# Moriya stirling engine fan build



## Technical Ted (Jan 20, 2022)

Test running my latest project, a Moriya stirling engine fan for my woodstove. Besides being able to use my machine shop tools I was even able to get my Prusa MK3S+ 3D printer into the act making the fan blade ( PTEG blue, my grandson’s current favorite color; he's 5 ). RPM varies with temperature, but at around 500 degrees it’s currently running at ~400 RPM. Should speed up when it gets broken in. Just a nice, gentle breeze to help move the heat around a little in my basement hobby shop.

The design is by Dr. James R. Senft and the drawings are available for free on the internet. I was happy with the fact that I had all the raw materials on hand except for the #4-40 socket head cap screws. Material costs have skyrocketed lately, especially brass and aluminum! And I like being able to make stuff with materials I’ve got on hand...

Mostly done now. I'm still thinking about the fan guard... I at least need something to pick the fan up quickly when it's hot incase something comes loose while running. 




Cutting the cooling fins in the cold end.




I trepanned the lightening recess on my lathe. Trepanning is always a little nerve racking especially when using a long, narrow tool.... make sure the tool isn't touching where it's not suppose to touch! I used Dykem to check for any undesirable contact. 





Brass sleeve bearing in the power connecting rod.




I made the displacer piston body out of a solid piece of stainless steel. Cylinder and end all one piece. Made the Hot end out of a solid piece of steel square stock. Flange, cylinder and end all one piece. No need for silver soldering...




The crank. Close fit, pinned and Loctite.




The displacer tube. Around 0.020" wall if I remember correctly. Not sure what grade stainless it is. Not free machining that's for sure!  Stainless has better thermal characteristics than making it out of aluminum, although a little heavier. It has such a thin wall weight doesn't seem to be an issue. 




Made a split brass bearing for the displacer connecting rod. (2) #4-40 screws hold the cap on. 




All the parts (except for the gaskets and base). The gland/displacer shaft and the power cylinder/power piston where both lapped in for a nice, tight, friction free fit. 




Ted


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## Cadillac (Jan 20, 2022)

Very nice job! Been on my to do list for awhile. Got two of the pelitier style ones at a flea market for cheeeap so the build went on the back burner. Great job


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## KevinM (Jan 20, 2022)

Technical Ted said:


> Test running my latest project, a Moriya stirling engine fan for my woodstove. Besides being able to use my machine shop tools I was even able to get my Prusa MK3S+ 3D printer into the act making the fan blade ( PTEG blue, my grandson’s current favorite color; he's 5 ). RPM varies with temperature, but at around 500 degrees it’s currently running at ~400 RPM. Should speed up when it gets broken in. Just a nice, gentle breeze to help move the heat around a little in my basement hobby shop.
> 
> The design is by Dr. James R. Senft and the drawings are available for free on the internet. I was happy with the fact that I had all the raw materials on hand except for the #4-40 socket head cap screws. Material costs have skyrocketed lately, especially brass and aluminum! And I like being able to make stuff with materials I’ve got on hand...
> 
> ...


I am looking for an engine project and this one looks very interesting.
Are plans available for this engine?


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## Technical Ted (Jan 20, 2022)

KevinM said:


> I am looking for an engine project and this one looks very interesting.
> Are plans available for this engine?





			http://courses.washington.edu/me355b/Fan_Project_Description.pdf
		


Ted


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## KevinM (Jan 20, 2022)

Technical Ted said:


> http://courses.washington.edu/me355b/Fan_Project_Description.pdf
> 
> 
> 
> Ted


Thanks, Nice design and perfect size for me.


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## Technical Ted (Jan 21, 2022)

If interested, you can see and hear it running here:






Ted


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## KevinM (Jan 21, 2022)

Technical Ted said:


> If interested, you can see and hear it running here:
> 
> 
> 
> ...


can you please explain your source of heat?


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## Technical Ted (Jan 21, 2022)

KevinM said:


> can you please explain your source of heat?



Just a plain, simple wood stove.

Ted


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## KevinM (Jan 21, 2022)

Technical Ted said:


> Just a plain, simple wood stove.
> 
> Ted


Duh, I wondered what the stovepipe was for, I didn't think that there might be a stove connected to it.


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## ErichKeane (Jan 21, 2022)

Thats really cool!  I think I should make that a future project!


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## KevinM (Mar 23, 2022)

Technical Ted, thanks for the plans.  Here is my version of the Moriya, it's almost silent.  I haven't decided on what to do for the stand.  








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IMG_3645.MOV



__ KevinM
__ Mar 23, 2022
__
engine
model
stirling




						Stirling fan


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## Lo-Fi (Mar 23, 2022)

Lovely! Thanks for posting


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## John281 (Mar 24, 2022)

I've been building one as well though I changed some of the features just because.  Almost done.  I just have the legs and piston yet to do.  I agree, trepanning the displacer cap was exciting.  That was a pretty deep, narrow cavity to cut.
Out of curiosity, what material did you use for the gaskets?  I plan to use some material that looks like exhaust gasket material.


