Window-wiper motion

[MrCamilleri]

It wouldn't be very many times per match. One or two?

[Jon Stratis]

Generally, if you use pneumatic s you want to use it for multiple things, in order to justify all the stuff that comes along with a pneumatic system.

Doing it with a motor would be fairly easy- and AndyMark PG motor/gearbox es you a nice output shaft you can use, or run that to a separate shaft using a chain and sprocket. With something like this, it's always a good idea to have a hard stop at both extremes, along with a limit switch at both extremes to tell you when you get there. Your code can then recognize that when one of the limit switches is pressed, it shoud stop moving the motor in that direction.

[PowerfulKitty]

You could use a VersaPlanetary gearbox, probably with a 100:1 reduction (as high as they go) and a BAG motor. Then you cold use limit switches at the top and bottom of the movement so that the arm hits the limit switch right where you need to stop. I'm not a programmer but from what I understand this is easier to program and set up than using encoders for a rookie team. Pneumatics could be an option, but if this is all you would use it for personally I would not want do have to deal with all that extra stuff just for one arm.

[Jim Wilks]

You can use a motor (with gearbox) and limit switches to stop motion at predefined points.

You can use a motor (with gearbox) and an encoder to allow you to stop at any point.

You can use pneumatics and the end points could be hard stops.

Don't bother with a servo as the restrictive FIRST rules on servos make them largely useless.

[Sparky3D]

Originally Posted by Jim Wilks

Don't bother with a servo as the restrictive FIRST rules on servos make them largely useless.

Actually, the servo rules this year are much more open than in previous years. It still wouldn't be the best choice to drive an arm with, though.