Member postings for old mart

M4 X 0.7 is the standard metric coarse thread, and the 8.8 is medium tensile strength.

You could dissconnect the motor connections and then try the on off switches. While the motor is disconnected, use a multimeter to see if there is any leakage. This is only useful if there is a very large fault. Some lathe motors are in a position where they can ingest particles of swarf if there is air flow through the motor. A 1/2hp replacement motor is not too expensive new.

If you don't have a manual for the WM240, then there are lots of results to be found by googling Warco WM 240.

A letter dating from the 60's from a firm that went bust is no valid reason for not trying the present company. They sell lots of older Myford parts, and who knows what they might have now.

Have you tried Myford? They advertise a lot on ebay, and would be worth googling.

Threading with a worn out die, you mean? And ending up with a crap thread.

The cross slide backlash with the leadscrew is nothing to do with the gib adjustment, this thread is getting confused.

How do you intend to produce 10mm on the end of a bigger bit of metal? What about getting a good quality 10 mm die and chuck that old one in the bin. Make sure it is a split die and make sure the diestock has the clearance to allow it to expand about 0.3mm and threading will be easy. If the work is turned to 10mm in the lathe and a slight lead in taper is on the end, then use the chuck in the tailstock (with the jaws retracted) to hold the die square and push at the same time as you start the thread.

Edited By old mart on 01/01/2021 21:55:37

That tapered gib doesn't seem to have the cutout for a single screw to adjust it, so there is probably another screw at the other end. It takes careful and delicate adjustment to remove the backlash and not have the lot get too tight. The front screw tightens and when things get tight, then back it off about 10 degrees and tighten the rear one. You will then be close and very small ammounts of adjustment will finish the job.

If you have split dies, they can be opened up for the first pass and then closed to get a good fit and better finish. Dies that are not adjustable are ok for cleaning up an existing thread, but not much else. Single point threading on the lathe if better if you have the tooling to do it. The higher quality tight tolerance threads come closest to the nominal diameter. If I wanted to produce a 10mm thread, I would start with 10mm diameter stock, not some other size.

There is a prefered direction, when the outside ends of the links face rearward. That said, there is no reason not to use them on a machine that can run in reverse.

Welcome, Martin, you will have to factor in slightly bigger work now, so that in the near future you don't regret getting too small a machine. The space available is an important factor.

I like the look of the Warco WM240B lathe, I wonder if the other members would recommend it?

Edited By old mart on 01/01/2021 20:25:30

You can probably eliminate most of the backlash, but you should run the cross slide through its full travel to be sure it doesn't get too tight at the extremes. The other possible source of backlash is the end play of the leadscrew, which may be adjustable by nuts, grubscrews or shimming. I would be pleased to get 0.05mm and think that ever getting less would be due more to luck than anything else.

If you look at the mills on the arc Euro site, they show the foorprint of each which is a most important aspect of buying for a limited space.

When the edges are sharp, they do not impart much heat to the work, but if the work gets very hot, it is time to look at the insert. It may be possible to sharpen the fronts of the triangular inserts on a diamond lap. I have one which is about 150 x 70mm and double sided, 400/1000 grit. If used wet, that type could give the inserts a new lease of life. For a twin insert cutter, you would have to sharpen them in pairs and match the thickness so they cut evenly in the tool.

An oily rag wiped over will work, fortunately, cast iron rusts very slowly and the slight browning is nothing to worry about.

By the way, welcome to the forum.

Edited By old mart on 01/01/2021 15:56:50

The pickle that br mentions is useful, as it will highlight any tiny areas of solder missed originally.

       It would be worth investing in a box of secondhand slip gauges, they have multiple uses, not just for calibrating micrometers.

I bought this 0-150mm micrometer when it came up on ebay, to replace the 0-4" which was stolen from me some years ago. It came with a full set of length bars and the photos show the heat plate that Rod printed to fit it.

Edited By old mart on 01/01/2021 15:44:29

Edited By old mart on 01/01/2021 15:46:57

Edited By old mart on 01/01/2021 15:47:33