Boxford TUD lathe query

[sparky mikeParticipant @sparkymike]

Hi ,I have a Boxford TUD lathe. Can anyone tell me what the cross slide thread TPI is for an imperial lathe, and also for the metric lathe.

Mike.

[Clive Brown 1Participant @clivebrown1]

10 tpi and 2.5mm pitch resp.

[sparky mikeParticipant @sparkymike]

Many thanks for that info. Is the top tool post slide the same pitches as above?

Mike.

[Clive Brown 1Participant @clivebrown1]

Yes.

[sparky mikeParticipant @sparkymike]

Just checked and 10  tpi so imperial which I was hoping for as most of the work on it will be in thous. So if I am thinking correctly, one turn of the screw would be 0.100 ” ?

Mike.

 

[sparky mike]

On sparky mike Said:

Just checked and 10  tpi so imperial which I was hoping for as most of the work on it will be in thous. So if I am thinking correctly, one turn of the screw would be 0.100 ” ?

Mike.

 

Yes. Just like it says on the dial.

 

[sparky mike]

On sparky mike Said:

So if I am thinking correctly, one turn of the screw would be 0.100 ” ?

Mike.

Correct. As manufactured, your lathe should have graduated dials on the two feedscews, each with 100 divisions; ie thous. (or perhaps the T version doesn’t have that luxury).

 

 

 

[sparky mikeParticipant @sparkymike]

I have the graduated dials but have not counted them yet. They have around four numbers marked on them, one being 0.5. Possibly this is half a turn. I will have to have a closer look.

Mike.

[sparky mikeParticipant @sparkymike]

On the cross slide top right hand front end there is an extra hole drilled which takes a socket head screw. This connects to a small square section steel plate around 1″ long which rides on the underside of the lathe bed. Is this original or has someone added it to get more support for the cross slide ? (To stop it lifting.?)

Mike.

[BazyleParticipant @bazyle]

The short one at the front on the saddle is a saddle lock. The plate should be cast iron not steel but may have been broken or lost. The long one at the back of the saddle with screws that you can’t see is to stop the saddle lifting – adjust to give a few thou clearance.

[Speedy Builder5Participant @speedybuilder5]

Mike,

That is tightened when you want to lock the saddle in one place (parting off). It is rectangular with two corners having a “foot” about 0.1″ high. This stops the rectangular piece turning when the bolt is tightened.

At the rear, there is a much longer plate that can be tightened up with the two bolts – used when you use a rear tool post with an inverted parting off tool and the chuck rotating in the normal (anticlockwise) direction.

Bob

[sparky mikeParticipant @sparkymike]

Thanks for that info.

The rear strip is held on with two socket head screws with lock washers. I wonder if the lock washers could be replaced with thackery type washers and would that be an advantage ?

On the face of the cross slide that faces the tailstock, there are two taped holes. Are they for a travelling steady ?

Mike.

[Speedy Builder5Participant @speedybuilder5]

Mike, the rear plate bolts should be plain washers. If you use spring/ dished washers, you will increase the energy used to move the saddle, and therefore wear on the leadscrew and ‘V’ ways. That rear strip should only be tightened when you want to lock the saddle down – typical rear tool post work or milling in the lathe.

Regarding the rear facing holes on the saddle – yes travelling steady.

Do you have a copy of the Boxford manual – a MUST for all new users.  have a look here:- https://www.model-engineer.co.uk/forums/topic/boxford-model-b/

just before you snap it off, the screw retaining the feed screw clutch is a left hand thread !!

Bob

[Grindstone CowboyParticipant @grindstonecowboy]

Pretty sure the TUD doesn’t have a feed screw clutch – not even a feed screw, in fact.

And as far as I know – I have a bench model C – that rear strip isn’t used to clamp the saddle, just set to give minimal lift with minimal drag. But quite happy to be proved wrong.

Rob

[sparky mikeParticipant @sparkymike]

Now double checked the TPI of both cross slide and top slide and both are 10 tpi. However, the graduated dials do not have 100 , but more garduations. See photos. I am wondering if they are metric and there is a mismatch here.

Mike.

[BazyleParticipant @bazyle]

It looks like the dial numbers are trying to be mm. If the lathe is ex school workshop they might have put the modified dials on as the kids wouldn’t understand imperial.

[BazyleParticipant @bazyle]

One of the things that has been on my todo list for decades is to make a larger diameter dial that fits over the existing dial with bigger spacing for the ticks for visibility on several of my tools. If you do this you can adjust the numbers.

[Dave WoottonParticipant @davewootton]

In the late 70’s early 80’s I worked for a machine tool supply and maintenance company and it was common practice to just change the dials on school machinery when converting to metric. Certainly in Kent, Surrey and Sussex education authorities were reluctant to spend out for a full conversion if a near enough alternative could be worked in. Technical colleges did get the full conversion but I was told it was deemed unnecessary for the standard of work to be carried out in secondary schools. From memory it was mainly Tom Senior, Marlow (for which we had the dials made out) mills, Boxford and Loughborough  training lathes, I think any Colchester’s got the full conversion, There were boxes of feedscrews, dials etc in dark corners for years after I left, so quite possible your lathe has been messed about with. It wasn’t me I hasten to add, all the school and college work was done by an elderly chap ( who thinking about it was younger than I am now!) called Jim who worked part time, he retired in about 1979 when I think all the conversion work had dried up.

[sparky mikeParticipant @sparkymike]

Interesting. Thanks for the info. Big question now is where can I get correct imperial dials ?

Alternatively, I have a friend who does high quality engraving. I could machine off the existing graduations and get him to engrave new on. Alterative would be to add the imperial graduations next to the metric if enough room.Some thinking to do no doubt.

I do have a high quality pantograph engraver here but it would take me hours !!  (or days !!)

Mike.

[duncan webster 1Participant @duncanwebster1]

Fit a DRO and forget dials!

[HollowpointParticipant @hollowpoint]

IIRC the Boxford dials are all the same and have 125 graduations. Something like:

0.001″ inch per division in imperial.

Or

0.02mm per division for metric.

 

I THINK!

[BazyleParticipant @bazyle]

125 graduations is for a 1/8″ leadscrew. I think you can initially wrap a piece paper round it with the right number of ticks. To make this if you have a printer you can draw a strip at a few different scales to get one that is a good fit. Lots of ways to draw it old fashioned style too.
Then make a new dial – it is very simple as it is just a bit of bar with a hole – it doesn’t even have to be the same diameter as the current one. Plastic or aluminium would do.

[sparky mikeParticipant @sparkymike]

Just seen a load of different sized dials for lathes on Ebay, dead cheap. Chinese of course. Possibly adaptable for my lathe. Mike.

 

[Howard LewisParticipant @howardlewis46836]

If you are certain than that the leadscrews are 10 tpi, you are looking for, ideally, 100 graduations for 0.001″ per division.  50 divisions will be 0.002″ per division.

Being modern, the bores will be metric, so will will need modification; either boring or bushing, to match the Imperial diameter leadscrews.

But don’t buy new dials that are smaller than the existing ones. larger will give a greater distance between graduations, making it a little easier to interpolate for smaller movements.

Howard

[sparky mikeParticipant @sparkymike]

I was thinking along the same lines. I will measure up the existing ones diameters and widths. If suitable the new outer ring could be fixed by a small grub screw after boring or sleeving it.

Mike.

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