Multi-material filament feeder/repurpose E1 stepper driver

jckray

I'm working on a multi-material feeder kind of like the Prusa MMU 2.0. I hoping to use the second extruder motor driver on the Duet 2 Wifi to run a stepper with a lead screw that moves the filament selector in front of the correct filament bay (I have attached an image to make this more clear).

I'm wondering what I need to do/if it is possible to repurpose the E1 driver for this. Right now the driver is temperature controlled in that is won't move unless the hotend is above a certain temp. I also need this driver to use absolute positioning.

dc42

I suggest you configure the extra motor as an additional axis instead of an extruder. You can hide the additional axis most of the time using the M584 P parameter, and make it visible only in the homing and tool change files when you need to move it.

jckray

Great thanks! That worked perfectly

zblairq

looks pretty much like this

https://www.thingiverse.com/thing:2893483

jckray

@dc42 This worked great. I have another question related to my filament feeder.

I am using a limit switch as a filament presence detector. Is it possible to set up a command to extrude until the switch is triggered?

jckray

@zblairq Yes I have seen that project. My goal is to make a much simpler less expensive filament feeder that works with a 5 driver board like the Duet 2 WiFi so that no break out boards are needed.

I have my project on Thingiverse https://www.thingiverse.com/thing:2992637

zblairq

@jckray its my work. remember its licensed gpl

zblairq

but im happy to have inspired you on your cloned design. if you wish we may share some options about it.

jckray

@zblairq I would be happy to chat with you about this, although it's a little off topic for the purposes of this thread. You can email me at johnkray@hydraresearch3d.com

dc42

@jckray said in Multi-material filament feeder/repurpose E1 stepper driver:

@dc42 This worked great. I have another question related to my filament feeder.

I am using a limit switch as a filament presence detector. Is it possible to set up a command to extrude until the switch is triggered?

The only type of "endstop" officially supported for extruders is stall detection, allowing you to extrude until motor stall. However, there may be a way to achieve what you want. Create another dummy axis, without any real motors (e.g. specify driver 11) and use the filament switch as the endstop for that axis. If the new axis is U, use a command such as G1 S1 U1000 E1000 Fxxx. Caution: I haven't tested this.

fma

@jckray, nice to see that you drive your design with a Duet

adam2070

Looks really interesting, i will keep an eye on this, I like the idea of a completely duet compatible solution.

Red Sand Robot

@jckray Looked at your project on Thingiverse and left a comment, but figured I might as well reach out here as well; definately interested in building one of these for myself.

Once you get firmware working I would be happy to test it as well and give some feedback. If you have a semi-complete BOM I'm sure I could find most of the stuff I would need lying around in the engineering dept. building at my university.

jckray

@red-sand-robot We are currently reworking it to include a filament cutting mechanism as we have been experiencing issues with loading due to a bad tip on the filament about 2-5% of the time. More info will be coming to the Thingiverse page fairly soon, we are very busy so it is hard to always keep everything up to date. We do not have a specific BOM for the filament loader as is is combined into the BOM for the printer we are developing. We can probably get a rough BOM for the loader at some point when we have time. The only challenging part is the stepper motor with the really long shaft. We had to have this custom made.

If you are interested in what we are doing, there is also information on our website https://www.hydraresearch3d.com/nautilus/

fma

I get very nice tip on PLA by removing filament with this macro:

G1 E-5 F3600
G1 E2 F3600
G1 E-47 F3600
G4 P5000
G1 E-100 F3600

I'm about to test my own version of filament multiplexer, but I'm a bit lost with the configs. Would you mind sharing yours?

jckray

@fma We have a fairly similar unload script, however, we are still having issues with consistency across all material types, specifically breakaway supports from E3D. I'm hoping to have updates on our progress including the config and scripts we are using some time next week. You can check our website and our Thingiverse page for updates, links below.

https://www.hydraresearch3d.com/nautilus/
https://www.thingiverse.com/thing:2992637

fma

Ok, thanks.

Where does the jam occur? Between the loader and the carriage?

jckray

@fma In occurs when loading the filament back in when right as the filament enters the nozzle. Some filaments, the breakaway in particular, have a slight bulge at the tip after unloading.

jckray

@red-sand-robot A supper rough BOM is now on our Thingiverse page along with updated files https://www.thingiverse.com/thing:2992637

gavatron3000

did the knife improve reliability? ive seen the prusa mmu2 struggle with the E3d breakaway also in videos

jckray

@gavatron3000 I have not tested the e3d breakaway since adding the cutting mechanism. I have had it up and running with the blade for a day and a half now. So far reliability is much better. I will let you know how the breakaway supports go once I have tested them.

fma

Where did you put the cutter? On the loader carriage, as Prusa did?

jckray

@fma Yes, it's on the carriage. I'll see if I can get some pictures.

jckray

@fma the cutter is using a standard Xacto knife blade. Here are some pics

fma

I'm thinking to add a cutter under the extruder. This way, cut tips stay in the hotend, and are pushed again by the new filament during the purge, so no need to evacuate them. Ideally, it would be nice to be able to cut the filament when it is still soften, above the melt chamber, but I don't think ti would be easy...