Golborne Vintage Radio

This may be a stab in the dark.I have recently aquired a Pultra Lathe and I am wanting to know what thread size the collet ,chuck retainer uses .
Regards
Robin

Which Model?
See http://www.lathes.co.uk/pultra/index.html

Alan

From memory, the Pultra lathes use either 8mm or 10mm collets. There is a book: "The watchmaker's lathe" by Donald DeCarle, one of the great horological authors, which has a list of manufacturer's collets and their dimensions, including the drawbar thread. I have a copy but it is not in its correct place on the shelf so could be anywhere. If it pops up in the next day or two I will answer, fully, your original question. I recommend getting hold of a copy of this book as it will give inspiration for attachments etc. It was later published as "The wachmaker's and model engineer's lathe". There do appear to be PDF versions available for download.
Rod

Thankyou for your replies.Mine is very simalar to the 17/50 i am after the threaded collet holder that secures the chuch in the rear tailstock .
Regards
Robin

I found my copy of the book today. As it is quite old it does not cover the "modern" 17/50 model. The 1750 is a 10mm lathe and I think of it as a clockmaker's rather than a watchmaker's lathe. The Pultra 10mm collets listed have a thread 0.389" diam and 1.0mm pitch.  I am guessing that it is the drawbar which you need, which is internally threaded to screw onto the end of the collet and draws the collet into the headstock. I am attaching  a photo of my watchmakers lathe drawbar and a collet.

My solution would be to make a drawbar and to use a scrap collet to make the necessary tap. As it is probably not going to be heavily used, the drawbar could be made from brass rod. The collets are hardened and would probably cut steel if the flutes were reasonably ground but just grinding three eqally spaced slots using a Dremel type tool would be adequate for cutting brass.  I am quite happy to give any further advice as I have spent a good deal of my working being paid to make swarf!
Rod[attachment=20321]

Thankyou Rod
That is the same as i had .I had 2 one fitted in the chuck side and one for the tailstock end. I t is painted grey with an add on fitted between on a base for mounting a grinder. I presume it is ex military stock due to the colour and came with a mahogany box of collets chucks and a tool rest similar to a wood turning tool rest. Its a pity it came with a manual unfortuanatly.I will try the tapping advice and look for some brass tube as i have brass bar but unfortunately the lathe does not have a hollow shaft.
Regards
Robin

If you have a look on "Model Engineer" there are several readers/members who are clock enthusiasts and I'm pretty sure they will have the answer to your query, or you start a new thread.