Shane, congratulations on a successful first run. You have put an amazing amount of effort into the design and construction. We only get to see a very short video showing the results of many, many long hours of welding, calculations, precision drilling and nutting out issues. Sincere thanks for taking us on your journey. Remember, it’s only a problem if you can’t fix it. Regards, Brian from NZ. 🇳🇿
I think that’s an absolutely amazing design and result. While I really loved the kind of chitty chitty bang bang feel of the last engine, this one feels more like an industrial unit. But it seems really efficient. And interesting that the seals can be made with relatively straightforward materials.
Hi Shane im sure you thought of this but where your seals are puffing out. I have seen similar designs that use a dish or bowl shaped back plate that supports the rubber all the way in with a round surface. With the flat surface you have a sharp wear surface. A great start I was amazed it started right up. You really are a great engineer. 😉
Hi Perry, You're spot on with the sharp wear surface, there are signs of wear already! I'll make a support dish / ring that bolts on and see how that does, many thanks
Nice engine and looks like it is going to be very efficient, practical and easy to maintain just those last few little tweaks. You can also make them from model size up to industrial size quite easily the way you have designed it.
There's a few online companies that can made custom bellows, either molded or 3d printed. Perhaps that can be a solution to keep it from bulging out. They would be accordion like.
I understand what you mean. If the idea of using diaphragms instead of pistons seems to have some legs then I'd be keen to explore these options., Many thanks
@@ShanePomeroy as you noticed, pistons as rigid objects preserve almost all compression, anything like a diaphragm loses compression because of elastic deformation to some degree. Harder diaphragm material means "crinkly" deformation losses (i.e. more friction). Pistons with appropriate machining of both piston head and compression chamber walls + o-rings and lubricant or graphite based lubricant, will always be more efficient, especially when you pressurize. And for Stirling engines especially, pressure is key for efficiency and viability for non-toy use cases like making backup electricity.
@@ppatil3655 I didn't really consider this in the design stage : ). It certainly is a problem! I'm currently fitting some support rings to reduce the bellows puffing out. I was hoping this design might solve some issues but I'll do what I can. You can get reinforced silicone that might be worth trying , Many thanks
Definitely impressed by the latest iteration. Well on its way to a functional stirling genset. You will find that rocket stove design will actually eat wood if you were feeding it full time, air is 2/3 rds nitrogen so controlling the air volume through the firebox will get you a far hotter flame with much longer lasting coals. If you watch the vid, the rapid warm up, you had the mouth pretty much plugged with un-burnt wood, effectively reducing the air to near stoichiometric ratio. If you don't already own a copy, you might find this a useful resource; Hot Air Caloric and Stirling Engines: A History v. 1, it is available online and covers everything from pre-industrial era all the way to stuff like the ARE harwell atomic heart pump, all in reasonable detail with any necessary math.
me to! regarding pressure gauge, Your quite right! My bad! I've just spun it over to check. It does bear the question if I should increase the ratio now? thanks
for the regenerator, u should put rock wool at the hot side, and put a heat break down at the midle of it .. heat loss via thermal conduction betwenn hot cold side are the biggest loss...
I look forward to buying one. Even just the engine part. I’d make a big fire in an oil drum and heat water in copper pipes and then pipe the hot water to run over the hot side of the engine. Then you aren’t limited to the space of the rocket stove. I know you want it portable but I just want an easy way to turn scrap wood branches and sawdust into electricity
The shaft that you have the flywheel on is long. If you were to add a fan of some sort to that shaft, and then duct the air produced from the fan, blow it over the cooling fins to increase the delta of cooling.
Congrats on the first run! Very nice design! Regarding possible enhancements, perhaps reducing the mass of the moving parts (pistons/rods) will make it run faster. I wonder how long a 3D printed plastic displacement piston would last.
Hi Shane . Amazing implementation from concept to running in about a month! You are definitely on the right track regarding easy ,cheap and reliable.I'm building a beta but it's only focused on the "reliable part" I have a couple of ideas for your diaphragm problem. One possible solution is a convex diaphragm plate using a taughter diaphragm and another is increasing diaphragm diameter with a reduction of stroke, although I would expect ridgidity requirements would increase with the shorter stroke.
