slow Drive system

[Thunder360]

You know tank treads arent a bad Idea because you will have a O degree turning radius. but I really wouldnt only use 2 Cim's I would use 2 Cim's and 2 drills at the same speed. Err I dunno if that would work, but I was always a huge fan of 2 wheel rear drive with 2 Cim's with 2 Pneumatic shifted gears.

But I bet most rookie teams will try to go direct drive with the drills. I always use a multi speed tranny with any motor!

P.S. Anyone have a good design for a 3 speed thats Pneumaticly shifted, I can only manage a 2 speed in the given space. And Im also having a down shifting problem its a lil rough, but thats expected from helical gears right?

[FotoPlasma]

Originally posted by rbayer
First, the CIMs are 5500rpm, not 4200. http://www2.usfirst.org/2003comp/Specs/Chiaphua.pdf.
...

According to that paper, the freespeed is 5342rpm, but it's 4356rpm under normal load. 4200rpm is a conservative estimate.

[KennethToronto]

No....do NOT use a 3:1 reduction and call it a day

We're using similar wheels and I'm reducing the CIMs by ~20:1

[Lord Nerdlinger]

Yay, we finished mounting the motors to the 5/8" coupling gear shaft and found that we could easily hold the shaft in place and trip the fuse, so we def need more torque. 1:20 sound excesive, I'll look into a 1:8 ~ 1:12 range.

Thanks

[Madison]

Originally posted by Lord Nerdlinger
Yay, we finished mounting the motors to the 5/8" coupling gear shaft and found that we could easily hold the shaft in place and trip the fuse, so we def need more torque. 1:20 sound excesive, I'll look into a 1:8 ~ 1:12 range.

Thanks

Rather than guess, use this White Paper as a starting point.

Then, take the information you learn about speed and apply it to torque and see where you end up.

Math is better than guessing. (Only marginally.)

[gc02]

Originally posted by wysiswyg
Actually you have them reversed. A three to one gear ratio would triple the speed of the robot and a one to three gear ratio would increase the torque of the robot by a factor of three. I believe your confusing the speed ratio and the torque ratio which simply enough are inverses of each other.

I think you have it reversed, according to dictionary.com here is the defenition of "gear ratio":

The ratio of the speed of rotation of the powered gear of a gear train to that of the final or driven gear.

[Al Skierkiewicz]

Lord,
I have to go with everyone else on this. The gear ratio sounds too high especially with the 9
' wheels. The chalupa motors are strong but the gear ratio will allow you to go fast only if you can get the robot moving. That is a big "if" since the gear ratio will provide so little torque. 8-12 feet per second is a good guide.
As to the electrical draw, the 40 amp breakers are the dominant factor and I would predict some heavy action on their part with this design. Turning will be your greatest draw.

[Sachiel7]

Like I've stated before, Our Team has (somehow) managed to get 15 feet per second with a 10:1 ratio using the 2 Chiphua Motors, and we still have loads of torque. We aren't a speed based robot...
Anyway, OUr drive is really nice and (if only) if chiefdelphi had a section dedicated to video clips, I'd show you our drive in action!
I might be able to get a file server and post a link in a while...
Anyway, we Haven't had any issues with it, and it works great!