Member postings for Mark Rand

For those sizes of stock a 6 tpi blade will work reasonably well. Coarser would be better. 14tpi is so fine that the blade is spending most of its time skating on packed in swarf.

It also has a 3/4" instead of the 5/8" leadscrew and the Super7 apron and Carriage, which is are improvement on the original ML7 one.

Edited By Mark Rand on 12/02/2018 23:37:46

Edited By Mark Rand on 12/02/2018 23:39:24

Has anyone else wondered about Britain's Silicon Valley or may be "Germanium Valley" in the 1970's? The likes of Maplin, Bi-Pre-Pack, Amstrad and a few others I can't remember, Even E. K Coles (echo televisions) and others in the London-Southend corridor.

Got all the units of my Monitor Audio MA2's re-rubbered (not 'foamed) 20 years ago, The foam was not a good design decision. I was amused when I brought the midrange units in and was told 'Ah yes, they're a standard KEF base unit'

PPS:-

Auditioned a Linn Sondek LP12 and thought is was awful. It rang like a bell compared with my Pink Triangle (made on a clapped out Colchester triumph!)

Edited By Mark Rand on 12/02/2018 23:35:25

Oops, Sorry! It wasn't intentional.

Curiously, camera tripod threads were historically (and should still be!) 1/4" and 3/8" BSW. But in about 1972 the ISO decreed that they were 1/4" and 3/8" UNC, thereby destroying another bastion of civilization. Luckily, most camera and tripod mounting threads are so sloppy that it probably wouldn't make much difference if they were BA 47.5° or ACME 29° thread forms...

Mea culpa:- I once had to use a 3/8x19 BSPT fitting in a 3/8x18NPT socket, at 2000psi! Why the H3ll British Steel at Port Talbot had bl**dy American threads on that instrumentation pipework, I never discovered. Luckily, It survived the four weeks needed for the work. To add to the weirdness, the stainless steel instrument pipework was all etched/printed with labels declaring it as 12.7mm OD .

Edited By Mark Rand on 12/02/2018 22:51:27

Is it worth getting a Kurt brush seal and retro-fitting it? You'd still be about £400 ahead on the deal compared with a 6" Kurt.

Edited By Mark Rand on 12/02/2018 22:17:19

Does that mean 1/2"x20tpi? If so, they won't fit any air tools in common use. Or is that just between the Series 25 connector and the swivel part?

Expiring minds want to know, having spent half the day recomissioning the compressor because I need to try out the plasma cutter, I've realised That I can either get a few more PCL fittings or get a few more-more Euro/series 25 fittings .

And then we have the Six Nations Rugby championship, which is played by England, France, Ireland, Italy and Scotland. The UK province of Northern Ireland/Ulster is part of Ireland/Eire for these purposes...

Bah humbug .

As above. A vernier caliper is not a digital caliper and vice versa. A dial caliper is neither.

Similarly, a live centre is one that rotates with the work, normally in the headstock, but one with bearings that is mounted in the tailstock is more properly called a rotating centre.

Calmly... Deep breaths... The nasty inexactitudes are gone now!  Ahh, that's better.

Repeating everyone els's comments:-

Calipers are quick to use and good enough for much work. Micrometers can be two to ten times as accurate for hand held ones and better than that for precision bench micrometers. Because of their respective constructions, micrometers tend to be far better than calipers for measuring the diameter of larger round pieces.

PS:- Anyone need a five foot Sylvac digital caliper? It was lying all forlorn in the scrap compound at work, calling out to me.

Edited By Mark Rand on 08/02/2018 23:17:16

Foolscap paper size actually predates the invention of America...

Chloride ions do quite a good job on aluminium oxide and aluminium is amphoteric. So, both ferric chloride and hydrochloric acid will work if the resist is stable in acid conditions. Don't bother with nitric or sulfuric acid. they'll tend to reinforce the oxide film.

