I like idea of the movable sensor shutter. It would give a relatively simple solution electronically.

Here's a thought to also simplify the solenoid turn-on. Have the coil energized most of the time except when the opto-sensor detects the light from the "shutter wheel" delay. Thus when the valve is mechanically opened, it will stay open, (assuming the solenoid generates enough force to hold the valve open but not enough to open it when closed). The solenoid than momentarily releases long enough for the valve to close when the optical signal is detected. This eliminates the need for a separate sensor to turn the solenoid on.

Wouldn't that cause the solenoids to heat up? They are already going to be hot from the steam. Keeping them energized most of the time would cause more heat.

With this being a 'bash-valve' engine, thought just use the bash rod to energize the solenoid.

 

@kgkfr, not to be too nosy, but are you using a master and slave type crank? Or some other crank and rod system you came up with?

The reason I'm asking is that in an earlier post, you said that the exhaust valve would be opened by the connecting rod. Been trying to wrap my mind around how your doing that. The original single cylinder engine in the link uses a stationary pin/pusher to open the exhaust valve. The rod and piston, thus the exhaust valve, are in a constant fixed relationship, so can't figure how the valve can be opened.

 

Wouldn't that cause the solenoids to heat up? They are already going to be hot from the steam. Keeping them energized most of the time would cause more heat.

With this being a 'bash-valve' engine, thought just use the bash rod to energize the solenoid.

Certainly the heat is a concern. The solenoids would have to be designed for near 100% duty-cycle at the operating temperature of the engine, but I would think that is possible.

My reason for doing it that way was to avoid a mechanical operated microswitch which would be prone to failure at the high operating speeds of the engine.

 

I'm unfamiliar with 6-cylinder steam engines. Do they have all pistons directly driving a single crankshaft? Does each cylinder operate on a 2-stroke cycle? Is steam injected for the complete power stroke or only the initial part?

 

I'm unfamiliar with 6-cylinder steam engines. Do they have all pistons directly driving a single crankshaft? Does each cylinder operate on a 2-stroke cycle? Is steam injected for the complete power stroke or only the initial part?

While not sure in this design, a "bash valve" engine is a two stroke. They bash the valve open, thus the name. In fact many people make them out of small two stroke engines, like a chainsaw engine. The piston has a pin on its top that pushes a valve open at slightly BTDC and closes it at the same point ATDC. The exhaust is then out the engines regular exhaust ports.

All piston type steam engines only inject steam for a small amount of time in the stroke. This is called the "cut off". After the cut off, then you get the "expansion" which lasts until the exhaust.

The valve gear on an engine like in a steam locomotive is adjustable, on the fly. When starting from a stop or going up a grade, the cut off is longer to give more power. Once you get up to speed, you give a shorter cut off to hold that speed.

 

My reason for doing it that way was to avoid a mechanical operated microswitch which would be prone to failure at the high operating speeds of the engine.

An optical switch could also be used here, instead of the microswitch. I know that kgkfr said the engine would get up to 1500 RPM, but that's around two or three times the normal speed of a steam engine.

 

@ kgkfr, sorry if I've taken over your thread. Just can't help myself some times. Back before I retired, I would design stuff at work, while my machine was running, for something to do. Steam was one of my interests. Your thread woke my mind backup to this.

Don't mean to undermine you, just trying to give ideas to a kindred spirit. If you want I'll shut up.

 

@ kgkfr, sorry if I've taken over your thread. Just can't help myself some times. Back before I retired, I would design stuff at work, while my machine was running, for something to do. Steam was one of my interests. Your thread woke my mind backup to this.

Don't mean to undermine you, just trying to give ideas to a kindred spirit. If you want I'll shut up.

Sorry been busy, had not looked for a while. Absolutely no problem, I will listen to any advice, there are some very useful ideas being posted.

I discovered the bash valve when researching steam engines, I had not realized they were used in 2 strokes (not had a lot to do with them for 40 years, since I left the motor bike shop).

