Member postings for Nigel Bennett

Erm... guilty as charged, M'lud. I used Don Young's drawings, but scaled down to suit. I built it purely as a test bed for Gas Producer Combustion and for exhaust systems. I drew out pretty well every part (there was a folder with a lot of them next to the loco) to the correct dimensions using SolidWorks 3D CAD. It was a vital tool for checking on the underfire steam supply and how it would all fit into place (or not) before I cut metal.

Thank you for your kind words and interest, Nigel.(Great name...)

You should have no problem with a Clayton on a Myford ML7, but you'll need a vertical slide for the milling work. The wheels aren't too large to turn, and you can even turn the crankshaft from solid, because I've done it.

Good luck with your project.

Mick

I can see now why you wanted to try it - and I had no intention of doubting that you love your son.

I've built a few wheels myself over the years and so know a little about them. As they are a highly-stressed and safety-critical item, it would be most unwise to risk his well-being by fitting a wheel that I believe would be fundamentally flawed in its integrity. Perhaps I phrased my comment badly, but I am deeply concerned that you are proposing something which you might regret if it goes - well, I suppose "pear-shaped" would be an adequate description.

Are you not fond of your boy, such that you want to kill him? It's a silly idea and I would strongly advise against it. There is no way that you could build a wheel strong enough using this scheme. Just leave it as "an interesting idea" .

ems-I do a Newall compatible console. I had a Newall setup on my S7 and the display would occasionally lose 10mm. It was unpredictable so I had the option of a repair job or a new console. Finding an intermittent fault is not easy and so I chose a new console. It wasn't that expensive - £300, I think. I bought another one for the Boxford 280 as I had Microsyn scales on that as well.

**LINK**

Been very pleased with the consoles. Usual disclaimer.

As far as I'm aware, the intention is that you machine the back away as a last operation - very carefully and gently - to expose the spokes. I imagine they're cast that way because the spokes on the 0G wheel would be so thin that they'd be impossible to cast otherwise - or at the very least they'd be chilled and be very fragile. If it was a split pattern - like the 5"G one - than getting the two halves of the mould to line up within a thou or two would be another problem.

Just take it steady!

By far the worst culprits for rounding the hexagon sockets are Imperial countersunk hex socket screws. Anything below about 2BA and you need an electron microscope to find the socket... The metric ones are better but I've lost count of the ones I've had to remove either by battering a Torx bit into the chewed-up socket, or using a centre-punch and hammer to try to unscrew it.

Yes, sorry for my typo earlier - I wrote 8000kPa and meant 800.

Generally speaking, metric steel cap head screws are supplied with a tensile strength of 1200kPa. Hexagon headed screws are only 8000kPa. (The marking "12.9" on cap heads - the "12" is the code for 1200kPa, and the first "8" of the "8.8" on hex heads is for 8000kPa). Hex grub screws are usually grade 14, but countersunk hex socket and button head screws are only rated at 10.9 as standard. No idea why! Unbrako do a special "Durlok" hex head screw with integral serrated washer - rated at 12.9 but I have never used them.

Obviously with stainless fasteners it's different.

Your typical cheese heads in steel are rated at 4. Some I've had from dodgy suppliers must have been rated about minus six...

I always understood that bolts were only partially threaded, whereas screws were fully threaded, but I suspect it's now just pedantic to distinguish them in this way.

If it was a metric pressure gauge it'd be time to go to the bar...

They're not that difficult to make - assuming you've got one to fit a chuck to! I made two and fitted studs from RDG. I can't now recall whether or not they were some funny UNF size or M10 x 1, but probably best to get the studs first. Yes you can make those too, but for the price, I thought buying them the best option.

I think Hopper's analysis of gear-changing whilst moving could be correct; it doesn't look like foreign object ingress to me.

Tufnol gears are original and are there to reduce the noise of the gear train as well as provide an easily-changed (but expensive) weak link in the gearing. RDG Myford still sell the gears, but I think third parties also sell them in Nylon and other similar materials.

You have a PM!

+1 for the Gordon Smith design. LBSC was notoriously cavalier in his safety valve design - "Nicks" usually summed up the size of the steam escape holes in the cap.

The use of stainless steel for boilers is not permitted within the NAME/S Fed/7.1/4"G rulebook. You only have a choice of copper or mild steel. Steel boilers must be welded by a coded welder, or else you must submit test pieces for inspection by a boiler inspector. Full traceability of all ferrous materials used is required. Hence before you even make a decision on what material to use, you must discuss the matter with your boiler inspector. If you are not a member of a model engineering society, then you will need to take out insurance cover via an approved Insurance Company if you wish to run the engine in public. (Were you thinking of re-mortgaging your house to pay for this?)

Many club boiler inspectors will not test steel boilers - and can quite legitimately refuse to do so if it is beyond their experience. Essentially, the decision of what material to use is what your club boiler tester is prepared to test.

Edited By Nigel Bennett on 01/03/2018 09:14:56

Leeds SMEE meet regularly on Wednesday evenings at Eggborough Power Station. Not a million miles from Donny.

Summer running days are second Sundays in the month (March - October) and a few summer Wednesdays. Next formal meeting is 7th February (Talk on the new Patriot loco), but we usually have a natter session every other Wednesday. We also do Monday daytime working parties. Come along and see us! (No disclaimer here - I'm the Treasurer!)

**LINK**

Edited By Nigel Bennett on 24/01/2018 18:23:36

It's not simply a case of volume of the boiler - it's the product of volume and working pressure. My Clayton steam wagon boiler, for example is only about 1 litre, but its working pressure is 5,5Bar. 5,5 Bar litres brings it well within the requirements for CE marking. Even my Tom Rolt in 3.1/2"G is below 2 litres in volume.

James, I'd join a club now. Go along to one of your local clubs as a visitor and see what they're about. They should welcome you with open arms - and you'll have a source of good information to tap. Aske their boiler inspector(s) for advice.

My friend's father built himself an anemometer (rather than a wind direction indicator) many years ago. He was amazed to discover from his recording instrumentation that there had been some massive wind gusts, apparently of a hundred miles an hour or so.

My friend didn't have the heart to tell him he'd been blazing away at the anemometer cups with his air rifle...

The RDG toolholders will not fit the Boxford toolpost. But they are very close to doing so. The dimensions of the angled faces are such that they will mate correctly, but the problem in fitting as expected is caused by two differences: the dimensions of the clamping flange, which engages in the tee slot of the holders, and the amount of eccentricity of the rotating cam operated by the socket spanner. Boxford make theirs to tighter tolerances and their eccentricity is about 0,5mm, giving rise to greater clamping for the same applied torque on the socket spanner. The RDG ones have about 1mm of eccentricity, enabling slacker tolerances and hence cheaper manufacture.

It is possible to modify the Boxford toolpost to accept RDG toolholders by grinding a bit more off the cam to give about 1mm of eccentricity, coupled with removing a small amount of material off the mating face of the clamping flanges if required. Note that these parts are hardened and once you've taken the material off, it's not too easy to put it back on.

Probably your best bet is to sell the Rapid toolpost and any holders and buy a complete RDTG set (Usual disclaimer). I kept mine and adapted it as above for use on my Myford Super 7 - so I could use the same tools for each lathe. I wrote an article in ME about it a little while ago.

But that's a bog standard one...

I have a pair of the Starrett clamps as in the original advert - but I only have one of the small clamp plates - the loose piece shown to the right. No idea where it went (Grrr!) but it has a tiny spring circlip affair in the hole so it clicks on and off the screw to retain it - as do the I-section ones. Beautiful pieces of work. Don't get much use but they do come in occasionally.