscsolutions.wordpress.com -
@dc42 I'm revisiting this design now and clearly seeing your logic here... I just can't seem to figure out a better alternative. It would have to be a fully custom board. I feel like it is kind of a waste running 4 1LC's, but I cannot see any alternative. The end capability would certainly be worth the hassle.
-
@br7408 Just for info, I used to run 6 into 1 hot ends before tool boards were available. Initially I used two 3HC expansion boards mounted on the same carriage as the extruders (I used a second XY gantry to keep the Bowden tubes short, so the machine was a CoreXYUV). When one of the 3HC boards expired, I changed the design to use a single 6HC board as an expansion board which replaced the two 3HCs.
I don't know anything about your design but if you use 4 toolboards, you'll likely need a tool distribution board as well so another option might be to use a 3HC plus one toolboard. It might be easier to package. Or even a single 6HC as an expansion board. You might end up with less redundancy. -
@br7408 an alternative would be running an rp2040 based custom board. That can handle up to 4 temperature sensor inputs so may well be just the thing
Owns various duet boards and is the main wiki maintainer for the Teamgloomy LPC/STM32 port of RRF. Assume I'm running whatever the latest beta/stable build is
-
@br7408 a single Mini 5+ as an expansion board would also work, and would have enough stepper drivers (5) and temperature input (3) adding a single temperature daughterboard to get a 4th temperature input (this would be a PT100 or thermocouple).
Ian
TronXY X5S with Duet 3 MB6HC and Roto toolboard : Cartesian bed-slinger with Duet 3 Mini 5+ WiFi and 1LC : RRP Fisher Delta v1 with Duet 2 Maestro : Polargraph with Duet 2 WiFi
-
@droftarts I'm going to need to run one additional board to control the 4 stationary extruders, so an additional Mini 5+ seems the best option there. On the printhead itself, I could run 4 1LC boards with a distro board for now... It will be like surgery hooking each one up, but I will design them as fully modular replaceable units. The form factor is no big deal as this printer is huge anyways. I am also trying to maintain tool changer capability with only the CAN and VIN wires going to the printhead. This is going to be a substantial undertaking, so when I'm not running this setup or testing it during the design phase, I can fully remove it and continue to use the printer with my other toolheads.
-
@jay_s_uk said in 1LC gcode for stepper application:
@br7408 an alternative would be running an rp2040 based custom board. That can handle up to 4 temperature sensor inputs so may well be just the thing
I will have to look into that.
-
@deckingman said in 1LC gcode for stepper application:
@br7408 Just for info, I used to run 6 into 1 hot ends before tool boards were available. Initially I used two 3HC expansion boards mounted on the same carriage as the extruders (I used a second XY gantry to keep the Bowden tubes short, so the machine was a CoreXYUV). When one of the 3HC boards expired, I changed the design to use a single 6HC board as an expansion board which replaced the two 3HCs.
I don't know anything about your design but if you use 4 toolboards, you'll likely need a tool distribution board as well so another option might be to use a 3HC plus one toolboard. It might be easier to package. Or even a single 6HC as an expansion board. You might end up with less redundancy.I actually thought about running an extra gantry, but I have enough room and a good mounting location for the extruders where they should be able to remain stationary.
-
@br7408 My main reason for using a second gantry was to keep the Bowden tubes as short as possible. They were about 150mm in length but if I'd mounted them on the frame (it's a largish printer), they would have been closer to a metre in length. My first attempt was to have the gantry passively driven by loosely strapping it to the hot end gantry but that wasn't very successful so I changed it to a driven gantry. AFAIK, that was the world's first CoreXYUV and the Duet guys made the firmware allowing both gantries to be homed individually. After homing, the UV motors were mapped to the XY axis so from a slicer point of view, it was just a CoreXY. Later on, I did some tricks with motion planning such that the UV gantry followed the XY gantry but within a tolerance of about +-30 mm. This meant that when printing circular features with radii less than 30mm, the extruders could be "parked" in the centre while the hot end printed the feature. But this is all digressing away from your OP
