Member postings for ega

Maurice:

I have successfully used the graphite-coloured Hallite jointing for making these washers. I believe propane attacks some kinds of rubber.

JAR QC tailstock toolholders:

I made some of these many years ago, use them all the time and wouldn't be without them. There are some photos in my Miscellaneous album. The Arrand design looks very good but, so far as I understand it, much more difficult to make. The JAR design involves dovetail slides and the turning of a morse taper. Lacking a mill, I did all the work on the Myford.

Tractor man: might you get your camera out and treat us to a video?

Vic:

Thanks. I assume this is the same as Renaissance Wax. New to me and I may give it a try.

John Horne 2:

I have a Calor Professional torch bought many years ago. At some stage I acquired a (?) American standard burner and made an adapter to use it with the Calor handle; could you solve your problem in the same way?

I have had a quick look at my torch and am slightly puzzled by the burner thread which seems to be rather more than 1/2" on major diameter and of 26 TPI. The *inlet* threads on these torches are BSP but the burner thread seems different. I say puzzled because I must have known what it was to make the adapter.

Vic:

Nice-looking tool. What is that attractive grey finish?

Lehman Archer and B.A. Taps:

I enjoyed the article, particularly as it is based on original materal.

The quotation from the LA catalogue gives the BA thread angle as 47 degrees; I had always understood it to be 47.5 and wonder whether this is a typo or, perhaps, there was a further change to the specification.

BA threads have metric pitches and it is interesting to see that the catalogue also gives a TPI equivalent. On the accuracy point, I would have thought that introducing a 127T gear would have allowed theoretical perfection. Is the "correct to within 1/53,300th" a reflection of the then state of the relationship between inch measure and metric? I believe it is only relatively recently that the 1" = 25.4mm equivalence was settled.

John Flack:

Apparently, the BA were treated to the reading of a paper on the making of triple surface-plates by none other than Joseph Whitworth at Glasgow in 1840.

Thanks to SillyOldDuffer and Michael Gilligan for their comments. I take the point about the material being threaded as, indeed, did JW himself. He stated in the following year that his proposed threads "are used in cast iron as well as wrought; and this circumstance has had its effect in rendering them coarser than they would have been if restricted to wrought iron."

I must now read the LAL/BA article in MEW 256.

Edited in vain attempt to remedy problem in quoting JF's post

Edited By ega on 13/06/2017 17:45:53

Eclipse pot magnets were tapped.

My first thought was to wonder if drilling the magnet would affect its magnetism.

Michael Gilligan:

Thank you for the interesting BSI extract. I was confident that given a little encouragement you would come up with chapter and verse!

Am I right in thinking that the underlying aim was to codify and reduce the number of standard threads? I'm not clear as to why the small BSW and BSF sizes were "strongly deprecated"; presumably there was some reason for the continuing interest in them? You mention the Meccano screw which was, I think, 5/32" BSW; this seems to have been the case when I bought a set for a teenager some ten or more years ago but by then it had a 3mm hex recess head and 1/4" square nut.

The BA thread form seems significantly different from the Whitworth standard and I guess might have been more expensive to manufacture.

richard and tracy:

I well remember the sleek Parker 51; my mother had one (her handwriting was beautiful to look at and hard to read).

In view of your obvious expertise in this area I plan to send you a query via PM about Montblanc ball pens.

Hopper:

Was that the same wise man who said "Two out of three ain't bad"?

Michael Gilligan:

"British equipment used BSW or BSF, as appropriate, for sizes down to 1/4" and BA for sizes below that"

Interesting cutoff point; 2 BA is pretty close to 3/16 BSF (and to M5). I wonder how much the odd BA sizes were used - in electrical equipment, perhaps.

It's a shame that British Standards are not in the public domain.

Nige:

You could compare the screw to a likely-looking tap if you have one.

At a guess, the gib screws are BA and an ordinary imperial thread pitch gauge won't cover the BA pitches.

Adrian 2:

Looks as smart as the lathe!

Neil Wyatt:

"Sadly, since then calculus has escaped."

I have numerous books on "diff and int" which are looking for a good home and which would help you or any other interested member to recapture the rapture of maths.

Getting rid of my late parent's library is like trying to give away fivers in the street!

I am grateful to Thomas Staubo for asking this question and to John Pace for answering it (and for his excellent article in MEW 215 and 216). The following is unlikely to be of interest to other than Quorn users.

When I built my own machine many years ago I was mystified by the drawing of this part (item 510), didn't put the hole in and have never missed it up till now, although I have used the tooth rest with its support attached to the column as normal. Departing from DHC's drawing was a bold step and I think I was influenced by the fact that the hole does not seem from his photos to be present in his own machine.

Now that John Pace has shown how useful the hole can be, I have put it in and in doing so have noticed that the lowest hole as drawn is the other way round from that in the photo and, indeed, from my own machine and DHC's!

Sadly, DHC is not here to help with these points but, on a different issue, those whose tilting brackets tend to slip should take note of the modification he outlined in ME of 5 September 1986.

Edited By ega on 09/06/2017 11:33:12

Cornish Jack:

I do hope the Perfecto is undamaged! Vinegar and brown paper for the head?

My Perfecto is also awaiting installation (and construction of stand) and meanwhile sits on old TV trolley. Mine is heavy enough that I remove the motor before moving the main machine so I can understand the need for ice.

(On reading Neil's serious comment): your accident and some of my own experiences remind me of the dangers inherent in working on one's own - probably a good idea to keep a mobile phone handy or maybe even subscribe to one of those arrangements for a call button on a string round the neck.

Edited By ega on 07/06/2017 18:29:51

Am I right in thinking that this is the only thread about Richard Smith's tooling system?

I was intrigued by the core idea outlined in MEW 248 and, at the same time, not clear about the detailed construction. A drawing of the device would have been helpful.

I have, of course, read the continuation in MEW 255.

Edited By ega on 06/06/2017 18:35:04

Nobby:

Thank you for the photos you posted and for referring me to your albums. Making a tailstock must have been a considerable feat.

Edited By ega on 06/06/2017 09:45:59

Nobby:

Your interesting post ended rather abruptly: I was hoping you were going to say something about how you replaced the tailstock and carried out the other modifications and improvements evident in your photo.