Member postings for Nigel Graham 2

Like Paul, I attend the exhibitions for several reasons, not just denting my bank-balance. Though I've to order prior to collection at "The Fosse" - yes, I've both bought a "civvy" ticket for one day, and awaiting me on another day will be a club stand-crew pass.

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I far prefer to buy anything on sight. I have no objection to purchasing by mail / Internet order, and do so from time to time; for real purposes like model-engineering, not "ordinary" stuff like clothes. So I value the traders, not least for the help I need sometimes to select what I want.

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I come away from the gleaming, brand-new top-award exhibits sometimes not sure if I am inspired or would have been better off with origami, but enjoy admiring the simply-shown on the club stands as much as the competition examples. I find myself looking at the patina on an older steam locomotive or traction-engine and like to judge it one well-built, well-loved and well-used.

I was not amused one day when admiring a 4" - scale traction-engine to overhear the visitor next to me complain to his companion about some small detail apparently not right. The honourably-patinated engine with a sooty chimney was clearly well looked after, and well-rallied. Where was the rivet-counter's engine, I thought. With no drawings available, my own long-suffering project will never be rivet-counting right - but I want it as near to original as sensible... and to work!

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There is though another, very important aspect I'm not sure has been mentioned much here - the social one. From chance meetings with friends perhaps in other clubs, to chance conversations with anyone else over one or another technical matter; and often the chance to seek advice. I recollect vaguely at one show, two or three of us visitors spontaneously becoming the informal Advisory Committee for some engineering problem of another visitor or a club-stand member!

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On Paul Kemp's first paragraph, I vowed not to go to Doncaster again after the terrible time I had trying to find the race-course in a city-centre full of dense, fast-moving, traffic. (I could not drive in London, You-Les or not.) Nor I was not impressed by the Doncaster horsey-set price of a supermarket pasty and a paper cup of DIY tea. On the other hand, I don't recall the ticket price being unduly high, and once in I did enjoy the exhibition and bought a few things. So for me, moving back to Harrogate was very welcome - but I do have other interests and friends in't Dales so its 300 miles from home is not too much a burden personally, despite the cost of petrol.

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A NAME Meeting I attended for my club a few years ago, I forget if pre- or post- Plague, mentioned a possible exhibition in the South-West, e.g. Exeter. This appears to have faded, but I don't know if anyone is considering reviving the idea. Aware of the repercussions of making such pronouncements I will have to admit, don't look at me - I'd struggle with a round of shandies in a brewery - but I'd likely attend if possible!

No - Do Not try to correct the mistake in a way that alters the wheelbase!

That is compounding the error and will lead you into all sorts of troubles.

Even a 1/16" is a serious error you'd need compensate for elsewhere: coupling and connecting-rod centres, piston-rod lengths, say. If the driving-axle is in the wrong place then you start putting the valve-gear in the wrong places.

However you correct the horn-plates, do keep the axle-centres to design.

A pair of asymmetric bearings is not quite Gold Medal winning but as long as the axles are where they should be, the locomotive should still work.

It is noticeable, and judging by conversations with other model-engineers, I am not the only one to have noticed that the larger traders are finding it more and more difficult to attend any exhibitions.

I'm guessing it's the best part of two weeks hard work for them, with the preparations and the post-show re-stocking; on top of the transport and accommodation, and now the congestion or low-emission fees being imposed in many cities.

It may well be easier for the smaller traders with fewer staff, smaller stands and less heavy goods to display; but I was surprised to see Reeves at Taunton MES' club exhibition several years ago. Their full show stand would have hogged the hall, in a school, but a single table with back-boards and two carousels of small items, was enough to show they exist, and to allow them to take orders for goods not physically there.

I think the snooker matches are still on at Alexandra Palace on what used to be also "our" weekend, and I do hope the venue can continue especially as it had re-furbished the theatre only a year or so before the pandemic; but I also wonder just how many cultural events London and other cities will lose.

Good point but the leak could be of air into the smoke-box. I'd start with that before thinking about a steam leak, which is harder to trace.

I'd also take those springs out of the valve-chests. Two reasons:

- They won't help seal a leaky valve face, but will add extra load to the motion-work which seems to have been behaving as it should, by the air-test.

- They don't appear to have solved the problem, and were a solution to a problem not yet diagnosed anyway.

If it's the slot in the steel frame that is oversize for the casting, which I would guess is probably bronze:

First establish which side - front or rear of the axle - of the slot is the over-cut one. Or if both equally, which will make the next bit easier by making the error symmetrical about the axle centre.

Then sweat a brass shim to the horn-cheek side(s) as appropriate. Since it is only a spacer to fill an unintentional gap between two static parts, and takes no tensile or shear lead, soft-solder would be fine.

