09 Nov 2007, 18:24
From a design standpoint they're a bit wierd - 8 turns of the wheel to 9 turns of the cable. I know Speedograph did have some left over but sold them to the yanks long ago and wanted a lot to remanufacture them in small quantities
The actual 8:9 ratio AND the direction of o/p rotation is what causes the problem. You can't do that in a single stage with normal gears which'll take plenty of torque - it can only be done with what are called screw gears. Look up any gear manufacturer's catalogue and they'll all state "low torque applications only, very susceptible to contamination" or words to this effect.
It could be done with a little gearbox and a pair of bevel gears doing the 90-degree bit, but that'd be £££ to replace a part that's relatively cheap and easy to replace. I'd be happy to just replace mine every couple of years....
...if they had any.
The actual 8:9 ratio AND the direction of o/p rotation is what causes the problem. You can't do that in a single stage with normal gears which'll take plenty of torque - it can only be done with what are called screw gears. Look up any gear manufacturer's catalogue and they'll all state "low torque applications only, very susceptible to contamination" or words to this effect.
It could be done with a little gearbox and a pair of bevel gears doing the 90-degree bit, but that'd be £££ to replace a part that's relatively cheap and easy to replace. I'd be happy to just replace mine every couple of years....
...if they had any.