Mamod SP2 stationary engine loco conversion

[Tom85]

Hi folks. It's long been an ambition of mine to scratchbuild a live steam loco, but without any engineering background or machine tools, the prospect always seemed too daunting - I wouldn't even know where to start. But recently, I came across an old Garden Rail article discussing the potential (and some partial drawings) to build a basic loco around a Mamod SP2 stationary engine, with the drive geared down using Meccano components... at which point, I thought, perhaps my ambition may not be as distant as I thought. So I snapped up a second hand SP2 on Ebay, and sourced the relevant meccano gears. Once my current adventures in plasticard are complete, this will be my next loco project.
Has anyone else on here ever tried something similar? If so I'd love to see the results.
By the way, I'm not sure if I'm allowed to share all or part of the article on here for copyright reasons, but its from the June 1994 edition and was called 'Steam on a shoestring'.

[SKGLB]

Search for a bit on the www.
An SP2 as a base with meccano parts

https://www.youtube.com/watch?v=nUZaMQZKMEg

Many also use a Mamod Minor as a base
https://www.tapatalk.com/groups/modelst ... 73458.html

https://www.tapatalk.com/groups/modelst ... -t246.html

Personally I would like this variant, I have already thought about it. The only difficulty with these variants is that I drive on 45mm rails. This leaves little space for the drive, since at 45mm the wheels leave almost no space for the chain drive in the frame.

hope you get some inspiration
Gerald

[Tom85]

Thanks for those Gerald.

I'll be sure to share some photos once work gets under way

[Boustrophedon]

The Mamod/Meccano engine hardly needs any conversion.

https://www.youtube.com/watch?v=LJ9Au76WGqw

[Tom85]

That one looks fun! Thanks for sharing.

My own project will - at least in theory - look a bit more like a 'proper' locomotive, and will do away with the Mamod drive band. I'm currently awaiting the delivery of various materials and tools, but once underway I'll share some photos.

[Tom85]

Started work on the chassis for mine this weekend - I'll share some photos once I've got something to share.

In the meantime I've been enjoying seeing the plethora of wierd and wonderful contraptions on Youtube. My current favourite being this brilliant little loco (the red one) -
https://www.youtube.com/watch?v=x1CzN54pIKw

It appears to be Mamod stationary-engine based, with the oscillating cylinder possibly located in the smokebox? Using a saddle tank design to hide the elevated boiler, allowing the mamod's firebox and burner to be used, I thought was pretty clever.

[Tom85]

So I've made a start on this project. I must say I stand humbled behind some of the amazing engineering skills displayed on this forum, but we all must start somewhere and this is where I'm starting, for better or for worse!

As my first project of this kind, I'm trying to keep it as simple as possible. The chassis is constructed from 30mm brass strip, used instead of steel because I'm told it is easier to work with, and bolted together with M2.5 nuts and bolts (I decided to leave learning to tap threads into the holes for a future project). For now, simply cutting metal and drilling holes in the right places is enough. I've used Essel wheelsets and bushes, and meccano gears, with the shafts enlarged with a reamer to 3/16 to match the Essel components. The drive shaft has a 12-tooth pinion, which engages a 57-tooth gear on the idler shaft, which then drives the front axle via sprockets and chain (14 tooth sprocket on the idler, 18 tooth on the axle) giving about a 1:6 reduction. I'm pleased (and pleasantly surprised) that it all rolls smoothly enough. The next stage will be to remove the cylinder assembly from the SP2 and affix it to the side of the frame to marry up to the ex-Mamod crankshaft.

IMG_20200629_210918.jpg (258.01 KiB) Viewed 8386 times

[tom_tom_go]

What sort of body are you planning to make and fit?

[Tom85]

I was thinking an Irish-style side tank with tramway skirts to hide the flywheel and everything. I'll have to sketch out a few ideas to mull over whilst building the working parts

[steamyjim]

Very nice work! I love projects like this so look forward to seeing the progress!

Re. the body work, I love geared locos that make a feature of the motionwork and gearing and don't hide it away.

[Old Man Aaron]

I like where this is going.

[Tom85]

Thanks for the interest guys. It's my first project of this type and I'm having fun with it so far.

Speaking of bodywork, any ideas on what is best to use / easiest to work with? The old Garden Rail article that got me started suggested aluminium, although I know brass is often used too

[Tom85]

After removing the steam unit from the Mamod, and attaching it to the chassis, I hooked it up temporarily to the boiler using silicon tube... and it works! I am almost unreasonably happy about this.

