# Maudslay Model oscillating steam engine



## cfellows (Sep 1, 2018)

Here's a video of my completed Maudslay oscillating steam engine.



Lapping the rotary valve to valve block took fixed the last of the air leaks, so now the exhaust is about the only air that is audible.

Chuck


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## kadora (Sep 2, 2018)

Nice smoothly running unusual engine .
Did you cast frame for this engine ?
Thank you


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## cfellows (Sep 2, 2018)

Thanks.  The frame was assembled from individual parts.  The feet, circle patterned brass insert,  and top bridge connector were CNC cut.  The sides of each frame are 1/4" brass tubing.  All the frame parts were soldered together and fastened to the brass base plate with screws from the bottom.


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## natalefr (Sep 2, 2018)

Good job !


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## Cogsy (Sep 2, 2018)

Beautiful engine and not a design I've seen before. Congrats.


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## spacy (Sep 2, 2018)

a very nice engine design and build


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## ShopShoe (Sep 3, 2018)

Chuck,

That's very nice. It reverses so nicely and runs at a nice speed. 

I also like the choices of materials.

Thank you for posting the build and the result.

--ShopShoe


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## Rickl (Sep 3, 2018)

Thanks for showing the engine. Very nice.


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## chucketn (Sep 3, 2018)

Very nice, Chuck. What was the inspiration for this engine? I have followed most of the build, and want to go through it again, but I can't find it. I see you posted about Maudslay engines many years ago, but this build evades me. Where did it go?
edit: found it, it was on the other forum... http://www.modelenginemaker.com/index.php/topic,8251.0.html


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## cfellows (Sep 3, 2018)

Thanks, Chuck.  I first saw a small sketch of this engine in a model steam engine book I bought at the Kewbridge museum in London probably 30 years ago.

https://www.homemodelenginemachinist.com/threads/henry-maudslay-steam-engine.1109/

For many years I looked for other examples of the engine on the internet without success.  Then, a couple of years ago I found a picture of a model which had been built many years ago.

https://www.bonhams.com/auctions/23024/lot/79/

With a 15 inch flywheel, it was about twice as big as mine and sold at auction for some $35,000.  Some years ago I had created some drawings of the engine, not knowing any of the dimensions, but, by studying the relationships of the parts to each other, was able to get a close approximation.  Then, several months ago I found a picture of a single cylinder model of the same engine.

https://www.gracesguide.co.uk/File:JD_2016_J_Spiller.jpg

With my mill/drill converted to CNC, I decided I could probably pull off the single cylinder version.  In the model pictured, the cylinder and crank are mounted outside the frame.  I changed the design of mine to be inside the frame.  Fortunately, I had cast iron flywheel that was only a little too big and much too thick in cross section, so I thinned out the rim on my lathe and thinned out the spokes on my CNC mill.  I also used CNC to cut the circle design brass insert, the feet, and the brass bridge part that supports the crankshaft.  The frame sides were assembled from some 12 - 15 parts soft soldered together.

I never knew for sure how the valve mechanism was supposed to work, but came up with my own design which is probably close.  The original drawing and models I found used an eccentric to supplement the cylinder motion, but I was able to design the stroke such that the cylinder motion alone was able to turn the valve enough without the eccentric.


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## chucketn (Sep 3, 2018)

Thanks for replying, Chuck. I was also in London many years ago, guided by my my English wife, while I was stationed in the UK with the Air Force.
Wish I'd paid more attention to the various engines on display back then.


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## Pmcguire (Dec 25, 2018)

Beautiful work!!


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## Donrecardo (Dec 26, 2018)

Nice work Chuck 

I found some more pictures of a Maudslay here  http://collection.sciencemuseum.org.uk/objects/co51031/maudslay-oscillating-engine-models


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## mirek111 (Feb 2, 2019)

Wonderful work!


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## Michel_Mike_Chaput (Feb 26, 2019)

Nice engine I like it !


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## bobs7-62steamair (Jul 4, 2019)

cfellows said:


> Here's a video of my completed Maudslay oscillating steam engine.
> 
> 
> 
> ...



Hi Chuck: Liked you oscillator engine design. Did u design or acquire set of plans? If acquired where was the source?
Thanks.
Bob E.


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## plipoma (Jul 5, 2019)

cfellows said:


> Thanks, Chuck.  I first saw a small sketch of this engine in a model steam engine book I bought at the Kewbridge museum in London probably 30 years ago.
> 
> https://www.homemodelenginemachinist.com/threads/henry-maudslay-steam-engine.1109/
> 
> ...


Would like to see a close up or a sketch of the valving.


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## gbritnell (Jul 5, 2019)

Sorry to say but Chuck is no longer with us. There is a comple Set of drawings in the file section.
The valve has both longitudinal and horizontal grooves to direct the steam and exhaust.
gbritnell


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## plipoma (Jul 5, 2019)

gbritnell said:


> Sorry to say but Chuck is no longer with us. There is a comple Set of drawings in the file section.
> The valve has both longitudinal and horizontal grooves to direct the steam and exhaust.
> gbritnell


Sorry, I didn't know! I've never accessed the file system, can you please direct me?


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## gbritnell (Jul 6, 2019)

Here's the link to the plans.
gbritnell
https://www.homemodelenginemachinist.com/threads/maudslay-brass-steam-engine-drawings.30809/


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## plipoma (Jul 6, 2019)

gbritnell said:


> Here's the link to the plans.
> gbritnell
> https://www.homemodelenginemachinist.com/threads/maudslay-brass-steam-engine-drawings.30809/


Thanks so much!


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## Harry. (Aug 19, 2019)

gbritnell said:


> Here's the link to the plans.
> gbritnell
> https://www.homemodelenginemachinist.com/threads/maudslay-brass-steam-engine-drawings.30809/



Hi, do you know which is the best type of grub screw for this please ? The plans say set screw #8-32 x 1/4", but do you know which is the best tip type please?
There seems to be several variants such as dog point, cone point etc: https://www.accu.co.uk/en/39-socket-head-set-screws

Thank you,

Harry


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## creast (Aug 20, 2019)

Really sweet engine there!


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