pic: 571's new gearz loose weight

[JessR]

Originally Posted by Salik Syed

What is the gear inbetween the 2 small gears that mesh with the bigger hi/low gears for?

Let me define the shafts, then you'll see.

There are 4 shafts in this tranny:

1. idler shaft
We also call it the synchronizer shaft, it transfers power from the drill motor to the input shaft. Using this extra shaft allows us to locate the drill motor right next to the fp motor and facing in the same direction.
The drill motor drives the idler shaft at about a 3.5:1 reduction. The idler shaft is geared 1:1 via a pair of plastic gears onto the the input shaft
2. Input shaft
(It's next to the fischer price motor in the foto) - This combines both drill & fp motor inputs onto a common shaft. THe fp motor drives a plastic gear on the input shaft. A second plastic gear is driven 1:1 by the drill motor idler shaft as described above.
3. Intermediate shaft.
About a 3:1 reduction from the input shaft, and drives onto either high or low gear on the output shaft.
4. Output shaft.
That's the one with the sprocket on it and the shift fork/hex sleeve between hi & low gears.

So - the gear you're asking about is on the intermediate shaft, and receives power from the input shaft at about a 3:1 reduction.

A side note, our #1 design goal here was to have the motors completely inside the tranny and have the motors run the same direction on both sides of the robot (the l & r side trannys are identical and face the same direction on both sides of the robot - we just use the other side of the output shaft).

Well - hot news from Atlanta -
I just spoke to the team in Atlanta, we're doing well but had a motor problem a couple of hours ago
- Someone's appendage came inside our chassis and smashed a drill motor brush housing, ouch!!
They finished the round on just on the fisher price, but the poor thing smoked at the end - just finished an emergency motor transplant with 4 new motors in time for the next round......(the tranny's are held in by about 6 screws each, so they come out pretty easily, thank goodness)

Hope you're teams are having fun if in GA.
Jesse.