Member postings for John Baguley

Hi John,

Could be 'Centenary' described by Martin Evans in ME vols 180 and 181. As Neil suggests, a photo or two would help identification. I think the Centenary articles are available from this website as a downloadable pdf.

John

Edited By John Baguley on 17/10/2013 01:14:05

Edited By John Baguley on 17/10/2013 01:24:25

Hi Graeme,

I didn't realise the meshing was adjustable until you mentioned it! I didn't touch the bush when I rebuilt mine.

Looking at the drawings I have, the bush for the drive axle is indeed eccentric. If you take the drive pulley off, the bush is fastened to the main casting with 3 clamps with 2BA bolts. If you loosen those bolts you will be able to rotate the bush and so adjust the mesh.

Hope that helps,

John

Edited By John Baguley on 09/09/2013 22:14:44

Ok Neil, I forgive you Sounds like you had a good day at Derby though.

You missed some cracking snap though!

John

Edited By John Baguley on 02/09/2013 00:11:11

Edited By John Baguley on 02/09/2013 00:11:30

Just got back from the competition which was an excellent day all round.

Winner was John Barr with his 3½" gauge Black Five

Runner up - Paul Hinchcliffe with his 2½" gauge Ayesha

Third place - Nick Elliot with his 3½" gauge BR Standard 75000

Other entries were Ben Pavier - 5" gauge Pansy, Terry Shields - 3½" gauge Juliet, and Geoff Eliott - 5" gauge Minx.

Thanks to everyone who supported the event.

John

Yes, it's the sanding lever. He's possibly moving it on and off to regulate the amount of sand put down rather than leave it on all the time?

John

Like Julian, I wouldn't build a loco without superheaters for exactly the reasons that he gives. For similar reasons of efficiency and pleasure of running a well designed loco I wouldn't build a valve gear without thoroughly checking the design first and improving it if necessary. If I am going to spend a lot of time building a loco I want it to perform the best that it can. Just a personal thing I suppose.

I regularly drive my brother's unsuperheated loco (have done today) and it's a very sedate engine to drive. It's performance is steady but nothing special. You also get a continual shower as the exhaust is very wet. On cold days you can't see a damn thing in front of you for all the steam from the chimney!

To go one further on superheaters - I think the only ones really worth fitting are the radiant type that extend over the fire and do give a useful increase in steam temperature, whereas the normal LBSC type that end at the firebox really only dry the steam a bit.

Doug Hewson did some tests on his Y4 when the original superheaters burnt out. He tried various types and the radiant type easily outperformed the LBSC type, cutting water and coal consumption by half. He did try the coaxial type as well but found them to be pretty useless.

I think superheat is probably more important for small locos with limited boiler capacity and small fireboxes. The last thing you want to be doing with such a boiler is continually pumping water into it and feeding coal into the firebox.

John

Hi Clive,

If you don't already know, the build was serialised in ME vols 144 to 148.

John

Not sure, I think it's an open rod valve gear as the rods are open when the eccentrics are towards the link. Crossed is when the rods are crossed when the eccentrics are towards the link. As Jason says though, four shaft TEs usually had crossed rods so I could be wrong.

John

Edit - Looking at Nigels photos, it is a crossed rod layout so the lead will decrease as you go from full gear to mid gear which ties in with what Nigel found.

Hmmm, wonder how you put crossed rods into a simulator - they seem to be set up for open but there must be a way.

Edited By John Baguley on 11/08/2013 21:12:55

Edited By John Baguley on 11/08/2013 21:15:34

Edited By John Baguley on 11/08/2013 21:21:28

Hi Nigel,

Glad you've hopefully got it sorted. I'll second Neil's comment on your workmanship

Neil,

Even when Stephenson's gear is correctly designed, there will always be movement of the die block in mid gear. It's inherent in the design. With the eccentrics correctly set, the movement of the die block should be twice the lap + lead. Think of the eccentrics as doing the same job as the combination lever in Walschaert's gear. Stephenson's is a little complicated in that the lead varies over the range of the reverser travel whereas with Walschaert's the lead is constant . Normally with Stephenson's, the lead increases as you move from full gear to mid gear. To avoid too much lead towards mid gear, the valve gear is often designed to give perhaps zero or even negative lead in full gear.

