10-09-2006 12:38 AM

Travis Covington

Re: pic: Team 294 Wheel prototype

You left the tapped holes in the solid model for the ring to mount to? Do you plan to use the rapid prototyped parts, or aluminum machined versions? I hope its the latter, because no RP process will produce that wheel with enough strength for a FIRST robot. Those wheels had a very small factor of safety as machined aluminum, RP is just scary. Maybe I am missing something?

10-09-2006 01:02 AM

AdamHeard

Re: pic: Team 294 Wheel prototype

We definately aren't planning on using these, especially since they are hollow. We will probably machine them out of 7075 aluminum (That's what's the engineers tell me; I just started learning drivetrains & machining this summer and I usually program).

We RPed them because the machinist wanted to show off his RP machine, and it's nice to be able to show team members something other than a CAD drawing.

I'm not sure what you mean about the holes, but the RP machine didn't like the tapped holes on any of the pieces and printed them as if they weren't tapped.

After talking with Cory from 254, we came to the conclusion that the 2005 models would be better than the 2006 ones because it allows us to adjust to different shaft sizes easier. What do you think about this?

10-09-2006 01:13 AM

Travis Covington

Re: pic: Team 294 Wheel prototype

RP is definetly cool. I am a little jealous

I couldn't say which would be better. I'd imagine you would know what size shafts you would be using that year, so the hub might not be that beneficial. I would say that 7075 is a little overkill though (and a little pricey too!) 6061 is plenty strong enough. I don't think any of the teams who have used those wheels have ever bent them.

10-09-2006 01:40 AM

Gabe

Re: pic: Team 294 Wheel prototype

For Triple Play, 254 graciously gave the dimensions of their wheel to 604. We changed the design to better suit our robot, keeping the width and diameter the same, but changing the spoke design. These wheels are a nice combination of functionality and beauty.
About your material choice, I would go for 6061 aluminum instead of 7075. That alloy costs a pretty penny, and is completely uneccessary. A quick glance through McMaster-Carr puts 7075 at twice the price of 6061. Our wheels for 2005 were machined from 6061, and for Aim High our wheels were 6061 as well.

These are our 2005 wheels, very similar to 254.

10-09-2006 01:44 AM

Cory

Re: pic: Team 294 Wheel prototype

Gabe--Your attachment seems to be broken.