I have a Clarke CL430 (CL500 without the Mill Head) which i bought from an industrial auction and the item had several pieces, tooling and stock missing.
​I managed to get a part refund so I kept the lathe, but one of the missing items is the Idler pulley and its mount to drop down to the lower speeds.

​Clarke can supply all the bits, but not cheap, so as a project I was planning on making it (any buying buys)

​I have taken the spindle speeds from the manual and worked out the pulley sizes I SHOULD need !, but would like a check.

​Does anyone here have this model lathe that could measure the idler pulley sizes for me ?, only the largest size is needed (as I can then calculate the others)

This image (from another forum post) is the pulley fitted that I am referring to.
http://imgur.com/tAriX5t

​Thanks for any help.

@Richard, thanks, anytime would be great, no rush. don't go out in the dark for me !

@John Rudd
​I have measured what I have and worked out the sizes, but the idler pulley could be a wide range, all subject to how large its main drive pulley is.
​The motor runs at 1400rpm, and the pulley sizes are 75 diam to 150 diam (which gets 700rpm), then 95 diam to 135 diam and 122 diam to 92 diam (all approx. sizes) and these all calculate out to the correct rpm according to the manual and my hall sensor which is fitted.

​The problem with the idler pulley is that it is driven from the motor pulley from a 50mm diameter pulley.
​So if i make the driven pulley on the idler at 100mm diameter this then gives the idler pulley a fixed speed of 700 rpm, which I can calculate out to get the correct sizes, however if I was to make the driven pulley 150mm diameter this would give other sizes as it would reduce the fixed speed of the idler pulley to 466 rpm.

​I am not bothered about replicating the speeds exactly, in fact if I could get it to run slower that would be better as 160 rpm is still a bit quick for a coarse screw thread cut, but I don't want to buy a 150 diam pulley and then find it clashes with other parts when tensioned up.

According to me, a 150mm driven pulley will give me 466 rpm, ,then a 93mm, 72mm & 50mm pulley would be required for the speeds. I might (depending on the recommended minimum pulley size for the v belt) go smaller to reduce the lower speed.

​Ideally a new variable speed motor would be nice, but that depends on tonight's Euro millions results…

Many thanks. That is perfect.