Member postings for Nigel Graham 2

I would suggest for milling such thin spring strip to with, clamping it rigidly between two pieces of sacrificial mild-steel and milling along the sandwich with a carbide tool, entering both support-pieces a little.

For tempering after hardening, a lead bath is about the right temperature for a tempering colour of dark-blue. Keep the lead just on melting-point, starting to crystallise on its surface - and avoid breathing any vapour! Leave the springs in long enough to ensure full soaking, though at the sorts of sizes here, that won't be long, a couple or minutes or so perhaps.

Note that the tempering colour is by oxidising, and the steel will stay bright (from post-hardening polishing) except when exposed to the air.

I used this technique for new springs for a 7-1/4"g Ken Swan-designed "Wren", and have known other constructors do so, successfully. I quenched them in oil - and carried out both operations outdoors, in the evening so still day-lit but not in sunshine.

Second attempt... diverted to verify something and lost the draught message!

I'd had a disheartening cock-up trying to make a pair of centring blocks for machining the crank-pins on 4"-scale steam-wagon's crankshaft. Roughing the shaft by milling revealed a loss of symmetry I put down to the two sets of original centres on flanges on the end, being misaligned with each other.

I'd milled the blocks from a piece of mild-steel bar about 2" square, thinking ahead to their possible further use as Stevenson's Blocks 50mm sq x about 40mm thick., with a 25mm central bore in each (and turning the embryo crankshaft's temporarily over-diameter ends down to match).

Try as I might, for reasons I have not established I could not make the stock square and parallel for its length - all of about 4 inches. "Only" a simple fly-cutting operation with the stock held between an angle-plate and the milling-machine table.

Decided to think only of the initial purpose, and selected the 2 most-square sides on each, indicating them by filing a generous chamfer along their shared edge.

Then... realised the centre-drillings for the crank throws are 1", errr... from the centre of a 2-less-a-bit" square?

Called myself all the names under the Sun, and reverting to Plan A, started machining to 98mm square two pieces of nominally 100 x 25mm flat bar; wondering where I could remove metal to reduce the massive overhung weight this would add to the shaft for its own off-set turning.

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So TODAY....

Spent a relaxing day in the sunshine at the club's track site, instead, by helping tidying the garden that has become as much a feature as its encompassing ground-level railway's shorter home circuit and the raised 16mm-scale track within that oval.

Then Eureka!, or something like it.

Collecting wind-blown litter and cutting brambles from the boundary hedge without cutting the dog-rose stems, must have swept the tubes in what passes for my mind, for I realised I can still use those 50mm blocks.

Never mind future use, beyond this one engine project. All I need do is set them out with the hole and the two centre-drillings off-set towards the one "square" corner.

So home, a brew then into the workshop....

By the time I stopped for a late tea, I'd set the centres on the mill (albeit with one mistake so it's a good thing cuboids have opposite faces...) then transferred each block to the 4-jaw chuck on the Harrison lathe to pilot-drill the holes 21mm, finishing with a quick pass by boring-tool to lessen the boring-head work to come.

(Why not finish-bore in the lathe? I want the blocks identical, and stand more chance if I use the milling-machine, with DRO, for the finishing operations. It won't be as easy to test the bores on the mill by using the crankshaft itself, it being nearly a foot long; but I have a milling-cutter with one-inch shank to use as a plug-gauge. 

A good find!

My bench-drill is a Meddings, though single speed-range and chuck only, but I am very happy with it. I often use the table/base as a surface-plate.

Spent half the morning searching for two sheets of steel I knew I'd purchased for a specific purpose, then for two conventional parting-tool holders I'm sure I'd bought.

Found the sheets. They are safe.

Did not find the tool-holders; now wondering if I had bought them.

Found a different parting-tool holder I'd forgotten I'd bought and so have not yet used; a Myford special for the rear-toolpost. That's immediately replacing the Sorba holder perched uncomfortably in a quick-change holder!

Also opened the box holding the same pattern tailstock attachment as George's... only to my dismay, the parts of it nestling in the foam packing are all rusty! I've not even used the thing yet. I'm going to have to dismantle it to clean properly.

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Break for dinner, some gentle gardening and tidying that upset several frogs and a small furry animal I could not decide if mouse or vole. Then back to machining the steam-wagon crankshaft.

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I'd roughed out the webs and pins by milling between a rotary-table and tailstock, but the emerging pins (still healthily above finished size) are visually off-centre, also shown by the cutter nibbling the corners unevenly.

I knew the three centre-holes in each end of the bar were correct to each other as I'd set them out very carefully by DRO. Thinking about it, I had not realised the part-machined bar at that stage was less accurate than I'd bargained for, so despite using a big angle-box to set it vertically, one of the two trios of holes must be displaced angularly from the other. Initially I thought that would simply give the engine a slight off-beat, but thinking more deeply shows the pins would not be parallel to the shaft, as the effect is to build in a very slow helical turn.

