The Stirling Engine Project

We explore the design of a 3D printed, water-cooled, rhombic drive Stirling Engine, and the addictive and complex process of its optimization.
Episode #2:
www.youtube.com/watch?v=viEu5...
Episode #3:
• The Stirling Engine Pr...
Facebook: / leos.bag.of.tricks

[@dfunited1]

"Without a way to quantify engine power, you're just jerking off in circles". That's one way to put it. Subscribed

[@integza]

This is just an amazing design! Thank you so much for sharing the project with us! Are you sharing the 3D model files? I would love to print one for me.

[@KimSeiji]

huuuummmm NICE. If you build this, you should paint it TOMATO-RED.

[@leosbagoftricks3732]

E-mail me

[@daylenhigman8680]

@@KimSeiji tomato crusher

[@JoshuaJoshua0]

frozen tomatoes powering a stirling engine tomato chopper

[@patrickfle9172]

The red sealing compound reminded me of you :D

[@newoldbrain]

How this channel hasn't got a hundred thousand subscribers is beyond me. Thanks Leo for your videos, and even more for your passion.

[@rogerdueck9725]

Love this video, it perfectly explains my thoughts on the sterling engine. I live in Canada where it gets to -35° Celsius for a couple of weeks a year and inside we have a fireplace roaring. I've always thought a sterling engine attached through the wall from the fireplace to the outside would produce quite alot of energy. Keep going with the project, can't wait for an update!

[@reynaldomartinez7978]

Your sterling engine design is unique from other sterling motors. Your on to something of immense value to all mankind. The is ready for simplicity. I wish you well in your endeavor. Live long and prosper 🖖.

[@StirlingLighthouse]

The stirling bug bites hard. Lol I just love the whole idea in these amazing engines. Your take on it is very nice! Cheers

[@jamesmaclean2]

Wonderful ! I have been building Power Stirling engines for 40 years, & never thought of a Plastic Body! Genius!! I also use thin Drawn Stainless Steel "Cups" most flour & sugar "Dredges". My Hot End gets Red Hot and I attach it to the threaded Stainless cylinder ring with brazing. I used to use JB Weld where you are using the Silicone. Great work & Thanks for show it to us!!

[@gammaleader96]

I like how you use whatever seems to do the job without staying at conventional materials and techniques. Looking forward to what this engine evolves into.

[@joecobra48]

Underrated. Thanks for outlining the psychological pitfalls.

[@gmeast]

I've been a Sterling fan since I was 12yo. I'm 69 now and still a fan. A Regenerator actually is very important for the overall thermal efficiency of the engine. Why I never thought of a Displacer/Regenerator combo' is beyond me. It helps to address the 'dead volume' issues associated with a dedicated, external regenerator and associated plumbing. Great Work!

[@quatrebillesblanches6442]

Je réfléchis à un bicylindre pendulaire avec deux grosses bouteilles d'oxygène et un des déplaceurs remplis de tores de cuivres . Je voudrais entrainer un volant d'inertie.

[@benderrodriquez]

After seeing this, I feel my life won't be complete if I do not build my own version.

[@StirlingLighthouse]

Do it! It's a lot of fun. 👍

[@danieljones317]

If I got that bug, I'd probably have to make one that would power a generator, and not a small one, either!

[@BobWidlefish]

Your life is not complete and will never be complete until and unless you finish yours.

[@kozmicre982]

Ray Id like to do the same but Id wind up using the coke can and paperclip model lol! It works Would be something Id like to experiment with using it to power a bicycle if it can be applied. I never tried but recently have curiosity rising so I'm researching it here soon.

[@williammartinez3392]

I relate!

[@JimNichols]

Thanks for the ride along and the video! Making these is difficult and sharing your experiences is a very caring act. Thanks again Leo!.

[@thecrikster]

That must be so satisfying when you hand crank that engine and it starts up :D

[@leosbagoftricks3732]

I was high for 2 days!

[@celalergun]

What an entertaining and educational video! Thank you for sharing your experiences with us. I really appreciate it.

[@michaelgardner1681]

Hey Leo, this is the first Stirling engine video I've clicked on. Thanks for the addiction warning. I haven't watched your other two yet so maybe you have already employed the MPD-L1060 in your dyno design. I found brushless motors to be an excellent load when used as elecrical generators. If you mount them to be rotatable about the shaft axis and measure the torque with a strain gauge you can get a very dynamic data set that is easy to read with microprocessors. The speed is easy to pick from the output voltage waveform.

