Member postings for Nigel Graham 2

With respect, is this about "levelling" the machine, or aligning it?

I would not be happy about doing anything that twists the poor thing, but strict level-ness is less important than strict straightness. If you need to test and adjust the lathe each time, there's summat not right!

A machine-tool should as far as possible be on a rigid surface, with all its own feet in natural contact, helped by levelling-screws to overcome imperfections in the bench, not to twist the machine (unless correcting existing warping).

The cabinet or bench itself might be on carpet if circumstances dictate, and does not need to be level to NPL standards, as long as that too is fully supported and cannot drift out of kilter. In fact the manual for my Harrison L5 advises using the levelling-screws in its base to tilt the whole assembly very slightly towards the suds-tray drain.

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{Only my L5 had the holes but lacked both the screws and the threads for them... Cutting threads for 1-1/8" BSF bolts, by hand-taps, in existing slightly too-small holes in 3/4" plate with a rather hard surface, in-situ, as I lay on the floor in a constricted space, is another story... The screws by the way, plus nuts, came from a unexpected stockist: Settle Coal, in the town of Settle!}

Edited By Nigel Graham 2 on 05/05/2019 00:35:43

I'm sure this must be an old dodge but I've not seen it described anywhere.....

Setting a vice to be parallel to the table travel usually involves a gentle tap here, a run across with the DTI, a gentle tap there, ditto; oops too far; repeat several times, have a cup of tea; a gentle tap here.....

So:

1. Clamp a longish, straight length of BMS bar centrally in the vice, just nip the vice holding-down nuts or clamps. Fit two small angle-plates to the outer T-slot.

2 Tighten a long bolt fitted with two nuts in one of the angles, with its tip against the face of the straight-edge close to the end.

3 A second bolt with two nuts in the other angle, but leave it just slightly loose.

4 Keep the straight-edge against the first screw, which thus acts a fulcrum.

5 The other screw therefore acts as an adjuster, with the DTI used close to the screw at each end in turn.

Further, I did not traverse the straight-edge along the DTI tip. Instead I clamped the DTI's magnetic stand to the vertical shears above table, then used the DIT in conjunction with the cross-feed dial; moving the table back before traversing it to the other test-point. Measuring both ends ensures keeping the fulcrum in contact and removes any slight off-set effect.

Finally, a few spot-tests along the bar to smooth out any slight defects in the bar ensured consistency, then a run along the section actually projecting above the jaw as a final test.

It sounds a faff but is easier to do than describe, and proved quick and efficient. The angle-plates don't have to be proper precision angle-plates either, as long as they are rigid. Mine happened to be, but more by instinct than deliberate choice, as they could simply be a couple of off-cuts of reasonably heavy "angle-iron", with tapped holes for the adjustment screws.

I've always been a very satisfied Tracy Tools customer!

I suspect the faulty ones are the rare things that can slip through almost anywhere.

Come to think of it I've always had good service from all our usual suppliers -

- and I can say a 5.5" dia X 1" billet of mild-steel doesn't half make a bang despite the corrugated cardboard wrapping, when posted through the letter box onto a hollow wooden floor!

Disposal: I don't know enough about chemistry to suggest how to deal with Sodium Bisulphate but you can neutralise Sulphuric Acid with limestone or chalk gravel (rock not blackboard, chalk). The reaction will produce a sludge of calcium sulphate, the mineral which occurs naturally in solid form as the rock, gypsum.

Anodising and plating tend to be more consistent if the electrolyte can be agitated in some way during the process. The nickel-plating firm for which I once worked used air blown through perforated pipes laid along the bottom of the tank. In a small scale you could probably use an aquarium pump and diffuser.

As well as e-Bay, if I recall correctly, Sodium Bisulphate is available from swimming-pool suppliers as "Dry Acid" - granular. Beware: dust!. It is used as a pH corrector in pools. The same suppliers also stock Hydrochloric Acid, or did only a few years ago, and Sodium Carbonate (washing soda, an alkali), for the same purpose.

Yes - I'd say the 2nd from right is a milling-cutter, for forming chamfers and slide-way dovetails.

3rd and 4th: possibly either change-wheel studs or tool-pots studs. Do they fit the appropriate places on the lathe?

Number 5 looks to me like some sort of broach.

6, the ball-ended pin, does not look like part of this lathe, but for something else entirely.

7 (from right): it's a bit thin-walled for the task but might have been a work-holding clamp for a milling or drilling machine table, especially given the presence of that milling-cutter.

