I like the addition of an encoder gear, and the structural improvements.
Guess that fifth motor turned out to be unnecessary? :rolleyes:
Can you summarize some of the updates made on this from the 2017 competition version for those of us who haven’t been intimately involved with the developments you have made in the last 6 months? 
There is relatively little material where those 775pro’s are face-mounted. What has been your experience with this particular pocketing configuration? Obviously, the main concern is the motor skewing off-axis, causing a non-ideal gear mesh.
We generally support the 775pro around the entire face (with pockets for venting), so I’d be interested to hear your experience with this configuration.
Thanks for sharing.
-Mike
One particular change I see they’ve made is that the 32DP gear they’ve selected appears to be a COTS (100?) tooth gear instead of the special thin gear that 2451 used in their gearbox. The pink element appears to be a spacer used to mount the shifter shaft to the green plate.
I too am curious about this. I realize that 2451 did this last year with the previous version of this style gearbox so I would guess that they had no issues, but details into this would be nice.
The gear is COTS, in particular it is Andymark’s 85t 32dp steel gear (judging from part numbers in their linked assembly).
Last years motor mounting plates, can be downloaded also from GrabCAD, had a minimum web thickness of .38" with the same basic geometry. This might have lead to a vibration with the twisting of the material under load like you pointed out. Though we had no issues with wear once we switched the spur gears to 4140. I wonder if the gearbox would have quieted down with additional support.
The off-season design has a third web running down to the main central spur gear shaft support bearing. This should add stability. This addition was just a different design on a different day.
In general we have been running 1/8" webs on our gearboxes for a few years with no issues. Some webs are wider if they are load bearing. Designers preference, no hard and fast rule.
Nick, I know you aren’t intimately familiar with the design of either gearbox, only having seen last years come together after it was designed. Please feel free to download them both and educate yourself on their design.
Main reason to redesign the gearbox was to switch to the COTS 32DP 85 Tooth Andy Mark spur gear, remove the fifth motor mount and reduce overall size and weight. Looks like we will save about .75lb for both gearboxes. And both gearboxes will weigh in close to a single 3CIM 2-Speed gearbox. We found four motors were adequate to keep them cool and happy for an entire season. The switch to a higher resolution encoder is probably overkill.
2017 Competitive Gearbox Solidworks Weight 5.48 lbs
2017 Off-Season Gearbox Solidworks Weight 5.11 lbs