11-30-2005, 02:12 PM
Hi Ron,
I made a small wheel at work today. With a 5/16 hole drilled in some neoprene, I press-fit it on the 3/8 wheel hub. Then I lathe-turned it down to 0.680, which is what I think the old wheel was originally. The neoprene is stiffer than rubber, and may not give as much friction to the turntable drive rim, but hopefully will not slip during the change cycle. The big end of the wheel has been shorn of its rubber, and I will laser-cut two rings of .030 steel, slightly larger in OD than the bare wheel, to mount up against it to make a "pulley" I can slip an O-ring of 1/8 cross section and 2" OD over. Since there are 20 small holes in the bare wheel, I will put 4 holes in each ring to line up the whole sandwich of parts for either adhesives or very tiny screws. I suppose if this doesn't work I can lathe-turn a bell-shaped nylon wheel with an O-ring groove in it.
As far as the inconstant speed, I notice that there is a degree of freedom present of the drive shaft for wobbling tangentially to the turntable drive rim, which could cause "wow" to happen. Why didn't they just stick with the worm-gear (I think) drive?
In any case, if I can get this drive going, then I'll investigate that stylus issue.
I made a small wheel at work today. With a 5/16 hole drilled in some neoprene, I press-fit it on the 3/8 wheel hub. Then I lathe-turned it down to 0.680, which is what I think the old wheel was originally. The neoprene is stiffer than rubber, and may not give as much friction to the turntable drive rim, but hopefully will not slip during the change cycle. The big end of the wheel has been shorn of its rubber, and I will laser-cut two rings of .030 steel, slightly larger in OD than the bare wheel, to mount up against it to make a "pulley" I can slip an O-ring of 1/8 cross section and 2" OD over. Since there are 20 small holes in the bare wheel, I will put 4 holes in each ring to line up the whole sandwich of parts for either adhesives or very tiny screws. I suppose if this doesn't work I can lathe-turn a bell-shaped nylon wheel with an O-ring groove in it.
As far as the inconstant speed, I notice that there is a degree of freedom present of the drive shaft for wobbling tangentially to the turntable drive rim, which could cause "wow" to happen. Why didn't they just stick with the worm-gear (I think) drive?
In any case, if I can get this drive going, then I'll investigate that stylus issue.