8, the disc with two handles, might have been made as a handle for the lathe's top-slide. It doesn't look an original part but could have been a past owner's custom-made fitting.

Finally, 9... could be almost anything! That does look like a bearing bush in the smaller end. I wonder if it was made as a secondary banjo for the lathe, to extend the change-wheel ratios possible - but that's only a guess. Like the ball-ended pin and the slotted bar, they might not be lathe accessories at all.

It is possible the mystery bits were intended for some user-built accessory for the lathe, but more likely were part of some project or other. Old machine-tools acquired umpteenth-hand tend to come with useful or even important bits missing, but with an assortment of strange-looking items, odd nuts and bolts, worn-out tools and such like!

I remember someone once donating my model-engineering club one of those old-fashioned, foot-cubed biscuit-tins, full of just such an assortment of small nuts, screws and odd-shaped bits of metal in fetching shades of verdigris and ferrous oxide. We tipped the lot out onto a bench to pick potentially useful from mere scrap.... Most items were innocent (and scrap) but it was just as well one club member was a police officer, for he was able to take away for proper and legal disposal, the dozen or so revolver rounds!

Today? Well, had a rest from engineering by going caving! I did enter the workshop on my return home, but only to collect the bird-seed and top up the feeder: the sparrows are eating me out of house and home!

Yesterday though... a few more hours making the umpteenth aluminium or PVC item to fit the DRO to the Myford milling-machine, trying to think how and where the vertical magnetic strip will go, so what I am building to carry the cross (Y) feed sensor won't prove to be in its way.

I used the now-installed long-travel (X) read-out for two parts, only to find they don't go together quite as neatly as hoped because I'd unwittingly mirror-imaged the datum ends!

Thank you for the tip, Nick.

'

John,

Re your Question about spacers.

A bit difficult to see from the angle of that photo, but the gear set does look a bit odd. I assume one of the wheels on the lead-screw is acting only as a spacer, well clear of the one opposite it.

The change-wheels should run on specially-made stub-axles often called "studs", with a threaded spigot on the inner end to go through the long slot in the banjo (the long arm), and be secured by a suitable washer and nut.

The banjo also has two radial slots so it can be swung to mesh different diameters of wheel.

With only one intermediate stud, as you show, you can use only 2 meshed pairs: pinion + CW1, CW2 + CW3. (CWs 1 and 2 are pinned together on the stud.)

Following approximately the set-up shown, number the change-wheels 1 to 3, in driving order from spindle to lead-screw. Assuming only one of the lead-screw wheel in the picture is actually meshed, with the other just being a spacer....

As set there, the drive pinion following the reverse tumbler pair should mesh with the first change-wheel, so that would have to be stood off the banjo face by a longer stud.

I am not familiar with the ML4 (mine is an ML7) but my guess is that the stud would have a large flange on it which both helps it sit properly on the banjo face, and places the change-wheels in the correct planes. As you have it there, all the change-wheels are a displaced inwards by a gear thickness.

On the ML7, the change-wheels are put on hardened, keyed steel sleeves of length fractionally double one wheel thickness, and which run on the studs. The wheels have matching key-ways.

Your photo of the 5 wheels and spacer shows they are keyed together instead by small mild-steel pins set into the holes clear in the photo. (The Drummond lathe uses the same arrangement.) I don't know if the intermediate wheels on your lathe run on similar sleeves or directly on the studs.

To erect the required train with single intermediate stud; once you've selected the wheels for the appropriate overall ratio:

The drive pinion engages CW 1.

Lower the banjo to give you room to work on it.

Thread CW 2 first onto the first stud (or sleeve & stud) on the banjo, with a spacer behind it if the stud is not flanged, so the plane of its outer face is just behind that of the drive-pinion's inwards face.

Thread CW 1 onto the same stud, outside of CW2, with the driving-pin connecting them. (In practice it might be easier to pin them together first but the result is the same.). This should put CW1 and the drive pinion in line.

Fit the nut and washer, or screw and washer, on the stud's outer end to keep the wheels in place. Move the assembly towards the banjo slot's outer end, out of the way, for the moment.

Now set CW 3 onto the lead-screw with a spacer to ensure it is line with CW 2. There should be a grub-screwed spacer to hold the wheel on the shaft, and that spacer will also have a pin for keying to the wheel hence the shaft: yes, it is there, in the photo.

