Member postings for Bob Youldon

Hi Tony,

I've always used meths; when we were preparing oil line joints for assembly and for cleaning fittings and threads etc, meths was found excellent. and I still use it today when using similar jointing media, Heldtite and similar also for cleaning surplus off surfaces following joint assembly.

Regards,

Bob Youldon

Hello Wallace,

It's simple to draw the draught angle on to the CAD image and as JasnB has said, machining allowance can also be included where required. What is essential is a good 3D printer, better the printer the better the 3D print.

Regards,

Bob Youldon

Good evening Wallace,

Re the castings, as received from the foundry they had been fettled and any risers or in gates had been removed, they must have spent some considerable time on them; the photograph of the stack of brake shoe rings is exactly as we received them from the foundry. I'm afraid I cannot help with their moulding and casting process, off went the pattern, back came the rings, simple as that!

Regards,

Bob Youldon

Good morning all,

Re:

Personally, I would have gone the laser cutting route for those brake shoes. It may have been easier. Provided of co urse that you could get cast iron solid, to then cut into slices of appropriate thickness.

Chris, laser cutting was considered and in the prototype passenger car the shoes were originally laser cut in steel, but it was the opinion of the building group cast iron against the steel bogie wheel is a much better propersition so therefore the decision was taken to go the cast iron route.

Seems a shame getting a pattern done like that without taking the opportunity of getting a bit more detail into them.

Eric, as the shoes are destined for use under passenger cars, there was a need to produce a simple repeatable component, there was a requirement for in excess of a hundred and in normal use they will never be seen.

I will say the effectiveness of eight shoes per car in stopping a loaded vehicle is very impressive.

Regards

Bob Youldon

Hello all,

Following on from DMB's post re the Brighton and Hove SMLE brake shoe rings please see attached photographs of the said shoes, including the CAD 3D drawing, the CI rings and pattern and an as received cast iron ring.

Regards,

Bob Youldon

Hello all,

I've worked out of the same wooden workshop for more than thirty years at our present address and I've never been troubled by damp or rust . When I built the workshop I included a vapour barrier, 50mm polystyrene block infill, all finally covered with an insulating board. The heating is via a thermostatically controlled fan heater set on its lowest setting, timed to come on twice a day, for an hour between 05.00 and 06.00am and again in the evening between 18.00 and 19.00pm. The essential component is maintaining air circulation, too many people experience condensation problems when the simple expedient of a little air movement together with a little heat will eradicate the majority of their problems. By introducing sufficient heating into the workshop those most valuable of our items the machinery, material stock etc, the mass of which also absorbs heat helping to avoid the dew point, at which condensate settles out on all that expensive machinery and turning everything brown. We pay fortunes for our machinery and tools, its not a big price to pay to look after them by a little heat and importantly air circulation.

There are a number of excellent heat recovery / ventilation units available, which will provide adequate levels of ventilation whilst recovering the heat from the waste air stream whilst introducing fresh warmed air into the work space.

Regards,

Bob Youldon

Hi all,

I've got a pesky little blighter somewhere in the workshop, so a trap was set................. nothing, but the so-n-so has eaten the chocolate, now i'm looking for a fat mouse with bad teeth!

Regards,

Bob Youldon

Evening Jon

Re: Get yourself a Jack Russel, whatever it is its a gonner.

They also make damm fine car anti theft and alarms as well

Regards,

Bob Youldon

Good evening Shaun,

Bazyle's suggestion re the GWR Toad drawings From Doug Hewson, although it is for 5" gauge it wouldn't be to onerous to scale it up for 71/4" gauge, fortunately the DH drawing does give details of both the underframe construction and running gear together with detail of the interior and I would recommend obtaining copies of those drawings. The works GA certainly shows the construction of the van itself but the GA of the chassis and running gear would appear as separate drawings and I'm not to certain the NRM even has a copy of those drawings.

Regards,

Bob Youldon

Good afternoon Pete,

As Luigi has said, soft pop valves are the way forward and if you are operating the locomotive at 100 psi then a 10% is the maximum permissible rise allowable. Both valves must be set to the same release pressure, there's no advantage in setting one valve higher than the other, you may as well leave it in your tool box! Please remember, these are the most important components on your locomotive and should also be carefully maintained.

It is useful to have a reasonably sized pressure gauge, 3" diameter or so, to say 200 -250 psi either certified or checked against your local clubs master for setting the valves when the locomotive is in steam, also it is a requirement to have a red line on the face of the dial (not as I've seen sometimes, on the glass) indicating the maximum permissible working pressure.

On a recent overhaul of a 5" gauge locomotive I took the safety valves apart to check the components and to my surprise one valve was partially scaled over, no doubt due to lack of use.

Polly Engineering can supply both a drawing and suitable springs should you wish to make up your own soft pop valves (usual disclaimer, only a satisfied user)

Please see below the partially blocked safety valve: -

Regards,

Bob Youldon

Good evening all,

Having had a think about the question, I'm certain around the time the POW was described by Martin Evans I'm certain Dennis Monk wrote a couple of articles on the six wheeled tenders, it may be worth a trawl through the Model Engineers of around that time.

Regards,

Bob Youldon

Good evening John,

The advantage of water jet cutting, if you ask the nice man will set the head over to cut at the required angle. mind you if we did the jop properly the brake hanger pin etc would be at the correct angle to match that of the tread.

