Adding dials to lathe handles

I was just curious if anyone had ever tried adding dials to their lathes. Google came up with people replacing or repairing existing dials on their lathes but my Super Adept doesn't and has never had dials so I don't have referance for exactly how far one turn sends stuff.

Some lathes with dials have them fixed, even forming a locking screw for the handwheel. So the most common modification is to make them resetable.
The other bone of contention for some is whether the cross slide dial shows amount taken off the diameter or the more sensible indication of distance moved.

Like Neil Wyatt, I am in process of resurrecting a Super Adept, although not as radically as Neil.

The Super Adept is an old Plain Lathe, dating from the days before dials were fitted. In those days, a turner made a chalk or pencil mark on the dial, gave a nudge and measured to see how much he had removed. Eventually they became fairly expert at knowing how far to nudge to take off a given depth of metal.

This bit of history is of little practical help to you.

A suggestion would be to mark the handwheel and then to measure how far the Cross slide advances for one turn of the handwheel. If it is 0.100" you will be fortunate (Have not checked mine yet)

The thread is almost certain to be Imperial, given the age of the lathe. (The Mandrel and Tailstock arbor are both 0.375" diameter, and the original pulley on the mandrel was Imperial diameters).

Once you know the pitch of the thread (or lead being a single start thread), you can think about how many graduations to put on the dial.

If the thread is 8 or 10 tpi, you will have either 100 or 125 graduations to make

If you remove the handle, it may be possible to drill and tap a couple of small holes (I am thinking 6 or 8BA or the metric equivalent thereof) and use these to fix a dial to the handwheel, Possibly in the form of a disc?

Within reason the graduations can be made as wide as possible within the limits of how large in diameter the dial (disc?) can be.

It will be interesting to know how you get on, so that others can follow suit.

Howard

Naturally I would misplace my box of dial callipers and dial indicators just as I find I need them.

Will trying to put a metric dial on an imperial thread cause problems? I heard that in america chinese mini lathe manufacturers put imperial dials on metric leadscrews.

Also somewhat unrelated but does anyone else have a threaded hole on the end of the leadscrew in the middle of the handle? Wondering if a previous owner tried to put a different form of handle on.

Getting 0.125" per revolution. Should probably of done that before now, 1/8" per turn is good general knowledge to have fo ones own lathe.

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125 divisions on your dial then ... if you want to work in thou'

However; there's no shame in using fractions ... for which any binary division would be useful.

MichaelG.

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...dare one mention the Metrinch again, so soon?

Handle is 1 5/8 (1.6250) wide. That gives a circumfrence of 5.10508... 5.10.../125 gives 0.041" between each mark. Wondering if that might be a bit crowded.

Trying a metric dial.

40mm dial size. 3.1750mm per revolution. Thought 0.025mm or 0.2mm increments would be good. For 0.025 that gives 127 increments. 0.2 is 158.75 which is a bit of an awkward amount so won't do that. 0.039" or 0.989mm. Very similar to imperial but I do prefer my metrics.

Metrinch? Don't they make mechanics tools? :v

Also I suppose I have to steal someones indexing head now.

Metrinch

Have now got my Super Adept, where, today, it ran under power for the first time in years.

Checking the travels with a DTI, the results were slightly variable.

CROSS SLIDE.

Travel for one revolution of the handwheel seemed to vary between 0.050 and 0.053"per revolution.

You would probably be safe to work on the basis of 0.050", giving a 20 tpi thread.

(0.053 would be a 18.86 tpi thread which seems highly unlikely)

TOPSLIDE

Ditto, As Cross Slide

So a Dial with 25 divisions would give 0.002" per division.

LONGITUDINAL TRAVERSE

This appears to be 0.083" pitch, (12 tpi). Pity that it wasn't 10 tpi and make life easy for us!

A Dial with 28 divisions would give almost 0.003"/division (0.0029642857" How fine do you want to go?)

A Dial with 42 divisions would give approximately 0.002"/division (0.0019761905" according to my calculator)

The only other advice that I can offer, is to make the dials as large a diameter as possible, to maximise the size of each graduation. Oh! and to measure FREQUENTLY, and to avoid disappointment, not to try to work to tenths of thou.

At least, this should provide a little food for thought.

Howard

Hit wrong button and duplicated posting, so have edited down this.  Apologies!

Howard

Edited By Howard Lewis on 20/04/2015 18:08:21

A bit of further advice, this is an old Imperial machine, and MOST unlikely to have ANYTHING on it that equates to metric. Despite your wish for metric graduations, I fear that you are going to finish up using Imperial graduations.

The chaps who made this lathe, MANY YEARS AGO, well before WW2, had probably scarcely heard of the Metric system, and worked by putting a pencil mark on the plain dial and then giving it a nudge, and measuring after taking the cut.

Horses for Courses and all that!

Howard I love you, I just triple checked the leadscrew and got 0.082" per rev. As opposed to the 0.125" I got before. How did that happen? I don't know. But you saved me a world of pain.

Call the 0.001" difference as my human error through trying to use dial callipers pressed against the bed for measuring.

For the next person needing to do this just measure the number of turns needed to move one inch.

Hi Rainbows

Just been and checked over my Adept and I think your 0.082 is really 0.0833333 which is the pitch of a 12tpi leadscrew. That fits with all the pre metric conversations that there has been on this thread. My recollection of some lathes produced through the transitional period for metrication was that cross slides were fitted with some sort of gear train, maybe an epicyclic cluster (but I never got round to stripping one out) to speed up the dial relative to the spindle and give a mechanical conversion from imperial threaded feed screws to a near metric 50 x 0.02mm on a speeded up subsidary dial.
I think this could be a way to get a sensible scale from a 12tpi leadscrew, perhaps using a 5:3 ratio that would give 0.050 per rev of the dial and also match the pitch and dial ratio that is on the cross slide and top slide (20 tpi.).

I will try to set out a sketch of this speeder drum in the next few days.
Bob D

Have been loaned a copy of Introduction to the Adept Lathe by Andrew Webster (12th January 2008)

This gives the history of the Adept and Super Adept with some of its forebears, and competitors.

It is an interesting read. It confirms the Leadscrew as being 12 tpi pitch, but does not mention the pitch of the topslide or crossslides. Although from what I have seen on mine, would expect it to be 20 tpi (0.050" for one turn of the handwheel)

At the Spalding Show there were three Super Adepts. One has been modified by a former working colleague who has fitted graduated dials to his machine.

It gives his E mail as [PM Howard or Neil Wyatt for Andrew's email details].

The Lathes website will also give some info.

Howard

Edited By Neil Wyatt on 13/05/2015 16:44:05

Andrew is about as informed about the adept as anyone, I'm sure he will be a happy to hear what other adept owners are up to but please get his address by pm'ing me or Howard as we don't put private emails up on the forum.

Neil.