my rotary extruder 1 drive upto 4 hotends

this is my rotary extruder been using it 1.5 years. so i thought i share it. i can put 4 hotends on but only have 3 now. its using standard ramps 1.4 with custom marlin. ext 1 drives filament ext 2 rotates extruders. i did have to add thermistor and heater to ramps. a servo lifts drive to rotate.

the table bearing is 618 nylon rings the rest is pla and petg.

prints multi material without need for waste tower. i use just 2 at a time for pva support or just 1. i have a 0.4, 0.6 and 0.8 nozzle so i dont have to change nozzles i have a hard time changing nozzles.

it is on the heavy side about 900g as i have it now. could be made lighter with cable drives though.

i have the unused nozzles parked with a antidrip over nozzle. still i get some ooze but with better retraction settings it could be much better.

i slice it in slic3r just like any multi material firmware takes care of rest. any slicer should work.

i have not posted files anywhere if there is interest i can.

here is a video of it working
[youtu.be]

Edited 1 time(s). Last edit at 07/21/2018 12:11PM by jm44807.

Very nice. I have always felt that the best way to do multi materials is to change the hotends on the fly as you do. I like the way you use only one motor to drive all the extruders but I would like to know how you get the motor gear to align with the stepper gear when the change is made. Looking at the video the drive gear seems to lift away before the change but how is this done?.
Having the nozzle and hotend moving into the common printing position has advantages in being able to use different materials needing different temperatures as well as avoiding scraping the unused nozzle across the print or dribbling plastic from the inactive nozzles..
I have made several attempts to do the same although without luck so far - my latest has two hot ends on a toggle mechanism although very different to the Stratasys toggle method. I hope to do a write up when it is working reliably.

Mike

Erased

Edited 1 time(s). Last edit at 07/22/2018 09:46PM by Holy1.

i use a servo to first pivot the whole drive motor up. its not directly connected to motor just pushes it up. when servo lowers it there is a spring that pulls it down so its floating. because of direction it turns the gear engaged pulls down on motor so the gear doesnt slip at all. this was a accident but works well. if hotend jams the motor will miss steps or strips filament.

the stepper turns the table in firmware you can adjust the angle it moves. i can adjust it to line up with drive gear it is basically 90 degrees. i then use slic3r to fine tune nozzle alignment. as you can see right now they are off a little bit.

WOW, you have really developed that idea well. I am sure you are proud of getting it working. Very nice work, you must have put a lot of thought and trial and error into it.

It reminds me of a revolver, maybe call it dirty Harry, or peacemaker?

A team of designers could smooth out the bumps, maybe throw in a circuit board, more logic and really complicate it, but you have a working unit. Great Job!

alot of trial and error lots of error lol. yea i was hoping someone could refine it some.

here is a better quality vid and i fixed a scraper that had come loose and refined retraction a bit now much less oozing.
[youtu.be]

Neat. Quite an engineering challenge to get all the hot ends to end up with the same XYZ offsets but you seem to have managed it well. One quick question - does the mechanism always rotate in the same direction or does it move back and forth? Just thinking that if it always moved say clockwise, it's going to plait the filament.

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it rotates both ways or the wires would get twisted