pic: 3 cim shifting gearbox from 2471
 

Re: pic: 3 cim shifting gearbox from 2471
 

Is this only supported from the chassis through those hex standoffs?

Re: pic: 3 cim shifting gearbox from 2471
 

Pretty nice.
Out of curiosity, did you waterjet the bearing holes and bolt holes in addition to the lightening pattens?
This past year, we only waterjetted the lightening patterns and outer profile, and then did all the mounting holes and bearing holes by hand with a mill (DRO!)

Re: pic: 3 cim shifting gearbox from 2471
 

I'm a little worried about those hex standoffs connecting them to the chassis, but apart from that it looks amazing!
How did you manufacture? CNC mill or something else?

Re: pic: 3 cim shifting gearbox from 2471
 

Having experience with a waterjet, the rough(almost bead-blasted look) edges are pretty easily recognizable as being cut by a waterjet. At least I hope that I am identifying that correctly.

Re: pic: 3 cim shifting gearbox from 2471
 

Did you cut smaller holes on the waterjet and then drill them with the proper drill size on the mill? or did you leave that section blank and then drill the holes?

If you water jet the holes to a smaller size then drilled them out with the proper size you could save time. You should do that on a drill press though so the drill bit goes into the center of the hole by itself. That's what I would do at least.

Re: pic: 3 cim shifting gearbox from 2471
 

For the #10 clearance holes, we left that section blank. For the bearing holes, we cut out like a 1" diameter hole so that we didn't have to center-cut with the bearing endmill.

I thought about making a center "pilot hole" for all of the bolt clearances, and I can't remember why we didn't do it. We certainly will in the future.

Re: pic: 3 cim shifting gearbox from 2471
 

We haven't had issues with just water-jetting the screw holes to the final size

Re: pic: 3 cim shifting gearbox from 2471
 

They are part of the equation. But no, they are not its primary mounting.
We made multiple sets of plates with multiple different machining techniques. The ones pictured were waterjetted in their entirety. When the bearing wholes were too small, we brought them to size with a half round file.
The hex standoffs just reach around the 2"×1" rail of the wcd chassis and bolt to the bearing block on the other side. The two bolts to either side of the output shaft are also used the mount to the frame. these plates were cut on a waterjet, but we have another set that was made on a mill.

Re: pic: 3 cim shifting gearbox from 2471
 

True, that should also just be water-jet cut. Bolt holes can be terrible.