That fault would be easy to diagnose initially, though the leak might be harder to trace, by air or steam; without dismantling anything yet.

Open the smokebox door, and watch or listen to what happens in there when you open the regulator (mid-gear, etc.!) To do this by air, connect the boiler to a suitable pump or compressor. You won't need full working pressure.

If a leak is audible but not giving a visible sign (as by air) hold a slip of paper or a feather in front of each superheater flue or by each accessible joint in turn. Or gently push a wad against each flue in turn and note which if any alters the sound. Testing cold by air, allows you to plug the flues' firebox ends with cloth or tissue-paper to enhance the effects in the smokebox.

If that reveals something leaking, you can then apply more sophisticated tests to identify where, needing disconnecting and blanking fittings.

Steve -

I don't know the Rob Roy deign myself but I do know it is a successful, popular design.

Do the drawings call for springs on the valves? They are not usually necessary because the steam pressure holds the valves against the port faces. Some engines have something like that called "balanced slide valves" but it is not a simple spring, and is to reduce the load on the valve to reduce the engine's internal power loss.

Were the valves leaking directly to exhaust? That will lose steam all the time. It should show as a blow up the chimney between the exhaust beats, possibly stronger if the regulator is opened in mid-gear with the drain-cocks open.

One cause, assuming the valve and port faces are as they should be, is the valve sticking on its spindle. I don't know if this locomotive uses cross-nuts or bridles to connect the valves to their spindles, but either way ensure the valves can "float" without end-play.

The same leak would occur of course when testing the locomotive on air, but probably masked by the compressor easily keeping up with it.

Notching up is unlikely to reduce the leak particularly, but as it reduces the amount of steam entering the cylinders at each revolution it will reduce the combined steam demand.

Springs under the valve nuts? To do what?

Is this on the track, hauling you on a driving-truck, or under test on a rolling-road?

Some drop in pressure on pulling away, I would expect, but it should stabilise and even recover with normal firing and driving. What happens if you notch up a bit?

Altering the blast-pipe suggests having to correct poor steam-raising. An air leak in the smokebox?

Thank you for that explanation, Michael.

In which case I wonder if moderately fine gravel would work just as well and may be easier to obtain. Flint gravel is the same material as sand and glass - silica- but the type of stone might not matter very much.

Sand or crushed glass?

Chemically they are the same so theoretically each kg of either would store the same heat for the same input.

However the problem may be that of heating enough of the substance to be effective. It is a poor conductor of heat and the coarser the particles I would expect the less conduction through the mass due to the intervening air, also a poor conductor.

Might a more effective approach be a solar water-heater that transfers its heat to the sand or glass via a matrix of tubes, rather like a boiler "inside out"? Or use storage-heater bricks?

Certainly no harm experimenting as you don't run into problems with dodgy fuels, fire safety, badly-made oil-heaters, etc.

My brother has installed a very effective solar-panel water heater on his home's flat roof, using two commercially-made panels plus one he built from an ordinary central-heating radiator painted matt black, inside a suitable glass-fronted enclosure. I can vouch for it having used the shower heated indirectly by the installation. (They also have an instant-heat shower for when there is not quite enough of Old Sol, in Southern Scotland.)

For my workshop (concrete-block single-skin walls with internal insulation, wriggly asbestos-cement roof with an insulated ceiling, crude "double-glazing", I use a small electric radiant heater when really necessary, but warm clothes and an hour of machining seems enough for bearable conditions.

Ball-sizing works very well in industry - including engine manufacturing - but they have the equipment including very sophisticated metrology departments and dimensional controls!

Piston-valves in full-size do have piston-rings but the ports are not simple radial slots. They are commonly triangular or parallelogram holes so the rings are always fully-supported on the diagonal bars, a bit like the wheels over point-blades.

Not something I've ever tried but I know this has been used successfully on miniature locomotives. I think they can be plain round holes, too, with a slight loss in port area perhaps.

On dividing a cylinder for rivet holes and the like without a rotary table, Try this:

A similar problem when needing make a strainer: lots of rings of holes, divided along and round.

You may need exchange a quick-change tool-post for a conventional clamp type for this.

Mount a broad metal block - I think I used brass - in the lathe tool-post, square it to the chuck by simple contact, then drill a hole of the correct diameter through it at about mid-length, from the chuck.

Mount the tube between centres and fit a suitable change-wheel to the back end of the spindle to use as a division-plate. If your lathe does not lend itself readily to changing the spindle pinion you'd need use the bull-wheel or some sort of compound-dividing.

Rotate the drill-guide on the top-slide and re-clamp it square it to the work. (Simply, gently push it against the tube).

Now use a small portable drill to make the holes, with the guide in light contact with the tube.

For the strainer, I just aligned felt-tip pen marks on the change-wheel, visually, to a fixed feature; but important work like a smoke-box needs some form of positive detent. For the length division, I used the lead-screw and a second change-wheel, isolated from the spindle wheel.