Nothing for it but to machine off the centring lugs and turn the shaft ends to an interim diameter to take a pair of clamp-on centre-blocks I will have to make.

Well, this is my first attempt at making a crankshaft, and from a hefty lump of very solid bar!

FullaFlava:

Finding metalworking blades of the right length may be possible but note that if your band-saw was made for wood-working it will probably be far too fast for sawing metal, especially steel.

Finally obtained the Round Tuit and Spare Minute (or 60) to repair my camera tripod, after frustrating attempts to hold the camera by hand to photograph progress on the crankshaft I am making.

The camera mount itself was long-lost: a simple rectangular plate holding the 1/4"BSW screw, and once fitted to the camera, held by a cam in a dovetail arrangement.

I found a piece of PVC plate about 8mm thick in a come-in-handy box; sawed the blank, drilled through, and counter-bored a generous recess so I can turn the sunken head of a shortened machine-screw by fingers. The tripod-head part is flat so the screw-head must be sunken slightly.

Machining the two dovetails was easy on the Drummond hand-shaper. I wanted a reasonable fit without needing machine-tool accuracy, so it was cut-and-try until the cam locked properly. It was also a test of a mounting method I have in mind for more "serious" work. Simply, I mounted the plate (50 X 43mm) in a V-block on its side in the shaper-vice, with a round tool shank acting as intermediate clamp, and cut along the length of the bevels.

Thus happy now, I managed to take a couple of half-decent shots of the embryo shaft on the milling-machine, but unfortunately, due to the cramped nature of the workshop, not from the side looking onto the rotary-table face.

Then proceeded to rough out the crankshaft's centre main-bearing, by milling. It will have to be finished by turning. If you want to see how un-square a milling-cutter end is, try using it radially to the work, to mill a cylindrical surface: the result looks more like a first exercise in Ornamental Turning!

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Drew a leaf out of the cricketers' book, and Stopped For Tea.

Evening: printed two auxiliary drawings of the shaft, from the original; one concentrating on the dimensions of the webs, the other giving the various diametral details. (This in TurboCAD, orthographic only - 3D CAD's lost on me. And not very useful in the workshop.)

"... fields in the middle of nowhere..."

I can understand that!

I am in one of the two Yorkshire Dales-based caving-clubs that each run its own annual "Gaping Gill Winch Meet". Gaping Gill is a huge "pot-hole" on the fell, some 2 miles of up-hill walking from the village of Clapham.

Some years ago our insurers wailed that their paper-work wouldn't work without the computer being fed a post-code. Now, surprising as it may seem, Royal Mail had not given the cave such a thing; nor does it deliver post to the flanks of Ingleborough.

The problem was solved by gaining permission to " borrow " a local post-code, I think that of the village shop. It's close enough and after all, to a database it's only 4 letters and 2 digits. It'd probably have worked if they'd typed " AA0 0AA ".

But three words though? I dread to think!

I wonder if some of apparent tardiness is from using anthracite straight from the kindling.

Anthracite has the highest calorific values of the natural varieties of coal, but is not so easy to ignite and build up a fire as a more bituminous coal, and in some boilers at least needs a fairly good draught.

I know some engine-owners use a mixture of coals, but it might be worth trying a softer coal first to establish a good fire-bed, before using anthracite.

I threw out another "I'm from Microsoft and you computer's reported a fault" call recently. That was unexpected because I have had none of those for a long time.

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Complaints here about the inertia and complacency of the ICO, but I've little confidence in Action Fraud, too.

You never hear back from it if you make a report, but that might be concerned with security so I can accept that.

My beef with it is that is very awkward and long-winded to use, and is clearly a database of classic form. I.e, written by someone brilliant at writing extremely complicated software while lacking the imagination or initiative to consider the user, and to realise that set menus of a few random questions immediately limits the system's scope.

You might expect it to accept forwarded e-mails for analysis... No! That's too obvious for the Access-jockeys to spot!

No. 3 looks as if it's to fit T-slots. Not a rather crude travelling-steady, perhaps? The paint seems to match that on the hand-turning rest.

I'm as intrigued as everyone else on the real meaning of those symbols, which I wonder may be visible by some accident of manufacture or aging rather than intent, but "Pad" printing?

That's a new one on me - I understand offset-lithography and screen-printing, and of course the inked-stamp form going back to William Caxton; but had not heard of that, so thank you for that link.

Screen Printing goes back to antiquity as an art form but its modern industrial version is used on anything from simple labels and dials to the very high accuracy and precision requires in mass-producing printed-circuit boards.

I would not use a car gas-strut to hold a small plastic machine-guard. They are designed to balance a far heavier mass than that, so would be physically very hard to handle.

Some machines, including my Myford VMC, use a basic toggle: just two links pivoted together at mid-point when both are in line. Pushing the joint while closing the cover down slightly makes the links go past alignment by a couple of degrees of so, against a small stop on one of them.

Yes - I concur. I've bought quite a few tools over the years from Tracy Tools, I'm about to place another order, and I have named them in response to a question elsewhere on here about suppliers of lathe tooling.