I don't know from the photo above if the grub-screw engages a keyway or shallow hole in the lead-screw end, hidden by being ""round the corner". It should do, to avoid bruising the lead-screw.

Now slacken the stud and the banjo nuts just enough to move things about. This is where having plenty of room to stand at the end of the lathe helps, as the next step can be fiddly.

Gently swing the banjo upwards while manipulating the intermediate stud, until each wheel meshes with its intended partner. They should run properly when the teeth are engaged with just light hand pressure. Nip the stud nuts and banjo nuts, test the set-up by turning the machine gently by hand (with the motor unplugged!); and when happy tighten them enough to hold the gear-train together in use.

Spacers: you can use a spare change-wheel as a spacer BUT ensure it won't foul another wheel and jam the lot up.

Well, that's found your first task for this lathe - making a proper intermediate stud and change-wheel spacers!

'

If you're setting this up to cut a thread, measure the first cut when it is no more than a fine scratch to ensure your change-wheel sums are right. (If you don't have the chart for the lathe.

'

(Or even if you do - yes, you've guessed how I know! I was using a Harrison L5 that caught me out with its feed-range gear-box.)

Edited By Nigel Graham 2 on 26/04/2019 22:34:18

I am sure this is a dialect word that used to be common in our family - Nottingham parents but my brother, sisters and I are all English Channel coast natives - but I've not heard anywhere else: twitchel.

A twitchel (you'll have to take my word on't spelling) is of course a footpath, but not a roadside pavement. So when at Grandma's in Arnold, if she directed any of us to a small nearby shop it'd be "Cross the road and go through the twitchel" - between two of the houses and gardens.

'

In Settle a couple of years ago I needed to buy a pair of wellies as I'd forgotten to bring a pair. The first shop didn't have any but suggested who might. I confessed being a visitor:

" Ah riiiight! Across main road, down through t' ginnel.... "

I found it. I've been visiting that area for long enough to know some of the glorious Northern English language. I've even found myself using up some constructions, like "were" where "was" is by the book; and "stopping" for staying (overnight). It's helped perhaps by a trace of inherited Notts accent: a twitchel is a path not a parth, and my home's facilities include a bath nor barth.

NB, that "t' " is silent, a sort of glottal stop. In some parts of the North-West, too, it'd be "reet" not that flatter, longer "raiight". In the Tan Hill Inn one night I heard someone ask about turning off the "leets".

Including Norse words: the stream called Fell Beck, on Ingleborough, is directly "Fjell Bekk" in modern Norwegian, meaning "Hill / moor stream."

And is "Aye" (Yes) from still-current Norse "Ja". pron. "ya", perhaps? Aye seems to have tenses, from what I've heard among Northern friends. The Assertive: "Oh Aye!" in response to a comment like, "That were a right good do" - perhaps with the suffix "were that!" for added emphasis. Or the Ruminative: "Aye...", almost a sigh with a slight upwards inflexion, perhaps when considering some sad event: "It were a bad do, that."

A lot of ancient geographical names seem exotic dialect but are really mundane when translated. Norway is full of Bla / Kvitt / Sna Fjells (I can't type the accented 'a' here): almost phonetically Blue / White / Snow Fells. Similarly why do we have at least two River Rivers in England? (Avon = River.)

And the Dorset village, Ryme Intrinseca, sounds right fancy. I don't know the Ryme part but the Latin, Intrinseca, was just a Church property term.

'

These might be family rather than dialect sayings, but asked "Where are we going?" Grandad's common reply was "There and back to see how far it is!". Try to persuade him to go for walk, and if he wasn't feeling up to it, it was "Can't, I've a bone in me leg!"

Told the price of something clearly over-priced or extravagant, Mum would ripost, "Cheap at half the price. We'll have two!".

Once I called round to my Aunt Edie, widow of a Nottingham miner, to find her swaddled in heavy-duty corsetry as she did the washing. "Oooh, Come in! " she said in her rich accent, then as she bustled around to find something to wear on top, "And 'ere's me in me disbuss!"

'

Years ago I knew someone who if asked what he was making would usually reply, "A lay-'ole for a meddler!". Of course it was....

Walking with friends in the Cotswolds one day, we mis-read the map, ended up inadvertently trespassing, and the farmer spotted us. He could have ordered us back but instead directed us onwards across the field "... to the obbley-eyed gate..." We thought it politic not to ask but to discover for ourselves what is an obbley-eyed gate. It's a decrepit, wonky one. Naturally, it'd be right - just needs a bit more universal agricultural fixative, aka binder-twine.