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That was done on my EW lathe before that yet had proper bench to stand on (not long after I'd moved home)! I used a battery-powered drill.

Thank you chaps!

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Andy -

Yes - that seems to have sorted it!

Thankyou!

TC 2021 puts an extra step in the Tools menu to find "Customise" but it's pretty obvious where it is.

I noticed it opens that tool and commands library which I learnt long ago, and is one TurboCAD function I particularly like.

Experienced users like to operate as much as possible with the so-called SEKE Keys (I forget what that stands for) for speed and to avoid what they regard as clutter along the top of the screen. That's a lot of combinations to remember to be effective though, and I prefer the more explanatory toolbar & menu route.

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I have my engine's partially-drawn GA on TurboCAD, and need refer to that to design the components. For example - and this is where I had that tools problem - I need know the distance between the tops of the cross-heads and the cylinder covers, to be able to design the stuffing-boxes and guide-bar mountings. It looks as if I'll need move the whole engine down a bit to give more room - the cylinder top altitude being more or less set!

The Tracy Tools chart that lives by my PC, tells us M7 X 1 is a standard ISO-Metric Coarse thread.

Beautiful work worthy of the original construction!

I don't think it'll get that grubby, Dave. Steve's making clocks not modifying steam-locomotives, with it!

Thank you. That's what I thought but it won't work.

The "Start" sign here is a little blue square with a square cross on it.

A left click on it does show Alibre and others, but they can't be drag-copied anywhere.

Right click does not open the Applications list directly, but a long "Settings" menu containing "Installed Apps". This is a more analytical tool, showing programme sizes and a degree of user's control over what is installed or not. Again, although Alibre is right at the top by starting with "Al", it can't be dragged onto the desktop.

Aaaargh! Problem solved! Only just spotted it!

The up-date has put a new Desktop symbol up, helpfully labelled "Alibre Atom 3D 27...". (So those first two digits are the version.). It was right up at the top corner, hiding among a lot of other things I'd not normally look at - the original symbol was a lot more noticeable!

Right, I have now deleted the V26 symbol and moved the V27 one into its place on my normal sight-line!

Oh silly-billy me. The digital equivalent of me putting a big spanner down on the bench then failing to find it five minutes later.

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One problem cleared. Now, what has IMSI done to my TurboCAD to make its easy bits harder?

I might learn Alibre Atom enough for simple, single-part 3D models and their elevation-drawings; but for more complicated parts, assemblies and geometrical constructions, need TurboCAD in orthographic only (much against its own will). Or a drawing-board....

So:

Originally using TC 2019 I up-dated it to 2021.

Yesterday I opened my wagon engine's GA drawing and was dismayed to find several tool-bars, including basic ones like the Lines menu and the Copy in Place tool removed from the screen, They are still available indirectly, but I could not rebuild my extensive tool-bar display.

Has anyone else found unexpected changes to their own TurboCAD tool-bar layouts; and if so, how did you correct the problem?

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On Alibre, its latest up-dates have switched off the Desktop starting symbol. It's there but inoperative. I thought you can make screen short-cuts from the computer's programme index, but not in Windows 11.

Instead I had to open it from a drawing - not so easy since Microsoft's changes ruined my carefully-built filing system and I have not managed to repair all the damage.

So how do I create a new screen short-cut for Alibre, please?

9/16 inch outside diameter of the thread, 18 threads per inch; UNF stands for Unified National Fine and is one of the American "UN" series industrial standards for screw-threads.

UN-series threads were fitted to a lot of motor-vehicles and military equipment in the UK at one time and the fastenings are available here; though perhaps not flanged nut. You might even be able to obtain one from a garage! It does not need be flanged though - use an ordinary full nut and a thick washer.

Hemingway Kits list a rotary broaching attachment kit, but I don't know its capacity (without studying the catalogue).

I've not bought one, though have built a couple of their other projects, and they come with instructions as well as drawings. The photographs with mine suggest they make the prototypes on a Myford or similarly-sized lathe, so within most model-engineers' workshop capacities.

I believe suds tanks quite commonly have a weir to trap the chips.

Though a full-loss system I did once use something like DMB's suggestion, made from a 1-gallon oil-can, simple screw-down valve and plastic tube, above my EW lathe. The problem I can see with swapping tanks about without a transfer pump is the sheer weight you need lift to some height!

I'd be a bit wary of using a windscreen-washer pump, because although it would deliver a suitable flow for a small machine-tool, some types use an elastic-vane impeller made from natural or synthetic rubber that might not last long in cutting-fluid with traces of lubricating-oil and tiny particles of metal.

For a larger machine, I suppose one could use a central-heating or washing-machine pump.