Apologies if this appears twice. I thought I'd replied but inadvertently closed the site while verifying references! Isn't the WWW fun... No?

Right, two suppliers immediately to my mind for HSS and HSS_Cobalt square tool bits or blanks: Tracy Tools and Arc Euro Trade.

For inserted-tip tools & their carbide tips: B.B. Cutting Tools, and Greenwood Tools.

Of suppliers of good HSS tools, Tracy Tools and Arc Euro spring to my mind immediately, though they, and others, don't seem to advertise in ME and MEW..

For carbide tips "our" main ones are JB Cutting Tools and Greenwood, both selling indexable rather than brazed-on tools.

Re Apple PSUs.

It's not only Apple who are bad at design details. I've had to cut short and re-terminate the lead on my Japanese-made vacuum-cleaner, because one of the twin conductors had been severed by the sharp edges, very tight fit and excessively tight bend radius of the cable-clamp.

And as for the German-made hacksawing machine I had to use in my days as a materials storekeeper for a company making precision screen-printing machines..... It was well made, but apart from one very good safety-feature, its design was abysmal. Though thinking about it I might be being unfair - the management might have not thought about it properly when studying the catalogue. I had to cut aluminium and BMS bars, down to fairly small cross-sections, but the machine had been designed for fairly heavy hot-rolled steel.

"re-imagined" (in Matthew's original post). A word normally I abjure but in this case it's just so appropriate to the twaddle from Apple! The sad thing is the Apple author presumably thinks he or she understands engineering terms.

Interested to see this lathe seems to be an IXL.

I owned for a while a larger lathe badged IXL, which from Tony Griffith's site was German-made, but by Ehrlich, and IXL was a dealer putting its own plate on things.

Took the partly-chewed out 2-throw crankshaft from the milling-machine to the lathe.

What's there so far is the result of a lot of rather hefty milling, chain-drilling and sawing, and yesterday using a ripping-cutter to munch the worst of the vaguely-square mass of chain-drilling ridges down to something approaching an 18-sided polygon section, so the turning won't so intermittent.

The lathe for this is the Harrison L5 with 3-ph conversion, so large enough to cope with some intermittent cuts by HSS tool, at shallow cut, gentle self-acting feed, low back-gear and moderate motor-speed though with the controller pointer still well inside the green sector; and indeed by the time I finished this evening I'd brought the "tabs" that will be the cranks themselves, down to near their crown radii.

I'm crossing my fingers that a length of the old "stock" surface still on the outer edge of one of the "tabs" will duly disappear. It's a bit close. The material was an off-cut of a scrapped axle from a narrow-gauge railway truck, so its surface is quite heavily rusted (though I've seen worse).

This is my first attempt at making a crankshaft, let alone sculpting one from some 11" of 2.5-ish dia. solid steel.

Assuming we are talking about anything bigger than a Mamod boiler...

Forget all that analytical stuff. The MELG Guide Book (latest has a white cover with orange titles) tells you what you actually need to know.

It mentions certificates only for steel boilers, but places so many obstacles in their way that making a steel boiler is for the professional only, for all practical purposes.

(Curiously the original EU Pressure Equipment Regulations that our hobby sort of uses, mentions only two materials for pressure-vessels: aluminium-alloy and stainless-steel; but not which of a plethora of their alloys and grades!)

Copper and cuprous alloys, and silver-solders and fluxes - purchase by what it says on the drawings, and if you buy them from reputable suppliers they are what they say they are on the invoice. You don't need certificates of conformity for them, for amateur construction not by way of trade, and nor should your club's boiler-testers demand them, though they might want to inspect progress.

Just don't use brass in any structural component including the bushes for clacks etc. Rather according to alloy, it can become brittle in some circumstances and conditions.

The question mentions stainless-steel. I am afraid that is irrelevant. I think it's still ruled out, but anyway it comes in so many flavours with their own welding characteristics, that whilst there is no logical reason against stainless-steel boiler shells in principle, it is definitely a material for the professional boiler-makers able to choose the right alloy and weld it correctly.

Continued in my inimitably slow way to set up my wagon's crankshaft for milling.

Spent yesterday aligning the tailstock borrowed from a dividing-head with the rotary-table bolted to an angle-plate.

Today was making clamps / driving-carriers to hold the shaft to the RT, a process giving a new lease of life to some very rusty steel that had been scrapped miniature-railway rail.

Rusty? As my Mum might have said, " It looks as if it's been dragged through a hedge backwards! " and not far wrong, certainly left lying under said hedge for ages. Still, it's not bad steel under the corrosion.

I'd had to make a centre for the RT too, which has a shallow 3/4 inch bored recess above a 1/2 inch BSW threaded hole, not a Morse Taper socket. Attempt One failed - the Harrison L5 lathe has a 3-speed gearbox on its feed-shaft and lead-screw, and if you forget and it's in the wrong setting, the thread is not what the change-wheels say.