pic: FP Gearbox Hubs


This is a ridiculously easy method of mounting to the FP gearbox, since there is no hex pattern on the inside like there has previously been.

This is a 7/16" mill bit set to a 10 hole, 1.75" diameter bolt circle .45" deep. We put a 3/8" hex in our center, but it can be adapted to literally anything. As shown the hub is 1" thick from solid round stock, this is a little overkill and we’ll probably shave off at least .25"

Special thanks to 2337, you guys have been great to us this season!

If you had posted this two weeks ago we’d have a functional arm by now :rolleyes:

Great part - I love it! That 3450 sounds like they’re doing great.

As pictured this part weighs ~.5 lbs though.

We would be in a lot of trouble if it weren’t for the generous machining support we have received from local teams like 2337 and 68. I can’t tell you how many hours of lathe time 2337 has donated.

Chris, if we had known it two weeks ago we would have been very happy, I’ll get a picture and show you our iterations of ideas.

Last week we used Rice University’s 3D printer to make an adapter that fits nicely into the fins of the gearbox and adapts it to a 1/2" hex shaft like yours. I’ll try to get some pictures of our winch assembly tonight.

I’m still slightly worried that the part won’t be strong enough so we may try to make one like yours for backup.

Not to go off topic here, but I’ve made FP hubs in a 3D Printer (Dimension SST1200) and they tend to split in between layers. When printing, insure that your axle is not on the machines Z axis or they’re extremely prone to splitting in between layers under torque. If your printer isn’t a layer type then you should be fine.

I’d be a bit concerned myself as well. It really depends on orientation of the hub during printing, with what machine, and material.

Since you said you would post photos of your “winch” assembly that makes me even more concerned…