I’m having problems with a Smart & Brown Model L lathe lever-operated headstock, specifically the collet-only version that uses dead-length collets 5159.

I purchased the lathe knowing there was an issue with the collet-closing mechanism. The headstock appears to be incomplete and messed around with and I’ve subsequently obtained a nearly identical headstock in the hope to understand how they work and hopefully get at least one of them working correctly.

One headstock has two “hooks” to push (or pull?) the collet-closer tube, and the other headstock lacks these hooks but may have used two dog-point screws to achieve something similar. Curiously, the closer lever is moved to the left in order to push the closer tube to the right and thus press the collet closed. That makes sense but I can identify no part of the mechanism that achieves this reversal of direction and I’m feeling fairly stupid to have drawn a blank on something that I would have assumed obvious.

I have a scanned manual for several different headstock versions and I may have a variant of the PDH headstock. Despite having dismantled and reassembled the collet-closer mechanism many times I am still unable to fathom how it should (and occasionally does!) close the collet. My headstocks do not feature the “obsolete toggle mechanism”.

I’m hoping that someone here has experience with this collet closer mechanism. If so, please let me know and I will try to frame some appropriate questions that will hopefully elicit the information to get this working.

Thank you.