Done it again! Forgotten certain punctuation marks give those silly wink etc symbols!

Hello John.

Those gears are the change-wheels, changeable to give different ratios between the spindle and the lead-screw (which you called a "drive screw" for cutting screw-threads of a range of pitches.

To give the widest screw-cutting range for the machine and the normal change-wheel set supplied with it, they are arranged to be set in single-layer or as you say, two-layer ("compound" configurations.

On many lathes the change-wheels are also used to give a uniform, fine surface, as well as for screw-cutting.

That pinion pair just below the spindle wheel is for reversing the lead-screw relative to the spindle rotation, so you can cut left-hand threads.

I'm not sure what the two "ears" protruding from the main bearing carry though.

Good to see you've put the poor old lathe back into decent condition!

I recall an awkward instance of it at work, with cap-screws and 'Nyloc' nuts - the action of the insert might increase the risk of galling.

These screws were no more than M5, possibly only M3 or 4.

The assembly was encased in an annulus consisting of two flanged rubber mouldings clamped together by pairs of stainless-steel plate rings bearing on the flanges, with lots of screws and nuts. The whole thing formed a short but very thick-walled cylindrical tube open at both ends, with equatorial flanges inside and outside.

And of course the seized fasteners had to be on the inner flanges! This was only about 80 mm diameter, maybe 40 or 50mm deep from each end of the case. Not much room for hands and spanners; certainly no room to cut a few pennies' worth of screw, even if that were possible without risking damaging probably a few hundred quid's worth of specially-made casing!

I could only try tightening the nut until the screw sheared before the Allen key, which luckily it did.

Steve's question shows the hole has to be quite accurate.

Whilst a hole-saw will rough out the bulk of the metal, even the rigid-bodied type will NOT give an accurate hole! They are not designed to do that, they leave a rough-walled hole, and tend to run eccentrically. Also, most of the readily available ones are sized for standard water-pipe and electrical conduit material in applications not needed a close push fit.

The older type of hole-saw, consisting of a ring of bandsaw-blade clipped into in a groove in the face of a large bush, is even less accurate.

Do use hole-saws, but be aware of their limitations, and use one generously under-size to leave accurate finishing by the various techniques described above.

A step-drill in a decent machine-tool may give the fit you need for the particular work-piece: try on an off-cut first.

A cone-drill can be used with care to give a tight fit, but obviously the hole will be tapered and diameter control is difficult. The significance of the taper will be controlled by the material thickness and the fit required.

Step-drills and cone-drills are not desperately costly from places like Screwfix and Toolstation (which also sell hole-saws), and very useful tools indeed. Assuming appropriately matching diameters of work and tool and the fit requirements, they can leave a finished-size hole needing no more than as the drawings say, removal of burrs and sharp edges.

I use all of the above for various tasks, obviously depending on material and purpose, and have even roughed out holes through thick plastic with a hole-saw, though that was somewhat fraught process as the tool is really intended for thinner and slightly harder materials than an inch of soft thermoplastic (PVC)! I did that 'cos I wanted to keep the central slug as bound to come in handy one day...

The galling is most likely to occur when both fasteners are of the same alloy.

It may be though that "ordinary" quality screws from the likes of Screwfix, whilst perfectly adequate for many applications, have rougher surfaces than high-quality so are on the road to galling straight away.

However, I have bought quite a lot of metric fasteners from Toolstation or Screwfix and have not so far had any gall.

Not only the Daily Wail that can't tell a train from a locomotive or think we use machines built for making the full-size locos. Far too many journalists in this country seem woefully ignorant of the most basic principles of science and engineering; regard these subjects as beneath their dignity; and so either do not ask, or do but are too dim or idle to relay the answers properly.

A year or so ago I looked up the web-site for a Major Model Engineering Exhibition, to ascertain times etc., and buy a ticket.

It carried a link to a daily paper's review of the show. Only it was from a year or two previously. The author started promisingly by recalling as a young boy, helping his uncle make small model ships. However, that was all the lazy, ignorant tyke could be bothered to see at the exhibition he'd been paid to visit and describe. The one photo was of a display of small static ship models; and the text more or less followed suit. There was basically no mention at all of model-engineering, of engineering projects from locos to clocks, i.c. engines to ornamental turning; of the numerous traders selling lots of engineering equipment.

And the paper? One you might expect to be more knowlegable, discerning and intelligent than the "red tops" when covering cultural rather than political matters: the Telegraph.

