Heinrici type stirling

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madjackghengis:
Hi Dean, you know you've got a beautiful engine going together there, and I mean no disrespect when I say this, but watching you put grub screws into a flywheel at an angle just reminded me how much I hate doing exactly that. Sometimes it seems like the only way, and it is seldom one gets a flywheel set up in such a way and gets to change it, but grub screws setting at an angle just isn't right somehow, and I always want to figure out an efficient and effective way to put them in straight, without making that part of the job take up more than its share of time and effort. In these model engines, it's a small thing and more an aesthetic factor than an engineering one, but I suspect it is the reason there are several full scale means of attaching flywheels with split taper bushings and other methods, just to avoid the less desireable method. I've got a couple of flywheels which will eventually have to go on the main shaft of a steam engine, and I'm not going to put angled grub screws in if I can work up the motivation to machine split taper bushings or something of the like instead. I don't mean to be derogatory, I've hated them in the smallest of engines, that fit in the palm of your hand, and find them equally distasteful in full sized working engines powering machinery and equipment. I keep thinking there ought to be a way to set up a made for the purpose, offset spindle arrangement which will allow drilling and tapping perpendicular in that very short space, and I keep trying to conceive of such a device. The complements were not to mollify you, I am truly intrigued and impressed by the vision I have of the engine and all its gyrations when it is running, especially the timing offset of the displacer arms versus the power piston arms, it's just that engineering seems way above the level of the grub screws. In any case, that engine is going to be a real winner and a work of art when it's done and running, I wish I could give a suggestion of a better way with flywheels, so I could use it too. All in all, you've got a truly great engine going together and I look forward to the video of it running. :jaw: :bugeye: :thumbup: mad jack

Dean W:
Jack, thanks for your thoughtful comments and suggestions. I just look at set screws for what they are, as little fasteners.
We don't think of them as being particularly elegant, probably because they are such a simple form.

Their best use in this application is probably in holding a key firmly into it's keyways. That won't work for this particular engine
because the one flywheel needs to be able to rotate on the shaft for timing purposes. However, a taper lock would work for
similar flywheel/shaft relationships. I've used those a lot in industry for holding sheaves to power shafts on large conveyors.
I've made a few, too.

For making your own, turn the taper on the lock and in the flywheel hub at the same setup and you'll have a perfect fit. Your main
limitation will be the size of screws needed for jacking out the taper lock to remove it once it has been snugged in. The
smaller the taper lock, the smaller the screws. I know from personal experience that down to 0-80 they work well. You can make
the taper lock part itself quite small and it will still function as you'd expect. The smaller they are, the thinner the wall of the taper
needs to be so it will compress from the pressure of the tiny locking screws. Make the largest OD, the outer rim, large and thick
enough to take the compression and jacking screws without stripping.

Show us what you come up with!

Dean

Dean W:
Hi all;

I'm going to run this engine with a Jerry Howell burner I built a few months back. It's small, at only about 2" high.
It came out pretty well, and puts out a nice uniform flame.

I have enough pieces made for the engine now that I can give it a test run. The picture above shows the flame
size I used for this run. This run seems really loud for a stirling, and on another run, I found out why. I didn't
have it mounted solid, just holding it with a gloved hand, and the base is vibrating this part of my work bench.
As soon as I lift it slightly off the bench, it's much, much quieter.

Well, it goes pretty darn fast. At this point, too fast to see what's going on! It also has a lot of poop, and
I can pinch the end of the crank pretty firmly between my fingers, and it just keeps going.

Still have to make the mounting feet, the firebox door, and splash on a little paint. Though it isn't in the
prints, I'm going to make a fan to be driven off a small pulley that will go on the right end of the crankshaft
to cool the cylinder fins.
I'll put more pics up as I get the finishing steps done.

Thanks for looking.

Dean

Stilldrillin:
Oh! My..... Oh! My..... Oh! ...... My..... :bugeye:

Dean, that is marvellous! :clap: :clap: :clap:

Success! Straight away...... :D

Blummin, WELL DONE! :thumbup:

David D

Rob.Wilson:
Hi Dean :bow: :bow: :bow: :bow: :bow: :bow: :bow:

Sounds great to me :thumbup: it really goes some :D ,,, thats a COOL /HOT burner , :dremel:

Regards Rob

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