Edited By Mark Rand on 05/02/2018 23:04:33

It could well be something like sodium benzoate, which evaporates/sublimes and then condenses on surfaces to give a microscopically thin protective layer. It gets used in the VPI protective paper that tools are sometimes wrapped with. Oddly enough, camphor has similar properties, just smells more.

Also, a megaPascal is 10 bars AKA approx 10 atmospheres AKA approx 145psi.

Simples...

My second hand 36"x48"x6" surface table was a grade 1 when it left Crown's works and also when it was later calibrated in 1998. Trouble is, even ignoring the wear since then, that's worse than the error I need to scrape out of the table on my surface grinder when I start rebuilding it. Luckily, via the gods of the interweb. I've got an autocollimator, mirrors, diamond dust, lapping plates etc. and a workshop that only changes by 2°C per day if I leave the A/C off.

So I have the fun of trying to make a surface table flatter than it is at the moment. I get so much fun out of rebuilding my toys that I sometimes wonder if I'll ever live long enough to make anything with them.

Oops, wouldn't have worked very well with a tailstock centre in the way...

Then you have the problem that aluminium extrusions are never round, so you neeed to turn the outside to use a steady anyway. .

I finally got sorted out trimming the heads of lots of M4 allen screws 25 thou shorter. Then mounted the collet draws I've been mackling up for the HLV.

Makes it easy to find the right size collets. Also easy to spot which ones have gone missing.

Edited By Mark Rand on 29/01/2018 16:45:37

Ooh. 2 tenth's oversize. Gonna need to swage that down to fit.

It's wonderfully satisfying when something comes out so well, especially when working 'between units'.

Can it also operate from bottled gas? That will be far more economic than 12V power generated by the car's engine. Other than that, make sure that the final heat exchanger (waste heat disposal) stage is cooled as well as possible, but giving it lots of room and a nice cooling breeze.

Edit to realize that it's multi-fuel. So of course it can run on gas.

Edited By Mark Rand on 28/01/2018 00:08:31

Could be worth turning up a top hat shaped plug to fit in the tube so you can use a tailstock centre to steady things.

For Philip Rowe, If you haven't found a supplier of EDM hole shooting, is it worth breaking up the drill with a small punch? I had luck doing this when an M3 tap decided to glue itself into some stainless steel.

My progress today was drilling and tapping all the mounting holes in the collet draws I'm making for the Hardinge. M4 thread forming tap in a battery drill was much faster than the coordinate drilling* in the milling machine. Tomorrow, I hope to drill and tap an emergency collet so I can slightly shorten the heads of the 36 Allen screws so they will fit into the drawer slides.

* Had to shorten the 3.7mm tapping drill to be able to get clearance between it and the drawer sides in the mill. The Beaver mill has got 17" max clearance nose to table and 0" minimum. Given that a tool holder and tool generally uses up a minimum of 5" and a milling vice might use another 2-4" this is silly, since it reduces the maximum work height to less than 9". In this case there wasn't enough clearance with an 8.5" work height.

Oddly enough, the next project will involve welding up an 8" riser out of bits and pieces that I've got. I'd already planned to make it for one specific job that needs doing, but I'm beginning to realise how useful it will be in general.

Readings should be corrected for local gravity and temperature for the highest accuracy. The weights are normally stamped with the standard gravity (normally 9.80665 m/S^2) and the piston is normally stamped fro the standard temperature (20°C typically).

Many 'happy' hours spent in power stations around the world with Budenberg dead weight testers (for calibrating transducers) and dead weight gauges (what we used for high pressure readings before transducers got reliable enough).

A dead weight tester is sufficiently quick and rugged to use that there is no benefit in using a bourdon tube gauge as a working master.

Edited By Mark Rand on 24/01/2018 23:05:28

For welding high carbon or dissimilar metals, I use Inconel 82 because I've got a big reel of it . EN36 isn't all that special in terms of alloying components, so I wouldn't worry about welding it with mild steel filler.