Amplifying a point in re Stewart's original post...

The vertical injectors did seem the norm on most full-size locomotives and many road vehicles, so it surprises me most miniature injectors are horizontal.

The starting-valve in these not only have a little help from that which makes apples fall, but are not ball-valves.

Their various types use instead, flap-valves hinged at the top and separate from the combining-cone, a flap-valve which is also part of the combining-cone wall and also hinged at the top, or a two-part combining-cone with the lower section drawn up to seal against the upper.

The types used on the larger full-size railway locomotives are quite elaborate even in simple mode. The exhaust injector is a very complicated beast!

I once dismantled and cleaned an injector from a two-foot gauge loco, and as I recall its non-return valve was of poppet type.

Clarifying my post above:

After posting it I looked again at the diagrams in the book, and realised I'd missed the function of the two cocks in the column behind the glass.

They are not for clearing and testing the sight-glass but are water-level try-cocks, so if the gauge broke it was still possibly to verify the water is around the right level.

Once realising that, the whole thing became clearer.

The ball-valve below the glass would be driven shut if the glass broke, preventing the escape of water and making it safer for the driver or fireman to isolate the broken tube from both water and steam by the normal cocks. The column would still be open to the boiler, allowing testing water-level by the try-cocks.

+++

The sketch found by Nick Clarke might have been an attempt to copy the auto-closing pattern without really understanding it; but more likely it was to lower the bottom fitting to give a better length of visible glass in a gauge designed for small boilers. LBSC may have used it for some of his locos because he designed mainly 3.5" and 5"g locos with limited water-level ranges and cramped backheads.

Why not simply place the water bush lower? A good question, the answer probably lost in model-engineering history!

I certainly agree with Nick on the cleaning problem it gives.

I wonder if it's designs like that one which the Boiler Code is really against.

+++

SillyOldDuffer - yes you are right. Making the gauge glass share boiler connections with fittings like injectors, as in your diagram, will almost certainly give the problems you surmise. That's why it's not done!

Does seem odd.

I can understand why the gauge would use independent steam and water connections; and why the connections should be direct - as explained. In fact all the designs and engines I have seen - full-size and miniature - follow those two principles.

However there is no obvious reason why the water and steam connections cannot be linked, unless such designs have given rise to odd problems of their own. It would be very unusual, but some full-size boilers, especially in very large plant installations had such a column as part of an automatic shut-off that operates if the glass breaks.

I have consulted The Good Book... aka Handbook For Railway Steam Locomotive Enginemen, (typesetting was cheaper in them thar days) pub. British Transport Commission, 1957.

This shows the normal gauges with glass and three test-cocks, but also shows a type with a pipe behind the glass, and with two test-cocks in that. A note, "Copper Firebox Backplate", on the cross-section of fitting and mounting, suggests GWR. Crucially, this pattern also has a ball-valve in the water fitting below the glass, so I assume this too, is an automatic shut-off, though the text does not say so.

If anything a parallel water column might ease oscillations in the glass as the water in the boiler sloshes about, but on its own, not part of a safety device, would make no difference at all to the gauge-glass' action. In which case it's a needless complication.

I can't help thinking the restriction in the Code is more "not invented here guv'", than serving any real purpose.

On a couple of points raised...

1) The standard designations look alarming with all those letters and numbers, but are fairly easy to find and to follow, and it may be worth keeping a copy with other references, like tapping-size tables.

I don't know our regular suppliers' criteria when selecting inserts to sell to us, for our use in conditions far more variable than in industry, including our using manually-operated machines not always in the first flush of youth (the machine-tools, not us!).

However, most carbide tips are really for production machines with very rigid structures and automatic feeds, clearing metal at very impressive rates and capable of very high surface finishes. In this area, their manufacturers' catalogues, intended for the precision-engineering trade, quote insert or insert-facet lives of typically 20 minutes at the tip's intended material, speed and feed! (I believe insert life and price is accounted for in costing the work and preparing quotes.)

2) Showers of swarf... make some form of guard or screen easily placed and removed, to keep the swarf where it belongs.

Since when has there ever been a generation that hasn't mucked at least something up?

There was a conversation rather like this recently, in my caving club. After we'd put caving's internal "politics" to right, someone pointed out we'd had a good old grumble, then wondered,

"What's the collective noun for === === Club members?"

The reply recalled a few times since, was, "A Grump of [===]!"

Naturally, Club name deleted to protect the innocent.

Right, so what's the equivalent here?