Awesome job working straightaway. If you share this diameter of your diaphragm outer inner, I’ll look For Mobility Tires of the same size if that helps
@@ShanePomeroy exactly Mobility Scooter Tires are very similar in that respect and come in a lot of different sizes. I have lots of worn out ones if it’s any help to you
Absolutely fascinating - It seems to me you have too much dead space in the setup - certainly the regen and cooling can be optimized - I think in your design the flow is laminar - great for low resistance not so good for heat transfer - I wonder what Philips used in the Rollsock seals- I seem to remember they had a long lifespan
I was thinking very simple when designing this but maybe I've overstepped the mark! Your comment on laminar flow intrigues me because not many people seem to talk about it in stirling engines. Do you think successful engines are turbulent flow? I've probably allowed a bit to much cross section in this engine but in my defence I was a little unsure what the rpm would be. From what I've read, Philips took a lot of effort to get the rolling sock design nailed down and even then the mechanics had to be spot on for it to be reliable. I think the main problem was if the piston went off centre the sock would rub on itself. All the best
@@ShanePomeroy Thanks for your detailed reply - Yes I think a more turbulent flow would improve the heat transfer - I wonder if it's possible to insert pressed mesh "fingers" down each transfer passage - that alloy-punched mesh ( in a style often found on customized car grille/vent ) that would jostle the air from side to side on its journey - Dont think it would be too hard to add and could run the full length even into the firebox section - you could also see if pouring cold water on the cooling side when it's running improves matters - if it does then perhaps boxed in a cooling tank on say the last half so as not to chill the regenerator?
@@ShanePomeroy Been thinking about your transfer passages - If you were to corrugate the mesh insert "fingers" by passing them through a pair of loosely meshed course gears then pull them through the entire length of the passages with some temporarily attached rods or wires they would make contact with the internal surfaces of the entire transfer passages and greatly add to the thermo conductive surface area - it would also stop them rattling - what do you think?
@@trevortrevortsr2 I think it might be the next logical step to try and achieve better heat transfer. I kind of messed up and made the heat transfer gaps to big (live and learn!). Many thanks
for the konky noise: try get some teflon rod ask a friend with a laythe to make a silencer to put between the two metal part that connect the rod (like a bearing holder in teflon .. usualy its the play of bearing loge that make the kling kling...
HiShane. Thank you for the videos. Question. Do both the diaphragms (pistons) contribute power to the crankshaft? I know that the hot side develops pressure to move the diaphragm out. Does the cold side develop pressure or vacuum or is it acting like a displacer to get the air back to the hot side so the cycle can start again? You have put a thought in my head, but I need to know what the actions are on the diagrams. You’ve developed a lot of experience and knowledge with this type of Stirling engine, so hopefully you will be able to shed some light on my query. Regards. Stephen. New Zealand.
Hi Stephen, I'll be honest, I don't know! I think the hot piston is moved by most of the expansion force and the cold side by some of expansion force until the part of the cycle is reached where the internal gases are being moved from hot to the cold side and the internal pressure drops. Not sure if that answers your question but that's all I know. This seems to have always been the problem with stirling engines, know one really knows exactly what's going on inside : ) All the best, Shane, UK
for normal people machining air tight piston is tricky .. and using car part with lub is not the best idea... membrane from home depot like kinda a good way , wath material is it? pound liner?
It is just normal black rubber, nothing fancy! I think it's natural rubber. I've heard that pond lining rubber is pretty good. The fabric is 100% cotton canvas painted with silicon sealant@@sunoncream1118
Oh yeah, flir camera, get a CAT S62 pro phone secondhand. The things are bomb proof and have a built in flir camera. I inherited my lads 3 yr old one and its still going strong, dead useful having a flir in your pocket that can record video and stills, and if you need to knock a nail in something, I recon you could use em for that too and not do any damage!
Hi Shane, I have a question. Why did you close the valve after the air inside is already heated? As I know, if you first close the valve and then light it, more pressure would build in the pistons and that creates more torque. Am I wrong? Excelent design btw.
Could you explain the theory of how this works? What us the long rectangular section that goes in the middle from one end to the other? What is inside the rectangular section?
Hi, the theory is the stirling cycle. There are plenty of explanations on the Web. The difference with this engine configuration is how it achieves this. Search alpha stirling engine. The heat exchanger tubes are empty
wow man!.. Dude, you have built a giant "essex hot air engine".. And an engine without pistons... nice job...I think this engine needs to be improved.. ....and moreover, there is no bulky "displacer" inside.. You have to improve this.
if u want get rid of one of ur build i would be very happy to have one running in my sallon instead of the ventilated stove ^^ i run some solar pannel but not much on battery and the winter dont produce much , some 8hour time 500 watt would be plenty more power to feed my 12 volt line ^^
If you can make this a low temp Stirling, that only needs warm water from a solar boiler than that would be a very cool thing to do also, no need for firewood anymore!😊
it had be great to make a pulley lifting weight for know the force involved also i noticed the stove design is all but pratical the door too narrow and no evacuation grid at the bottom for let the ash fall wonder why the heart cant be sized as standard log for cheminee warming for the end i feel the word easy a bit overrated
Heh. It runs on first try. You may use some sort of one way valve to bulge diaphragms to outside. And some rubber band between cylinders to negate extra work/not optimum buffer pressure.
