18 replies to this topic

[johnR]

While I wait for my wiring loom I thought I'd try my hand at something different! I bought a non working 1960's clockwork Hornby O gauge engine on Ebay and I'm gathering parts and materials to convert it to steam. The challenge is that there are no plans available that I can find and being a small model there's very little room for the necessary parts and I want to keep it looking as stock as possible. I have some copper pipe and end caps to be silver soldered together for a boiler, a lovely little working pressure gauge, a Mamod whistle which will be mounted horizontally at the rear of the boiler and a selection of tiny gauge copper pipes. I've bought a modelmaker's lathe that I need to collect and then I can start building. In the meantime I've been experimenting with a card and plastic scale version to see if everything will fit - I've already found that I need to reduce the diameter of the cylinder by 5mm and increase the length of the connecting rod so the cylinder can sit over the front axle which it would otherwise foul as it moves.

The cardboard disc on the trial model will be replaced by the two heavyweight metal webs of the cranked rear axle which hopefully will act as a flywheel to allow it to run smoothly.

Edited by johnR, 29 January 2023 - 07:07 PM.

[DeadSquare]

How do you intend to heat the water ?

[Richard_]

Brilliant project - good luck with it!

[jonlad]

agree, looks like a great project! Please tell me you plan to get the exhaust steam to come out of the funnel      oh and dont forget the pressure relief valve  

[johnR]

How do you intend to heat the water ?

I 'm thinking I'll put a meths tank in a tender with a small pipe to a burner under the boiler 

[johnR]

agree, looks like a great project! Please tell me you plan to get the exhaust steam to come out of the funnel      oh and dont forget the pressure relief valve  

the exhaust steam will come out of the cylinder and up a 1/8" pipe into a hole I've drilled in the funnel, the pressure relief valve will double as the filler under the dome. 

[DeadSquare]

 

How do you intend to heat the water ?

I 'm thinking I'll put a meths tank in a tender with a small pipe to a burner under the boiler 

 

Your problem is going to be, getting a large enough heating area to generate sufficient steam on such a short boiler by just heating along the length of the bottom of your boiler, and a larger flame that 'licks' up the sides of the boiler will burn the paint off the tin-plate body.

[johnR]

 

 

How do you intend to heat the water ?

I 'm thinking I'll put a meths tank in a tender with a small pipe to a burner under the boiler 

 

Your problem is going to be, getting a large enough heating area to generate sufficient steam on such a short boiler by just heating along the length of the bottom of your boiler, and a larger flame that 'licks' up the sides of the boiler will burn the paint off the tin-plate body.

 

Yes, you're right - the burner will only be able to access half the boiler - I have seen a superheating burner where the single pipe loops through it's own flame vapourising it - rather like some mountain stoves. As you say, I need to restrict the heat to the bottom of the boiler to protect the paint. I'm going to lag the copper boiler sides and top to retain heat.   

[Steam]

Great project.
There are going to be lots of challenges to overcome. A metho burner will likely wreck the paint regardless of the type. Looping through the flame causes thermal runaway and will chew through the fuel too fast to heat the boiler properly.
The best option would be a flue boiler (flame tube) with a butane burner, cleaner, hotter and keeps the flame away from the paintwork.
And there are plenty of plans, ideas etc on the web for converting and building steam trains, trams etc to give inspiration.

[johnR]

Great project.
There are going to be lots of challenges to overcome. A metho burner will likely wreck the paint regardless of the type. Looping through the flame causes thermal runaway and will chew through the fuel too fast to heat the boiler properly.
The best option would be a flue boiler (flame tube) with a butane burner, cleaner, hotter and keeps the flame away from the paintwork.
And there are plenty of plans, ideas etc on the web for converting and building steam trains, trams etc to give inspiration.

I did consider gas, but the boiler is only 100mm long and 35mm in diameter so putting a flame tube of any worthwhile size in would further reduce running time?

[DeadSquare]

If you build your permanent way on a slope, it would save a lot of bother, as the loco could just roll down it.

[Steam]

Great project.
There are going to be lots of challenges to overcome. A metho burner will likely wreck the paint regardless of the type. Looping through the flame causes thermal runaway and will chew through the fuel too fast to heat the boiler properly.
The best option would be a flue boiler (flame tube) with a butane burner, cleaner, hotter and keeps the flame away from the paintwork.
And there are plenty of plans, ideas etc on the web for converting and building steam trains, trams etc to give inspiration.

I did consider gas, but the boiler is only 100mm long and 35mm in diameter so putting a flame tube of any worthwhile size in would further reduce running time?

From experience the size of your boiler may well prove too small. And given the thick wall tube it will use all its water and burner heat just to heat the cylinder. Your boiler has a volume of 54ml. The hornby rocket 3.5 inch gauge had a boiler of 60ml, gas fired fire tube and thick wall and was seriuosly under boilered.

[johnR]

 

 

Great project.
There are going to be lots of challenges to overcome. A metho burner will likely wreck the paint regardless of the type. Looping through the flame causes thermal runaway and will chew through the fuel too fast to heat the boiler properly.
The best option would be a flue boiler (flame tube) with a butane burner, cleaner, hotter and keeps the flame away from the paintwork.
And there are plenty of plans, ideas etc on the web for converting and building steam trains, trams etc to give inspiration.

I did consider gas, but the boiler is only 100mm long and 35mm in diameter so putting a flame tube of any worthwhile size in would further reduce running time?

From experience the size of your boiler may well prove too small. And given the thick wall tube it will use all its water and burner heat just to heat the cylinder. Your boiler has a volume of 54ml. The hornby rocket 3.5 inch gauge had a boiler of 60ml, gas fired fire tube and thick wall and was seriuosly under boilered.

 

I'm new to steam so it will be trial and error - I've seen a video of an 0-4-0 tinplate loco like mine running on steam so I know it can be done - it's just the engineering! Do you think a thinner walled brass tube would be better for the boiler?

[johnR]

If you build your permanent way on a slope, it would save a lot of bother, as the loco could just roll down it.

Not much of a challenge though is it?:)

[Steam]

 

 

 

Great project.
There are going to be lots of challenges to overcome. A metho burner will likely wreck the paint regardless of the type. Looping through the flame causes thermal runaway and will chew through the fuel too fast to heat the boiler properly.
The best option would be a flue boiler (flame tube) with a butane burner, cleaner, hotter and keeps the flame away from the paintwork.
And there are plenty of plans, ideas etc on the web for converting and building steam trains, trams etc to give inspiration.

I did consider gas, but the boiler is only 100mm long and 35mm in diameter so putting a flame tube of any worthwhile size in would further reduce running time?

From experience the size of your boiler may well prove too small. And given the thick wall tube it will use all its water and burner heat just to heat the cylinder. Your boiler has a volume of 54ml. The hornby rocket 3.5 inch gauge had a boiler of 60ml, gas fired fire tube and thick wall and was seriuosly under boilered.

 

I'm new to steam so it will be trial and error - I've seen a video of an 0-4-0 tinplate loco like mine running on steam so I know it can be done - it's just the engineering! Do you think a thinner walled brass tube would be better for the boiler?

 

It can absolutely be done and I am not trying to put you off, rather give the benefit of previous experience. The thinner the wall the faster the water will heat.

unfortunately meths, while being an easy choice is not a particularly good fuel for steam. a stationary engine which really does no work will be ok but something that needs to have some torque will struggle. and the bigger the boiler the longer the run but the harder to heat.