Steam plant for a Graham Industries VR1A

A couple of years ago I got a Graham Industries VR1A and made a simple horizontal boiler which was heated with gel fuel to run it. This worked well but I decided to make a better steam plant for the engine... because I can.

While visiting Blackpool Model Boat Show last year I acquired a Brue boiler made by Helen Verrall-Stait for a very reasonable sum. The boiler came with wood cladding and a chimney but no fittings. Most importantly, it did come with a test certificate and paperwork.

A quick rummage in the bits box produced some fittings and the chimney was replaced with one from another boiler.

I wanted the burner tube at the rear of the boiler and of course some means must be found to secure the boiler to a base. (Otherwise it may wander off when I'm not looking...)

So this is what was required -

• A firebox for the boiler which should be raised 12mm to allow a Bix 009 burner to function efficiently and have sufficient ventilation.
• A means to affix the firebox to a base.
• It should have a door on the front so the burner can be lit (and to allow for observation of the burner flame).

Parts marked out ready for drilling.

The firebox will be made from 0.5mm brass sheet, mounting brackets from brass angle, boiler supports from brass flat section.

For those who like to know the size of things, where it is practical to do so, pictures are taken on a 1cm grid.

Edited By Henry Artist on 09/04/2017 06:41:12

Brass sheet has been drilled.

So have the brackets and boiler supports.

The individual brackets and boiler supports are then sawn off.

A mitre box and razor saw give accurate cuts. The smaller holes are 1mm and the larger are 2.2mm.

Two of the mounting brackets have adjustment slots milled out with a 2mm cutter.

With the holes in the firebox drilled it is guillotined to size and the opening for the burner cut with a fretsaw. Horizontal cuts are made for the firehole as it is easier to do this while the metal is flat. The rest of the material is left in place to provide structural integrity during the rolling and silver soldering processes.

1/32" rivets will be used as pins to locate the brackets and supports during silver soldering.

I was struggling to come up with an effective design for a latch for the firehole door which is 20mm wide. Then I realised that if I angle the front of the firehole gravity will hold it shut.

The firebox has been rolled in a 3-in-1 machine, clamped and silver soldered.

It will stay as a complete ring during the other silver soldering processes to attach the mounting brackets and boiler supports.

Once the silver soldering is completed a fretsaw is used to open up the firehole and a razor saw used to cut through the join and the tube. This tube will form the clamp to attach the firebox to the boiler.

With the silver soldering completed it is time to make the base plate for the firebox.

A piece of aluminium sheet (0.9mm) and brass sheet (0.5mm) were cut to size. Transfer punches were used to mark the location of the screws.

The aluminium sheet serves several purposes -

• It prevents unwanted marks on the brass sheet.
• Eliminates burrs on the brass sheet during drilling.
• Ensures correct alignment of the mounting screws during soldering.
• Will help to prevent the nuts being soldered to the scews. (Been there. Done that.)
• Prevents distortion of the thin brass sheet during soldering.
• Will act as a drilling template when it is time to mount the steam plant on a board.

To make the hinge on the firehole a length of 2mm OD, 1mm ID brass tube was silver soldered to it. The ends of the tube were cut flush with the sides of the firehole and the middle bit milled away. A similar procedure will be used to make the hinge on the firehole door.

Also in the above picture you can see the Bix 009 burner that will be used in this project and a second firebox for a marine steam plant.

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Thanks for taking the time to post your progress and methods Henry. It's informative for others that may wish to follow a similar path someday. - It's what this site is all about.

IMHO there are not enough 'build logs' on this site.

Nick

The aluminium and brass sheets are taped together and drilled.

A test fitting shows that they go together in a satisfactory manner.

Four brass M2 screws are soldered to the underside of the base plate and the firehole is soldered to the firebox. The inside of the firehole is cleaned up with needle files.

Glad you are enjoying it Nick.

I kinda wondered about the lack of build threads on this site too. When I was returning to model engineering a few years ago I always found build threads fascinating. (I still do!) But it was frustrating that while they often showed what had been done, they rarely explained how and why...

Some views of the firebox without the boiler in the way.

Two screws will be used to secure the base plate to a board. They are hidden inside the firebox in a vague attempt to keep the appearence of the finished steam plant fairly neat.

Stainless steel M2 threaded rod is used to clamp the firebox to the boiler. This will (eventually) be cut to length.

Wow, rather neater than mine 9by a country mile).

Are you poosting the build in real time - you're making good progress!

Neil

I have a few "helpers" Neil.

This steam plant will have a line shaft because I like my engines to do some work. (And running accessories makes them more fun to play with.)