[@PALM311]

I completely understand your addiction and I completely understand your need to build these engines. Around 15 years ago I saw my first Stirling engine and it immediately transformed me into something I didn't recognize.....and I have never looked back. The addiction has become so strong I bought a Bridgeport a lathe and a plethora of other machine shop tools. My background as a machinist also came into play. I live for these engines.. well that and metal detecting. But these engines are certainly at the forefront of a lot of my free time. I live in the snow belt so I have a lot of time to work on these engines when I can't swing a detector. I have to say that your engine is absolutely beautiful! you did a fantastic job on it. That is an engine that any builder would be proud of! You'll get the bugs worked out of it, that I'm sure of. These engines look so simple and so easy and yet they're extremely complex as you were saying. I made the mistake of thinking it was a cakewalk making one of these engines and I failed miserably again and again because of that. I didn't give these engines the credit and the respect that they deserved on the onset of building these and I paid for it with failed end product.

[@eddiesines3398]

Loved this presentation.. I built one way back in the 1970's and yet the rabbit hole was very deep... Great engineering!

[@donk.5730]

I am more impressed with your ''stick-to-it'' attitude more than the actual engine. Thank you for the factual , no nonsense , very helpful project. Keep on , Sir. !!!

[@Random_How-tos]

This is the most awesome thing I’ve seen in a long time.

[@kr6dr]

I designed a simple dynamometer that has a mountain bike brake rotor mounted to the shaft and an arm supported by a bearing on the shaft which has the brake caliper mounted to it. The arm is linked to a small hydraulic cylinder. The length of the arm and the diameter of the hydraulic piston are such that a pressure gauge will give a direct read-out of foot pounds of torque in pounds per square inch. I am hoping to build a Stirling engine that is light enough to power an aircraft. Thank you for sharing your work. It is inspirational!

[@diretodotuneldotempo8495]

Congratulations, you make a fantastic job!! I have seen a lot of Stirling engine videos at internet but yours shows a trully revolution at the area!! Making the cold side of engine with plastic material will keep the cost of equipment achieveble by the majority of people!!

[@anandawijesinghe6298]

Leo, as a dynamometer use a permanent magnet model aero electric motor as a generator. Couple it directly or via a belt drive to one output shafts of the engine. Measure its output with a small digital wattmeter. First Calibrate the efficiency of the generator itself using an identical motor to drive it. Measure the speed using a tachometer. Use an identical second motor to drive the first motor used as the generator. The input and output power to motor can be measured with digital wattmeters. The generator can be loaded with 3 identical resistors in a star connection. Instead of digital wattmeters, ammeter and voltmeters can be used to measure input and output power. For example, the output load resistor current can be measured with an ammeter. The power output is 3x I×I x R where I is the current through each resistor. Obviously, the efficiency of the generator is equal to the output power divided by the input power. When using a second motor and a resistor load, the efficiency of each motor/generator is equal to SQRT (3 IxIXR/W) where W is the input power read by the digital wattmeter. This efficiency should be about 95-99%. Then the engine power output can be measured as equal to the ojtput wattmeter reading divided by the generator efficiency at that speed. Speed dependence of generator efficiency could be a problem, so you will have to measure it at various speeds. The motor-generator setup would facilitate that.

[@propylaeen]

What an elegant design. Could help looking deeper into 3D-printed ceramics or some aerogel parts to deal with thermal issues. Very good editing style! Thank you for sharing.

[@johngillon6969]

I have been wondering just how many stirling engines there must be out there. I am starting on my third engine. I built one that i remember seeing when i was 10 in a popular science magazine 1960 . I found the article on the internet, and after 62 or so years of yearning to build one i did. These are wonderful toys for 74 year old dudes to play with, in my opinion.

[@zinahe]

As always, your projects are worth the waiting, well-thought-out and very informative. Thank you for sharing.

[@leosbagoftricks3732]

Thank you very much!

[@blk77sunshn]

This was very fascinating! I wholeheartedly enjoyed your video ! Your Stirling engine has to be one of the most unique I've seen to date. Thanks for sharing.

[@jimkelly4372]

Hello, Leo, Excellent videos! I will be watching more of them. Keep up the great presentations!

[@mbunds]

That's a beautiful build! Thanks!

[@hopsgarage5513]

Very cool, and it sounds great. I remember reading about a Army project for a sterling engine generator, something like 30kw with a swash plate crank. They used helium for the working gas but it kept leaking out. Keep up the great work

[@maxdelaserna9540]

Amazing and beautiful Sterling engine. Great job.

