Identifying thread on antique lathe main spindle

[SpeechlessCalm]

I hope it's not too far 'out of scope' to post this enquiry here. It's totally not a 'today' type of issue, but I figure (and hope) there's likely to be folk with the depth of knowledge needed.

I am trying to identify the thread on the shoulder segment of the main headstock spindle/quill of my old lathe, so I can have an adapter built to switch an eccentric chuck assembly from this lathe to a slightly moremodern lathe.
The lathe in question is old, like mid-1800s. It's treadle powered, notwithstanding the electric motor and belt drive that I have fitted to it. Family history has that the lathe itself was handbuilt and it has no identifying marks at all on it, just stamped numbers on elements to identify sizes and gradations or screw locations. It is likely that it was built in England, although Australia is a possibility. It's also possible it is a no-name knock-off ... although some of the fittings are quite exquisite. I'm not seeking to 'identify' the lathe itself, just this one thread.

I have numerous chucks and other fittings that screw nicely onto the spindle, but only the one 'male' example ... the spindle itself.

Using a ruler I get the spindle thread as 1" diameter, and approximately 9.5tpi (7 turns in 3/4 of an inch) - see top-left and middle-left images in attachment. Using a metric rule I see 14mm for 5 turns, FWIW (top right image). The closest thread 'comb' I have (and I do not have an extensive collection) is marked 9G 7/8" and it is not a perfect fit (middle-right image).

The lathe itself has a thread chasing assembly (unusual design where the headstock spindle itself moved) built into the back-end of the headstock (bottom image). That assembly has a threading option that matches the shoulder thread, and it is marked as '3'.

 

[L Vanice]

Easy one, once the lathe is identified as an English ornamental lathe. Looks like it is the No. 3, or 1 inch 9.45 TPI Holtzapffel thread, standard on their 10 or 12 inch swing spindle noses.

threads on Holtzapffel lathes

Definition of the threads on Holtzapffel lathes.

www.sizes.com

Note these thread standards were originated early in the 19th century using hand cutting tools, which is why the pitches and diameters seem a bit odd by today's customs.

People fortunate enough to own and use a fine old (or new) ornamental lathe should be aware they are not alone, and could join a group of like-minded individuals for access to help and resources.

The Society of Ornamental Turners

www.the-sot.org

This site (Practical Machinist) has a section for antique machinery, so the thread might get moved there. https://www.practicalmachinist.com/forum/categories/antique-machinery-and-history.19/

Larry

 

[SpeechlessCalm]

Thanks very much. I thought it'd be 'easy' for someone with the expert / esoteric knowledge. My 9.5tpi wasn't far from the fact :-)
I'm glad I mentioned the bit about the No 3 option in the chasing assembly :-)
Nose, not shoulder?
I guess that also means that if I want to make an adapter I'll probably be best to use the lathe itself, given the inbuilt thread chasing facility.

 

[L Vanice]

I thought it'd be 'easy' for someone with the expert / esoteric knowledge. My 9.5tpi wasn't far from the fact :-)
I'm glad I mentioned the bit about the No 3 option in the chasing assembly :-)
Nose, not shoulder?
I guess that also means that if I want to make an adapter I'll probably be best to use the lathe itself, given the inbuilt thread chasing facility.

Holtzapffel called what is now known as a spindle nose the mandrel nose. The nose is the part that, on most lathes, is used to attach a work-holding chuck or similar fixture. A shoulder in this context is an unthreaded step on a shaft, normally found adjacent to the threads on a spindle nose. More modern practice is to make the shoulder closely fit a counterbore in the chuck and make concentricity of the chuck depend on the fit of the shoulder rather than depend on a tightly fitting thread.

Larry

 

[john.k]

I saw a Holzapfel lathe valued on a TV program........surprising the value wasnt great ,but the valuer also separately estimated the cabinet of tools (chisels,gravers),which was worth more than twice what the lathe was.

