Small vintage lathes

[Greybeard]

Nice finish for a first go, too.

Thanks. I gave it a polish with some fine wet-n-dry but I was very pleased with the finish I got.

[Greybeard]

From https://www.model-engineer.co.uk/forums/postings.asp?th=171047
Myford used three different spindle nose threads for the ML4, all Whitworth profile:
Earlier ones were 7/8" x 9tpi or 7/8" x 12 tpi.
Later ones were 1 1/8" x 12 tpi, the same as the ML7 but with a smaller register diameter ( 1 1/8" instead of 1 1/4" ).

The register on my lathe is 1 1/8".
I'm counting 7 thread peaks in half an inch which doesn't tally with the information above. Should I be taking the first peak as zero? In which case I have 12 TPI.

[RDfella]

GB - One tooth to the next tooth = one tooth (if you see what I mean!)

[Greybeard]

GB - One tooth to the next tooth = one tooth (if you see what I mean!)

So, counting first tooth as zero then. That makes the count sound correct.

[BagONails]

Sounds right GB. If the first peak is 0 then the next adjacent peak is 1 and so on. If the thread is 10 TPI the first peak (not counted) will be set at 0" and the first complete pitch will be at 0.1" the second at 0.2" etc. and the tenth will be exactly at 1.0". i.e. the pitch for 10 TPI = 0.10"

Thread pitches are measured in the same way as a wave form (pitch = wavelength) i.e. take any two identical adjacent features on the thread and the pitch is the distance between them. Usually you would choose either the peak to peak or valley to valley distance as these are most easily distinguished.  By the same method, TPI or Threads (pitches) Per Inch is the number of adjacent peaks that will fit exactly in one inch along the thread.

Metric thread pitch is given in mm distance only so an M6 x 1 thread is 6mm nominal diameter with a pitch between any two adjacent features of 1mm.

[groily]

I have the attached (which I've probably linked to before, so apologies if repetition), saved from a now-defunct site, printed off and stuck about the place. There be other similar charts, but one way or another, darn useful GB, saves me ages having the relevant sections stuck on the walls of the shed.
(The tapping drill sizes are probably for about a nominal 80-85% so I don't treat as gospel, especially in small sizes like BA where I often go a fraction smaller.)

Under the BSF section, you'll see the standard 1 1/8th pitch is stated as 9 TPI, so the Myford headstock thread is a bit of a one-off by the looks of it.

[Greybeard]

Thanks guys. More information than I can swallow at the moment 🤔 but no doubt in time it will become clearer. 👍

I've downloaded those charts Groily, thanks 👍

[Greybeard]

I bought a faceplate that didn't fully screw on to the lathe spindle. I have a spare 3" chuck backplate. I marked out the backplate through the holes in the faceplate and drilled and tapped M6. I bolted the faceplate backwards to the chuck backplate and centred it. I sharpened a pointy boring tool to match my Imperial thread guage. I mounted the tool on the lathe and moved it into the thread groove. I turned the lathe by hand back and forth and kept removing the assembly to try the thread on the lathe Spindle. Eventually, I got the faceplate to snug up tightly to the spindle shoulder.

I'm not yet ready to experiment with real thread cutting.

I have now been able to face off my new faceplate.

Is this an example of shaving a Yak?

[RDfella]

Next, try turning your lathe into a mini-mill by putting the cutter in the chuck and mounting the job to the toolpost.....

[Greybeard]

Next, try turning your lathe into a mini-mill by putting the cutter in the chuck and mounting the job to the toolpost.....

One of the things I'll try one day when I've collected more equipment for holding things in place. 👍

[Greybeard]

I now have a powered cross-slide!
https://youtu.be/X_Udygg9Yfc

[RichardL]

Thought I could share what I've been playing with on my lathe besides skimming and polishing break drums. These lathes have their own level of addicting. You guys who've been lathe owners and machinists forever have to forgive guys like GB and myself, who get excited over some pretty small stufff. I delayed showing any of this until done because, as a novice, I figured I'd have to throw it out once or twice before having a keeper. Fortunately, for me, that wasn't the case.

Anyway, I wasn't happy with the small cross slide ball crank that came with my lathe, so decided to try making one from a bent Suburu steering link graciously provided by my daughter. Other than the ball end, the tapers and curves are mostly by "etch-a-sketch" handle action and files. I gotta say, I'm pretty happy with it (and, too much, myself).

Richard L.

[Greybeard]

I gotta say, I'm pretty happy with it (and, too much, myself).

Brilliant repurposing! 👍

Those rotary scales are a lot nicer than the ones on my ML4.

[RichardL]

I gotta say, I'm pretty happy with it (and, too much, myself).

Brilliant repurposing! 👍

Those rotary scales are a lot nicer than the ones on my ML4.

The one behind the new crank is custom, maybe as a project in the vocational education program this lathe was in before we were born. The original was quite small in diameter, like the one on the compound rest in the picture.

Richard L.

[RichardL]

GB,

Do you have the flat dials or some like these? Maybe these are a custom upgrade.

Richard L.