Off season special project (Gearbox)

Technical Technical Discussion
1

So this is our new gearbox about to be machined. It’s for a special project we’re doing. I wanted to ask if it looks okay and not suspicious about whether it will fail.
Specs:
-4 Cims
-9:1 GR
-Dual Output Shaft
-14lbs

https://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-xpf1/v/t35.0-12/10612017_654542821307776_963012347_o.jpg?oh=85962f27b749b00fec3fb2ce78d819c0&oe=54043CB8&gda=1409567397_1731ffa08bc754d4380dd1044e156ef4
https://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-xpa1/v/t35.0-12/10638898_654543977974327_614849481_o.jpg?oh=a653e935938daee12c250c4f993645e4&oe=5404328B&gda=1409571220_887be08ac5f76b5db90515df7ad57636

2

Plate and gear materials? That’s probably got more to do with whether it’ll fail than anything else combined…

3

It’s AL 7075 for gears, AL 6061 for plates and shafts. besides the cims the rest is all 316 stainless steel.

4

Looks really good!
From just looking at it, I don’t think it would fail. It’s hard to get a good view of the plate design because they’re dark black, but it seems like the center part with the three center bearings isn’t too well connected to the outside parts. Check out picture of 254’s gearbox plate design for some inspiration if you’d like.

5

https://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-xpf1/v/t35.0-12/10650410_654543121307746_291154979_o.jpg?oh=09af46acdac46ce3f476026d4579fb19&oe=5403CFD2&gda=1409548431_b9385d124e78b7ba9261a7c5e8c4251c
Here’s the plate view

6

6061 shafts? Make them 7075 at least, or some kind of medium carbon steel if you can.

7

For .500" hex shafts that aren’t cantilevered in gearboxes, 6061 is likely strong enough.

That said, vex pro sells .500 hex shaft that is a great fit for their products at a pretty reasonable price.

8

Hmm this thing is supposed to last atleast 3 years. So yeah might change shafts to 7075 then.