[@EvilMrMahler69]

Thanks be to youtube algorithm for bringing this one up. Amazing design, you are lightyears ahead

[@colinellicott9737]

Love this subject. Designed a Sterling engine 40 years ago - wow - that was tough to type. Have had a warm place in my heart for them ever since. The Reverend was a phenom. Check out the Philips Stirling engine. Cool stuff.

[@awizardman]

man you made me stay the entire video, great job!

[@manavestnation]

I used to work for a canning company and the packs were wrapped in shrink film, the heat tunnels that the packs passed through to shrink it would feel hot from the outside. As it happens they had cold water drains running underneath them. My idea to them was create a sterling motor that extracted the heat from the outside of the tunnels with the other end in the cold water. From my understanding the hotter one side is in relation to the other produces more drive. We had 3 massive units that would run 24/7. They wouldn't spend the time even considering it even though we had engineers doing nothing half the time. I am sure it was possible and would have produced a lot of energy over time. It would not have been anything like your design though. You speak of optimization but those units were at a constant 160 degrees C. If anyone can figure out a good design i would think companies would take it up as how many companies shrink wrap their packs and saving energy is becoming a big issue in industry.

[@shannonbailey5475]

I have a toy sterling engine, but want to build a thermoacoustic resonator with reasonable power. One thing you might consider is a hybrid thermoacoustic / sterling engine which uses a speaker for the piston and another speaker driver inside the chamber to move the displacer, while making the displacer far less dense and much lighter with air holes (think swiss cheese displacer which doesn't get so close to the heated surface), which has much shorter travel and requires less energy to move back and forth due to much less linear motion. This design would be all electronic powered by a microcontroller and audio amplifier and some fast accelerometers or linear position sensors. Efficiency of heat engines is limited by thermal difference, and the holy grail is high efficiency with low thermal difference. Also measuring the power produced in this case is easy, speaker output is the sine wave output into a resistive load with voltage and current monitoring through the microcontroller. But I love this video, thanks for making it, but as you can see, I've caught the mental sterling bug. There are some very interesting commercial thermoacoustic devices and research lab prototypes out there to gawk at.

[@Julian_Kulenkampff]

Thanks! Awesome engineering always :D I cant wait to see more contend like this.

[@derekbrn]

Fantastic - super interesting project and well-done video as usual. Keep it up, proud to be a Leo Fan Boy!

[@derrickboatman1560]

I have been fascinated with Stirling engines for many years. never tried to build one I think I may have to now. Great video, you got a new subscriber

[@tleitch6360]

Subscribed and Liked. Really like the way the information is presented. More logical and better explained than lots of other channels. I hope you will continue this project and go into the actual power output across temperature ranges. One thing that did occur to me was the use of a passive water cooler using the heat difference to induce flow. That would, for me, be an intersting addition to the project.

[@NeilStainton]

Well done on your brilliant design. I built a small eddy current dynamometer about 20 years ago for characterising small electric motors. However the interesting thing about a sterling engine is its efficiency, not is power output which is low. So measuring the output power of your engine in its current configuration is pointless, because you cannot measure the power in, and therefore you cannot optimise it. You probably need to change it so the power in is through a electric heating coil, then you can measure Watts in and compare that with Watts out.

[@avramitra]

As always, great content. Waiting for the improved version of your Stirling Engine.

[@tdumnxy]

Really enjoyed this video. Good luck!

[@Asyss_Complex]

This is so satisfying to watch. Thanks for sharing!

[@fuelban]

Excellent video, totally captavating stuff.... Thanks ..... Thom in Scotland.

[@sethg6157]

It's criminal that you only have 3k subs! This is amazing!

[@MCSTNDTCAFAG]

Thanks! Well explained and well put together.

[@sp277]

Great video, Leo. Congratulations. I love Stirling engines since the 80s. Without the Internet, the most I could get was to find a great technical book about them in the university. There was little material information to get about Stirling engines. I remember that when the Internet was initially fledgling, to "test" how was it: the very first query that I submitted was precisely "Stirling engine". I still remember the feeling of getting all that information! Wow! Internet was great if it could easily get all that info about a theme that was so "difficult" to know in those days.

[@gusmartin6053]

These engines are fascinating to me as well! I tend to like the variations that are capable of running on low temperature differentials. They run beautifully smooth and suffer much less from melting and oxidizing components (provided you don’t try to over clock them). The big challenge with them is reducing friction as much as possible. That’s very difficult with so many moving parts. Great video! I suffer from the same obsessive behavior, but it’s so much fun so I wouldn’t have it any other way.

[@calvinh9453]

You sir just gave me a new project that thing is amazing!!!