The crank set up is not master and slave, it is pins to limit the movement of the spider,similar to this one on Youtube.
http://www.youtube.com/watch?v=6NPpelLCIkk
I did try master and slave originally but because the exhaust valve is is operated by a pin passing through the piston crown, offset from centre lifted by a shoulder on the top of the con rod (see picture) there was different angle of movement between the master rod and the slave rods and bizarrely different stroke lengths, 1 and 4 were the same but 3 and 5 longer and the pistons hit the crankcase, I could not believe it, I Googled and found nothing about it, so I checked my animation and it showed 3&5 (and 2&6 but to a much smaller extent) came about 2mm further down but reached the same tdc as the rest, something to do with the path the spider follows not being a perfect circle, I guess, anyway changed to limit pins and it works.
Engine RPM. I was able to put compressed air to 1 cylinder just to send the piston down attached to the crank and the amount of torque was amazing even at 20psi, so I do not think it will be necessary to run the engine above 500rpm or even less (I don't like high revs, that why almost every vehicle I have owned was a diesel.) it will just be a mater of stepping up the drive pulley ratio if it makes it to the ride on mower.
Heat Affecting the solenoids. Yes that is a concern, I will just have to try it and see, it's the only way to test.
The shaft encoder arrived this morning, so I was looking at the Arduino site to try to get my head round the job, then I checked the forum here (sidetracked again).
Using micro switches and opto sensors is probably the best way considering the operating environment, but I would like to give it a go with the encoder or disk with slots and a processor, but now which Arduino or similar board do I need, more research needed.

 

So your using ideas from two motors, I like it. I never saw that video on the Cyclone motor before, thank you. You probably have seen the Cyclone site - http://www.cyclonepower.com/ They show/link to some of the patents and drawings.

Some where in my menagerie of stuff, I have some plans in a magazine that was called "Strictly IC". They were a model internal combustion magazine that has since gone out of business. They ran a series on an electronically valved engine once. If your interested I'll look for it and scan the part about how he did the circuit for it's valve timing.

Most bash valve and uni-flow engines use piston porting for the exhaust. In a radial engine it could also be done this way, and still collect and recycle/condense the exhaust. By making a circular ring manifold, that was sealed to the cylinders at the exhaust port level. It would be a second larger diameter ring concentric with the main crank case ring. Just an idea.

Here's a link to the original book written by the inventor and builder of the Uniflow engine, J. Stumpf, you might like. The site in the link has a lot of old steam books in PDF form for free. https://archive.org/details/unaflowsteamengi00stumrich

 

So your using ideas from two motors.

Yes when I was researching I found the cyclone engine and thought it was a very neat concept, especially the idea of exhausting straight into the crankcase. The Youtube clip shows one of their waste heat engines, if you look at the drawing of cyclone engine you will see they are using piston porting on that engine with some sort of heat exchanger wrapped around it. I had thought of building an IC radial engine and spent sometime looking at them, fantastic pieces of engineering, but because I could find no practical use for one and the engineering tolerances would be a finer than in a steam engine I opted for the steam engine. It was not until after I had come up with my own design for the piston mounted valve that I found this http://www.greenpatentblog.com/wp-content/uploads/2012/03/Figure3.jpg which showed how they were operating their piston mounted reed valves, if I had seen this before I wold possibly have done things differently but I think the method I have now, all in one and fairly simple should work OK , just setting one complete valve up now to try it.
If you can find the magazine easily I would certainly like to see the section on the valve control, but please do not got to great lengths to find it.
Just had a look at the unaflow sight, there's a lot if interesting reading there.

 

I'll be splitting fire wood for a day or two, but will get the magazine looked up and scanned.

Would you mind sharing the link to that patent?

They are doing some thing that I came up with trying, but much easier and more elegantly. I thought if you could have a valve that would release the compression on the return stroke it would
1. free up some power from the rest of the engine
2.exhaust all or more of the dead/cold steam and condensate from the cylinder
3.be used to push spent steam from the exhaust into the condenser for recycling in the system.

I see your using oilite bushings in the con rods. Have you heard of DU bushings? Much higher PV ratings and can even be run dry. Found a real inexpensive place to get both them and the oilite. http://www.asbbearings.com/ They are the manufacturers for most of the other brands, and sell to the public at the prices the name brand guy's actually pay for the bearings.

 

OK thanks.

The link to the patent, I had not got it just that page bookmarked, but I had a quick search and remembered I had seen it on the "green patent blog", did a search on "Cyclone" on their site and found the full patent for the waste heat engine, I wish I had seen that before I had started the project. http://www.greenpatentblog.com/2012/04/07/cyclone-power-adds-a-modern-twist-to-the-steam-engine/ there are links to 2 patents on this page.

Never heard of DU bushes, marvelous thanks, I shall be using them for the rods and for the valve in the piston.

 

@kgkfr, I was wrong about having the article on the engine. It never was in the magazines that were saved, it was in another magazine altogether, Home Shop Machinist. But did find a link to the guy who built/developed it. http://www.evicengines.com/
Sorry I didn't keep my HSM magazines.