The best multi-speed transmission

[MrForbes]

I had a chance to look at the cheesy poof transmissions in Atlanta, they had a display with all the parts sitting there. The parts look familiar somehow...sort of like the parts in an AM shifter, only lighter. They are beautiful!

I still haven't figured out what the advantages are to having a lightweight drive transmission, though.

[Lil' Lavery]

Originally Posted by squirrel

I still haven't figured out what the advantages are to having a lightweight drive transmission, though.

More weight to use elsewhere. This year the poofs really didn't need it (weighing in a stunning 86 lb.s before adding the ramps), but many other teams would have like the extra couple pounds to play with.

[MrForbes]

I can understand making a manipulator transmission as light as possible. The problem I see with a light drive transmission, is that the saved weight might be put higher up on the robot...resulting in a tippy bot.

Wheels, frame, and drivetrain is where you want the weight to be.

[Guy Chriqui]

I think that the best multi-speed up to this point in terms of sheer engineering is that 254/968 gearbox they have been flaunting around at all the regionals my team has attended. The gears are astonishingly light. 1.3 lbs a gearbox made my jaw drop the first time I had the whole thing handed to me. It really is hard to argue against the sheer awesomeness that is that gearbox, really makes me want to one-up them and make something 1.299 lbs!
-Guy

[Ken Loyd]

For the past two years Team #39 has tried to use the transmissions that come with the KOP. We felt it would be easier to help rookie teams if we had to overcome the same problems they had. After the Banebot problems this year we do not want to use them next year. My question is, do you think the KOP will have the Banebot transmissions next year? If they do, I think we will return to the AM trany.

Ken

[Brandon Holley]

Originally Posted by Ken Loyd

For the past two years Team #39 has tried to use the transmissions that come with the KOP. We felt it would be easier to help rookie teams if we had to overcome the same problems they had. After the Banebot problems this year we do not want to use them next year. My question is, do you think the KOP will have the Banebot transmissions next year? If they do, I think we will return to the AM trany.

Ken

Will the KOP have banebots next year?? My guess is probably...

After experiencing the problems they had with them this year, will they be the same exact banebots 56mm trannys?? my guess is no...


FIRST learns from their mistakes, and I think after seeing the huge struggle teams had with these this year, they WILL correct it.





As far as trannys go....254/968...the thing is just unbelievable. If you haven't seen it yet, hop around delphi and check it out:
http://www.chiefdelphi.com/media/photos/28070
http://www.chiefdelphi.com/media/photos/27018

Serious props to the guys over on the left coast for designing this thing. My entire team was drooling over it (and the rest of your guys robot ). Travis, thanks for explaining the hard anodize process to me, its definitely something we'll be looking in to.

[Travis Covington]

Originally Posted by squirrel

I can understand making a manipulator transmission as light as possible. The problem I see with a light drive transmission, is that the saved weight might be put higher up on the robot...resulting in a tippy bot.

Wheels, frame, and drivetrain is where you want the weight to be.

Agreed... however, I would much rather cut a chunk of my 10 lb lead block off than have to drill a bunch of holes in the rest of the robot because we forgot to put on the LED, the team numbers, or the PVC flagpole mount... you get my point.

[Alpha 997]

Originally Posted by Lil' Lavery

More weight to use elsewhere. This year the poofs really didn't need it (weighing in a stunning 86 lb.s before adding the ramps), but many other teams would have like the extra couple pounds to play with.

Yep. Exactly.

[Travis Covington]

Originally Posted by squirrel

I still haven't figured out what the advantages are to having a lightweight drive transmission, though.

The removal of weight from any system is an advantage. It gives you the ability to use that weight elsewhere, for another system, or simply as a buffer when you add things you hadn't planned to add. The argument I have heard is, "When you remove 4lbs from the base, you are just gonna end up adding it to the arm!!" Wrong!! You cant have that mentality when you design things... any weight savings from any system is an advantage. Hell, if we wanted to, we could add a 4lb block of lead to the VERY bottom of the robot, below where the CG of all the material that we removed was. Thats a pretty obvious advantage right there, and we havent changed the weight of any other system on the robot. Also, the removal of weight from rotating parts increases efficiency and acceleration. Just like lighter weight flywheels help your engine rev faster, lighter gears enable your motors to start and stop more quickly.

[MrForbes]

Originally Posted by Travis Covington

The argument I have heard is, "When you remove 4lbs from the base, you are just gonna end up adding it to the arm!!" Wrong!! You cant have that mentality when you design things...

I agree! but having that weight already committed to the drive base forces the rest of the robot to be as light as possible.

[Alpha 997]

Originally Posted by squirrel

I agree! but having that weight already committed to the drive base forces the rest of the robot to be as light as possible.

Good point. But the extra weight somewhere else would still be nice.

[Travis Covington]

Originally Posted by squirrel

I agree! but having that weight already committed to the drive base forces the rest of the robot to be as light as possible.

And then when you are 4lbs overweight, you drill two thousand holes in everything to remove the weight...

I can see where your argument is valid had we sacrificed strength for weight savings, or something similar... But in our case, we sacrificed nothing, and saved nearly 10 pounds total from our previous years chassis and drivetrain with the same if not better robustness and strength.

[Alpha 997]

Originally Posted by Travis Covington

And then when you are 4lbs overweight, you drill two thousand holes in everything to remove the weight...

I can see where your argument is valid had we sacrificed strength for weight savings, or something similar... But in our case, we sacrificed nothing, and saved nearly 10 pounds total from our previous years chassis and drivetrain with the same if not better robustness and strength.

Where did you guys get the transmission?

[Doug G]

Originally Posted by Alpha 997

Where did you guys get the transmission?

They designed it and built it!! They have been redesigning / refining their shifting transmissions each year since '02 I think.

Here's their '02 shifting transmission...

oops.. a better pic in CD-Media

Sure have come along way since then! I'm not sure how much more improvement can be done.. 6 motor CVT's?

[Alpha 997]

Originally Posted by Doug G

They designed it and built it!! They have been redesigning / refining their shifting transmissions each year since '02 I think.

Here's their '02 shifting transmission...

oops.. a better pic in CD-Media

Sure have come along way since then! I'm not sure how much more improvement can be done.. 6 motor CVT's?

Ohh... Did 254 build theirs too?