[@anaglog77]

Really cool stuff mate I look forward to seeing more! :)

[@AttilaBlade]

Good to see your engine in working condition. The regenerative displacer is one of the biggest challenge I think. Low friction, good volume of steel wool, but the stainless steel better for this, and the low as possible leakage. I mean the displacer leakage how big portion of gas not goes trough the regenerator section. For a long time usage the cold side plastic part should be shielding from the hot side with a trap for the flame also some high temp insulator blanket between the surfaces. Are the gears in good condition? I will follow your work, because it is so detailed and precise. I like to use 3D printed parts, but actually mine doesn't work well. So keep up the good work! Congratulation! BLADE

[@leosbagoftricks3732]

Thank you for your detailed observations- I am going to work on that displacer/regenerator part, along with building the dynamometer to evaluate the results. So far the mechanical drive train seems to be holding up to the job.

[@jimgraham6722]

Yes, in my experience steel wool displacers catch fire at higher power settings. Stainless mesh tends to worker better but is harder to work into shape.

[@HoffmanTactical]

I've been thinking about 3D printing one as well, you have done an incredible job!

[@DaveWeagle]

You are right about that trap! I feel like many an engineer has spent their career searching for the answer to stirling engines and CVT's. My mind has been on this for 20 years! I like the next step of measuring. Please show that dyno build!

[@dod180]

Gorgeous work

[@pjmr666]

Amazing stuff! Cool desogn and you are able to explain and break it down in a very good way!

[@novanut1964]

the displacer shape reminded me of a Sloan toilet/urinal flush valve inner parts, great video

[@TheWindGinProject]

Thanks for sharing. All points made were spot on and I agree 100% regarding the warning of how a Stirling Engine build / design is going to be very addictive for those with mechanical interest. Yes it does seem fairly straight forward at first glance. :-)

[@MrFreddiew1]

Love it..Great job, technically excellent. Thanks for sharing.

[@ArcanusLibero]

A great project. Thanks for sharing.

[@canhobiatolyesi3650]

Congratulations my friend, great job.

[@whegerich]

You, sir, are incredible! I salute you.

[@andylee4296]

Very very good job !!

[@smferreiro2610]

Great job! I'll try it myself!

[@christianseiser5547]

Print the upper parts in ASA, this is able to work in hot ambient (Print-Temperature ca. 240-260°c) and you can close the cappilars by flushing it once with e.g. isopropanol, an alcohole. I printed a little Arielle for my daughters aqarium of it. I placed the figure some minutes hanging in a closed glas with a shape of alcohol on its bottom. The cold steam is enough to do the job. While drying, the surface gets fluid and melts together - so the capillars disapper. If you let it too long in the glas, the chemical melting gets deeper in the figure, so it gets weak and may loos its form. so, be careful. ... and of cause .. dont breath in too much of it 🤪

[@delusionsnyc]

Brilliant, Leo!!!

[@chloeeqzi]

Leo: Man you are getting really good at this. Nice production value and easy to follow commentary. I like the window into the mind of Leo and how you make decisions. Have to call you for questionable use of the word Sexy as it pertains to any part of this project. I am grateful people like you find this stuff addictive so I can do my part for the world and watch South Park. Please save me a space on the exit pods near you. I’m afraid I will be eaten by the locals for having mostly useless skills when push comes to shove. More projects please.

[@akshayanoop533]

Great work👍👍👍

[@MrBhudon22]

Thanks Leo for shared. Really interesting stuff. Not to get some tin cans setup....

[@drmed92]

Awesome work 👌!

[@edcammarata6430]

Great, i learned a lot as far as the addition thing u are so right,please make more videos

[@vmiguel1988]

Great content! Keep going!

[@StofStuiver]

Nice vid m8. Immediately voted up when you warned about stirling engines addictive properties. ;]]

[@ManualdoMotorStirling]

Very nice to follow the construction of your engine and I am happy that you visited my channel. Really, what is simple about a Stirling engine, it is not at all simple to get good results, the amount of challenges that the engine presents, is addictive. Let's see your dynamometer, I always wanted to make one, it will be a pleasure to see your walk.

[@leosbagoftricks3732]

Thanks! I am in the middle of the dyno project now- as usual, I am going too far...

[@user-yg5rn8li2y]

@@leosbagoftricks3732 pla plastic will go

[@synapticaxon9303]

You're sucking me back into my old stirling engine obsession. :) But if you could maybe create a github repo with your fusion360 and/or stl files, you could get some contributions from nerds like me. Help us, help you, help everybody. Thanks man!