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## Technical Ted (Mar 24, 2022)

KevinM said:


> Technical Ted, thanks for the plans.  Here is my version of the Moriya, it's almost silent.  I haven't decided on what to do for the stand.
> 
> 
> 
> ...


Awesome! What direction of rotation does your blade turn? When facing the front of the fan, does it turn clockwise or counter clockwise? From your video, it appears you are starting it by spinning it clockwise. If so, did you change the timing to do so. The power piston is 90 degree off from the displacer. Mine, built per the drawing, rotates counter clockwise....

Nice job!
Ted


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## Technical Ted (Mar 24, 2022)

John281 said:


> I've been building one as well though I changed some of the features just because.  Almost done.  I just have the legs and piston yet to do.  I agree, trepanning the displacer cap was exciting.  That was a pretty deep, narrow cavity to cut.
> Out of curiosity, what material did you use for the gaskets?  I plan to use some material that looks like exhaust gasket material.


I'm not sure what Kevin used, but I ordered gasket material from McMaster Carr and made the 3/16" thick gasket out of (3) 1/16" pieces. Works fine!

Edit: Sorry! Correction, I actually used some material I had on hand. I had it on my McMaster wish list, but found some I already had on hand.

Ted


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## Technical Ted (Mar 24, 2022)

John281 said:


> I agree, trepanning the displacer cap was exciting.  That was a pretty deep, narrow cavity to cut.



I posted my build on another list and was asked for some details about the trepanning. I'm not sure if this list allows cross posting or not, so I'll repost here for those that might be interested in how I did mine:

=====================================================
Here are pictures of my tool and I put it back in the holder so you can see the setup. First, it's best to start off with a quality tool bit. You need to have everything as short and ridged as possible. Make sure there is clearance (the tool gets narrower towards the shank). This can be double checked when in the lathe using a test indicator as shown in one of the pictures. The tool needs adequate clearance on the sides as well. Doesn't take much on the inside of the recess, but takes quite a bit on the outside. The cutting edge goes right on center and it NEEDS to be the only thing on the cutting tool that touches the work piece. I marked the tool up multiple times with Dykem to check for rubbing... which would have lead to big problems. When I saw a section rub, I took the tool to the grinder to grind a little more off. I used lots of cutting oil and stopped to clear out chips frequently. I took my time and all turned out very well.




















=====================================================


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## wachuko (Mar 24, 2022)

Very cool build !!


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## JRaut (Mar 24, 2022)

Hey, I built one of those too a couple years ago!

I never bothered building a guard for mine either; maybe I should with little tykes running around.


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## wachuko (Mar 24, 2022)

KevinM said:


> can you please explain your source of heat?


I had the same question, hahahahahahaha... could not figure out where the heat source was coming from, hahahahaha too funny.  Even more so since the first post it is clearly documented that the source is using a stove... man, I need to sharpen my reading skills, lol


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## KevinM (Mar 24, 2022)

Technical Ted said:


> Awesome! What direction of rotation does your blade turn? When facing the front of the fan, does it turn clockwise or counter clockwise? From your video, it appears you are starting it by spinning it clockwise. If so, did you change the timing to do so. The power piston is 90 degree off from the displacer. Mine, built per the drawing, rotates counter clockwise....
> 
> Nice job!
> Ted


Clockwise. I bent the fan mount the wrong direction so I had to rotate the power piston crank to -90 degrees off the displacer to get it to blow forward.  After drilling a hole in my had I wasn't thrilled to make another mount.  I hate sheet metal.

The airflow over the cold end helps a lot, I used just a flywheel for the first testing and the cold end got pretty hot, therefore efficiency was not great.


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## KevinM (Mar 24, 2022)

wachuko said:


> I had the same question, hahahahahahaha... could not figure out where the heat source was coming from, hahahahaha too funny.  Even more so since the first post it is clearly documented that the source is using a stove... man, I need to sharpen my reading skills, lol


I missed that in the original message.  Who would have thought that the stovepipe in the picture would be connected to a stove.


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## ErichKeane (Mar 24, 2022)

KevinM said:


> I missed that in the original message.  Who would have thought that the stovepipe in the picture would be connected to a stove.


  I actually figured it out right away because as soon as I saw this I was like, "This would be fun to put on my shop woodburning stove! I should mention that!  Oh, looks like he knows  "


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## Technical Ted (Mar 24, 2022)

Good job! I thought it was running in the opposite direction from mine. More than one way to skin a cat!

Yes, the fan drawing air through the fins does help, even on top of a hot wood stove. Nice design and I can feel the hot air blowing from mine!

Definitely a fun build!

Ted


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## Technical Ted (Mar 24, 2022)

ErichKeane said:


> I actually figured it out right away because as soon as I saw this I was like, "This would be fun to put on my shop woodburning stove! I should mention that!  Oh, looks like he knows  "



Maybe I should have mentioned the "stove" part in the thread title! 

Ted


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