Robinson Patent Hot Air Engine

[Jasonb]

Looks good, hope to see it in the flesh next week.

 

[Blogwitch]

So looking at your finished video, and your comment, it looks as though for this Polly models version it does require the heavier flywheel counterbalance weight.

So eventually, when I get to make mine, I will leave the weight on the flywheel and remove it if it still jumps about.

Great model BTW

John

 

[deverett]

John, no you do not NEED the balance weight. I've had another run this morning with the engine bolted down to a proper base and it runs quite smoothly.

Dave
The Emerald Isle

 

[deverett]

EPILOGUE

I spent quite a bit of effort in adapting the Polly castings to make the model more representative of the full size engine. Within the last week, I was reading through some old Model Engineer magazines and one from May 1946 shows a cut away Robinson engine in the Science Museum, London.
Well, blow me down! The picture shows a Robinson exactly like the Polly model, so all my efforts were in vain. So, anyone building the Polly Robinson can go ahead knowing that their version is quite to scale.


In a letter by J.F. Perrin in June of the same year, he relates that these engines were used by the Post Office.
ROBINSON HOT AIR ENGINE LETTER 20 JUN 1946.pdf

Dave
The Emerald Isle

 

[Jasonb]

Thanks for posting those Dave. Interesting to read a bit more about the speed regulator, I have gone for a working one on mine as per the Alyn drawings and can see it being drawn in just buy turning the engine over by hand with no spring on the stem. Graham suggests two small holes in the disc so the engine does not come to a complete stop and this is what was on the full size engine he based his models on. I did point him towards your thread the other day and he says if you ever fancy a chat his phone number is still the same.

 

[deverett]

I did think about putting in a working governor and during my earlier building phase, made one. I decided against fitting this in the Resurrection phase because of (another) possible air leak.


Dave
The Emerald Isle

 

[Tom Jamboretz]

Well Dave you have made a fine machine and can truly be proud of your accomplishment. Congratulations!

 

[deverett]

Thanks, Tom.
It was your question to me about this engine earlier in the year that made me complete it.

Dave
The Emerald Isle