Shaft couplers

[KennethToronto]

Does anyone know where I can find a 5/16'' clamp on coupling for the Atwood output shaft?

I've looked far and wide but I can only find 5/16'' set screw coupler (found at mcmaster)

[sanddrag]

What if you took a couple (or a few) of McMaster Part No. 9964K11 and welded them together?

[BillCloyes]

They can get rather pricey, but "trantorqes" might be a solution for you. They are available through small parts inc, (as trantorques) and mcmaster (as keyless bushings). We almost waited too long to get ours, as of earlier this week Small parts is back-ordered till almost Feb. Mcmaster, however, got them to us in 2 days. My team has used these for five or six seasons and I have personally experienced no real problems with them for the last three.

-Bill

[KennethToronto]

the reason I'm looking for a coupler (obviously) is because the output shaft on the Atwood is not long enough for our gearbox design...we have to extend the 5/16'' shaft.

hmm..the keyless bushing looks interesting

[KennethToronto]

Is there anything inherently wrong w. using a 5/16" set screw coupling to "extend" the length of the shaft?

[ChrisH]

Originally posted by KennethToronto
Is there anything inherently wrong w. using a 5/16" set screw coupling to "extend" the length of the shaft?

It depends on how you define "inherently wrong". There is nothing illegal or immoral about doing so.

But as Woodie has said so often "Set screws inhale audibly". Basically set screws are ok to use for holding a key in place or possibly keeping a lightly loaded gear or sprocket from drifting on the shaft. They should not be used to transmit significant loads. Since this application is apparently for a drive, the loads will be significant.

Think about set screws for a moment. It doesn't seem all that great an idea to use an inclined plane (screw thread) to generate a normal force that is in turn used to generate a shear force that resists a torque. Dimpling the shaft can help, as it greatly increases the shear force geneated by the normal force. But a set screw and dimpled shaft are no match for a keyed shaft and sprocket or gear.