The design of Stephenson's on traction engines is actually quite poor anyway. The suspension of the expansion link at the top is always going to give poor valve events compared to suspending it in the centre as done on most locos. Perhaps the designers of traction engines weren't too fussed about getting equal cut offs etc. !

John

HI Nigel,

Right, I've put your dimensions into a valve gear simulator and you are quite correct - the valve will not crack the ports with the eccentric settings given by Hughes. The angle needs to be something like 65° for that to happen. The other alternative is to shorten the valve to reduce the lap but the question is:

Is the 82.5° angle correct and the valve dimension wrong, or

Is the valve dimension correct and the angle wrong?

John

Hi all,

Even with the die block in the central position (Mid Gear) you should still get enough valve travel to just crack the ports. The expansion link does not merely pivot about the mid position - it physically moves backwards and forwards due to the difference in the positions of the two eccentrics. Moving the gear towards full gear just increases the amount that the port opens. Have a look at any of the valve gear simulators to check this out.

John

Edited By John Baguley on 11/08/2013 12:03:11

Hi Nigel,

That's strange, you should be getting something like 9mm travel on the valve when the crank moves from front dead centre to back dead centre. If the eccentric throws are correct (0.75", 19.05mm) then the only thing I can think of is that the eccentrics are not set correctly. I can't see anything obvious from your photos though

John

Edited By John Baguley on 11/08/2013 01:22:14

Hi Nigel,

Does the valve only move 1mm over a complete rotation of the crankshaft or just the 90 degrees?

John

Hi Nigel,

The drawings are correct. The valve should be wider than the outside of the steam ports by an amount equal to the 'lap'. The 'lap' enables the steam to be used expansively and more efficiently. The position of the valve eccentrics relative to the crankpin determine the position of the valve edge at piston dead centres, not it's physical dimensions.

John

edit - Jason posted whilst I was writing

Edited By John Baguley on 10/08/2013 18:11:12

Hi Neil,

Yes, you'd be very welcome. There'll be food etc. laid on

John

This year's Curly Bowl is being hosted by North West Leicestershire SME on Sunday Sept. 1st at the Hermitage Leisure centre, Whitwick, Coalville, Leicestershire LE67 5EJ (see Events Page)

At the moment we only have 4 entries and really need 3 more. The competition is open to all LBSC designed locomotives in 2½", 3½", and 5" gauges (Modifications are allowed). Anyone interested in entering should contact Steve Eaton at:

[email protected]

The competition is more fun than serious and the aim is to find the loco which performs best to how Curly would have wanted. All you have to do is fire the loco up, give a bit of history, and do a couple of laps to make sure the loco is running ok. The actual judges then take over and drive the loco and award points for performance, finish, etc. There are cash prizes for 1st, 2nd, and 3rd places, and, of course, the winner receives the actual Curly Bowl to keep for a year

John

That's Dick Allan with his William Francis. The P2 in the other photos belongs to Peter Gardner with Simon Clough's Olympiade in the background.

John

Try GLR Kennions. They list the Keith Wilson design king which I think is called King John.

Also Blackgates list the James Perrier version - some of those castings may be suitable if GLR can't supply.

John

Edited By John Baguley on 30/07/2013 01:17:01

Hi Yorkie,

The Princess Royal will almost certainly be the old H P Jackson/Clarkson design. I'm just finishing off rebuilding one for a friend and have copies of the drawings. Is yours the four cylinder version or just two? If you need any help just ask.

John

Maybe there is (or should be) a maximum size for photos in your album? The thread mentioned looked fine to me right from the start.

John

Just looked and my photo of the Myford steady is still the same size so nothings changed there.

Edited By John Baguley on 17/07/2013 12:05:08