View Full Version : Has anyone built a Heron Steam Engine?
Lee in Texas
07-07-2007, 11:56 PM
I'm getting parts for one. I got bronze bearings that are the subject of another thread. The ball is a 5" dia spun copper sphere from an industrial supply house. What kind of oil should I use? I'm sure some steam will blow through these.
In trying to get this thing figured out, I'm wondering if a Heron really built one. It seems like it could have a LOT of friction if made by hand tools, not to mention escaping steam due to loose tolerances. It would also be very easy to get the ball off-center and result in a wobble, and more friction. Not saying it wasn't possible...just seems hard to believe.
Eh, it will be a fun project. It's going to be brass, copper, and bronze polished up like a mirror.
Anyone have photos of one they built?
07-08-2007, 12:21 AM
Lee, tried my luck at spinning but failed in several attempts. The sphere is made up of two semi-spheres from door knobs and silver brazed together.
Cheated on the pivots. Only one pivot is for steam in and the other pivot has two ball bearings that support the pivot and has no access to steam. Very little friction and will turn fast at less then 5 psi.
If displaying it is run on air. If water and fire is added there is a problem in that at first the steam condenses in the sphere and then when it builts enough pressure to start turning it spits hot water at you.
Lee in Texas
07-08-2007, 12:28 AM
Wow. It's beautiful. I hadn't thought of blocking off one "leg". Sounds like a good idea though. I didn't think about it spitting hot water either. Would taller legs help reduce that?
Would it solve the problem of spitting to use a single piece construction of the jets such that it passes all the way through the sphere, and which has an exhaust hole or holes at the centerline. In this configuration the sphere would have to have a lot of water in it for there to be enough to reach the exhaust hole in the jet tube.
The assumption I'm making is that your sphere has independent jets that terminate just inside the sphere.
07-08-2007, 04:04 AM
07-08-2007, 11:12 PM
I have read a couple accounts of these being made. I can't find them at present. Possibly Model Engineer for one of them. I recall one guy had a lot of trouble with friction, i.e. too much friction to overcome. He ended up suspending the ball by a chain (I think) and got it working like that. Might have helped also because a vertical axis allows the nozzles to stay out of the water?
07-09-2007, 12:41 AM
f you were to extend the tubes inside any large amount, wouldn't you increase the friction and inertia you'd have to overcome to start spinning it?
Also you'd have the drag from the water on the tubes that would also slow it down, also, you'd be stuck with trapped water and require a valve or another method to remove it. Possibly a tube (run through the convenient 'dummy' leg) that would enter through the center and be positioned to miss the reaction tubes inside yet ride just off the bottom of the shell, so the water would be forced out that tube and routed back to the boiler or 'wasted' somewhere safe maybe valved to close it when the unit heated enough to prevent more condensation?
on reading that I think it would be easier to leave them surface mounted....
07-09-2007, 01:31 AM
It's funny that a few thousand years later we have ctitics complaining that he couldn't have gotten it to run, because they have used material that "proves" it is undoable.
It was a toy at the time, could be considered a "proof of concept", if it were invented today. It worked, as I read, and it, eventually, led to steam engines, about 20 PSI, then to 100's of PSi, then 1000's.
In the meantime, it gave birth to the IC engine. Burning fuel air combination can also make pressure, so here comes the Benz engine, the Rudolf Diesel engine, and, eventually the jet engine, and the space shuttle. Confined energy released in a controlled manner.
Gary and a couple others have made them and seem happy.. They are not 90 % efficient, hey, they WORKED, as toys. When you got to the 1820's, the steamers were, maybe, 5 % efficient. Still got investors to put up the bucks. Mebbe the efficiency was less expensive than keeping a stable full of horses to do the same job.
Investors will do that, you know.