pic: FRC 1771 Swerve Module

[Aren_Hill]

Originally Posted by sdcantrell56

Cool. Specifically what is on the wheel to take the hex shaft. Look for the second revision in a little bit

the wheel has 2 pieces of .75" o.d. aluminum round 6061 with a 3/8ths hex broached in it. those 2 pieces are welded onto the waterjetted wheel sideplate

[Akash Rastogi]

sorry to be a total noob, but what motor do u use to drive? or any drawing of the inside or an exploded view would be awesome. Thanks.

[hillale]

they use the cims in the other chassis picture with chain travelling to the modules to drive the wheels. Inside, there are just bevel gears going from the vertical shaft to the shaft the higher side sprocket is mounted on.

[Ice Berg]

I'm considering a swerve drive for next year, but I've been having trouble finding hex shaft and sprockets that match. The only place I really know to look is McMaster. Where did you guys get yours?

[hillale]

Originally Posted by Ice Berg

I'm considering a swerve drive for next year, but I've been having trouble finding hex shaft and sprockets that match. The only place I really know to look is McMaster. Where did you guys get yours?

We had a local sponsor make us custom 7068 aluminum hex shafts to fit the sprockets.

[sdcantrell56]

I am using 2 cims into a custom gearbox per side. It is a single speed transmission. Also the best way to get sprockets to match hex is to buy plain dore sprockets and broach them into a hex. Hex stock shaft is very cheap and can be bought at mcmaster.

[AdamHeard]

Originally Posted by sdcantrell56

I am using 2 cims into a custom gearbox per side. It is a single speed transmission. Also the best way to get sprockets to match hex is to buy plain dore sprockets and broach them into a hex. Hex stock shaft is very cheap and can be bought at mcmaster.

However, 7068/7075 hex shafts that some teams are using have to be custom made.

[sdcantrell56]

Is 7068 or 7075 really necessary for a hex shaft that is short in length and supported on both ends. I would think that it would be plenty strong enough since you dont have to worry about a keyway.

[AdamHeard]

Originally Posted by sdcantrell56

Is 7068 or 7075 really necessary for a hex shaft that is short in length and supported on both ends. I would think that it would be plenty strong enough since you dont have to worry about a keyway.

I really doubt 6061 hex shaft would hold up in that situation; I haven't run the numbers, but I doubt it would work well in a place like the shafts in a drive.

[Ice Berg]

In the picture above, of the module with a blue wheel, I was wondering how those sprockets drive the shafts. It doesn't look too me like they're hex, or keyed.

[Aren_Hill]

Originally Posted by Ice Berg

In the picture above, of the module with a blue wheel, I was wondering how those sprockets drive the shafts. It doesn't look too me like they're hex, or keyed.

Right behind that snapring you see is a 1/2" hex followed by a step of 1/2" round for a bearings then it steps down to 3/8" hex for the wheel then at the very end it turns into 3/8" round for another bearing and snapring.

[Ice Berg]

Well, my team doesn't have the machining capabilities to make a shaft like that, however, I thought about it and I think I've found a simpler solution in terms of machining. Instead of lathing anything on the hex shaft, we would use a 3/8" shaft all the way through, and where we needed bearings (on either side of the module) we would make a sort of bushing whose inside would be broached to a 3/8" hex, and whose outside would be a 5/8" dia. circle. This way we could put a hex shaft through the center and use a 5/8" bearing around the outside, and snap-rings to hold it all in place.