Member postings for ega

Roderick Jenkins and Michael Gilligan:

Thank you both for your helpful comments. I recall the lobate silver steel point from some years ago, the problem being that the out of roundness could not readily be detected by a micrometer; rolling the bar on a flat surface would give an indication, however.

A quick google suggests that some "precision" ground bar is indeed centreless ground and I notice that the manufacturers of silver steel emphasise the precision of their product so I think the point about the grinding method is unresolved. My impression is that industry would want to use the quickest and cheapest method. I did see references to the annealing of silver steel.

I like the black bar suggestion although I think that I would have difficulty in buying a short length and therefore I will probably go for silver steel and try to obtain an assurance about its roundness.

I have used hole saws for this kind of job and agree that clearing the swarf is the main problem. More recently I became aware of the rotabroach type of cutter from an article in MEW. Apart from cutting more freely, these have the advantage that they do not require a pilot so the blank is free of a central hole and they cut true to size and leave a good finish. The blank is relatively small because of the greater width of the teeth and they are rather expensive when bought new; cheaper used ones can be resharpened, however.

Ian S C:

I follow, but your method would depend on there being enough of the spindle and chuck available to clamp on.

Didn't Myfords come up with a security device on their big bore machines?

A friend was repeatedly reversing his lathe whilst testing something and was surprised to have the empty three jaw chuck spit out one of its jaws (which he says he managed to catch!)

I have been planning a rack feed tailstock along the lines of Anthony Mount's and, like him, wondered what to make the new barrel from (ME 4211 p746). He opted for silver steel thinking that PGMS might bend when the rack was cut. Martin Cleeve also favoured silver steel in his 1956 article although for other reasons. I assume that Anthony Mount's barrel did not distort since his project seems to have been very successful.

Does anyone know why this should be so or have any more general advice to offer, please? It occurs to me that the depth of the rack in proportion to the barrel diameter may come into it. Anthony Mount's was 32mm and mine is 1 1/2". There is also the keyway to consider which in my case would be at 90 degrees to the rack.

Silver steel is relatively expensive and, instinctively, I feel that apart from the danger of distortion a piece of BMS would do the job provided it was dimensionally accurate and of reasonable surface finish.

Neil Wyatt

Thank you. My hard HSS knurl on hard HSS pin is theoretically wrong I believe and I anoint generously with moly grease. When and if my pins need replacement I will certainly consider bronze - better "tribologically" but presumably less resistant to shear.

Neil Wyatt:

I know it's possible to cut hard steel on a bandsaw but I am curious as to how you did it (or would have done it).

My caliper knurling tool uses two 1/4" Clarkson-type broken endmills as pins retained by nuts on the 1/4 thread; my original hardened (?) silver steel items wore rapidly.

I found some food for thought from these postings.

I have been running my Myford and Warco Mill/Drill from the one Newton Tesla CL750 box for several years by the crude method of powering down, unplugging the one machine and then plugging in the other machine. When buying the package of CL750 plus two motors from NT I made clear how I planned to use it and they seemed quite happy. The CL750 is pre-programmed and so KWIL's point whilst clearly valid seems not to apply (so far as I am aware the CL750 can't readily be programmed by the user).

Michael Gilligan:

Thanks for the link to the fascinating Wiki. I am confident that "ingredients creep" applies to a great many products and that this normally only comes to light if the PR department decides it's "new and improved".

I shall make a point of not trying to teach my grandmother to weld soap!

In his book Simple Workshop Devices Tubal Cain gave some advice on straightening copper tube - probably a less challenging proposition than stainless wire - which involved first annealing the material (unless you know the composition of your wire annealing it will be guesswork, of course). He then pulled the tube through "gag jaws" in the bench vice; these were made by drilling a hole through a piece of wood the length of the vice jaws and then splitting the hole with a saw so that the wood gripped the tube as it was pulled through. Another method involved using the lathe as a powered drawing tool in which one end of the tube is, in effect, hooked over the toolpost and the other end is pulled through the jaws of the chuck by operating the self-act.

Michael Gilligan:

Thanks for your comments. When I rang the help line, in response to my saying I thought that the product was less transparent than before, they mentioned that the proportion of glycerine had been increased . Apparently, it has been made in India for twenty years which surprised me. I can still manage the welding trick by leaving the sliver on the wetted replacement overnight; it was this "soft" characteristic that made me think it might be suitable for the anti-scaling purpose.

Needless to say, the helpful woman on the help line had not heard of Punch's "Two years ago I used your Soap, since when I have used no other".

PS: punch line rather than help line!

Edited By ega on 18/08/2015 12:51:23

There is also Stan Bray's "The Compact Lathe" - "the sort of lathe that is easily portable".

Chris Gunn:

Good point about unplugging but when working at the end of a long extension cord there is a temptation to ignore this. All my portable power tools have a short lead terminating in a push fit connector so disconnecting is no problem.

Are the holes radial or axial (ie cross holes or lengthwise)?

If radial as I assume, drill the first hole, insert a close-fitting rod, move the work and align by sighting the rod.

The kitchen is a kind of workshop and deserves consideration; good luck with yours!

Long ago I tried to follow GHT's recommendation of soft soap to prevent scaling but I have never had much success with the anonymous product I obtained from a friend answering this description. From memory it was indeed green but, years later, it has turned a dark chocolate colour.

I just turned up Tubal Cain's thoughts on the subject in WPS 1. In the absence of ceramicist's "Anti-Scale Paint", he favoured powdered chalk mixed with water or meths and, whilst aware of the horologist's practice of using soft soap, surprisingly had not tried it himself.

"Bar soap" here at home is Pears and the list of ingredients mentions a number of sodium compounds which suggests it is unsuitable if I correctly understand the Wiki disambiguation entry; the Pears helpline did not know whether it was a sodium or a potassium process. One should obviously read the label but it seems that the production process may not be given, so my question is: does the mention of sodium compounds indicate unsuitability for this purpose?

Roderick Jenkins' suggestion may be the answer but who needs 5 kilos?

John W1

I'm glad that you don't suffer from vibration; no doubt individual susceptibilities differ. Nicholas Farr has made an interesting point. As has already been said, these tools need firm handling but a "white knuckle" grip seems likely to make the problem worse. I don't think the modern soft start feature has been mentioned - definitely an advantage when turning on a 9" grinder!

FWIW, I see that Colin Furze wears gloves when angle grinding.

Did anyone mention the very useful diamond cutting discs now available at affordable prices?

I second the comments about white finger, use anti-vibration gloves and try to avoid grinding for more than a few minutes at a time.

My Willson slant bed goes against convention by listing 0.625mm pitch on the gearbox chart, not a common thread so far as I know. It is, of course, an imperial lathe but a useful range of metric threads is instantly available and it has true conversion via a 127/125 pair.

The chart lists some imperial oddities also, such as 4 3/4 tpi, and I think the designers just "did the maths" and put the results in what would otherwise have been blank spaces!

John Stevenson:

I seem to remember seeing somewhere that Myford lead screws were made by a "thread whirling" process - I assume this meant some kind of rolling process.

I found this rather charmingin its way:

https://www.youtube.com/watch?v=zIz1WIlyYgI

No answer to their phone (01664 454566) today so I suppose this excellent firm may well have ceased to function.

I wanted to ask about their QC tail stock tooling as mentioned by SteveI; I should be glad to see a photo and to know how it works. I'm guessing the interchangeable holders are held on a short taper but have no idea as to how they would be held?

Arrand items sometimes turn up on eBay but I have never seen the tail stock tooling offered.