Member postings for John Baguley

I get mine from Southern Temperature Sensors:

http://www.southerntemp.co.uk/

They do much thinner wall tubing (316L) than the ME suppliers in both metric and imperial sizes. They also advertise on Ebay but usually only in short lengths.

Usual disclaimer.

John

Frances,

I'm sure that the bearings on the ch pumps are water lubricated which is why they are not sealed from the liquid. I doubt if they will last long being run dry. As Jason suggests, they can be used for pond pumps but are not self priming. I've never found them to last very long in that application though.

John

Check out Adam Booth (abom79) on Youtube. He uses 'metallisation' all the time for building up worn shafts. The equipment he uses looks like an oxy acetylene torch which is fed with metal powder that melts in the flame and is sprayed onto the worn metal. Looks quite simple to do and very effective.

John

The inlet ball valve of the pump may be leaking under pressure and allowing some of the water to go back into the tanks instead of into the boiler. It's also possible that the pump is simply not big enough to maintain the water level.

John

Nice turnout from the 2½" gauge lads as well Thanks for the video Stew.

John

Hi Derek,

Have sent you a pm regarding drawings.

So far as I am aware, the BL Scotsman was designed by E W Twining and had nothing to do with Henry Greenly.

HG did produce some excellent coal fired 2½" gauge designs for Bonds of Euston road which are quite capable of pulling a person or two. It was just Bassett Lowke that seemed to not want to progress beyond simple spirit fired boilers.

John

I've used them on several 2½" gauge locos with excellent results. Also used PTFE on piston valve heads with equally good results. With these smaller bores though I haven't used backing O rings and just relied on the plain PTFE rings on their own. I fit two thin rings side by side with the gaps 180° apart to prevent leakage. It is essential to allow clearance for expansion when the rings get hot.

I haven't done it yet but I've thought of using graphite filled PTFE for the rings as this material is harder and springier than virgin PTFE and may not need the backing O rings in the larger sizes.

John

Mark,

the drawings show the safety valve bushes as threaded 3/8" x 26.

John

Hi Bri,

I would think that the 4mm bore to feed the regulator is far too small for a 5" loco. I use larger than that for a 2½" gauge!

Is your problem with silver soldering the leak on the foundation ring simply due to a lack of heat? You're going to need a hell of a lot of heat to get it hot enough. Are you using a propane torch or do you have oxy acetylene or similar?

John

Edited By John Baguley on 08/05/2016 19:26:39

HI fizzy,

Have you tried Halfords high temperature enamel? I used it on my Helen Long smokebox and it's still good after 8 years. They do matt, satin, and gloss versions.

John

Hello Peter,

Yes, it's got 8 divisions. You might be able to get a suitable gear ready made or perhaps adapt a complete unit from a lathe with the same size leadscrew (4tpi) if there is one.

Will send you a pm with regard to the manual.

John

Hello Peter,

This is the dial fitted to mine:

I don't think it's an original part though as it looks homemade. I've had a look at the manual and there is no mention of a screw cutting dial so possibly the lathes didn't have one when originally built. I would expect one fitted at the factory would have had a cast body.

It looks pretty easy to make one. Couple of bits of bar soldered or welded together, with a spindle, dial, and gear wheel.

John

Just had another look at the manual and there should be a leadscrew guard that bolts onto the end of the apron where mine has the dial. That was obviously taken off and lost when the dial was fitted.

Edited By John Baguley on 25/02/2016 12:14:42

Edited By John Baguley on 25/02/2016 12:23:41

My Triumph T160 with Norman Hyde 1000cc kit has a Norman Hyde toothed belt conversion to replace the old Triplex? primary chain. Hasn't been on the road for a few years now (must get it rebuilt!) but never gave any trouble when it was running. The belt's not rubber though. Can't remember what material it is offhand but some type of plastic (polyurethane?) I think.

John

The ones I've made so far have all had the return bends silver soldered with Silverflo 24. No problems with them yet, touch wood! I've now got some Silverflo 20 so will use that next time. I use fully radiant superheaters with the return bends right at the back of the firebox so they keep a bit cooler. Would be nice to be able to TIG weld them though.

John

Hello Martin,

As Julian says, I made a study of the Jim Ewins formulae and converted them to easy to use spreadsheets.

**LINK**

Also, as Julian says, the formulae are not the be all and end all and they don't 'fit' a lot of published designs, not that that itself means the formulae are wrong. It could well be the designs that are wrong. Jim really just came up with his formulae to try and establish design criteria based on some published designs, some of which worked well, and some not so well.

After much thought on the subject I think the critical areas to concentrate on are the engine factor Ee and the free gas area of the tubes versus the area of the grate. Personally, I now don't think the Keiller factor Kt is of any importance in 'our' sizes. It's pretty much accepted that only the first few inches of the tubes contribute much to the heating effect as the flow is laminar rather than turbulent in such small tubes so the length is pretty immaterial within reason. That also means the boiler factor Eb is not really valid and I think can be ignored.

So, my latest thoughts are that you should design the grate area to match the cylinders (steam consumption) and then try and get enough tubes in the boiler to match that grate area i.e. 12 - 15%. Also, fit a properly designed valve gear to make the best use of the steam produced. Most published designs have pretty poor valve gears. Oh, and use as much superheat as you can get to increase efficiency!

John

Hi Mark,

Smith and Alan list it as Dark Grey BS632.

John

I had cause to measure the centre height of my ML7 from the top of the cross-slide a few years back and I got it to be 2.0625".

John

Hi Dave,

No, there's no means of locking the spindle. I just put it into the lowest gear to remove chucks etc. I've only got one chuck useable at the moment and I need to machine some more backplates to suit some others that I've got. Unfortunately, the spindle thread is not a common size so ready made backplates aren't available.

I've completely rebuilt mine and repainted it. It came from a friend who bought it over 40 years ago from a government surplus supplier. There's a plate on it which says it came from the Royal Radar Establishment and another which says it was refurbished in 1955. It had just sat on my friend's garage floor for the 40 years and unfortunately most of the headstock bearings had developed pits in the inner and outer races due to the spindle remaining in the same position for all that time. All but the two main bearings at the chuck end of the spindle had to be replaced.

John

Hi David,

Yes, it's virtually identical to my Denham Junior Mk 2.

Looks like yours has raising blocks though to increase the centre height?

John

Hello Phil,

It sounds like it's what is known as a 'Goodall?' Valve.

**LINK**

These are usually filled from a spray type pressure bottle with a length of tube on the end that fits onto the valve.

John