The best multi-speed transmission

[Alpha 997]

AndyMark's transmission is alright, but I've seen many that are just as good and much lighter. What do you guys think is the best multi-speed transmission that are also light and durable?

[Alex Cormier]

you're own custom gear box. whatever your heart desires and your machining capabilities. you can build the best one ever. It doesn't matter who's is best. I see if you made one and it works on the bot and is effective you have reached your goal.

other then that general stuff, i do love the orginal 33 4 speed auto which 1126 has adapted for the last 3 years.

[Lil' Lavery]

The 254/968 transmission was quite impressive this year, weighing in at a shocking 1.3 lb.s. It was obviously lighter than virtually any other shifting transmission (and most single speed) in FIRST, could take input from 1 or 2 small CIM motors, and worked without a hitch.
The AndyMark's are fantastic for their reliability, ease of assembly, flexibility (can take 1 or 2 small CIMs, Large CIM, or even a FP through an AM planetary), low weight and cost, and durability. They have several areas teams can lighten them even more will little trouble (namely the cluster gears and mounting plates).

[Alpha 997]

Originally Posted by Alex Cormier

you're own custom gear box. whatever your heart desires and your machining capabilities. you can build the best one ever. It doesn't matter who's is best. I see if you made one and it works on the bot and is effective you have reached your goal.

other then that general stuff, i do love the orginal 33 4 speed auto which 1126 has adapted for the last 3 years.

Yeah. But building our own gear box won't be easy. We don't have enough machines to make a transmission. The best thing we got is a mil. I’m trying to build or own drive train and wondering which transmission is the best to use. I’m looking for a light weight, multi-speed one. 254’s transmission was impressive I wonder where they got them from.

[Alpha 997]

Could you guys be so kind as to show me photos and purchase information to the transmission that you think is great?

[Cody Carey]

Dewalt transmissions are an awesome choice. Under 100 dollars for a three speed shift on the fly transmission; you really can't beat that anywhere else.


Joe P.'s White paper should explain everything you need to know.

[Joel J]

254/968's are great. Looked at them in the pit, and I could barely feel the weight of them. On superficial inspection they also seemed really efficient for a direct drive setup. AM's are good also, just make lighter side plates..

[sdcantrell56]

254's are custom built using some pretty exotic techniques. I could be mistaken but I heard that they are planning on using Andymark gears next year to make them easier to build which will in turn make them heavier. I did look at them in the pits and they were absolutely amazing.

[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.

[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]

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.

[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.

[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.

[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