Phil,
There were 2 types of cone clutch fitted to veteran Douglas 2¾'s. The early type was smaller and was housed within the gearbox pulley - the later type, being larger, was carried outboard of the pulley, but stil part of it. The LDMCC's 1912 has the early type - some years ago the cente boss of the cone split - down the keyway. I effected a repair by clamping the 2 halves together and machining a register at the end to accept a retaining ring. This then held everything in place while I turned the rest of the boss to a true diameter. I then machined up a steel sleeve and pressed it onto the boss (having removed the retaining ring). As far as I am aware, the clutch hasn't given any further problems.
Regarding the supply of keys - some of the older sizes are not easy to find these days. It is often quicker to set up a bit of mild steel in the lathe and part off a couple of discs of the required diameter and thickness and then saw out sections to the required depth.
Whilst we are on the subject of keys, Mr Douglas favoured the use of 2 keys on taper fit sprockets/pulleys - this is bad practice - the taper should do the driving, the key just keeping everything in place while the nut is tightened. The addition of a second key at 90 degrees to the first makes it almost impossible to get the taper to seat correctly - thus making the fit less effective.
Regards,
Eddie.
