Locomotion boiler

[cplmickey]

For my next project i was looking for something different in 7 1/4 and a set of Locomotion drawings came up. It's not a passenger hauler but I thought it would make an unusual model. It took me some time to work out from the drawing just how the boiler fits together and it's complexity plus the fact that it is a structural component made me decide that perhaps this one should be bought from a professional.

I contacted a very respected boiler manufacturer and he told me that he had made one of these but it was extremely difficult and he declined to give me a quote. I was grateful for the honesty in his reply but if that's the case for an experienced professional what chance does an enthusiastic amateur like me stand.

Has anyone ever made one of these boilers and if so have you any words of encouragement for me. I've never seen one of these models completed so do I assume that the designer expects too much of the model engineer?

[kwil]

There is one at Colchester DSME I believe and mine has yet to run. The boiler is quite complex, can be done with care, patience, jigs and a lot of help and luck.

[davebreeze]

I've got those drawings and intend to build it some day. I didn't think it looked too bad, what is it that makes it so tricky?

Kwil,

I remember you kindly sent me pictures of your jigs, I've got them filed away for future reference.

[kwil]

You have to hold a considerable amount of material inside the shell to make up the pads and to secure them whilst silver soldering. It is all a matter of the right amount of heat (a lot) and the number of heats you have to carry out to progress the job. You then have to hold the cradles that carry the boiler and the axles to a tight tolerance. The cylinder and regulator mounting bosses are quite massive and the boiler feed pump boss is below the boiler centre line and so has to be held correctly in its place. All possible, just tedious and if on a commercial basis, very labour intensive.

By the way there is a serious error in the dimensions of the overhead motion arms (don't ask) you have to modify the original drawn sizes or else the piston rods do not track correctly, ie straight up and down!

[SteveW]

Guys,

Just found this thread and was pondering the difficulties outlined above. I've had the bits for this design, including the Reeves boiler kit for a very long time now but I do recall thinking that some of the elements of the boiler design were a bit daft.

1. The blocks of copper that reinforce the boiler belly from four o'clock through to eight o'clock. I've heard that one boiler inspector rejected these on the grounds that it limited the water flow under the fire box and would compromise it. It occurred to me that this extra copper was in the wrong place. Given the cyclic forces between piston thrust at the top of the boiler and the wheels at 4/8 o'clock the copper between these points will be under cyclic stress. Better to put any reinforcement at these points, not in the belly of the boiler. Plus using big chunks of copper is a bit clumsy.

2. Why solder the wheel cradles to the boiler? Given suitable bushing/internal reinforcements the cradles would be far better as bolts on-able. Any good reason not to?

Comments?

[nonort]

Could I suggest that a word with one of the TIG welding boiler makers would be a good idea. Ive seen and tested several of Steam Technology's boilers. Very impressed Marco knows what he's about.

[rogsteam1959]

Does anybody know what the difference is between the drawings from maxitrak out of the greenly archive to the drawings from reeves for the locomotion?

[SteveW]

Jan 23, 2015 21:29:02 GMT rogsteam1959 said:

Does anybody know what the difference is between the drawings from maxitrak out of the greenly archive to the drawings from reeves for the locomotion?

Which drawing set do you have?

I've got one of the Reeves drawing sets and a set of images for a German version maybe in 5".

[rogsteam1959]

I am thinking about to buy a set. But don't know which one is better. That one from maxitraks greenly archive or reeves!
The set you have in 5 inch is from holzapfel? Switzerland?

[SteveW]

Rog,

The drawings I described as 'German' are by a Martin Burkhard and labeled ATELIER. There is an address which looks like it could be Swiss. I've lost track of how I came by these scans which are/were entirely for study purposes only.

My Reeves drawing set includes newer releases: Feb 1998 Sheet 4, Feb 1999 Sheet 3. I guess the rest are original and in inches/fractions.

The Burkhard drawings are from August 1985. They do look very good and are 5" (127mm) guage and in metric.

For my convenience I photographed my Reeves drawings to give me easy thumb nails of the various details without knackering the main set but it was a quick job and still show the paper folds.

I've also got a scan of a letter (dated 2007) from an Allan Smith in Devon to (I believe) Mr Piddington raising points he's had to address.

I was lucky enough to have been allowed to climb over the actual locomotive at Darlington and have a bunch of fairly unstructured photos of the various bits.

I'm guessing I'm swerving off topic by by now and I am going to be off-line from Monday until at least 18th Feb unless I can get internet access in the middle of nowhere. Maybe a PM to perhaps join some ends up?