Member postings for Clive Brown 1

It is possible to grind a hss tool, suggest you start with a smallish blank, say 5 - 6 mm square. Alternatively, I have a parting / grooving tool made from a broken section of "all-hard" hss hacksaw blade in a home-made holder. Works very well

Edited By Clive Brown 1 on 11/04/2023 08:26:12

I wouldn't contemplate tapping this thread without first screw-cutting in the lathe. However, if you really must do it that way, then 3 taps, used bit by bit, 1,2,3 - 1,2,3 etc etc might get through the job. The torque required will be very considerable. Holding the job will be a problem. You are going for a full depth thread. Is this necessary? Boring out to, say, 21.5 to 21.6mm would make the work easier, with little loss of thread strength.

I'm very out of date with starters but the Lucas motors I've opened up in the past were series wound so swapping the field supply will mean, I think, altering the internal coil connections so not entirely straightforward, especially as the conductors are very heavy and stiff.

For my Princess of Wales bogie I bought mine from Reeves. About 0.034" thick, ie 20 /21 swg. That's the only thickness that they offer. Are you going to use it for main springs?

Edited By Clive Brown 1 on 05/04/2023 14:41:02

According to the Lathes.co.uk website, Boxford centre-height is actually 4 5/8", so the 9" faceplate should fit. My 5" Boxford was supplied from the factory with a 7.5" faceplate, I don't remember a 9" size being offered. I soon added a 9" faceplate though, machined from a casting that Reeves used to supply. I think that mounting this casting was about the only time the original was used. However, the greater utility of the larger faceplate is due to its considerably greater number of slots, 12 IIRC The original Boxford one had only six and they never seem to line up with what I want to do.

I made one borrowing from the Hemingway and Harold Hall designs. I liked the idea of the plates adding side support to the arms. This seems to work well in practice. Mine is sized for my Boxford. The knurls are 25mm dia. from Arc, which are perhaps a bit larger than most. The rest is mainly from material "in stock". Maximum working diameter is 50mm.

I think the "bluntness" referred to by the OP is the cutting edge of the SCMT insert, not the nose radius. SCGT inserts, primarily for non-ferrous metals, are considerably sharper on the cutting edge.

I'd have thought this application cries out for a suitably ground HSS tool, say from a 6mm square blank. Low cost, effective and no need buy an additional insert tool-holder.

Can't see the taper as deliberate to compensate for jaw lift. Would that really work? 2 -3 thou in 9" seems as much as I might expect for a low-cost Chinese vice made 3 decades ago.

I don't see any significant risk at all, provided it passes a hydraulic test satisfactorily and it's soundly constructed from adequate materials.. There's nothing inherently wrong with soft solder caulking. Very many boilers have been so constructed in the past and provide years of good service. My Simplex boiler for example at >100psi WP.

For small Stuart engines, 20 - 30 psi would be ample for demonstration purposed.

I doubt if there's much, if anything, to choose between the two materials as far as the bluing function goes. Cutting the v-grooves for construction would go much better in brass I think but that, though elegant, seems an OTT method to me.

Interestingly, I've just followed up a few of the links in Michael's link and they seem to be dealing primarily with lever types, but don't list Verdict, which is almost like the name "Hoover" in brand awareness.

My thought, FWIIW, if I were to own just a single dial indicator, as the OP seems to suggest that he will, then it most definitely wouldn't be a plunger type. My Verdict lever indicators are used constantly. I can't remember when I took a plunger model out of its case.

Lever type are far handier and more versatile.

Edited By Clive Brown 1 on 13/03/2023 09:24:59

Isn't a transition metal still a metal?

Could be a short length of hss attached to a mild steel shank. More common in days gone by.

Steel is an alloy of iron and carbon, but carbon is not a metal.

Edit:- posted too soon!

Edited By Clive Brown 1 on 11/03/2023 19:26:43

RDG might have what you need.

I've heard it called "Dog's Breath".

I think an absolute maximum rate would be difficult to establish, but Wiki. quotes 3.7lb / mile for GWR Pendennis Castle, when competing in trials against an LNER A1 on the East Coast Main Line. The A1 used more coal to deliver a poorer performance.

Edited By Clive Brown 1 on 08/03/2023 20:20:41

Thread rolling was a normal production process where I worrked at Joseph Lucas back in the '60s. There were specialised machines that rolled the blanks between 2 flat die plates. These were capable of very high production rates of high quality threads.