 

[boslab]

There’s a good book by holzaphel excuse my obstinate spell checker , it was in 2 volumes, ornamental turning
I got them from a library in 1974 so a long time ago, but stuff in there stuck in my head, even now
Mark

 

[SpeechlessCalm]

There’s a good book by holzaphel excuse my obstinate spell checker , it was in 2 volumes, ornamental turning
I got them from a library in 1974 so a long time ago, but stuff in there stuck in my head, even now
Mark

Thanks Mark, I've downloaded several of the books that these replies have lead me to, and have been flipping through them. I have not yet managed to identify, or obtain working instructions for, my headstock thread chasing assembly or my eccentric chuck but it was allowed me to identify - and hopefully use - a lot of the bits-n-pieces. Sooo much to read, sooo much tolearn :-)

 

[boslab]

It was a big thing among the gentry back then, a gentleman’s hobby, turning, rose engines and all that good stuff, the Victorian gent liked his tech!
Mark

 

[neanderthal mach]

If that spindle nose really is attached to one of the ornamental turning lathes? I'd highly recommend this book. https://www.teepublishing.co.uk/books/woodworking-woodturning/ornamental-turning/ There's even a bit of detail about the non standard threads used on a whole lot of this equipment before todays thread standards became common.

 

[L Vanice]

There’s a good book by holzaphel excuse my obstinate spell checker , it was in 2 volumes, ornamental turning
I got them from a library in 1974 so a long time ago, but stuff in there stuck in my head, even now
Mark

The Holtzapffel books are very special. You can buy an antique first edition set of all five volumes for about $1600. This set was originally bought by John Hick when he was the owner of the Soho Iron Works in Bolton, England, famous for building steam engines. Holtzappfel lathes were mostly owned by very wealthy men. See a brief biography of John Hick and his company here: https://discovery.nationalarchives.gov.uk/details/r/8e06026b-cd85-4e51-8117-c60be36e0d1a

https://www.biblio.com/book/turning...YH6e39881tvuSzHUKqr-e_hN8x5lB6c3tlnjmA3akTsV0

Fortunately, there were some paperback reprints of some of the five, and those are relatively cheap.

Larry

 

[SpeechlessCalm]

If that spindle nose really is attached to one of the ornamental turning lathes? I'd highly recommend this book. https://www.teepublishing.co.uk/books/woodworking-woodturning/ornamental-turning/ There's even a bit of detail about the non standard threads used on a whole lot of this equipment before todays thread standards became common.

It's a pretty basic 'ornamental' lathe, alas no Rose Engine in the shed [1]. It has a 5' bed, a moving-spindle[2] thread chasing headstock, a lovely little eccentric chuck assembly (which I'd like to try and use on my modern woodturning lathe), and pretty much normal stuff otherwise. Photo of headstock assembly ...



Thanks. I will also take a look at that book.

1. As far as I can ascertain the original owner / user started a pharmaceutical company in England and he, or a son, subsequently moved to Australia. The lathe was passed to my father in Australia and, in turn, came to New Zealand with me.
2.There's doubtlessly a proper term for this assembly - sorry, this is not at all my field of expertise - but I've not yet found it. The entire main headstock spindle moves along its axis, guided by engaging a male-female thread pair at the outer end of the headstock. The latter is shown in my OP photo.

 

[boslab]

Just a headstock assembly, there’s an indexing ratchet just behind the spindle nose, handy if drilling using the carriage and lay shaft drilling/milling spindle.
Mark

 

[SpeechlessCalm]

Just a headstock assembly, there’s an indexing ratchet just behind the spindle nose, handy if drilling using the carriage and lay shaft drilling/milling spindle.
Mark

I have the whole lathe that goes with that headstock. I just thought that photo would cover off on the headstock assembly, the source of my inquiry. I've also got boxes of items and tools that may or may not go with the lathe. Some I have been identifying (e.g. expanding mandrill) from flipping through some of the books that these replies have lead me to.
I'm loving the learning :-)