Impressive that you are at the level of figuring out a novel design like this, and it runs on first try!
Shane, congratulations on a successful first run. You have put an amazing amount of effort into the design and construction. We only get to see a very short video showing the results of many, many long hours of welding, calculations, precision drilling and nutting out issues.
Sincere thanks for taking us on your journey.
Remember, it’s only a problem if you can’t fix it.
Regards, Brian from NZ. 🇳🇿
I think that’s an absolutely amazing design and result. While I really loved the kind of chitty chitty bang bang feel of the last engine, this one feels more like an industrial unit. But it seems really efficient. And interesting that the seals can be made with relatively straightforward materials.
For a first run I would say that is Brilliant, and because you have built a few can diagnose the main issues to sort - keep them coming.
Hi Shane im sure you thought of this but where your seals are puffing out.
I have seen similar designs that use a dish or bowl shaped back plate that supports the rubber all the way in with a round surface. With the flat surface you have a sharp wear surface. A great start
I was amazed it started right up. You really are a great engineer. 😉
Hi Perry, You're spot on with the sharp wear surface, there are signs of wear already! I'll make a support dish / ring that bolts on and see how that does, many thanks
Very nice! Waiting cooler system and power measurements.
That’s pretty impressive. Good engineering and construction.
Very good starting point, looks great... thank you for sharing
Nice. Well done 👍 I look forward to it generating electricity. Cheers J
Can the output power be used to drive air for the fire and coolant to increase temperature differentials?
I think there is great potential for this. I'll try and solve the basic problems first and then see what can be done, cheers
Nice engine and looks like it is going to be very efficient, practical and easy to maintain just those last few little tweaks. You can also make them from model size up to industrial size quite easily the way you have designed it.
What a wonderful build. Hope it can give som torque too.
Brilliant work!! KISS principle compliant!
The waste heat could be used to make hot water.
There's a few online companies that can made custom bellows, either molded or 3d printed. Perhaps that can be a solution to keep it from bulging out. They would be accordion like.
I understand what you mean. If the idea of using diaphragms instead of pistons seems to have some legs then I'd be keen to explore these options., Many thanks
@@ShanePomeroy as you noticed, pistons as rigid objects preserve almost all compression, anything like a diaphragm loses compression because of elastic deformation to some degree. Harder diaphragm material means "crinkly" deformation losses (i.e. more friction). Pistons with appropriate machining of both piston head and compression chamber walls + o-rings and lubricant or graphite based lubricant, will always be more efficient, especially when you pressurize. And for Stirling engines especially, pressure is key for efficiency and viability for non-toy use cases like making backup electricity.
@@ppatil3655 I didn't really consider this in the design stage : ). It certainly is a problem! I'm currently fitting some support rings to reduce the bellows puffing out. I was hoping this design might solve some issues but I'll do what I can. You can get reinforced silicone that might be worth trying , Many thanks
Best one I ever seen, brilliant mate. Cheers.
Definitely impressed by the latest iteration. Well on its way to a functional stirling genset. You will find that rocket stove design will actually eat wood if you were feeding it full time, air is 2/3 rds nitrogen so controlling the air volume through the firebox will get you a far hotter flame with much longer lasting coals. If you watch the vid, the rapid warm up, you had the mouth pretty much plugged with un-burnt wood, effectively reducing the air to near stoichiometric ratio. If you don't already own a copy, you might find this a useful resource; Hot Air Caloric and Stirling Engines: A History v. 1, it is available online and covers everything from pre-industrial era all the way to stuff like the ARE harwell atomic heart pump, all in reasonable detail with any necessary math.
Can't wait to see it connected to a generator and pumping out power!
me to! regarding pressure gauge, Your quite right! My bad! I've just spun it over to check. It does bear the question if I should increase the ratio now? thanks
for the regenerator, u should put rock wool at the hot side, and put a heat break down at the midle of it .. heat loss via thermal conduction betwenn hot cold side are the biggest loss...
I look forward to buying one. Even just the engine part. I’d make a big fire in an oil drum and heat water in copper pipes and then pipe the hot water to run over the hot side of the engine. Then you aren’t limited to the space of the rocket stove. I know you want it portable but I just want an easy way to turn scrap wood branches and sawdust into electricity
A beautiful thing!. Well done sir.
Congratulations!!!! Simply amazing and even more so that it ran the first try!! You really know your stuff!!
