19-11-2015 18:44

Oblarg

Re: pic: 3 cim shifting gearbox from 2471

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

19-11-2015 18:54

thinker&planner

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!)

19-11-2015 21:40

asid61

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?

19-11-2015 22:35

thinker&planner

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.

19-11-2015 22:49

akoscielski3

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.

19-11-2015 23:26

thinker&planner

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.

19-11-2015 23:27

MichaelBick

Re: pic: 3 cim shifting gearbox from 2471

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

19-11-2015 23:42

Bryce2471

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.

20-11-2015 00:00

akoscielski3

Re: pic: 3 cim shifting gearbox from 2471

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