Live axel on kit skyways?

[Bill_Hancoc]

I tried to search this and didnt find exactly what i wanted but ill give it a shot.

We need a quick way of mounting the kit skyways to shaft that is smaller than the ID of the skyways. we dont want to have to use many machine tools since our resources are limited. is there an easy quick way to do this?

any ideas welcome


thanks Bill

[Veselin Kolev]

There are two answers.

If you want to run a shaft through the bearings, which are 3/8", just get an aluminum spacer. For example, if you want to run the wheels on 1/4" shafts, just get an aluminum rod with 3/8" OD and 1/4" ID. These are very common at OSH, in fact our robot uses a bunch of that metal for our manipulator. However, the ID is actually less than 1/4", so we just drill it out on a drill press. You have to be careful to keep concentricity, but it can easily be done. So yea, just drill that stuff out to whatever
ID you want.

If you are talking about taking the bearings off the skyway and powering it, like having a shooter wheel on a powered shaft, it can also easily be done. The bearings are .875 OD, so the hole in the wheel is .875 ish. However, there is a flange to keep the bearings from going in, which has an OD of a little less than .750". You can press a .750 shaft into it, which can have the proper bore drilled into it for your uses. This can't take too much torque, but its easy. If you want it to take more power, this is what my team did for our shooter wheel:

We drilled out the flange (making a through .875" hole in the wheel) and glued in a cylinder of aluminum with a .875" OD and .5" ID, which was keyed. Along with the glue, we used four steel rivets through the wheel and into the aluminum to transmit most of the torque. It is a very nice and easy way to do this, and you just need a drill press. (or if you're really skilled, a hand drill). I'm sure if you guys dont have a drill press, there would be some team willing to let you use theirs. Just make sure you have a .875" drill bit, and use a low cutting RPM :D

[Cody Carey]

The bearing wouldn't work if it is a live shaft I don't think... try finding some thick-walled tubing, and set-screwing it to the shaft, then fix the wheel to the tube.

[Madison]

For what it's worth, remember that the bearings on the 8" Skyway wheels accept a 3/8" diameter shaft while those on the 6" wheels accept a 5/16" diameter shaft.

[Ben Piecuch]

For some non-drive applications, we've used bronze bushings to adapt from an over-sized bearing onto an undersized shaft. They take up much less room than a bearing, so it's easier to find sizes that fit. Otherwise, if you can find some tubing that fits just right, you're all set.

What diameters are you trying to fit together?

BEN

[Veselin Kolev]

See if you can find some bearings with the same OD as the kit bearings, but with a smaller ID (as in the size you need).

Good idea. In fact, here are some bearings that would work for this:

Mcmaster parts:
6383K14 -- 1/4" ID, 7/8" OD, 1/4" wide
6383K15 -- 5/16" ID, 7/8" OD, 1/4" wide

Your standard, open ball bearings, less than 4 bucks each.
Just tap out the old bearings, and hammer in the new ones.

Madison - while the 8" skyways are always 3/8" sealed plain bearing wheels, you can order the 6" skyways with either 5/16" flanged bearings or 3/8" plain bearings. Our 2005 and 2006 both use 6" skyways with plain 3/8" bearings.

[Bill_Hancoc]

I need the wheel to be driven for the shooter

[Madison]

Madison - while the 8" skyways are always 3/8" sealed plain bearing wheels, you can order the 6" skyways with either 5/16" flanged bearings or 3/8" plain bearings. Our 2005 and 2006 both use 6" skyways with plain 3/8" bearings.

Ah, okay. I used 6" wheels we had laying about the shop and so I didn't realize you could specify what you wanted while ordering them. Good to know.

[sanddrag]

What I've done in the past for a prototype is found a washer that fits right into the little step in the plastic in the hub. Put ont on each side. Put some threaded rod through. Couple nuts to clamp those washers into the wheel real tight. Couple more nuts to hold the first nuts. You're good to go. Balance may be a problem though.

[Cuog]

if you use a clamp type system using a piece of rubber inside as a spacer will help to eliminate vibration and keep it close to balanced if you take your time when making it

[Derek Bessette]

We used taper locks from McMaster Carr (http://www.mcmaster.com/)

We just bored the skyway wheel to 7/8" and put in the taper lock. We used a 1/2" shaft. McMaster sells these for all standard sizes. They are a little expensive, but they do a great job.

Here is the part number for the ones we used: 5926K16

Good luck!