It did throw up a couple of issues though. The chain seems quite loose when running, I'll try removing a link or two. Also, the engine only runs in one direction - this I was expecting, but for some reason I thought it would run the other way! This means the engine and flywheel are at the back of the chassis, not the front as expected. Could this be changed around by swapping the steam and exhaust pipes around? (nb. I really don't know much about this stuff).

Next steps will be to fit the boiler and firebox, and deciding whether to use the Mamod solid-fuel burner, or construct a meths one. The latter would probably perform better but would involve learning to silver-solder, so I haven't made my mind up yet. The bodywork also needs some thought; if anyone can advise what the best material to use for this is, and the best way of cutting sheet material (tin snips? hacksaw? jigsaw?) I'd be really grateful for the advice.

IMG_20200707_123429_2.jpg (151.56 KiB) Viewed 8180 times

[steamyjim]

After removing the steam unit from the Mamod, and attaching it to the chassis, I hooked it up temporarily to the boiler using silicon tube... and it works! I am almost unreasonably happy about this.

It did throw up a couple of issues though. The chain seems quite loose when running, I'll try removing a link or two. Also, the engine only runs in one direction - this I was expecting, but for some reason I thought it would run the other way! This means the engine and flywheel are at the back of the chassis, not the front as expected. Could this be changed around by swapping the steam and exhaust pipes around? (nb. I really don't know much about this stuff).

Next steps will be to fit the boiler and firebox, and deciding whether to use the Mamod solid-fuel burner, or construct a meths one. The latter would probably perform better but would involve learning to silver-solder, so I haven't made my mind up yet. The bodywork also needs some thought; if anyone can advise what the best material to use for this is, and the best way of cutting sheet material (tin snips? hacksaw? jigsaw?) I'd be really grateful for the advice.

IMG_20200707_123429_2.jpg

Good to see it working - well done!

Swapping the inlet and exhaust will reverse the engine.

What about tracking down a Mamod meths burner, or one of the aftermarket replacements. Personally, I'd learn to silver solder - it's not the 'black art' that people say it is, and it's very handy!

I'd suggest you hunt down a copy of Building Small Steam Locomotives by Peter Jones, he talks through various methods for bodywork and then describes a step by step example.

[Tom85]

Thanks Jim - good call on the book recommendation. I've found and ordered a copy. Hopefully should be really handy.

I'll post further updates as things progress

[Garethh]

After removing the steam unit from the Mamod, and attaching it to the chassis, I hooked it up temporarily to the boiler using silicon tube... and it works! I am almost unreasonably happy about this.

It did throw up a couple of issues though. The chain seems quite loose when running, I'll try removing a link or two. Also, the engine only runs in one direction - this I was expecting, but for some reason I thought it would run the other way! This means the engine and flywheel are at the back of the chassis, not the front as expected. Could this be changed around by swapping the steam and exhaust pipes around? (nb. I really don't know much about this stuff).

Next steps will be to fit the boiler and firebox, and deciding whether to use the Mamod solid-fuel burner, or construct a meths one. The latter would probably perform better but would involve learning to silver-solder, so I haven't made my mind up yet. The bodywork also needs some thought; if anyone can advise what the best material to use for this is, and the best way of cutting sheet material (tin snips? hacksaw? jigsaw?) I'd be really grateful for the advice.

IMG_20200707_123429_2.jpg

I found with sheet brass I could score it with a scalpel and the carefully bend until it snaps on the join. Can’t remember what thickness I was using though!

[steamyjim]

Any progress on this project? Was rather enjoying it!

[Tom85]

Hi Jim,
Sadly not - unfortunately I haven't had anywhere near as much hobby time as I'd like of late. I have however been reading up on silver soldering, as my next job will be to scratchbuild a meths burner, having decided to make my own based on Peter Jones's design. So watch this space (not too closely though!)
Cheers,
Tom

[Tom85]

Just silver soldered myself a burner!

IMG_20201012_172741.jpg (252.13 KiB) Viewed 6020 times

[Old Man Aaron]

Well done. Certainly better than the burners I've tried to solder up..

Once you get those wicks fine-tuned, that should make an excellent steam producer. If you've not already, it might be worth adding a filler pipe running out and away from the hole in the reservoir. As the burner heats up over a run, the meths will expand and vapourise further. An open hole in the reservoir so close to the lit wicks could result in a fireball!