Ramblings of a Deranged Kludge

[Kludge]

Okay, so anyway, I had this strange idea for a steam engine - two cylinder, double-acting, self-starting & reversable. Okay, that's not strange. It only becomes strange when I get my hands on a concept.

Steam engine basics: cylinders, pistons, valving and a way to make the valving work. Easy. So why complicate such an easy machine? Because I can.

Of the many devious ways I've thought up, this is one. First, the cylinder rotates back and forth between two positions. The wall at each end is drilled to provide a port to the end supports. The supports have two ports at each end, one for intake and the other for exhaust. When the cylinder is in one position, the cylinder goes one way and when it's in the other it goes the other. The cylinder rotates in kind of a snap action, operated by a mechanism on the piston rod crosshead that trips at each end of the stroke. I've got a few ideas on this but none selected. Yet. (Actually, that idea came from the electric engines.)

At the moment, I've got only one minor problem which might not even be a problem. It's heat. As the engine warms up, the cylinders are going to expand ever so slightly. The end supports will expand slightly less and the piston will probably not expand enough to keep up with the cylinder. So how much clearance should I leave so leakage is minimized and nothing's going to lock up? Or do I really need to be overly worried about expansion?

I have a few other ideas, pretty much from the same med-induced haze. Fun, huh.

BEst regards,

Kludge

 

[Maryak]

Kludge,

If you use the same material for piston and cylinder, (or cylinder and rings), that part of the problem goes away. One end of the cylinders needs to be able to expand, probably easier if this end is opposite the Xhead and the base plate for the cylinders is your reference point with everything expanding away from it and the Xhead. If not then your crankshaft journal bearings need mounting in a dovetail with a gib to cater for this expansion and control sideways movement.

Are you going to use 2 eccentrics for reversing or do you plan on using 1 slip eccentric?

HOW HARD do you want to make this ??? ??? ??? : : :

Best Regards
Bob

 

[Dhow Nunda wallah]

Kludge, good to see you still making easy things the hard way

The only haze here at the moment is induced by self-medication (currently ethanol and tomato juice)

Is this something like a rotary valve crossed with a flame-licker type valve toggle action?

I may have quite the wrong end of the stick, but my world view has never been regarded as orthodox

Cheers mate. I'll be keeping an eye on this one.

Rgds, Lin

 

[Kludge]

Taking things out of order, it's not how hard I want to make it, just how unnecessarily complex. Like so much else in my really strange mental sketchbook, it will be built in keeping with the Goldberg-Python Principle (Anything simple can be made highly complex through the employment of any of a number of non-complex methods.) purely for the sake of doing so.

Okay, onward and off at a slightly oblique angle ...

If you use the same material for piston and cylinder, (or cylinder and rings), that part of the problem goes away.

Brass (probably 360) all around since it's easy to get and work. Besides, it's pretty. The pistons will be 3/8" in diameter and the cylinders the next two sizes up in hobby brass tubing soldered into one happy piece with a 7/16" outer diameter. The ports I think will be 1/8" in diameter (maybe a skosh bigger) and centered something like 3/16" from each end which, in turn, establishes the minimum depth to which the cylinders will go into the end pieces. These sizes aren't carved into much of anything except melted butter at the moment so may increase drastically as materials present themselves. (Or, stated another way, I haven't noodled around Home Despot yet. )

The end pieces will be connected by plumbing as far as the steam and exhaust lines go which can also mess up the expansion problem since they'll be on top of the engine providing an uneven stress situation as it heats.

One end of the cylinders needs to be able to expand, probably easier if this end is opposite the Xhead and the base plate for the cylinders is your reference point with everything expanding away from it and the Xhead. If not then your crankshaft journal bearings need mounting in a dovetail with a gib to cater for this expansion and control sideways movement.

On the itty bitty version, I don't see this as being much of a problem since I may be able to use a connecting rod I came up with that allows for expansion. On larger versions, this can be a real interesting problem which may require me to add a bit more complexity to resolve. I may have to invent some rather ingenious way to absorb the expansion through an intermediary link or two between the crosshead and the crankshaft. I'm sure Rube, Monty and I can come up with something outlandish. Keep in mind that practicality is not a factor.

Are you going to use 2 eccentrics for reversing or do you plan on using 1 slip eccentric?

Too conventional.

Reversing will be done by that horrid method of swapping the steam and exhaust through a single hand-operated lever. The engine shouldn't care as far as porting goes and I won't have to do anything fancy with the valve mechanism.

Side note: I'm kind of strange about hardware. I like the way bridge screws in watches fit with their heads fitting nice and close in milled countersink whatzits so they're absolutely flush with the surface and there's practically no gap between them and the bridge they're holding in place. Every watch screw I've encountered in a mechanical movement has had a straight slot head with the slot cut with precision, often with what appears to have been a slitting saw. I'd like to say that's how my hardware will be made but I don't think I'm good for the degree of precision involved. None the less, I do like the appearance and hope to employ it as much as possible in both steel and brass. One thing I don't want to do is wind up with boring hardware.

Best regards,

KLudge

 

[Kludge]

Kludge, good to see you still making easy things the hard way

You mean there's another way? :big:

The only haze here at the moment is induced by self-medication (currently ethanol and tomato juice)

That's bad for you, you know. Far better if you lose the tomato juice.

Is this something like a rotary valve crossed with a flame-licker type valve toggle action?

Kind of, yeah. I need to get emachineshop running on my tablet so I can sketch it out (along with a few other bits of madness) and slide over to this machine. Why the tablet? Because I can take it out on the beach once the weather settles down (There's a reason it's called the Monsoon Season. ) to enjoy the sun, sand, ocean ... whatever else happens to be around.

I may have quite the wrong end of the stick, but my world view has never been regarded as orthodox

Thinking so far outside the box that the box is no longer part of the landscape may not be orthodox but it is delightfully creative and fun. It also makes others think which is pretty cool in itself.

Best regards,

Kludge

 

[Dhow Nunda wallah]

Kludge, sorry if this is OT on the thread, but I tried to PM you and no joy, hope you aint down the gurgler mate.
I'll try this way and beg the indulgence of members and moderators.

Kludge, if this msg gets to you, please let me know, the PM setup on this board is a little, errrr.....

over on the HSM site, Evan has declared a shed full of miniature valves (tubes) ex military.
Knowing your interest, I thought I'd pass this on.
Evan is in Canada, which, in my terms, is pretty close to Hawaii.

"I have boxes of tubes. I wonder what they might be worth?

In particular I have a good collection of military peanut tubes. If anybody is restoring old aircraft radios and needs some just ask."

URL is
http://bbs.homeshopmachinist.net/showthread.php?t=34112
Best regards,
Lin (in WA, that's Western Australia, not Washington)

 

[Bernd]

Lin,

I beleive Kludge has, as they would say, "left the building".

Bernd

 

[rake60]

Yes Kludge had requested a leave of absence.
I hope he will be back again!

Rick