pic: Highlander Robotics reverted gearing shifter

[Oblarg]

Originally Posted by Joe G.

The dog shift assembly is on the primary output shaft, just hidden by the CIM motors -- what you're seeing above is the much more visible encoder mount and coupling.

That makes a lot more sense, thanks.

[asid61]

Very clever! I like the idea of using extra reductions on a low gear.

[Chris Fultz]

what are the gear reductions and the rest of your drive train?

[Joe G.]

Originally Posted by Chris Fultz

what are the gear reductions and the rest of your drive train?

High gear is 6.4:1, low is 11.4:1, giving us speeds of about 8 and 14.5 feet per second, riding on 4" treaded colson wheels, set up in a belt driven WCD with sheet metal construction. Utilizing gears that we had on hand was a high priority for this design, as budget for offseason improvements is next to nonexistant, and this played a large part in driving these choices. Future iterations would likely have a larger reduction spread and faster high gear, as long as the game calls for it.

[asid61]

Any reason why you opted for a low of 8 fps instead of something like 5?

[Kevin Kolodziej]

Did you make a custom output/shifting shaft for this gearbox? It seems that the stock WCP shafts don't have enough room to fit two gears on the high side and still be secured through a bearing at the plate. We've been investigating a very similar concept and if the stroke of the shifting cylinder is limited to less than 1/2", it looks like it might be possible, with some creative use of spacers for the low side gear. I'm interested how you solved this issue.

We're not comfortable making a stepped hex shaft like the WCP shafts are. The AM dogs work on 1/2" hex shafts, but the dog profile is different between WCP and AM and would introduce some backlash into the system when reversing directions.