I found an old Wilesco line shaft that would be suitable. I wanted to be able to lubricate the bearings. I could just drill a 1mm hole in the top of each support and countersink it. Then I remembered some really nice oilers that I got from my friend Jin...

Holes drilled and tapped M3, the oilers were secured with Loctite 603.

I think they look pretty good.

Time to start putting things on the base board. You can just see it in the picture with the minions.

You can use anything you like for a base board. Generally whatever you happen to have to hand. This one is actually a wooden chopping board bought in the local supermarket. It measures approximately 40cm by 28cm and is made of beech which is a nice hardwood.

It comes shrinkwrapped in plastic which saves me from having to wrap it in clingfilm before glueing sheets of paper to it. (A spray adhesive like 3M Craft Mount works great.) You can glue the paper directly to the wood if you like. To get it off later just soak the paper with white spirit to release the adhesive. Obviously this works best on unvarnished wood. Cartridge paper is ideal but inkjet printer paper is fine too. The point of all this is it gives me a convenient surface I can draw marking out lines, scribble and jot notes on without marking the board beneath.

Some time is spent placing the components of the steam plant on the base board and then moving them around until I'm happy. If this bit goes here will I have enough room for that bit there? Can I reach a valve without buring my fingers on an adjacent steam pipe? Will there be enough room for everything? Pipecleaners are a cheap and easy way of simulating pipework. Tin cans, blocks of wood, and bits of tube can all be used in place of components yet to be built.

Some thoughts on plumbing. (For novices. Old hands can skip this bit.)

The most common sizes of pipe that I use on my little steam engines are 3mm, 4mm, 1/8" and 5/32". Pipe benders like this - **LINK** - are great. They are available EVERYWHERE and prices vary wildly (from about £10 to over £30 for the same <expletive deleted> tool!) so shop around. For tighter bends I like to use Du-Bro pipe benders which you can get from all good Radio Control model shops. Just remember to anneal the pipe before you try to bend it.

Silicone hose is a handy way to make temporary pipes. If you get the right size it can be a push fit on existing metal pipes and be steam tight. (Usually about 1mm undersize on the internal diameter for the silicone hose.)

Unless you are playing with real, honest-to-God, superheated steam you don't need to use silver solder for plumbing connections. Soft solder will work just fine and it's easier to correct mistakes. Solder paste is a popular alternative to electrical solder and flux.

How to make neat pipework without tears.

Many people seem to struggle with making neat plumbing on model steam plants. Often this is because they fasten all the components down to the base board first then try to connect them. It can be a devil of a job to get pipes to fit. I take a slightly different approach. (Other methods are available. Just go with whatever works for you.)

I usually start with the boiler as this often has the most pipes connected to it. Having worked out roughly where everything will go - see previous post - the boiler is fastened to the base. Then I select a component I want to connect to the boiler. Let's use the hand pump as an example.

The hand pump is placed on the base board in approximately the position I want it to be. Then I make the pipe from the boiler to the hand pump. Only when I am satisfied with the pipe and it has been connected from the boiler to the hand pump is the final location of the pump marked, holes drilled, and fastened to the base board. And so it continues... First place the component on the board, then make the pipe, then fasten the component to the board.

Back to building a steam plant...

The Bix 009 burner has been installed in the firebox and tuned in accordance with the comprehensive instructions that came with it. You can buy Bix burners here - **LINK** (Shameless plug! )

The boiler has been test steamed. It works! Yay!

The boiler was then temporarily connected to an MSM Tyne marine plant for further testing. Since it ran the Tyne engine in a satisfactory manner I felt more confident about this project. (Well there are always those nagging doubts... Will the boiler be big enough? Will it make enough steam?)

Using the procedures detailed in the previous post, the VR1A has finally been connected to the boiler.

The engine is mounted on a block of wood to give clearance for the flywheel.

Between the engine and the block of wood there is some aluminum sheet. This prevents the engine becoming stuck to any varnish or paint that will be used on the block. (Been there. Done that. Had to use a gas torch...)

A T piece has been fitted at the steam outlet from the boiler so orphan engines can be run in future.

Progress continues...

With the burner intalled beneath the boiler and the boiler connected to the engine we have the basic elements of a functional steam plant ready for a test run.

A Mamod flywheel was fitted to the engine and connected to the line shaft with 2mm nitrile rubber drive band. This works waaay better than the springy metal drive bands. I affixed some Wilesco workshop tools to a board for the test run. So much more interesting to watch an engine driving something...

Edited By Henry Artist on 02/05/2017 20:52:33

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Well done that man.! ......... Excellent.

Nick

love it,exelent thread and vid is good.thanks for sharing

Very Nice!

Neil