hi everyone,
our team is looking for a DS gearbox for using on transmission.
the two gearboxes we are looking at are the Andymark’s EVO shifter and the VEX ball shifter.
we have two main requirements for the gearbox:
what are the advantages and disadvantages of the two?
thank you
My team has not run the VEX Ball Shifter (yet), but I have inspected and/or consulted on several robots that used them. Those teams seemed to be generally pretty satisfied, and I have seen no pattern of issues. Others with more direct experience should comment further.
We did run the EVOs in 2017. They are extremely reliable compared with every other gearbox that we have used – 89 competition matches* so far, with no issues and very limited maintenance. We clean them periodically to remove carpet debris. What sold us on them was ease of use. They come pre-assembled, including both the shift cylinder and the encoder. And of course, the tech support from AndyMark has been outstanding.
*Five regular events and one off-season, AOTW. One more off-season until we retire the 2017 'bot!
The bigest drawback of the EVO related to the ball shifter is the price, and since in israel we need to pay an extra of 42% for the import, its even worse.
Is the price difference really worth it?
Also the fact that the the EVO use an unusual pinion gear for the cim motor makes a little problem.
AFAIK the only three gearboxes that are out-of-the-box compatible with the AM14U chassis are the TB Mini (i.e. the stock gearbox), the 3CIM4U, and the EVO shifter. Of those, only the EVO is a shifting gearbox. I’ve heard good things about them, but have no experience personally.
From Vex, none of the gearboxes are out-of-the-box compatible, but they have a guide to using their products with a kit chassis. Pretty much any gearbox can be used, but you’ll need to add the proper mounting holes.
If you’re looking for ease of compatibility with the kit chassis than the EVO will probably be the way to go.
The vex gearboxes can be mounted by drilling holes to mount them, but it requires a decent amount of precision.
Having used the Vexpro ball shifters and the West Coast Dual Speed gearboxes, I prefer the WC ones because we’ve experienced some warping with the plastic casing of the ball shifters by the end of the season.
It’s actually not that bad. You just take the 3rd stage support plate, press a bearing through both the stage and the AM14U sideplate, then clamp the plate in place. Then you just match drill through both. It’s a little work but nothing a decent FRC team can’t handle.
EVOs are more expensive. Comparing at the 2 CIM 2 stage configuration, the difference is about $100. Considering that competitive auton will likely require drive train encoders, adding those to the Ball Shifter will cost about $50, plus whatever you spend to mount them.
For us, the EVO’s reliability* and ease of integration is worth the extra $50. Every team has to make that calculation for itself.
*Reliability is worth a lot to us, as I think it will be for any team playing in the district format. Time between matches is short, and a gearbox repair is very likely to mean missing your next match.