Just finished the prototype. We will be installing a pair of these in our 2003 robot and testing this Fall. Weight including angle mount is 4.8 lbs each. Still working on the shifter design.
Couple of questions.
Any plans to publish the drawings?
Have you thought about or designed a way to use the CIM instead of FP?
Is the mount really strong enough? I can imagine some pretty high loads on the bolts (or is it welded or something like that?) attaching the angle aluminum to the shaft collar in a robot bouncing up and down.
So - what’d you end up using to final drive the gearbox? Did you pull the pinion off a DeWalt motor?
I followed Dr Joe’s method and used a planet from a second stage. I was tempted to run the 2nd stage missing a planet and still may try it after the initial testing is completed.
This design is flexible in that the transmission adapter has a lot of room to add countershafts. I could have designed it for the CIM and added more support between the transmission adapter and the motor plate. As it is the only parts that have ‘real’ drawings are these two main pieces. The clamp collar is held on with two 1/4-20 bolts but I think I like the OCCRA solutions and will replace the lower section with a block. I will test first 'cause you cannot learn unless you break something first!
BTW,I am looking for some suggestions on shifting mechanisms 
.
how is the XRP transmission shifted? is there a part that slides back and forth, or something that rotates, etc…
also, i recall Joe J. said that the XRP transmissions had 3 speeds to 'em. is this the case with your transmision?
There is a piece that rotates (the black thing behind the torque limiter) to three positions. It rotates, but it’s a relatively large diameter so its not too far from linear movement. It takes a good amount of force to move (very rough estimate - 5lbs) and has pretty strong detents on each position. Of course, this isn’t really enough info to build anything off of…
I haven’t taken one apart, Andy, so I can’t really suggest how something larger than that little black knob can be fixed to that rotating shifter peice. Please keep us updated, though.
An update on our testing this Fall.
The dual motor works well. We made a thicker spacer to hold the last ring gear as the torque out of the two motors was causing the clutch to trip when set to drill. The palstic gears on the Bosch are holding up well. We tore a brush out of one of the Boschs when the clamp collar was not full tightened and the unit spun. No problems with the motor mount to the gearbox. We also smoked a FP motor, it was an abused one from this past season and running at slow speed while turning the robot hastened its demise.
The Dewalt is flawless, it stays in gear and can take serious reversing loads. This was how we found out about the clutch slipping and requiring the thicker spacer.
I cannot wait to see what we get for motors this year!
so is this the drill motor that we will be getting or are we going to get the ones from last year that almost fell apart?
Nobody will officially know until kickoff. That drill motor is the same that we had in the 2004 kit. The transmission was bought separately from DeWalt. Numerous teams have been experimenting with the transmissions during the last year or so.