New Improved DrJoesDrillShaft

[archiver]

Posted by Dodd Stacy.

Engineer on team #95, Lebanon Robotics Team, from Lebanon High School and CRREL/CREARE.

Posted on 12/4/2000 4:33 PM MST


In Reply to: New Improved DrJoesDrillShaft posted by Joe Johnson on 12/2/2000 7:27 PM MST:



We had multiple disasters in 1999 around failure of marginal shaft splices on the drill gearbox outputs (mea culpa). Great for character building and education in the supportive wonderfulness of the FIRST community, but really a bummer way to spend a competition, compared to watching the games and digging all the kids and 'bots.

In 2000, we made replacement shafts per Dr Joe's drawing - thank you, Joe - slightly amended by reverse engineering of the originals (third decimal place, Joe!). Talk about a difference! Advice to any new teams from 4 year's fumbling:

1) Make shafts, long enough to mount a shaft bearing next to the final drive sprocket.

2) Run the gearbox in Hi. Do your final stage of gear reduction between the shaft and the drive wheels. Mount the drive sprocket on a Trantorque. You can change the sprocket, and - running the box in Hi - it won't slip.

3) Limit your gearing to a 7-8 ft/sec speed if your strategy is for a fast game - the torque loads work well for the drive system, and your drivers can't handle any faster anyway. (Yeah, yeah, I know) If you can develop enough traction to play a grunt pushing game w/o flunking the carpet destruction test, you're own your own for all of the above.

My real reason for writing is to ask the community's opinion on the following question: Is it within both the rules and the spirit if someone arranged to have a machine shop fabricate (with materials in the SPI catalog) shafts per Dr Joe's drawing and make them available at cost to any and all teams? Teams could take a hit against their SPI budget for the material and pay the machine shop's nominal charge. I think that's what we have done in the past, just making it available to all, regardless of resources.

I'm not offering to do this, mind you. I'm just asking. This has been an incredible pain in the past, and I'm just interested in how we can help new teams focus on the main business and avoid the bs. So, what do you say?

Dodd