Wednesday, December 31, 2008

Drivetrain Build Completed

At long last, after one more visit to Mike's, my new drivetrains are done (or 99% done). We shot some video that supplements the R2LA VI DVD drivetrain tutorial, it can be fount here:

Part 1
Part 2

I used the Dremel cutoff wheel to trim the motor mount bolts to size to avoid having them interfere with the chain, and I needed to cut down the bolts that secure the motor to the motor mount as well.

Next, I took the plunge and drilled out the 1/2" ankle bolt holes for the channel pieces.

The ankle bolt holes will house a 1/2"->3/8" bushings, and these bushings need to be ground down a bit, as they are longer than the channels' wall thickness.

The drivetrains are pretty much done, other than having the bushings pressed in, and having the channels painted white.

Now comes the inevitable fight to get the motors to fit into the battery boxes. Also, these motors only run on 12 volts, whereas my droid currently supplies 24 volts to the motors, so my power needs to be adjusted. As I'm running out of vacation time, I'm not sure how soon I'll get to those tasks.


Calvin Thomas said...

I've been watching you guys build these motors from the start.
On your batts, You can just connect the 2 batts for 12v. by running pos. to pos. neg. to neg. and pull off 1 of the batts to the motors.
But you probly allready know this.

How do you attach the foot shells to the motor assy?

Victor Franco said...

Thank you Calvin. Of course, the credit for the design goes to Mike, as does all the help he provided with the build.

The foot shells are locked in place due to two factors. The first is that the top channel fits the inside of the shells exactly, so the front-to-back location is set. The left-to-right position is set due to the leg's ankle in the channel. This is the same way things work on my current H&A drivetrain. Hopefully that makes sense.


Calvin Thomas said...

Hey Victor,
I was watching the videos and I was wondering.
Are those motor setups free wheeling when the power is off?
The reason I ask:
Currie scooters makes a gear for the motor that is free when the power is not applied.
Here's a site:
It kinda looks like the one you guys use on the motor.

Victor Franco said...

Hi Calvin,

No, the motor setups won't free wheel when the power is off, the gears we are using are locked onto the NPC shafts.

There is certainly a part of me that would love to be able to push R2 short distances when he's powered off, but on the other hand I like that the gear head motors are self-braking, and that I can park R2 on a sloped surface without having to worry about him rolling away. I suppose the ultimate solution would be a way to easily disengage the gear from the shaft on demand.