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Drew's Planetary Geared Extruder

by Ellindsey Dec 25, 2012
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really cool design for an extruder. I am currently making a rework to fit on the anet a8 frame. It keeps the gear setup and overall body of your design but adds a quick-release mechanism to the idler. I will comment again when all is finished, printed and tested.

Thank you for including the .scad sources!

Great work, I'm looking forward to trying this out.
Here's an easier to read list, and I already changed the R4RS bearings to R4-2RS per the comments.

6X R4-2RS bearings

1X 1614RS bearing

3X 625 bearings

4X 1/4" diameter,

1 1/4" long shoulder screws

4X hex nuts for the ends of the shoulder screws

1X 50mm M5 bolt

1X M5 hex nut

1X 50mm M4 bolt

1X M4 nut

2X washers to fit M4 bolt

1X spring to fit on M4 bolt, about 3/8" long

1X SMC KQ2H04-01AS push-fit connector

4X 6-32 flat head screws, at least 2" long

4X 6-32 hex nuts 8X 4-40 screws, at least 1" long

3X 4-40 screws, 1/4" long

9X 4-40 hex nuts NEMA 17 motor

4x M3 screws to mount the motor MK7 drive gear

does it work after one year? a Video would be nice :-) smuk

Still works well after a year! The only problem I've had is with the drive pulley slipping on the bolt I'm using for a drive shaft. Had to make my own keyed shaft with a file and dremel tool.

very cool, and thanks for the Video .. actually i have an nomal Extruder but i think about an bowden .. and this geard look very cool .. i will made a plan about this :-)

is the "R4RS" bearing a R4-2RS 1/4" inner, 5/8" outer, .196" height?

The bearings I used match those dimensions. I bought them as a batch off Ebay years ago, so I have no idea what the real specifications are or who the original manufacturer was. "R4RS" is what the tube of bearings was labeled with.

I would like to see something like this modified to work with the dremel bit extruder. Should really just require the top plate hole size change, space for a small bearing between the top plate and the dremel bit. The gear holder part will need a smaller hole and place for set screws to clamp down on the dremel bit. I might attempt it if I have a chance. Never done and mods this detailed.


No-hob extruder

What speeds are you able to print at with this gear ratio?

I have only tested it up to 60mm/sec so far. It should be able to print at 150mm/sec, I'll be doing further testing to determine just where the top end limit is now.

Further testing shows that it will print reliably at 100mm/sec. Attempting to print at 300mm/sec is not reliable, as the pulley slips against the filament at that speed.

This use could planetary gears could reduce the width of mobile extruders making multiple side-by-side extruders more practical or to allow for larger x travel. This is a very nice idea. This extruder clearly doesn't move much and that is very good, but your idea would serve even more in a moving x-axis print head system. :-)

Really tidy design, thanks for posting this :)