Boulton and Watt 1802 steam engine

[propclock]

I recently completed this engine. It is fairly true to scale and seemed weird at the time.
For example, a 8" flywheel with 3-48 and 2-56 screws for the main bearings? Also
wedges and cotters for bearing mounts. many hours on split bearings and all bolts and nuts are square.
Nice gun metal castings from England. The Long D valve was a challenge.
Not sure how much interest there is in this engine, I have a lot of photo's if there is interest.
But this video covers most of it. The original had a stack of bricks, but I made A frame supports for the main bearings.
Corian /wood base. Runs really smooth. All delrin on the wear parts as it is an air runner. Ran 6 hours at a show recently.
and Kids like the motion.

The video

 

[Charles Lamont]

That looks to be very nicely made. Runs beautifully.

 

[Chris Rayner]

One of the engines which galvanised the Industrial Revolution. I presume this is built from this kit: Polly Model Engineering: Stationary Engine Kits - Anthony Mount Models

 

[propclock]

Yes you are correct. not sure if any castings are still available some had cast iron flywheel and cam ring . Of interest to me is the cam ring on the
patent pictures show the cam ring squarish and that makes sense it would give improved valve timing but for the model maker it would be a nightmare.

 

[minh-thanh]

Nice moving engine parts .
Congratulations !

 

[Steamchick]

As the "cam-ring" has been replaced by your eccentric, it is an allowable deviation from their Patent. Mr Boulton was quick to extract licence fees from anyone who copied his Patent, so you have avoided that! - As many did around then, leading to the wide variety of engines at the time.
Love it! - Very well presented. Congratulations!
K2

 

[Chris Rayner]

Yes you are correct. not sure if any castings are still available some had cast iron flywheel and cam ring . Of interest to me is the cam ring on the
patent pictures show the cam ring squarish and that makes sense it would give improved valve timing but for the model maker it would be a nightmare.

It is still advertised for sale on their website. I was considering ordering a set until I saw your model. Storage might be a problem for me.

 

[vederstein]

I believe I've seen the actual engine. It's on display at the British Science and Technology Museum (or whatever it was called).

Great work you've done.

 

[Chris Rayner]

I believe I've seen the actual engine. It's on display at the British Science and Technology Museum (or whatever it was called).

Great work you've done.

This one 'Bell-crank' engine, c. 1799 | Science Museum Group Collection

 

[Steamchick]

Thanks Chris, But this Bell Crank Engine has a "conventional" eccentric driving the valve gear, not the Eccentric "can-wheel and follower" that PropClock explains/demonstrates for the Boulton and Watt patent.
But the Bell Crank does connect the piston rod to pump rod and crankshaft.
K2

 

[Chris Rayner]

Thanks Chris, But this Bell Crank Engine has a "conventional" eccentric driving the valve gear, not the Eccentric "can-wheel and follower" that PropClock explains/demonstrates for the Boulton and Watt patent.
But the Bell Crank does connect the piston rod to pump rod and crankshaft.
K2

Indeed. I doubt that Boulton and Watt produced many engines which were precisely identical, but this is the one in the Science Museum to which vederstein refers.

 

[Jasonb]

Anthony Mount mentions a larger 7hp engine in the museum that is similar to the one he based his model on, the one you link to is a wooden model at the museum. I think this is the one AM talks of Bell-crank Engine by Boulton and Watt, c. 1810. | Science Museum Group Collection

Polly still do his range of engines but most tend to be cast to order these days rather than off the shelf. If storage is an issue it could be done without castings to a smaller scale