TDS 1/1 G.B.L Spindle Nose Specs and Thread???

[dazz]

I'd like to make a couple of accessories for my lathe, one of which would include making a spindle nose with an MT3 at the other end to fit in the tailstock.

To do this properly, I'd like to know the specifications for the spindle and thread form. I could copy my spindle, but I don't know haw far it is away from nominal specs. My copy wouldn't be a perfect match so I might end up with something that doesn't fit or is not accurate.

Given the history of these machines, I assumed that they would be the same as a Boxford. I also assumed it would be easy to find this information on the internet. I couldn't find any solid data, just guesses and opinions.

I contacted Boxford and they told me that the thread is a Whitworth form. I've measured my spindle and drawn up the results in the attachment. The first page shows the spindle thread as measured complete with construction lines. I used the 3 wire method to measure the diameter. My wires were roller bearings and I rechecked the measurements, so I am reasonably confident that they are OK.

The second page compares the measured thread form with a Whitworth spec. Apart from the 55 degree angle and 8TPI, they are not a brilliant match. Different diameter, crest and root forms.

I realise that so long as I get the register right, the thread isn't absolutely critical. It will take the same amount of time to make a copy as it will to make a spindle nose to specifications so I'd rather make the job to the right measurements.

So does anyone have a drawing or specification for the spindle nose and threadform? There must be others that would find this information useful.

[Denford Admin]

A Mechanical man here thinks its a 1.5" BSF with the tops skimmed down to 1.4864"

What do you think ?
I could have a quick look for a drawing to confirm ?

[dazz]

Hi

*Edited version*
I mis-read the previous post so this is a modified response.

The thread has a mixture of imperial BSF (angle, TPI) and UNC (assymetric roots and crests) features. It doesn't seem to match any standard thread.

It's a reasonable amount smaller than a standard spec Whitworth. If it was a Chinese lathe, I could blame it on slack manufacturing tolerances, but it's too much difference to be a mistake on an old Denford lathe.

The welding looks like a pre-schoolers finger painting but the quality of machining and fitting on my lathe is totally excellent.

[Denford Admin]

Have not been able to find a drawing yet (can't spend long on it)
Re the drawings - I'm starting to make some sense of the old drawing system- the trouble being with the drawing index book - everything is scattered around and in purely date order.

I was thinking that I could photograph the index pages, and put them up for someone to type in order for us to find drawings quickly - if anyone is willing to do it - let me know

Have also sent your word document to Pratt Burnerds (chucks) to see what they make of it.

[dazz]

Hi

I am sure if you posted photos of the drawing index book, people (like me) wouldn't mind reading through them to find any specific drawings.

[Andy B]

I was thinking that I could photograph the index pages, and put them up for someone to type in order for us to find drawings quickly - if anyone is willing to do it - let me know

I pm'd you about this back in January - I'm certainly keen to do this, if you can photograph or photocopy the pages.
I'd even spend a day at Denfords and stand in front of a photocopier, if your management would let me do that!
Once the drawing list is in electronic form, it should then be quite easy to identify the assembly drawings and, from those, generate parts lists - of course, if spare parts/service booklets were ever produced for the manual machines then lists could be produced from those.

Andy

[Denford Admin]

Ok - I'll photograph the old drawing index

The old drawing system is starting to make some kind of sense now, and I'm sometimes able to find a relevant original "sketch" in the drawers

Unfortunately no-one here now knows much about the old machines and all I have to go on is a very dis-organised set of cabinets and drawers - any help indexing it to make it easier for me to find what people want to know, would be appreciated.

Management are not keen on scanning all the drawings and just giving them all away ! But it would be ok to give out the odd drawing / manual page

[dazz]

Hi

I used to be the No.2 manager in a drawing office with over 35 draftsmen on CAD workstations. The pre-CAD drawings were all stored on microfilm in stacks of drawers. The volume of drawings on record required a big data base just to reference them.

Your book is the same as the data base. The drawing numbers were allocated sequentially to each new project just like your book. Sheet 1 of every project was the drawing list that listed all the drawing numbers, revisions and titles that were part of that project. This made it dead easy to figure out what drawings were needed.

Every drawing office is different but they all have the same requirements. Identifying drawings in a project is a fundamental requirement. I bet there was/is an equvalent type of document that grouped drawing numbers by project at Denford's. Possibly the project drawing lists were updated and held by each draftsman for their projects, so they might be hard to find if they still exist.

I am glad your managers retained the drawings. They are irreplacable.

[Denford Admin]

For what its worth, I have put the drawing / sketch book in the downloads section:
viewtopic.php?p=2893

Although there must be more to the old drawings than this

[dazz]

Hi

That's really interesting. A true treasure trove for anyone needing info on their machines. It looks like the book is divided into categories/projects so their won't be a separate drawing project list. They have combined the master drawing numbers and projects in the one book.

Regrettably I don't see anything relating to TDS 1/1 G.B.L lathes so I guess there is another book either earlier (definite), or running parallel (possible).

I am sure people will appreciate your scanning efforts.

[Denford Admin]

I have heard rumours about drawings being archived and microfilmed in the past - I wonder if thats where these pre-1974 drawings are now ?

Unfortunately no-one here knows anything about it (or has forgotton)

[dazz]

Hi

Based on "The Book" I reckon microfilmed copies of every drawing Denford produced would probably fit comfortably in a shoebox, two at the most. Far too easy to throwout.

Just as I wild retorical guess, they were turfed after someone decided the microfiche reader was taking up too much room.

I find it interesting that now that we are well into the information age, so much information is now so casually discarded.

[Denford Admin]

One of the draughtsmen was still here until a couple of years ago (IV in the book)

I'm hoping to contact him, and get him on the forum - he could answer mechanical questions about most of the old machines very easily.

So, its not just information that is casually discarded, but also people, with vast knowledge and experience