live steam stationary engine

[bigsteel]

i wasnt sure where to post this so ill just do it here.
i've taken a small detour from my logging layout as i need to have track laid before i can do anything else.so i've started building a small stationary steam engine out of nothing but scraps.it will be approz. 1/8 scale and will run a converted *cox IC engine.but heres my question:the boiler is only 3in diameter and i dont know which boiler type to use, firetube or monotube.the monotube apparently generates steam faster,but the firetube is apparently easier to control,so any live steam experts out there,which one should i use?--josh

*the IC engine was for airplanes and only has a bore and stroke of about 3/8 by 5/8 so its quite small.

[TinGoat]

Hi Josh,

Take a look at Garden Railways Magazine from March 2006.

Jeff Young's article: Pots, porcupines, and flues which discusses the pros and cons of different boiler types.

For a stationery boiler, I'd consider a verticle boiler made from a Kelly Kettle.

[bigsteel]

thanks for the link TG,it helped alot,my boiler will be semi-scale so the tea kettle would work for this but would not look right.im trying to model a small industrial engine on a trailer,like what was used on a farm to run small machinery.thanks.--josh

[steamhead]

Hey...That's a clever idea...!!! How is that COX engine going to work with steam..?? Please elaborate a little on how you're going to set this up....I might try it myself....

[bigsteel]

well gus,the cox engine is similar to the second to last engine on this website in "early engines" COX Engines.i removed the glow plug portion and replaced the head with a new 2 piece brass one with a small bearing in the center of the two pieces,i then soldered a copper pin to the piston to push the ball up allowing steam to enter and as the piston goes back down it lets the valve back down.and as you can see in the picture,the piston travels far enough down to let the exhaust steam exit.ill also put a copper sheath over the radiator fins to make it LOOK more like a steam engine.and a pipe will be connected to this going to a condenser and back into the tanks! (and just for kicks,this engine im using IS 52 years old and runs perfectly!)

as for the boiler,i have made a shell out of an old propane torch tank cut to about 6in tall.this is where my question came in on which type of boiler to use (which is still undecided).ill be using an old small side burner from a gas grill to heat the water and a super small tank of propane disguised as an oil tank for fuel.

the gearing portion is simple clock gears that will run a small winch or machinery from a belt.

i hope i answered your question and you could maybe build your own junk box steam engine!--josh

[bigsteel]

oh and i forgot to mention,the boiler is going to be vertical (similar to a donkey engine in overall design).--josh

[steamhead]

That's really neat....Will you have some type of flywheel attached to it..?

Looking at the engines...I wasn't aware that Cox built anything larger than the .049's, which are the ones I'm familiar with. That .15 looks just like what you need....To be frank, though...I wouldn't mess with that engine; there's got to be just a precious few around anymore....

[bigsteel]

well,its too late now...its already been soldered too and cut up to turn it into a steam engine.although i do have 2 more of the same kind.which because of what you told me ill probably just leave as is or sell to a model rebuilder of some sort.i never though of an old gas engine being rare,ill have to figure out exactly which one it is.

and yes i will have a flywheel attached to it,it took a perty darn big one too right now is a temporary one which is a steel flywheel 2in in diameter!--josh

[Russ Bellinis]

Is the propane tank of a thick enough gauge metal to be safe to use as a boiler? How much steam pressure are you going to need? You have to think of safety before you start building a steam boiler. Also what are you using for a burner to heat the water? If the burner concentrates the heat to too small a spot, it could cause a hot spot that will weaken and melt through.

[bigsteel]

the propane tank is approx. 1/16 in thick and i belieive will hold the needed 40-60 PSI.the burner wil be the small kind off the side of a grill,but if that doesnt work ill try to buy one commercially.--josh

[bigsteel]

update,i have bought a bunch of 3/16 and 1/4 copper tubing,as im going to use a monotube boiler,and have made the brass mounts for the gearing and motor.and if i have enough tubing and brass left over,im building a second TRUE steam engine from scratch out of nothing but copper plumbing parts and a firetube boiler ,i think i've been bitten by the steam bug,so i have to keep telling myself (you dont have money for large scale live steam) --josh

[steamhead]

That's good news....We used to have a steam engine waaayyyyy back when we were kids. It was European made and had three or four different accessories that were attached to it via belts...Really neat set-up. All that stuff is still available, but the prices are sky high. Some come up on eBay now and then...
Keep us posted on your progress, and let's see some pics...

[bigsteel]

those little steam engines are cool but way to much for my tadstes even on ebay.--josh

[bigsteel]

im buying some brass scarps form a local machine shop and was wondering,how hard do you think it would be to make my own round burner? i mean i've seen burners for sale and the butane wouldnt burn hot enough to damage the brass,and all the burner really is is a chunk of brass with a TINY hole in it for gas to escape and burn right? or am i way off base here?if i cant find a grill burner small enough this may be my only choice except paying 100+ for a machined burner.--josh

[bigsteel]

her are some update photos,the first is the outsid eof the boiler the hole on the left is the water pipe and the pipe on the left is steam.the shot of the inside shows the monotube.its really going to be quite basic.the stack is 3/4in pipe and is a little long now but will be trimmed shortly.and i've also started building a burner from 3/16 bras pipe and a valve from a MAPP gas plumbers torch.anyway's here it is.--josh