First "working" version of new extruder prototype.

First “working” version of new extruder prototype.

This entire thing is 230 grams, that is without bearings, but I am using 3x 10mm IGUS RJ4JP, which add just 18 grams, so let’s say 270 grams with complete hotend.
I hope to cut down on weight even further by using non-metallic gears or by drilling out some material in the big gear (25 grams alone).

In this video I am running a torture test to see how hot the motor will get, not looking too bad yet, only ~60C which is not a problem for the nGen parts. I also have the stepper current set very high so there is plenty of headroom.

Then biggest thing I am not happy about with the design is how the rod is not at all secured in the Y direction, it seems to be okay but I am considering closing up the front hole.
I left it open so I could attach a knob for turning the extruder manually, but I may have to drop that.

Why is there so much space between the stepper and the hotend? It seems there are standoffs between these parts.

That is where the bearings go, I am using 10mm rod and the bearings OD is 19mm which means there is a bit of an offset.

If you are going to so much effort to reduce weight how about designing it for sf-1 bushings? Cad the holes 14mm. They always come out smaller for me. Then drill out with a 14 mm drill bit. First backwards so the bit doesn’t grab to much then forward to finish. I would love to see it milled out of aluminum to help with heat dissipation.

Hehe I’ve already ordered SF1s, but the IGUS bearings are already extremely light, so it’s more due to size. I’m hesitant to sacrifice the quiet operation of IGUS bearings though.

@Oystein_Krog SF-1s are quiet too.

Is there more info posted elsewhere about this drive? Has it been used to make parts yet? I considered these motors once but they didn’t seem to have much torque, not enough that could be made up in gear reduction in my estimation. But maybe I was wrong to write them off.

@Jeff_DeMaagd Yes the stepper has been used to print parts, see the link to the ultimaker forum.