Re: omni drive transmissions
 

I'm sorry, I misquoted the price, the actual price of a slab of that size is 200. Here is the mcmaster-carr product number for the sheet we got.

8752K518

Sorry for the confusion.

Also back on topic, we originally went with the 45° omni design in cad, but decided to go with the mecanums. Here is the inventor render of the omniwheel bot. Also, if you have access to a waterjet (or even if you don't) you can try and setup a way to get those mecanums cheaper. We contacted AM and just got the sideplates for 180 dollars, and we fabricated our own rollers from brass tubing bought off of mcmaster and sheets of rubber which we then jetted out the rollers from. It ended up saving us about 100 dollars for the set overall.

http://www.chiefdelphi.com/media/photos/29534

Also theres a bonus, a very lengthy discussion on the design for you to read through :-D

Re: omni drive transmissions
 

I think the debate on the BB transmissions has been settled... in favour of Banebots.

Comments on the BB transmission reliability comes from the initial batch of gearboxes that were shipped in the KOP two years ago. Through an effort between teams, FIRST and Banebots the reliability issue was identified as an insufficiently hardened final stage carrier plate. Banebots took responsbility for the problem and issued every FRC team replacement, properly hardened, carrier plates, and then took additional steps to toughen their gearboxes.

As far as I know, teams using the new carrier plates and/or new transmissions have had no issues with the BB transmissions.

The BB transmissions are ideal for omni-drive drivetrains as they are extremely easy to use in direct drive (as opposed to chain drive) applications. You just put the wheel on the output shaft, saving all the weight of the chain and sprockets, as well as the potential failure of having the chain come off. In my experience, the upgraded Banebots make for the most reliable drive system out there.... and we've got a mecanum drive with four of the 12:1 gearboxes on board with two regionals and several demonstrations behind them to back it up with.

Jason

Re: omni drive transmissions
 

are they a hex shaft or keyed

Re: omni drive transmissions
 

Bane bots are keyed. we used them on our mecanum bot this last seasons with the 8" andy mark mecanum wheels. Honestly engineering the actual drive train was a piece of cake. We made a cad file of where we needed to drill holes in a sheet of 1/4" aluminum and then printed it out and drilled it in our smithy(drill press mode). The real troublesome part mecanum or holonomic drive is the programming. you need a way to keep your bot going straight. If you look on TBA our bot didnt fair well at the NASA VCU regional but we eventually got the kinks worked out in our programming and got the thing to drive reasonably straight. Dont worry so much about the calculations, those are easy, worry about programming, that is very hard and takes a long time to test. On average, teams that i have talked to take about a year to develop a good mecanum/holonomic code, so plan for this to be a rocky season

Re: omni drive transmissions
 

well we have plenty of help this year with programming including our new mentors Chas(former student now at college programming king) and Lexi(from g&t conveyors)

Re: omni drive transmissions
 

I'll agree that the newer line is more reliable than the previous, but disagree that it is the most reliable option. I would bet the reliability of a dual stackerbox or single toughbox is substantially higher.

Re: omni drive transmissions
 

well i have read enough information on the bb trannies to be confident they wont break on me and that there level of reliabillity is up to par with andy mark


and seeing as how we have like 10 of them ill give them a try after i discuss it with our mentors