pic: Team 973 2009 Robot - RAPTOR

[JesseK]

Originally Posted by AdamHeard

We initially trimmed them with dykes that were custom ground to have no back angle, but while being lazy I found that a table belt sander works great (not sure if fine grit is required, it's what we used and it worked great for us).

We're using our pneumatic tube cutters for our new belting when it comes in. The cutters work wonders in stopping pneumatic leaks, so we're hoping to get a clean cut on the Rounthane every time. We're using the tiny gator connectors for everything though, because we couldn't get welding to work during the build season .

[xAlLKnoWingOnex]

it looks amazing i wish i got to see it work in person

[Michael Corsetto]

Originally Posted by Cory

In 2006 we turned the rollers for our practice bot on a 13x40 lathe (fairly common size for any kind of school machine shop with lathes) without much difficulty.

As long as you have the travel it's not too hard to do it manually. Takes a long time though.

Making the grooves wasn't too hard for us, I was referring more to putting a 1" ID through the entire 26" tube, is there a way to do that too? I'm not a very skilled machinist at all, I just know enough to get by. Does 254 drill out the middle of their rollers?

[Cory]

Originally Posted by Michael Corsetto

Making the grooves wasn't too hard for us, I was referring more to putting a 1" ID through the entire 26" tube, is there a way to do that too? I'm not a very skilled machinist at all, I just know enough to get by. Does 254 drill out the middle of their rollers?

The rollers we made in 06 were out of thick wall PVC tube, so they had the bore through the middle already and we only had to bore an inch or two out larger at the end.

The problem with them was that PVC is extremely heavy, and each roller would have weighed around 7-8 lbs. We ended up having to get a shop to remake them out of ABS for the weight savings.

It's possible to drill a 1" through hole in the roller, if you drilled from both sides with a series of varying length drills, but that's obviously not an ideal solution.

[roboticWanderor]

Originally Posted by Cory

The rollers we made in 06 were out of thick wall PVC tube, so they had the bore through the middle already and we only had to bore an inch or two out larger at the end.

The problem with them was that PVC is extremely heavy, and each roller would have weighed around 7-8 lbs. We ended up having to get a shop to remake them out of ABS for the weight savings.

It's possible to drill a 1" through hole in the roller, if you drilled from both sides with a series of varying length drills, but that's obviously not an ideal solution.

but then how were the ABS roller's bores made then? it seems a long bore like that would be almost impossible in a flexible material like ABS

[Cory]

Originally Posted by roboticWanderor

but then how were the ABS roller's bores made then? it seems a long bore like that would be almost impossible in a flexible material like ABS

There's plenty of ways of doing it. In 06 the NASA model shop made our competition rollers. They turned them to the correct diameter/length/put the grooves in.

They did the boring in two different operations. They stood them up on end in a very large CNC mill and used a series of drills of increasing length to bore all the way through. After they had the through hole they put them in another CNC mill and contoured the larger counterbore for bearings/plugs on each end.

That's just one way of doing them. They can easily be done on the lathe with enough travel, or very accurately by someone who specializes in gundrilling. Our rollers this year were made for us by another sponsor who did everything on the lathe but the hexes on the ends, which they milled.

[AdamHeard]

Originally Posted by roboticWanderor

but then how were the ABS roller's bores made then? it seems a long bore like that would be almost impossible in a flexible material like ABS

The sponsor who made them specializes in all sorts of "tubing" and this really wasn't an issue at all for them. The lathes had several times the travel required, and there are all sorts of "accessories" that will stabilize parts will being turned (like a follow rest). Pretty much, I walked into their shop expecting them to say no as I was asking for too much, and they laughed like what I had given them was no challenge at all.

[ginosoprano09]

Originally Posted by roboticWanderor

I really like ya'lls rollers , made from ABS eh?
care to mention where you got the material and how you machined them so nicely?

Just saw this robot in action and who could've imagined that it was going to be in your alliance