Regards,

Bob Youldon

Good evening Les,

I suppose you could invest in a CNC mill if you want six hundred brake shoes or more, but for six then the simple way is as previously mentioned, that is on the faceplate. An alternative may be to get a steel stockholder to cut a ring from which you could machine the shoes. Another method, draw up the shoe and get them water jet cut. If you are into CAD, you could draw them up, send the drawing off for 3D printing as a pattern then have them cast, again alright if you need dozens, but by the time you've done all that you could have almost finished them from stock material!

On the tender they can be made from steel stock as they are generally only used as a parking brake and probably steel would be suitable for those on the locomotive.

Regards,

Bob Youldon

Evening all,

I think you will find a 2cwt anvil has a resonable built in rust allowance!!!!! Seriously though our blacksmith might give his a bit of a wipe over with a bit of cotton waste now and again.

Regards,

Bob Youldon

Good evening Bob,

What ever you do, do not use monel for stays; you didn't indicate which locomotive boiler you were involved in, but I'll take a guess it is one of the Martin Evans designs; he did on a number of designs specify monel for stays and from my experience of using monel as a stay material it can present considerable problems should you need to reheat the boiler, the monel has by then taken on an almost impenetrable black patina that is most difficult to remove. My choice of material would be to use copper rivets for the side stays with heads on the inside of the firebox and drawn phosphor bronze for all other stays, e.g. roof and longitudinal stays, all being silver brazed after fitting.

Regards,

Bob Youldon

Hello Richard,

It is always interesting when the question arises, what should the beginner start on, well the first thing is join a club or at least couple, look and listen, then you'll start to tease out what will suit you best. I've always said directly you start to make that first cut then you're in there with the rest of us, you're no longer a beginner.

I certainly subscribe to the idea of 3.5" gauge for your first locomotive, what you need is a well proven design without any vices, together with perhaps a written description, drawings and castings also need to be available, don't buy all the castings at once! In all of my many years as a miniature locomotive builder, perhaps too many! I think the locomotive that will always fit the bill is LBSC's Maisie, simple, uncomplicated, no difficult machining problems, straightforward and hundreds built over the years; a construction book is also readily available. I've seen all kinds of examples from the dog rough to cup winners, but they have all one thing in common, they go well.

If and when you do get started, build the bogie first, as one old chap said to me it'll give you something to push up and down (not on the dining room table) and it'll give you that extra impetus carry on.

Have a look at this chap enjoying himself: http://www.youtube.com/user/ianp6155?blend=6&ob=5

Also have a trawl around on the internet for LBSC, Maisie, there are plenty of photographs, links etc and if you are anywhere near the Bluebell Railway, they're building one 12" - 1ft much the same just the bits are a bit bigger!

Best of luck with your project.

Regards,

Bob Youldon

Hello Dan,

Re: The clips that hold the boiler to the frames at the bottom of the firebox: Do most people use these to fix their boiler or is there a better way of fixing the boiler? Also, the drawing shows that the clips are screwed into the outer firebox shell. If I was to do this, I would surely need to make bushes here also? Instead of screwing the clips into the firebox, could I just solder them straight on?

Don't drill anymore holes in the boiler, they are always a source of potential leaks; with Juliet the bottom of the boiler is level, simple, fix to the inside of the frames a piece of square or a 1" or so of brass angle at the correct height and the boiler can expand on that, you can keep the boiler from lifting by using the cab front plate, but usually the pipework is enough to hold it in position. I've built several 31/2" gauge locomotives where the boiler is held down by the same principal.

Regards,

Bob Youldon

Hello Dan,

Re: The clips that hold the boiler to the frames at the bottom of the firebox: Do most people use these to fix their boiler or is there a better way of fixing the boiler? Also, the drawing shows that the clips are screwed into the outer firebox shell. If I was to do this, I would surely need to make bushes here also? Instead of screwing the clips into the firebox, could I just solder them straight on?

Don't drill anymore holes in the boiler, they are always a source of potential leaks; with Juliet the bottom of the boiler is level, simple, fix to the inside of the frames a piece of square or a 1" or so of brass angle at the correct height and the boiler can expand on that, you can keep the boiler from lifting by using the cab front plate, but usually the pipework is enough to hold it in position. I've built several 31/2" gauge locomotives where the boiler is held down by the same principal.

Regards,

Bob Youldon

Hello Ronan,

Seems a whole of work when the staple is the component at risk, that is unless you had made it from a single billet of heat treatable steel and then the staple becomes the item at risk. I'm of the opinion, leave it to the experts for both locks and security, that together with a monitored alarm system may help in detering the bandits.

Nowhere is safe; the new entrance carpet complete with force coat of arms went missing from a Police Station front counter area only to be discovered several weeks later in a local public house!

Regards,

Bob Youldon

Good Morning Stewart,

Martin Evans didn't describe the building of the LNWR Precursor, he did a series on the 0-8-0 G1/G2 locomotives. I suspect the design your friend has aquired was by Don Young to his excellent Etna design, sadly Don died before completing the series in his magazine Locomotives Large and Small but the design is now maketed by Reeves 2000 under the Etna name and it may be worth asking them if they have available those few back issues covering the early part of the construction. Also may I suggest your friend makes contact with the LNWR society, who may be able to assist.

Regards,

Bob Youldon