pic: Double-Trouble Shuffle

[rob_c]

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[billbo911]

Wow, what a change from the original! So, what was the reasoning behind all the changes?
Did you need a higher torque to weight ratio? Did you achieve it?

Or maybe I should just ask for some specs.

[Racer26]

Is that a double doozy hooked to TWO AM shifting transmissions in series? giving 4 possible speeds?

EDIT: Oh, I see now, the "shuffle" is an AM Toughbox rehoused.

I just had a thought though that would be interesting:

What if you connect 3 AM Shifting Transmissions together (with different ratios in each) such that you would have 8 speeds, and then coded the software to shift it automatically, based on encoder velocity.

Useful for FRC? Probably not... but cool? Absolutely.

[apalrd]

Originally Posted by 1075guy

What if you connect 3 AM Shifting Transmissions together (with different ratios in each) such that you would have 8 speeds, and then coded the software to shift it automatically, based on encoder velocity.

We had a four-speed in 2004. http://www.chiefdelphi.com/forums/sh...ad.php?t=26490 talks about it, with a whitepaper http://www.chiefdelphi.com/media/papers/1580 here. It shifted automatically, based on encoder speed, so any increase in power demand (e.g. pushing) would lower the output speed and the software would shift down to give the increased torque.

[Racer26]

Sounds like pretty much what I was describing, with 2 shifting stages instead of 3 or 4... Cool.

[Mr. Ivey]

Good Afternoon,

Yes the Shuffle has grown quite considerably. We swapped out the CIM for the Double Doozy from AM, and stacked the little devil! It runs at a turtle pace, about 7 RPM, but produces 251 foot pounds of torque! That's more than some small cars. Although it is quite a little beast, at this point I don't know if we are going to use it on the bot. We shipped with an arm, but before the FedEx man could get it on his truck the students were already changing it. That is why the original Shuffle was re-built into the Double-Trouble Shuffle. But they are looking at even more options now.

Mark

[billbo911]

Originally Posted by Mr. Ivey

Good Afternoon,

Yes the Shuffle has grown quite considerably. We swapped out the CIM for the Double Doozy from AM, and stacked the little devil! It runs at a turtle pace, about 7 RPM, but produces 251 foot pounds of torque! That's more than some small cars. Although it is quite a little beast, at this point I don't know if we are going to use it on the bot. We shipped with an arm, but before the FedEx man could get it on his truck the students were already changing it. That is why the original Shuffle was re-built into the Double-Trouble Shuffle. But they are looking at even more options now.

Mark

With 250FtLbs of torque, assuming you have accounted for all the losses in the different stages of transmission, and 7 RPM, you should be able to lift your robot on a 1.5 ft. arm over 3 ft. in less than 4.5 seconds. I'd say that is quite a successful design.

Dr. Joe,
Are my numbers right?

[Mr. Ivey]

I do not believe the student that ran the numbers accounted for the loss in the different stages, but I will ask. The real issues is the spread between the gears under the weight with the lever arms. I am somewhat concerned that there will be so much between the teeth, that somehow, they will disengage. The side plates are Lexan, 3/8th inch to be exact. We were talking about using aluminum side plates, but to achieve the weight and the bearings fit at the correct depth we would weigh more than I think allowed. We are cutting it close, very close. We will see what these students come up with.

Mark