Filament drive instead of belts

[hoff70]

Belts can be expensive as well as hard to find and the same can be said of machined pulleys. My current printer is a Rostock which uses timing belts but a lot of progress has been made with filament drives for delta bots. The Kossel comes to mind in case anyone wants to search and check it out in action.

Anyway, I figure the Morgan would be a good candidate for a filament drive plus the drive wheels shouldn’t require any modification for it. Perhaps use the existing slots or drill some small holes in the rim for the filament to pass through.

Here are some filament pulleys I reckon would work:

http://www.thingiverse.com/thing:34116

I may print a couple and experiment myself!

[Quentin Harley]

Check out the light branch in the morgan repository… Already a work in progress!

[hoff70]

OK, Found the files. I really need to learn openscad.

[hoff70]

I went ahead and printed the Kossel pulleys:

I may have to fidget with the height a bit but it will be fun to mess with!

[jade39339]

Hmmm, it would seem you would need to keep the filament under some kind of tension at all times to make sure it feeds (winds correctly around the spindle). Otherwise you run the risk of the filament not spooling correctly on the windings. I could see this possibly working if the motor was mounted on the top frame and at a 90 degree angle. That way in theory the filament could naturally made to be always under tension. You would need to add a pulley at the base of the drive wheel to affix it to the drive wheel.

My 2 cents!

[hoff70]

Good point Jade. I’m hoping that just the tension provided by the adjustable bracket will be enough. I’m thinking that since the string will not have to wind around the drive wheel it will, hopefully, stay in the capstan grooves. I did a mock-up here:

And it seems pretty stable moving it by hand. Under power may be a different story!

This deal is a must-have for stringing though:

http://www.thingiverse.com/thing:36366

[jade39339]

Usually, in systems like you pictured above. Between the motor and the drive wheel is a tension-er pulley setup like on old reel-to-reel tape recording systems used to always keep the tape under tension. I’d copy what they’ve done there, because it works and prevents backlash of the tape(filament) in this case.

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