Can I fix this stepper easily?

Hey, during one of my recent 3d prints the extruder motor system clogged up and the stepper promptly ceased to move filament.

The stepper still makes the correct noise and moves, but there is no output from the gear box on top of it. This is what the gearbox looks like now - minus the planetary gears because they are all in good shape:


As you can see, the sun gear rotates around and slides off the axle easily. The axles still outputs power, so I know the problem is from the sun to the planetary gears. Now, I’m guessing the sun was pressure fit? Or welded, or something. Whatever the case, I know it should be attached to the axis. Since it slides around now, do I have any hope of fixing it?

Thanks

Get a piece of shim stock and press fit the gear on the shaft. Or Use Loctite Red 271

http://www.leevalley.com/en/wood/page.aspx?p=40946&cat=1,43456,43407

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Probably not, but is there a set screw in the gear under the grease?

Well it certainly wasn't welded if its spinning freely now! Probably a poor interference fit and the combination of overload and the grease has allowed it to turn and polish the roughness the fit was relying on.

If the pinion has no grubscrew your best bet is probably spot-welding at the end of the shaft and pinion, if you have access to suitably rated equipment (this is quite fine work for welding).

Both shaft and pinion are likely to be hardened which limits the other options. The pinion appears to be shouldeless so there's no way to use a roll-pin or add a grubscrew I suspect.

MarkT:
Both shaft and pinion are likely to be hardened which limits the other options.

Loctite?

…R