Ohh Well another trans down the tube

[andy]

Originally Posted by Matt Reiland

I had really hoped to the game would require monster power this year so we went ahead and worked on our next evolution of the shifter. Added the third motor and a servo shifter. However it is apparent that this will be overkill for this years game. It was, however, fun to design and build and it looks cool too!

Sadly I have to miss this entire build season due to a plant launch down here in Doraville. But hey I am already in Atlanta for the Championships!!

I know the feeling...
Just finished a two motor two speed...
*sigh*

-Andy

[kevin.li.rit]

Originally Posted by andy

I know the feeling...
Just finished a two motor two speed...
*sigh*

-Andy

It doesn't mean you've wasted your time, a two motor transmission will still be useful. There will always be some shoving and you'll still need to get from point a to point b fast.

[Tom Bottiglieri]

yeah.. we've had a 2motor (drill/atwood) 2 speed transmission for a few years now, and we've decided to use it again this year.. some of the engineers didnt think it would be necisary, but after a whole bunch of *debates* the 2 speed finally won out.. ive got pics of last years atteched if anyone is interested

[tkwetzel]

Two summers ago, my team (116) spent the summer developing a gearbox. It is a two motor, two speed gearbox with a weight of 10.0 lbs. We have posted documentation on it for other teams to use. This documentation includes blueprints, a parts list, 3D images, and other technical information. I will try to find where this is located, so that you may retrieve it at your convenience.

[Wetzel]

Team 116's whitepage on our two-speed gearbox can be found here. Elgin, it couples the drill and chalupa together. It can also be made with just a mill and lathe.


Wetzel

[BenSanders]

I'm not a physics major but I have designed and built a two motor two speed pneumatic shifting gearbox and competed with it in competition. I think the two motor system helps but I think it could be argued that that much power is wasted on a FIRST robot. with only 130 lbs of robot there is no way that you can transfer all that tourque to the ground. Your wheels will spin out before your motors will stall. I think using one motor per side and adding some sort of skirt or other mechanism to transfer the weight of another robot to the ground is the way to win the pushing match not adding more motors. what does everyone else think?

[KenWittlief]

last year a few teams build wedges to give them a protective and pushing advantage as you pointed out

problem was some bots didnt handle being 'lifted' a little and were tipped over in shoving matches - and tipping another bot will get you disqualified.

if you lift the side of the bot you are pushing against, all that does is transfer most of the weight to its rear wheels - they can still push back just as hard, but you have altered their center of gravity, and there is a good chance you will tip them.

[Matt Reiland]

Originally Posted by BenSanders

I'm not a physics major but I have designed and built a two motor two speed pneumatic shifting gearbox and competed with it in competition. I think the two motor system helps but I think it could be argued that that much power is wasted on a FIRST robot. with only 130 lbs of robot there is no way that you can transfer all that tourque to the ground. Your wheels will spin out before your motors will stall. I think using one motor per side and adding some sort of skirt or other mechanism to transfer the weight of another robot to the ground is the way to win the pushing match not adding more motors. what does everyone else think?

I don't think that having a multiple motor drivetrain is wasted power. Maybe if you are using 2 wheel drive or slippery wheels. However, we were using treads and our robot last year was quite fast for a first robot, and in high the motors would be at stall if it encountered a pushing match. With only 2 motors you are severly limiting the power of your drivetrain. As debated before more motors can give you the same torque at a higher speed.