Murdoch's Oscillating Engine

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SignalFailure

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This project has been in my head for four of five years. I started building it about 3 months back and apart from the flywheel is almost complete.

It's my take on William Murdoch's very early oscillating cylinder engine (said to be c1785!) and features a normal piston type valve activated by the oscillation of the cylinder rather than an eccentric.

The original has a wooden cylinder with everything else in iron - as my blacksmithing skills are poor I had to simplify the A frames that support the crankshaft and the main bearings.

As I didn't have any suitable brass for the cylinder or valve chest I made them in mild steel and the piston is cast iron. It's therefore probably unsuitable for running on steam!

It's running on a foot pump here hence the jerky motion - it's not run in enough yet to work off my aquarium pump.

I've included a picture of the original for comparison.


http://www.youtube.com/watch?v=ny2OehkQdiY&feature=youtu.be

IMG_2286.JPG


IMG_2287.JPG


f36p134.gif
 
That's a very nice adaptation of the engine in the drawing. Simple and elegant. I like it, a lot!

Chuck
 
Glad to see you're still at it Paul. Another nice example of your modeling skills. Thm:


BC1
Jim
 
Well done Paul.
I wondered what you had been up to!

John
 
Thank you Chuck, Jim & John ;D

It's crazy but I'm stuck trying to accurately mark out the flywheel - I've tried twice and just can't get it right :mad: I bought two 4" discs of brass at a show last year and with current prices I'm loathe to start cutting until I'm happy with the layout.

Seems I need something better than my wobbly homemade lathe detent. I'm sure I've seen posts on the subject here but damned if I can find them!

 
It's not like you to make a wobbly unless it's an oscillator :)

John
 
Nice to see a fresh design, I like it as well. Oscillating engines are always interesting to watch running.

Jan
 
Very nicely done Paul, and a great adaptation of the original drawing. Once you finish up the flywheel that will only make it all the more attractive. Nice modeling!!!

BIll
 
Thanks for the kind comments.

Pete, I'd need to invest an awful lot im equipment to emulate Bog's method - I've got a mini lathe and a poor micro-mill with very little tooling. I plan to mark out the three corners for each space between the spokes then drill & file :big: as I have nothing to hold or align the disc on the mill and doubt if it would cut that thickness anyway.

Watch this space!
 
That "Murdoch" guy had some smart ideas for so long ago, I think he was the one with the gaslight and "flier" too.
You have brought his ideas back to life beautifully Paul.. ;)
Stew.
 
Cheers, he also invented the compressed air delivery system used in banks etc! He worked for Boulton & Watt just don the road from here. Genius!
 
Paul

Get hold of a copy of the latest model engineer, it may have just the answer you are looking for

Pete
 
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