2 3/4hp Tapers

[RobertC]

Hi

I wonder if anyone can help save me some time! I need to find out the degree of taper for the following on a 2 3/4hp machine (it has a 2-speed gearbox if that makes any difference).

Gearbox primary drive (the side that is threaded 13/16”x28tpi LH)
Gearbox final drive (threaded 7/16”x20tpi)
Crankshaft taper for flywheel

By the way, does anyone know of a supplier for the 13/16”x28tpi LH nut?

Thanks for any help

Robert

[Chris]

Hi Robert
    I cannot say that I have actually measured each of the specific tapers you have listed but from experience all tapers that I have machined on Douglas crankshafts and gearbox shafts in the past have been 5 degrees.
Chris.

[Doug]

Robert,

While I was repairing a TS 2-speed gearbox I took some dimensions and made a drawing of the main shaft. The angle is five degrees as Chris mentioned.

While not specifically measuring the angle of the taper on the sleeve gear (I only had to re-bush it) I did record diameters and lengths as best as possible. Trig-ing those out, I get something more like 3.5 degrees.

Tapers are a bit fiddly, if they are off just a little bit the fit is awful. So best to match up against what bits that you might have (if possible) rather than worry about a theoretical value.

-Doug

[RobertC]

That's great, thanks very much.

Robert