H-1 Extruder Slippage

[TomCircuit]

I'm making some progress again with my H-1, but seem to be running into problems with the Direct Drive Steve's Extruder - it seems to "slip" a lot, particularly when feeding at low rates.

The large white reduction gears, outside the frame, are turning fine - but the metal rollers do not always seem to want to roll. If I make the tension really light, I can get them to roll, but then the filament doesn't feed reliably. If I increase the tension, I'm back to the rollers not wanting to roll. When the rollers are not rolling, neither are the small gears inside the frame. At all times, however, the large reduction gears external to the frame are rotating properly.

I have to admit that even while I was assembling the extruder, I was a bit mystified as to how the reduction gears actually transferred power to the rollers. So, maybe my lack of faith is influencing the performance?

At this point, I think I'm looking at tearing down the extruder and re-building. I've ordered the new black frame pcs to replace the clear pcs that came with my H-1 kit last summer. Anticipating the re-build, I figured I might as well upgrade in the process. Any suggestions during the re-assembly? Something to pay attention to that I might have missed the first time around?

Thanks in advance for any assistance!
-tom

[CrazyE]

My first idea: Check the tightness of the big bolt that holds the two white gears and one roller. As I recall, if too loose the rollers don't turn properly. I also seem to remember that if too tight things don't turn at all.

I hope this helps.
Larry

[tom10122]

Tighten the bolt closer to the stepper motor as tight as it will go

[TomCircuit]

Thanks to both of you for the replies. My upgraded nylon pieces arrived today, and I did teardown and rebuild of the extruder this evening - this time paying extra special attention to the step about sanding the small face of the combination gear to spin freely when loaded. That seemed to help a LOT.

I also paid a lot more attention to how power is transferred to the drive roller - it's all about the tension across the long-bolt (nearest to the stepper). Where I failed initially, I think, was to not have gear stack on the long bolt spin freely, so I couldn't tension the long bolt without binding the gears. That, in turn, meant that there was little power transferred to the drive rollers - therefore "slip".

With the additional sanding, I was able to tension the long-bolt properly, and subsequently tension the drive rollers properly - it seems to be working MUCH better now! Printing a test right now (my son's favorite flexible snake) and so far so good.

Hooray!

-tom