it’s a gear, so you need the layers to be perpendicular to the rotation to give it a chance, but the final drive interface came up off the gear like a tophat. It was not a good candidate for FDM. Realistically, it wasn’t a good candidate for resin either. The tophat really needed to be metal with an interface into resin or nylon for the gear to gear surfaces.
nah there’s a difference in print line orientation on all the slicers I’ve used. When printing functional parts like that, especially mechanical ones, you really got to pay attention to printing orientations
Resin was one of my early thoughts. The original Nylon is pretty tough, and they kept breaking gears. (I think he was overvolting it) He tried replacement boxes but they just broke immediately, he managed to get a couple of original gears at $80 a piece, but they didn’t last long either.
I think the right answer would have been to replace the motor with something that had a higher Kv and done a belt drive. (like electric skate parts with a little more ratio)
Jikiya@lemmy.world 1 month ago
At 100% infill, it’s all wall. Though the better bet is probably using the printed part to make a mold.
pineapplelover@lemmy.dbzer0.com 1 month ago
Not sure, might be different. Like the infill might go side to side but walls go up and down. So increasing walls might still give more strength.
rumba@lemmy.zip 1 month ago
it’s a gear, so you need the layers to be perpendicular to the rotation to give it a chance, but the final drive interface came up off the gear like a tophat. It was not a good candidate for FDM. Realistically, it wasn’t a good candidate for resin either. The tophat really needed to be metal with an interface into resin or nylon for the gear to gear surfaces.
mrgoosmoos@lemmy.ca 1 month ago
nah there’s a difference in print line orientation on all the slicers I’ve used. When printing functional parts like that, especially mechanical ones, you really got to pay attention to printing orientations
Landless2029@lemmy.world 1 month ago
For a use case like this it would be a good use case to do 3D printed casting.
3D print the part. Mold out of silicon. Then make the final part in resin.
Or just buy the real part.
There’s also ways to make plastic parts via injection at home.
rumba@lemmy.zip 1 month ago
Resin was one of my early thoughts. The original Nylon is pretty tough, and they kept breaking gears. (I think he was overvolting it) He tried replacement boxes but they just broke immediately, he managed to get a couple of original gears at $80 a piece, but they didn’t last long either.
I think the right answer would have been to replace the motor with something that had a higher Kv and done a belt drive. (like electric skate parts with a little more ratio)
Landless2029@lemmy.world 1 month ago
I bet there’s some good threads in RV cars forums for stuff like this.
I didn’t even consider belt driven.
rumba@lemmy.zip 1 month ago
Yeah, even annealing it didn’t help much. I think the original part of the injection-molded nylon was a bit under-specified.
It would have been a good project for metal, but it would have been 4 years in the box and cost more than the original ride-on.