Shifting from base to flywheel. Pneumatics

How does everyone feel about making a “transmission” in which you have a piston that when has air in it, pushes two gears the side that were on top of two others to now under two different gears (if you know what I’m trying to say) and when has no air, pulls them in switching from having the 8 motors powering the flywheel to the same eight motors now powering the base? What do you guys think on idea wise for this? We are just about done and would just like to see what a few others have to say.

Our robot is like this. We have 2 motor banks of 4 motors each geared for high speed internally. Normally these banks act independently of each other, but our transmission locks the two banks together and then sends that power through a single flywheel when we activate our transmission. The perks of an 8 motor flywheel aren’t that great, and it isn’t the biggest advantage from a 6 or even 4 motor flywheel. That said, I really like the 8 motor drivetrain. We can push other robots and move across the field faster than most other robots as well. It also wasn’t as much of a decision between 10/12 motors for our team as we already used pneumatics on other sections of our robot.

We’ve found it to work well in testing, though it still needs to be tuned, and then competition tested. So far it is promising for our team, but I strongly encourage other teams to think before adopting this strategy. These robots are harder to build and harder to maintain than non-transmission robots, and they come with some serious downsides, especially if you can’t build a transmission that works the first time every time.

@maxshep98 . We love how fast our robot moves also! But as of right now the gear ratio on the flywheel is the number one thing. Our base is awesome but our gear ratio for the flywheel we aren’t sure of. Our robot is completely built so no turning back now, however, have any ideas for a gear ratio. The members of my team are saying 1:25 (I think it is what they are saying) for what we need. What would you maybe say?

I think that 1:28 is the bare minimum. Also the transmissions…One of the senior members of my team told me that all it takes to screw one over is too ram it at the right time and the whole system is busted. I really feel that transmissions should not be used for TWO of the most important systems that your robot has. If it work for you, go for it.

I must say I can’t quite agree with that statement.

We started with a 1:25, but we found that ratio to be too high for our system. We have a 1:18.75 right now and it seems to work alright.

Transmissions can be very robust if you build them correctly. My robot has two, and after some tweaking, we have gotten to the point where the shift is 100% reliable, and ramming the robot while we are shifting will do nothing to change that. Plus, the actually act of shifting takes probably around 1/8 of a second, so you will be hard pressed to ram at that exact moment.

I never find a situation where having a transmission is useful, most of the time it is a burden to have and operate. I don’t doubt that many teams have found good uses for them.

@maxshep98 . What has mostly made it 100% on shifting?

maybe a ratcheting gear with two gears side by side or maybe a guaranteed conversion mechanisim