Does this look infected?

[JohnnyRobot]

My M2 extruder drive gear has been like this as long as I've had my printer. But now, I'm starting to wonder... Is this normal?
https://www.youtube.com/watch?v=J4BybP6vzyA

[jimc]

yeah man its loose. tighten it. makergear gave you the little allen wrench for it. i dont even know how your printing like that. your retraction settings must be all screwed up. a little blue locktite on that setscrew might be in order.

man i thought i was going to see another quadcopter injury lol

[JohnnyRobot]

It's been printing fine... Still is, as I write this.

The thing is, my first impression was that it was loose (+/- 1 year ago). So I tried to tighten it. But it wouldn't go any further. I can remove the screw, and remove the gear, but when I put it all back together(and tighten), it has the play shown in the video...

Is there a shim or something that should be in there?

man i thought i was going to see another quadcopter injury lol

[jimc]

no the setscrew needs to just tighten down on the flat of the shaft. be sure the setscrew threads arent messed up. pull the drive gear completely off. using the hex key turn the setscrew so it threads completely through the gear and falls out the center. it should spin freely the entire way. it could be there is some old loctite on the threads already making it so it wont tighten down right.

its probably printing fine because you have your retractions setting jacked way up to compensate. once you correct the issue you will need to retune your settings for sure.

[JohnnyRobot]

Wow. What a difference that makes.

The threads were goobered up on the set screw. I reamed it all the way through a couple times and then it went through smooth. Tightened it up - Loctite Blue. Hopefully that's the end of that.

Retraction distance went from 4 - 6 mm to 2mm. no more globs on first few layers! I wonder if coasting will work now?

[jimc]

haha sounds about right.

[rpollack]

The newer extruder drive pulleys have a larger set screw that holds better. We still get them from SDP-SI but they have been very difficult to work with and our supply is tight at the moment. Once we have enough to put in stock, I'll post here.

If you know another company that makes small spur gears, please let me know.

Rick

[askernas]

Great, I have been looking to replace my extruder drive gera as well.

Blue Loctite has worked wonders in the past, but I've had issues cleaning out the grub screw, and I think my tiny Allen screw tool is starting to get a bit worn..

[nelsond6]

I was swapping out my hotend with the new v4 and noticed this exact same issue on my drive gear. I was not able to tighten it all the way, but its a little better then before.

-Dan

[triddle]

The newer extruder drive pulleys have a larger set screw that holds better. We still get them from SDP-SI but they have been very difficult to work with and our supply is tight at the moment. Once we have enough to put in stock, I'll post here.

If you know another company that makes small spur gears, please let me know.

Rick

I need a replacement filament drive gear. It is loose and the set screw is rounded out so I can neither tighten it down nor loosen it to remove the gear. I suppose I will have to drill out the set screw to remove it. Does anyone have a link to the new part with the larger set screw that Rick mentioned? I was able to find all of the other parts I need on the web site, but I couldn't find this one.