simonwass
Part of the e-furniture
Cecil Pagets 2-6-2 of 1908. Engine number 2299. Would make a fascinating model....
Posts: 472
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Post by simonwass on Jan 28, 2007 0:08:11 GMT
I have a desire to emulate Roy (C.R.) Amsbury's skill for producing small working fittings. For my 14xx I need a 7/8" pressure gauge, a 3/4" duplex vacuum gauge and a 5/8" pressure gauge for what is in full size the carriage heating supply. I also have a drawing of the GWR combined vacuum/steam brake control that incorporates the ejector all in one unit. At about 3/4" OD it will be a challenge!
Anyone know how to obtain the small watch gears used for the gauge workings? Are there places that repair watches nowdays? Has anyone seen piles of old watches on car boot sales, I haven't been to any but will start if I'm likely to find old battered cheap watches!
Has anyone on this list made their own gauges?
Simon.
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Post by baggo on Jan 28, 2007 1:33:18 GMT
Hi Simon,
Do a search on Ebay for watch parts or spares. There's usually someone getting rid of boxes of old watches and spares. I bet if you ask around you'll find quite a few people with dud wind up watches that they can't be bothered to get repaired!
John
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Myford Matt
Statesman
There are two ways to run a railway, the Great Western way, and the wrong way.
Posts: 621
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Post by Myford Matt on Jan 28, 2007 19:34:22 GMT
Sounds tricky, but I wish you luck. Can you tell me a bit more about Roy Amsby. I've not come across that name before.
Cheers
Matt
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Myford Matt
Statesman
There are two ways to run a railway, the Great Western way, and the wrong way.
Posts: 621
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Post by Myford Matt on Jan 28, 2007 19:47:37 GMT
Assuming you are going for classic Bourden-type gauges there is a nice little little summary here: en.wikipedia.org/wiki/Pressure_measurementTwo tricky bits stand out for me. First and foremost the tube. Making it, let alone calibrating it and getting it to respond linearly, is probably the kind of voodoo the manufacturers like Budenburg kept to themselves. Second, and this doesn't seem to be mentioned often. How do you make neat little round bits of glass, preferably with a nice bevelled edge?! Perhaps you should chat to some hobby horologists and telescope makers. All the other methods look either inappropriate to your aim or impossible to scale down. Nice project though - keep us posted. Matt |
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Post by Laurie_B on Jan 28, 2007 21:46:45 GMT
Sounds tricky, but I wish you luck. Can you tell me a bit more about Roy Amsby. I've not come across that name before. Cheers Matt Roy Amsbury was a very skilled model engineer who was around (I think) in the 1960's and 1970's.He wrote a number of articles about making pressure gauges and scale appearance boiler fittings which appeared in Model Engineer c1973.His maxim was "why not build to scale". He made a number of award winning model locos,one of which was an excellent GWR 51xx tank loco. Here are two pics of the loco and the backhead.The pressure gauge and duplex gauge (as well as all the other fittings) were made by Mr Amsbury. Sorry about the picture quality as they were obtained from Martin Evans' book on model steam locos.   |
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Myford Matt
Statesman
There are two ways to run a railway, the Great Western way, and the wrong way.
Posts: 621
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Post by Myford Matt on Jan 28, 2007 21:53:07 GMT
Nice pics - thanks Laurie.
That backhead is truly impressive; looks as though it was run too.
Simon, I can see now why you chose this guy to follow.
Cheers
Matt
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simonwass
Part of the e-furniture
Cecil Pagets 2-6-2 of 1908. Engine number 2299. Would make a fascinating model....
Posts: 472
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Post by simonwass on Jan 28, 2007 21:55:39 GMT
Matt,
Roy Amsbury was a Derby society member. A list of his feats include the 5" gauge GWR compound 4-4-2 'President', the 5" gauge Western region B-B Hymek (complete with working hydraulic drive!) and the 5" gauge Baby Deltic. He also did a GWR 2-6-2 no. 5199 which I guess was also in 5" gauge.
President was described in ME from vol 148, the Hymek from vol 160 & 166 for the V8 engine and the Deltic engine was in ME from vol 170. He described how to make a duplex vacuum gauge in issue 3825 and did a series on small boiler fittings in issues 3457 - 59. Just to show how fine the gauges are, the vacuum gauge bourdon is 0.062 bore and 0.064 OD! This is only reading -14.7psi at maximum vacuum so needs to be thin. A 120psi pressure gauge bourdon is 0.064 ID and 0.070 OD, both are machined from sifbronze rod.
As an aside, did anyone know that Sydney Smith from Nottingham invented the pressure gauge? Patent 11711 22nd May 1847. It used a diaphragm working on a rack to turn the pointer.
Simon.
ps, John, I've asked everyone at work but no luck, I'm going to try the local jewelers then the car boots (I have no desire to start car booting though!). I did think of a wanted ad in the Ad-Mag.
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Myford Matt
Statesman
There are two ways to run a railway, the Great Western way, and the wrong way.
Posts: 621
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Post by Myford Matt on Jan 28, 2007 22:53:12 GMT
Thanks Simon
I'll have to try and get hold of 3457-9 - looks like fascinating reading.
I would have thought charity shops would be a good bet for old clocks/watches.
Cheers
Matt
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