Round keyway question.

[Carld]

Round keys are very strong. I built several barrel stave cutting machines and we used a cutter head with many staged insert cutters and it required two round .500" round keys at 180 deg from each other on the shaft. I had to cut the shaft with a round nose endmill and compute the depth of cut so there was no slop. I think I built 5 machines and it was alway tricky to get the shaft keyways just right with no slop. The cutter head was powered by a 10 hp motor if I remember correctly and swung from side to side as it cut the stave.

A Dutch or Scotch pin is usually a tapered pin installed as shown in the opening thread photo. I always used a set screw in place of a pin and locked the set screw with locktite. I never had one fail or escape.

[Swarf&Sparks]

I recall from some part of my mis-spent youth, a heavy machinery coupling using 3 tapered pins.
The setup was 3 tapered "keyways" with 3 tapered pins.
Each pin had an adjusting screw to drive it tighter into the matching taper, removing any sign of lash. This was part of PM.

Anyone encountered these couplers, or has my fading memory combined two different couplers?
These were on some very high torque applications in heavy industry.

[lazlo]

Well I sure don't see anything wrong with Dutch pins.

So is a Dutch pin (key) the same thing as a Scotch key?