The perfect 2 speed Transmission..... features...
 

what are some things to make a nice 2 speed transmission into a perfect one... like u know common problems with crappily designed 2 speeders.... also some nice addons you can think of to make it better.... all i could really think of was to add wheel encoders and a ratcheting tensioner on the transmission, and to have the pneumatic screw directly into the tranny instead of like on some ghetto rigged ubolt and to use 2 PNEUMatics instead of one big one going across..

Re: The perfect 2 speed Transmission..... features...
 

Some of the below may apply to transmissions of any type

Fast shifting on the fly.
The correct amount of backlash.
Along with the above, very very little room to be between gears, never a possiblity of both gears engaged at once.
Proper alignment.
No loads in undersirable directions (ie side loads)
Gears and shafts poperly spaced and captured - This one is very important. If you don't know how to do it or what I mean by that, we'll disuss it.
Both sides shifting at the same time.
All timed motors always spinning in the advanced direction while the robot is moving forward.
High durability.
Low maintainance.

Most of all, the driver nor software should not have to take any precausions when driving or shifting whatsoever. The transmission should perform sucessfully by its own mechanical doing no matter what the driver's input is. The mechanics of the transmission need to be robust enough to downshift at full speed and shift while switching between forward and reverse and shift up and down multiple times in a row very quickly and shift while turning clibming, etc any crazy thing you can think of (ie. drive into a wall)

The forces and situations that robots encounter in finals rounds I'm sure are far beyond any testing most teams do. Good drivers know the limits of their machines, but great drivers have machines with no limits. I say as soon as your robot runs (during the build period) you should run it hard. Put it through every torture imaginable. Then by the time ship comes, you'll hpefully have it made bulletproof.

Re: The perfect 2 speed Transmission..... features...
 

low weight

Re: The perfect 2 speed Transmission..... features...
 

easy enough to build in 6 weeks

Re: The perfect 2 speed Transmission..... features...
 

One word...reliable!

-Kyle

Re: The perfect 2 speed Transmission..... features...
 

make that indestructible!

Re: The perfect 2 speed Transmission..... features...
 

Simple... true that...>! infact last year ours was pretty reliable but stuff kept breaking like chain and stuff!! arrrghhh....
here is a picture of the tranny for 2005:
it has a FP and CHip....
the only thing i'm reallly worried about is using the skinny 1/8" plate shifting fork i don't think it should be too much of a problem....
i was really hoping to put the Output sprocket inside the transmission but that wasn't possible... or at least practical compared to teh current config..

Re: The perfect 2 speed Transmission..... features...
 

by gears properly spaced do you mean simply add the pitch radii and for the shafts secured you mean like collars and whatnot.... or is it something else?

if we build this thing it will be probably the hardest one to build so far.... esp considering the 1/4 " shafts, tiny parts, and the tight squeeze, our first 2 spd tranny was like 12X4X6 inches!!!! this one is like 4X4X2! (actually smaller if you don't count the extra empty plate for mounting) i mean for this thing i will have to countersink holes etc... so that screws don't hit gears etc etc... while on the last one we'd just move the gear forward some ... they were 20 pitch gears too! and like 1/2" face width ...

Re: The perfect 2 speed Transmission..... features...
 

Never Use the drill transmitions. I know that they are more then likely not going to be included in the kit this year I think a way to make a good trasmition into a great one is to run the motors into the gearbox directly without having anything inbetween (like a preassembled drill transmition) because two years ago our gearbox (a two speed shift on the fly) was almost perfect except for the fact that we would blow a drill transmition almost everyround. I got so good at fixing the drill transmitions that I could reasemble them blindfolded!

Re: The perfect 2 speed Transmission..... features...
 

Jeez folks.. what is with all the drill bashing lately?

I know MANY teams (mine included) that used the drill transmissions las year with NO problems.

That's right, we ran a drill motor/tranny combo all season last year powering our arm shoulder joint (under SERIOUS shock loads) with no problems. None at all. The original tranny is still in that robot today.

Everytime someone posts on these forums "never use the drill transmission! They blow up all the time! We destroyed 80 kabillion of them!"
I wonder: "What the HECK are you guys doing to that poor gearbox?"

Personally I hope we see it back in the kit.
(I know everyone thinks FIRST has ruled them out, but I'm still waiting for the OFFICIAL confirmation, not this speculation stuff, that they're not coming back in 2005.) The drill and tranny (when not used for drive) make an EXCELLENT high powered mechanism motor. Lots of power, lots of reduction, small package.

Seriously,
3 competitions, lots of severe shock loading, no problems.
What are you guys doing wrong?
What am I doing right?

John

Re: The perfect 2 speed Transmission..... features...
 

Heck John, we have used two drills for a two drill transmission the past two years, and we won two regionals with it!

I love the drills, they are small, lock when not moving, and just great motors.

Re: The perfect 2 speed Transmission..... features...
 

Thoroughly agree with you... we used the drills with the transmisions in 2003, 2002, and 2001 with no problems. I remember asking the same question as you last year--what are all these people doing so wrong that they can't use the transmissions?

I'd love to see the drill and it's transmission in the kit this year as well.

Re: The perfect 2 speed Transmission..... features...
 

For the people with successful use of the drill motors, did you run them in high or low gear? We had them in high gear in 2003 with no problems at all but in low gear in 2004 we had to rebuild/replace each maybe twice.

Re: The perfect 2 speed Transmission..... features...
 

We ran them in both high and low, with no problems

Re: The perfect 2 speed Transmission..... features...
 

WE had no problems with the drill transmissions and have used them in combination with the chips in two different transmissions (a 2 speed and a single speed). They are fairly easy to mount and we ran them in high gear. Although we used the drill transmissions and the mounts provided, I do not like the mounts. They are flimsy and you have to be careful not to overtighten and warp them. Everyone should take apart the drill transmissions at least once just for fun :ahh:. The thing to be careful with when you are using the drill transmissions is to make sure that the transmission and the drill motor are securely held together and that you use enough zip-ties to lock it in gear properly.
-Aaron