Denford Software & Machines

Out of curiousity, I checked the speed ranges on my Synchro (the one with the 12 speeds controlled by a lever on the headstock, not the electric control version). Lowest I can get is 70rpm, highest is 1550, by fiddling with the settings of the variable speed pulleys. Closest I can get otherwise in one go, is 80 rpm - 1200rpm, instead of the claimed 65 -1600. I changed the belt, because the old one had worn down to 19mm wide instead of 22mm when new, but to be honest, it doesn't seem to have made any significant difference.
It doesn't bother me seriously, because I should be able to do all I want with those speeds available, but I'm just wondering if the claimed speeds were ever achievable, or am I just missing a trick somewhere. It seems to me that the geometry of the speed change mechanism is capable of moving the pulleys through a range of 3-1, but to get the claimed speeds, given a backgear ratio of just over 5-1, would need to move the pulleys through a range of 4-1. Everything under the end cover looks original, nothing looks to have been changed or butchered. Anybody got any ideas?

Mine is similar. I wondered about it then decided it wasn't worth worrying about. You'll rarely want to use top speed and then not for long because of the noise.

Pete. wrote:Mine is similar. I wondered about it then decided it wasn't worth worrying about. You'll rarely want to use top speed and then not for long because of the noise.

That's what I suspected. I'm still curious to know why the machines as built differed so much in respect of speeds to that which Denford claimed for them, and indeed, printed on the plate on the headstock top. I don't suppose that knowledge is available any more. My Raglan, with a similar variable speed pulley system couldn't get the speed range Raglan claimed for it, so Denford weren't alone in this
Anyway, at present mines driven via a very old Jaguar inverter, so old it doesn't have speed control, so if the speeds really annoy me (it will be insufficiently low bottom speed ) then I'll just have to upgrade to a modern inverter. Oddly, I don't find top speed particularly noisy.

Richard