more steam than you can poke a stick at.

the time has come.

for what? huh?

a bicycle. steam powered. bear with me... this will be a long thread and there will always be some long haired yahoo that cant read that goes "what just happened?"

it all starts with an old hobby of mine, strapping engines to bikes. (nikes? nice typo :))

recently they have been banned in my state. great for the few of us that came to rely on them... be that as transport or financial gain, so what... the point remains that a few of us have been royally screwed over...

anyways, i still have an income but the repressed fascination with steam is rearing its ugly head again.

so, why not bypass this silly law by using its loophole? no internal combustion means steam and stirling are all good to go still :) electric? wtf do i want a battery for? limited range? do you know how FAR i can ride on a tank of fuel?

anyways. this thread is just really for me to raise some ideas im stewing over, see what people think...

starting off. the engine. using a machining kit is probably quick and easy, but i dont like it. the same reason a local steam enthusiast once lamented over..."they're toys"

this guy has a steam shovel in his shed... sentinels, a stanley...yeah...he wanted small feed pumps built to work, not look pretty. real 1/4 or m6 studs,not these piddly lil 4-40 joke things...


yes, they are toys. i wouldnt trust a 8 pound model engine to do the job im expecting and to last for any length of time... great for the shelf, useless as a practical concern. scale models? why? i see no point... usually ;)

so really, im best making some type of v twin double acting doodad, about 1"x1" i guess, with variable cutoff, no need for reverse...and built like the proverbial brick outhouse. thats the fairly easy part... probably start with a brush-cutter crankshaft and bearings, work up from there...

i always liked the single stepped piston compound concept, but its extra complicated. single cylinders require heavy flywheels and dont always self start. multiple cylinders makes things extra complex. and the only way i can see a single piston compound being a self starter is with three cylinders and some seriously late cut off. a v twin is the best compromise...

getting into boilers. flash, obviously.


im thinking a multi-fuel camping stove...ie, diesel, kero, petrol...whatever, it will burn it, with a nice blue flame.

25' of stainless 3/16 brake-line wound in a fancy pattern. probably on a pentagonal former- on paper it allows for the best coverage with two alternate winding patterns as i make it. even 3 or four patterns if im particularly bored? anyways. the more that flame impinges on tube, the better! turbulence is sometimes helpful!

can always add more pipe if needed!

stainless has bad heat transfer... so what? im contemplating pressure/temperature that will pop copper. also, it scales.

(any thoughts on cupro-nickel pipe, with 10% nickel? corrosion/scaling wise? maybe if i back off on the pressure and heat a bit? its cheaper...)

encase the lot in a cylinder of refractory, burner in base, etc etc. contemplate ducting the exhaust off over the cylinders to keep them nice and hot :)

now, feed pumps.

probably just cam/eccentric drive off the motor. makes self starting pointless... aint no steam if it aint running! but then again,. as long as its primed and isnt leaking... pfft, it doesnt need a clutch on a bike, just a freewheel!

which raises an interesting point. two, actually.

1...could i have the check valve on the boiler function as a feed /pressure regulator? ie, at partial throttle, low load, the water is bypassed back to the tank as the boiler pressure is still higher than the release point? set flow for full throttle, and the boiler pressure is a bit more regulated. thats the way im seeing it. have a safety blowoff on the output, sure, but regulate the input... save making variable feed pumps.

2...would it be possible to use an injector on a flash boiler, and if not...why not? they inject feed water into a boiler using the steam pressure of the boiler itself... so once a flash boiler is primed...i cant see why an injector wouldnt work?

making an injector that DOES work could pose a challenge though, im sure :) especially a SMALL one. boring accurate venturis at only a few mm diameter...or grinding drill bits...

back to point 1... there also needs to be some regulation of the flame... thats simply an adjustable, spring loaded steam cylinder that has some fancy linkage to the fuel valve to cut the flame as pressure increases...iunno? temperature controlled? a bimetallic strip? probably the best...as the heat absorbed will depend on the steam production which will depend on the amount of feed water... whereas overpressure could be simply over primed and cold...no point turning the flame down then, is there?

so, by using heat control... if its idling, the flame will go right down. open throttle, release steam, add water, cool combustion chamber...flame rises. anyways. something to think about...

engine driven air pump to keep the fuel tank pressurised...

lubrication? sealing the crankcase is fine for that end, but what about the cylinder? im not thinking a piddly 200C or so here but dull red... 600 or so :) will teflon glands survive, though the motor itself wont be that hot? or do i start looking at authentic materials, graphite, etc?

i think that covers just about all major points to consider... but i could carry on all night...


as it is...the few steam bicycles i see on youtube look awkward and ungainly. and delicate. flimsy. cantankerous.

i want something i could jump off a curb.

im trying to avoid any need for manual input other than lighting. i reckon i got it pretty well sorted, in my head at least!



and of course, a fat wheeled schwinn stingray chopper makes for the perfect candidate for starters :)


a whistle to scare the bejeesus out of anyone within fifty yards... now where did i see the plans for the steam "organ"? play a lil tune whilst chuffing along...

:)



would a mini radiator from a PC work as a condenser? tiny turbine driven fan :) or just dump the exhaust back into the feed water tank through a check valve?


now im being silly... but distilled water does call for some type of recirculation or else its that limited range factor again... i have no idea how to de-scale the lime from a 25 foot length of coiled tubing! (caustic? in which case...condenser be damned! free exhaust!)


someone better have some (helpful) input!