pic: FRC 1771 Swerve Module

[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.

[sdcantrell56]

That method would definitely work although bigger bearings are more expensive and its heavier but if thats how you have to do it then by all means use that method. It will definitely work and would be less labor intensive.