Dake Steam Engine

[JorgensenSteam]

I am creating a separate thread for the Dake Steam engine.

 

[bearcar1]

Well that is pretty slick. Reminiscent of a Wankel in a peculiar way. Thanks for the information and back round on the Dake engines, Pat. I'd definitely like to see a set of drawings, just to scour over for days on end if nothing else. How large did these engines get to be as far as HP and size? Too bad they did not become more popular. The one page in that drawing states that they "are suited for high speed applications" such as pumps and ventilation usages. interesting.

BC1
Jim

 

[fltenwheeler]

The Dake article I wrote as well as full CAD drawings have been uploaded to the "Downloads" section of this forum.

Thank You

Tim

 

[zeeprogrammer]

Very interesting Pat.
Thanks for posting this.

 

[SAM in LA]

Pat,

Awesome package you put together for the Dake engine.

It is a very interesting design.

I, and I'm sure many others, really appreciate all of the effort that you are putting into documenting your fathers work.

Keep up the good work.

Regards,

SAM

 

[gbritnell]

I built one many years ago from plans that were published in Live Steam magazine. It was very picky about lubrication because of the sliding parts. It's kind of like a Scotch yoke affair with on square 'piston' sliding inside another. Mine would run sometimes quite well and other times hardly at all.
gbritnell

 

[GordTopps]

Thanks for uploading this Pat

Very interesting

Regards
Gordy

 

[lastpatriot]

Bob J. modeled the Dake from these pages of an old Audel's book that he had.
I did a full writeup and CAD drawings on the Dake a while back, and sent it to a publisher out west, he has been sitting on them ever since (quite frustrating).
Had I known about this board, I would have put it all here in the plans section.
If the publisher does not get off dead-center pretty soon, he will loose his opportunity, and I will upload it all to the plans section.

The Dake borrows heavily from a previous Roots design, but with some neat additional features added by Dake such as using the inner piston as a slide valve.
The Dake is one of those off the wall designs that does not look like it would ever work, but in this rare case, the engine actually works very well, and was manufactured up until the late 1950's. It was used in specialty applications like ship steering engines, capstan hoists on steam ships, winches, and in mines because it was dust-proof by being totally enclosed.

It is equivalent to a typical two-cylinder double-acting steam engine, but it only has three basic moving parts, which are the inner piston, the outer piston, and the crankshaft/flywheel assembly. No eccentrics, no rods, no links, but fully reversible by reversing the steam and exhaust supply using a valve that looks exactly like that used on the old locomotive air brakes.

The Dake runs with virtually no vibration, and I belive it probably produces an almost constant torque similar to a 3-phase electric motor. It can be used in any position, since it is totally enclosed (with adjustments for oiling).

Oddly enough, the Dake was one of the more commercially lasting steam engine designs ever built (manufactured up until until the 1950's), and very ahead of its time in sophistication, but virtually unheard of in the steam engine world, because it looks like something from Mars.

I started making the Dake piston when I was very green, and made it on the rotary table of the mill. It did not turn out exactly flat, but looked flat. When I put it in the mill vice to cut the edges, it rotated, sheering off a new looking 1/2" carbide bit and wasting about 4 hours of work (I was slower then too). The drawers cleaning came after I found out that a 1/2" carbide bit was $40.00 plus shipping.

And a botched Dake piston pictured below.
Almost had that sucker done, and it rotated in the mill vice.
Lost a nice carbide bit on that deal, and I would weld it up, but it is cast iron.

If it's a grey cast iron it is weldable, the trick is not the filler metal, I've successfully welded grey cast numerous times.
I've used E7018, 308 stainless, and nickel rods, nickel is very expensive.
Preheat the entire part to a dull red, run your pass, chip/peen/brush your passes, heat to dull red again, bury it in a bucket of dry sand, or I've even used dirt & gravel cause it was convenient. Wait a few hours or until you can stick your hand in there and it feels barely warm, then your done.
The main problem with welding cast is the filler metal wants to shrink / cool faster than the cast.
That's why some perfer nickel rod as it doesn't shrink as much as other metals.
When the filler shrinks too fast it developes a crack along the side or toe of the weld (where it meets the cast).
Preheating keeps the cast from pulling the heat from the weld causing it to shrink (build up stress) and pull away from the cast.
Peening the passes relieves the weld stresses, keep it hot if it's going to take awhile to fill it up.
Post heating and slow cooling controls the shrinkage and greatly reduces the stresses.
Years ago I had a couple of long time welders bring me a flat head engine head to weld up it was cracked from the middle of the diameter of a cylinder (underside of the head) to and up the side, and across the top to the water inlet port (thermostat). I used two rosebuds to heat it, welded it with 308 stainless, peening in between passes, post heated it, buried it in dirt/gravel.
They had it machined, and it worked fine there after.
A couple of points I should mension, first thing I did was to stop drill the crack, and vee it out. Second the dirt where I live (the desert) is more like dust and drier than a popcorn fart, don't use moist soil as it will suck the heat out too fast.