Which extruder to choose?

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sheepdog43

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3DRapidClone
I see! The 5:1 geared nema stepper is a bit over geared right? So it slows retraction a bit? Seen anyone try to gear it down to 3:1 if that's even necessary? Im hoping an astroyn damper will fit too but it probably won't due to it needing to be close together.

You would be doing double duty and getting the worst of both systems, the complexity, ineficiency, and hassle of a geared extruder, and the added cost of a geared stepper all to accomplish what you could do with just a geared extruder.

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hercek
That is the reason I use printed gears. 5:1 (common for geared steppeers) is too much. Your retract speed will be low (probably below 50 mm/s). My opinion is one should have retract speed at least 100 mm/s for ABS with 0.5 head.

I agree 3:1 is closer to ideal, but from a simplicity standpoint, the geared stepper is just so much easier to live with on a day to day basis.

If we could get a 2:1 or 2.5:1 geared stepper, I would jump all over it.

If you want a 2.5:1 ratio with no gears my modicum will do that if you change the 20T pulley for a 16T pulley. While my extruder is complicated, I feel the complexity is intimidating at first but worth it to me. I hate to double post but I just saw your desire for a 2:1 to 3:1 extruder. I feel the same way, I tried slanted gears in the past to reduce lash, it chewed my bearings up in 300hours. Then I tried to get my hands on a 000struder or whatever its called, and saw the price of the 60T pulley + the amount of work to convert it to bowden was not worth my time as well as the 5:1 ratio.... I figured I could design my own, after a dozen iterations I feel this one works very well for my needs. The filament pushed is very close to the feed gear and basicaly has no place to escape and become a tangled mess, I suspect this thing will push flexible filament with no issues through a bowden setup. This setup will chew right through filament if I use a vice to clamp it down. With proper fittings I reduced the retraction length and increased retraction speed. All a function of the belt drive. Its also much quieter than any geard extruder... I have since melted my airtripper extruder as well as my geared extruder for ABS goop.

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StickyLube
@AndyCart

About the Gerg's Wade extruder..do you know if someone is selling an entire kit for assembling it?
Cos all I have found till now are thinginverse designs, and I am not even sure which one is the most reliable for 1.75mm filament.

Check out my Cherry Pi IIIS 'thing' on Thingiverse [www.thingiverse.com] all the plastic parts are there. In addition you will need a NEMA 17 stepper, a hobbed M8 bolt and nut plus some M8 washers, 3 x 608 bearings, a 1/8 BSP 4mm pneumatic fitting, a 30mm x M3 screw, 2 x 50mm x M3 screw, 4 x 8mm x M3 screw, 4 x M3 nuts and two springs. The design is meant for mounting on 2020 extrusion. There are various pictures of it on Thingiverse and the Cherry Pi thread.

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Edited 1 time(s). Last edit at 03/13/2015 10:06AM by jmf.