Member postings for old mart

Bronze would be very good as long as you pay attention to regular lubrication.

It should have 1.75mm pitch available, as that is a common one (12mm metric coarse), so you need to find a way of doubling the speed from that which will give 3.5mm pitch.

A photo of the wiring going into the motor would help, if I'm right, just swapping the correct two wires might do the trick.

The thread will be a trapezoidal form, 30 degrees. As it is a fine pitch, it would be easy to make a new nut using lay down tooling and inserts. There could be room for a second nut to the left of the existing one to make a better antibacklash setup.

The thread will be a trapezoidal form, 30 degrees. As it is a fine pitch, it would be easy to make a new nut using lay down tooling and inserts. There could be room for a second nut to the left of the existing one to make a better antibacklash setup.

Welcome, Chris, I know Woking quite well, I used to live in Godalming, just down the line.

The Smart & Brown model A has a linked belt from the motor to the 3 speed gearbox which is 1/2" wide and takes 1 1/2 hp. Mike got it off a while ago and took out a link and it is still going strong. I bought some 13mm as a spare, but it hasn't been needed yet.

An old trilby hat would do

3M do a product called White Scotchbrite, it is felt, no abrasives in it, probably designed for use with lapping compound.

Edited By old mart on 24/05/2020 16:20:56

These leadscrew handles come up frequently new on ebay and considering the cost of refinishing yours would be an option.

J Hancock has it in a nutshell. It pays to compare the teeth overlap while the jaws are out of the chuck, you really need three teeth minimum engaged when the jaws are at maximum opening.

It's a very generous offer, Chris, but as there are a bewildering number of variations in chuck jaws, you will need to post the chuck size, make if known and all the dimensions of the jaws including the tooth pitch. They are probably a common type from the 80mm Chinese chucks, but some measurements would help confirm that.

Edited By old mart on 24/05/2020 14:34:50

Fantastic replica. The last real one I saw was inside the Tank Museum at Bovington, I often wonder if it was TEL's.

One thing I forgot to mention is that while you are winding the spindle by hand, is to keep the leadscrew nuts engaged throughout. Reversing the spindle at the end of each cut will automatically move the saddle to the starting position. It doesn't matter how far you go back, but two extra turns will take care of any backlash in the gearing.

Take the handle off to expose more thread. It could be 1/4 BSF, or 1/4 UNF even, as the lathe is a South Bend clone.

By the way, the preferred direction of movement is from left to right relative to the photo's. If the machine is used occasionally in reverse, that is ok.

I've seen the vise before, but not sure where, maybe fishing fly making?

I'm in favour of the test bars and have two, both with MT2 at one end, one is about 7 1/2" long and the preferred one which was not available until well after I bought the first is about 11 1/2" long. They have centres in the ends as well as the MT. If you chuck up a bit of steel or brass bar and turn a 60 degree end on it and put a bar between that and a DEAD centre in the tailstock, an indicator can be used to check the heights as well as the alignments, and if the MT end is in the tailstock alone, it can check that out. They make it easy to check chucks as well.

I favour this type, the only drawback for me is the effort needed to take links out and re-join the belts. As far as I know there is no easy method, just brute force and my fingers are arthritic.

I favour this type, the only drawback for me is the effort needed to take links out and re-join the belts. As far as I know there is no easy method, just brute force and my fingers are arthritic.

Myford gears are a coarser pitch than S&B ones. A shame as they are plentiful.

There is info available from lathes UK on the Sabel:

https://store.lathes.co.uk/print/ms580c

Edited By old mart on 23/05/2020 14:43:21