Moteur Oscillant double effet

[SBWHART]

Thanks Chaps

Thinking about Peters comment on the stability of the base, I've bin running it lose on my surface plate, decided to clamp it to a chunk of wood to see if this would have any effects, and it does seem to run better.

Her's the vid of the no 1 running.

[ame]http://www.youtube.com/watch?v=IRJ9s9h4nlE&layer_token=143fa5b93328b9a5[/ame]

Enjoy

Stew

 

[winklmj]

Aswesome job. Neat looking and running engine(s). :bow:

 

[SBWHART]

Thanks for your kind comments Mike.

Stew

 

[bearcar1]

SMOOooooOOOTH! Nicely done Stew, what a great runner and it looks terrific as well. Thm:

BC1
Jim

 

[arnoldb]

Very well done indeed Stew !

Darn, now that one's on my "Have to build one" list as well, and its all your fault :big:

Kind regards, Arnold

 

[SBWHART]

Thanks Jim/Arnold

Sounds like the old projectitus is breaking out again :big:

Stew

 

[Maryak]

Stew,

Very Nice build. :bow: :bow:

Best Regards
Bob

 

[cfellows]

Nice runner and a great looking engine. This is one of my favorites of the small, bar stock steam engines.

Chuck

 

[kustomkb]

Nice job Stew!

Runs and looks great.

 

[SBWHART]

Thanks Chaps

All I've got to do is do the same trick six times over with this lot:-

;D :big: ;D :big:

Stew

 

[NickG]

Stew, that runs perfectly. Will be a brilliant powerplant for the boat people. :bow:

Nick

 

[SBWHART]

Thanks for you comments Guys

Well the last week as bin a bit slow in the shop domesitc duties called but I've managed to change this

Into this

Times Seven

I made a crude manifold and tried running all seven at once but the best I could do was six, some of the ports on the manifold were hogging all the air, so the supply to some of the engines was low, but you'll get the idea.

[ame]http://www.youtube.com/watch?v=2szI_OkvrEQ[/ame]

Stew

 

[doubletop]

Nice one Stew

Just need a lot of oil, leave them running and go for a long cold warm beer (or cup of tea). Once run in they'll go on 5psi

Well done

Pete

 

[Blogwitch]

Very nice indeed Stew, just like juggling handsful of worms.

Hope to see them in the flesh over the weekend.


John

 

[winklmj]

Call in the Terminator...the machines are multiplying.

 

[NickG]

They were trying to get away too! Stew, absolutely brilliant :bow:, just need to make the 7 boats now ... Get cracking! :big:

Nick

 

[cfellows]

I've been looking at the plans for this engine with an eye toward converting it to a slight larger version using inches instead of metric and spotted a couple of things that I questioned.

The port in the cylinders is 1.7mm whereas the matching ports in the frame are 2.2mm. I understand that spacing of the holes in the frame is important to get the correct overlap during power strokes with no overlap at top and bottom dead center. However, couldn't the same goal be achieved by making both the cylinder and frame holes the same size, say 1.9mm? Or is there a good, thermodynamic reason to decrease the size of the steam passages as you get closer to the working end?

Another question that came up is the axial positioning of the cylinder holes. Why not move them closer to the cylinder ends, perhaps obviating the need for the axial transfer hole from the inlet port to the cylinder exit. This would also allow the use of larger holes in both the cylinder and frame for the passage of steam since the two frame holes would have to be further apart.

Chuck

 

[doubletop]

Chuck

I took the view that the larger holes in the port face allowed the port to be fully open for a longer period otherwise it will only be fully open at one point in the stroke. Look at the port as being a 2.2mm x 1.9mm slot. If you move it further out the slot would need to be longer to cover the same angular change.

Pete

 

[fcheslop]

Hi Chuck,I build this engine at a reduced scale to go into a small steam launch I'm currently building and have drilled the ports so theres a 2 thou overlap on the holes as its seems to be common practice on oscillators that are going to work for a living although it does waste a little steam it improves the performance greatly as the port opens sooner on the inlet and closes later on the exhaust.Theres a book called Model Stationary Engines sorry i cannot remember the author and he goes into the porting of oscillators as does Tubal Cain in his simple steam books
best wishes Frazer

 

[SBWHART]

Theres a book called Model Stationary Engines sorry i cannot remember the author and he goes into the porting of oscillators as does Tubal Cain in his simple steam books

Hi the book refered to is:- Model Stationary and Marine Steam Engines by K.N.Harris it was published by Percival Marshal & Co First Edition 1958 revised 1964 I don't think it will be in print any more and i can't find an ISBN number on it. I got my copy as payment for some work I did on a friends Model traction engine.

Any party interested in the info can send me a PM, (I'm not trying to sell or pass the book on)

Stew