[@ravener96]

Do you happen to know how you get high pressure working fluids working? I always wondered how you get the power piston working since the gas behind it has to be a similarly high pressure

[@onestoptechnologies7305]

@@ravener96 I'm not totally sure I understand your question, but I'll take a stab... It has to do with the large surface area of the top and bottom of the displacer coupled with the localized change in pressure due to temperature.

[@gotbread2]

I can relate to this. From time to time I also have the urge to build one. Sadly I don't have the manufacturing capabilities so I got a small teacup version and like to watch it

[@StirlingLighthouse]

I had the same issue. Limited tools and equipment. But that didn't stop me from trying. I just used what I had and the satisfaction is priceless.

[@peterhertz4789]

Fantastic! Hat off!

[@leosbagoftricks3732]

Glad you enjoyed it

[@leofortin912]

Hi, Leo this is another Leo. I have build a stirling engine and fussed with a displacer. Idea I came up with was to use course steel wool as there are more air gaps than fine which allows for better heat transfer between between hot and cold strokes. I also used small pieces of 1/4" mesh screen and very thin large washers to capture the course steel wool and form the displacer piston.

[@leosbagoftricks3732]

I would love to see a photo of this assembly!

[@daylenhigman8680]

A thermodynamically pleasing design

[@TheNaboen]

this is brilliant!

[@yogimarkmac]

Several years ago I got sucked into Tim Sefton's Kickstarter Stirling engine project. Got nothing for my several hundred dollars. It's the technology that's always just out of arm's reach. I developed a heliostat prototype hoping to eventually be able to run a Stirling engine off of solar power, but never got a practical engine to try it with. Keep the flame alive brother.

[@carlbrenninkmeijer8925]

so good, thank you!

[@alleneakins1]

Great work. Love the design. If you get moderately favorable dyno results, you should try hooking it up to an electrical generator. I would love to see how it fairs/how much electrical power it could produce.

[@divobravo3133]

So cool. Well done.

[@DavidD6969]

Great information thanks

[@BogdanTheGeek]

For the dyno I would suggest using an electromagnetic break system(a tube within a tube with iron powder between them and an electromagnet in the center tube would do the trick) with a load cell to to get the torque, but I cant wait to see what you come up with.

[@onestoptechnologies7305]

Could he use an off the shelf DC micro motor connected to a variable resistor with an ammeter?

[@kennethalmond8922]

Very nice video. I've been into DIY solar/powerwalls the last 3 years, and the addiction of finding / processing used 18650 cells into large batteries is a similar addiction. I'd LOVE to acquire (build I guess) a stirling engine in the 5-10hp range as a wood fired generator - but as you know, there's nothing available on this that I can find or buy in any reasonable price range. Again, really enjoyed this inspiring video - good luck on your work.

[@itanc1]

love this! i did enjoy it. muchly

[@IntenseGrid]

Very nice!

[@shanemiller6947]

Hello buddy wanted to tell you you have the very best engine build on the KZbin trust me iv watched them all thanks for you tinkering on this project I'm going to try my best to run with you on this project design iv never seen anything as nice as this setup very well achieved keep going with this I'm wanting to see someone use this engine to do something cool a fan or some kinda of electric generator needs a good use for this engine thanks your new friend Shane

[@emekae330]

This is so cool!!!

[@marcosvaleriociencia1021]

Olá amigo!! Very nice !! Você é meticuloso e este rombic está incrivel! Você mostrou todas as partes do stirling, belo trabalho!!! Grande abraço, Rio de Janeiro, Brasil!!!!!!Eu adoro os stirlings!!!😃😃😃

[@tomwilliams2753]

I too am afflicted but with an Alpha....really enjoyed this presentation....subscribed....looking forward to the dyno project. I would like to be able to measure the mechanical output once my engine is optimized.....I agree that Stirling Engines are addictive and mentally stimulating.....thanks for sharing your work.

[@leosbagoftricks3732]

Glad you liked it! more to come!

[@mike87364]

dood this is amazing

[@HyperspacePirate]

The thermal isolation with this thing is super impressive

[@jell_pl]

thanx for great video :) and i can also confirm that this topic can be almost toxically addictive :D

[@gromit7573]

Stirling engines are highly addictave and often called a 'gateway project' to even more hardcare projects such as quadcopters and even small scale hydroelectricity.

[@RustyInventions-wz6ir]

Just found your channel and Subscribed. Nice work

[@minercraftal]

That’s crazy! To make a pla 3d printed engine really run on heat transferring!!! Excellent job and idea!! I never thought this way before!😂 And now, it’s time to make an EXTRA big size engine now!😂

[@marcangelodonelo5656]

Wow this is great

[@ronniebrummett4995]

Love it bud.