CupCake Pilot Assembly

MakerBot CupCake, all motors installed

As of a weekend ago, we are assembled! There are changes to be made, but they’ll clean up along the way.

Notes from the process:

All of the cables will get proper cable management. I won’t show closer pictures of them until they do.

Broken plywood idler pulley from MakerBot CupCake

The glued-up plywood idler pulleys from the early CupCake batches — besides wobbling because the bearings press-fit way too loosely — are fragile and break. The plastic idlers in the recent kits are a much better idea and the print your own pulleys from Zach are a great blessing — or should I say, FABulous.

Broken idler wheel from MakerBot CupCake plastruder

During my first prints, I could hear a loud clicking at fairly regular intervals. Eventually when I went to tighten the extruder’s idler wheel because the filament was slipping, I found the wheel was broken. Fortunately a spare was included in my kit. Unfortunately, replacement necessitated completely dismantling the extruder.

MakerBot CupCake motor plate with enlarged idler pulley mounting slot

While everything was apart, I lengthened the idler wheel mounting slot (not the first to do this) so the wheel can tighten further onto the drive pulley. In theory, this should lead to even more rapid breakage. In practice, it hasn’t yet.

Countersunk inlet in MakerBot CupCake PTFE  barrel

Finally, I’d been having trouble with the leading end of new filament catching and jamming when it got to the opening of the PTFE barrel. I used a countersink bit to funnel the inlet, being very careful not to let unmeltable PTFE shavings fall inside where they’d jam the extruder nozzle.

I should have countersunk further, because although it’s less prone to jamming, it still does occasionally. I’ve taken to tapering the leading edge of the filament with the “wrong” side of a diagonal cutter before feeding it into the machine, but I’d really like to fix the barrel.

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