pic: TechnoKat Transmission 2003

[Andy Baker]

Originally posted by sanddrag
A few months ago I was doing some numbers on this drivetrain and found that a 60:40 ratio would be much more effective in place of the 50:50 ratio. The 60 being on the final drive stage. Your center to center distance remains the same. The ratio difference in the original design I think is too big and you could have a more practical sprocket reduction (or a greater choice in wheel size) after the gearbox with the new ratio. What do you think?

In reference to the TechnoKat tranmission shown in the CAD pic above, I wish that we did have some further reduction in this gearbox. Our main drivetrain mechanical problem this year was AFTER this gearbox, where we had a 11:40 ratio to reduce the speed before driving the tracks. The torque that the 11 tooth gear saw was high and we stripped gears. (however, we had no problems with this gearbox)

Originally posted by sanddrag
Given the game is accomodating, my team is seriously looking into building a drivetrain very similar to that of team 226 next year. To make our life a little easier, I was wondering if you can provide any dimensions on the side plates and bearing hole locations. Do all the shafts' axes of rotation lie in the same plane? Also, I was wondering the length of the side plate spacers. That would be very much appreciated.


A couple more questions:
Is the Chiaphua shaft and the central shaft 3/8 or 1/2 diameter? And how is the Chiaphua shaft attatched to the Chia's armature output shaft: is it pressed, welded or keyed?

Finally, (Kyle is right) I have freed up some time at work and I will be able to do the white paper on this gearbox, which is a dramatic improvement from 2002 gearbox. My goal is to be done with it by IRI (July 18) and have hard copies to hand out at IRI.

Sand... to answer some of your questions:

Yes, all of the axii line in the same plane, with the exception of the drill motor.

The length of the side plate spacers... I need to look at the prints for that one. I think that they are around 1.2".

The CIM motor was keyed to the inside of the 12 tooth gear shaft. This 12 tooth gear was on a 3/8" shaft, a 32 pitch gear was pressed and welded onto the same shaft (mated with a 14 tooth pinion on the drill motor)... and this shaft/gear assembly was broached for an 8mm shaft with a 2mm keyway, mating with the CIM motor.

Andy B.