The shaft that you have the flywheel on is long. If you were to add a fan of some sort to that shaft, and then duct the air produced from the fan, blow it over the cooling fins to increase the delta of cooling.
That's a pretty good idea! Thanks
@@ShanePomeroy of course, if I can help let me know.
The last time I was this early Stirling was a obscure Scottish clergyman.
very cool. i wonder what kinda power you could make with an alternator
At the moment, not a lot! A bit more work yet : )
Congrats on the first run! Very nice design! Regarding possible enhancements, perhaps reducing the mass of the moving parts (pistons/rods) will make it run faster. I wonder how long a 3D printed plastic displacement piston would last.
Bealtifull assemble...I like knock knock knock´s sounds...The biguest engine stirling! Congratulation from Brasil and thanks to share.
Hi, the knock, knock is actually a bearing I forgot to tighten, cheers
Hi Shane . Amazing implementation from concept to running in about a month!
You are definitely on the right track regarding easy ,cheap and reliable.I'm building a beta
but it's only focused on the "reliable part"
I have a couple of ideas for your diaphragm problem. One possible solution is a convex diaphragm
plate using a taughter diaphragm and another is increasing diaphragm diameter with a reduction
of stroke, although I would expect ridgidity requirements would increase with the shorter stroke.
Great! It lives! Now, let's tune it up
Excellent work! Well done mate - running on first try... impressive!
Awesome project! Thanks for sharing.
Wonderful! I can't believe it ran so smoothly on the first try! I really like your design.
Cheers, lots of work to do yet!
Awesome stuff, can't wait to see some power tests.
Really awesome work!
Congratulations!
Awesome job working straightaway.
If you share this diameter of your diaphragm outer inner, I’ll look For Mobility Tires of the same size if that helps
If you’re doing this as plans or a kit, I’d like to buy it . I think what you’ve achieved is awesome.
You've got me thinking about tyres! I was wondering about wheelbarrow, tyres because their pretty squishy
@@ShanePomeroy exactly Mobility Scooter Tires are very similar in that respect and come in a lot of different sizes. I have lots of worn out ones if it’s any help to you
Great machine, can't wait to see the next iteration!
I wonder if this could run a few woodworking machines via some belts. I would totally consider buying something like this for my woodshop.
Lovely job. Well done!
This is an incredible machine you’ve built. Well done!
Золотые руки! Это шедевр в стирлингостроении!
Amazing work !
Absolutely fascinating - It seems to me you have too much dead space in the setup - certainly the regen and cooling can be optimized - I think in your design the flow is laminar - great for low resistance not so good for heat transfer - I wonder what Philips used in the Rollsock seals- I seem to remember they had a long lifespan
I was thinking very simple when designing this but maybe I've overstepped the mark! Your comment on laminar flow intrigues me because not many people seem to talk about it in stirling engines. Do you think successful engines are turbulent flow? I've probably allowed a bit to much cross section in this engine but in my defence I was a little unsure what the rpm would be. From what I've read, Philips took a lot of effort to get the rolling sock design nailed down and even then the mechanics had to be spot on for it to be reliable. I think the main problem was if the piston went off centre the sock would rub on itself. All the best
@@ShanePomeroy Thanks for your detailed reply - Yes I think a more turbulent flow would improve the heat transfer - I wonder if it's possible to insert pressed mesh "fingers" down each transfer passage - that alloy-punched mesh ( in a style often found on customized car grille/vent ) that would jostle the air from side to side on its journey - Dont think it would be too hard to add and could run the full length even into the firebox section - you could also see if pouring cold water on the cooling side when it's running improves matters - if it does then perhaps boxed in a cooling tank on say the last half so as not to chill the regenerator?
@@ShanePomeroy Been thinking about your transfer passages - If you were to corrugate the mesh insert "fingers" by passing them through a pair of loosely meshed course gears then pull them through the entire length of the passages with some temporarily attached rods or wires they would make contact with the internal surfaces of the entire transfer passages and greatly add to the thermo conductive surface area - it would also stop them rattling - what do you think?
@@trevortrevortsr2 I think it might be the next logical step to try and achieve better heat transfer. I kind of messed up and made the heat transfer gaps to big (live and learn!). Many thanks
for the konky noise: try get some teflon rod ask a friend with a laythe to make a silencer to put between the two metal part that connect the rod (like a bearing holder in teflon .. usualy its the play of bearing loge that make the kling kling...
You must be pretty chuffed. Congratulations.
Hola Shane, donde has conseguido el volante de inercia, que motor a máquina lo tenía ?, gracias, un saludo.
Not sure what engine it was, it came from a friend. I'll ask next time I see him : )
Very nice job !!!!
HiShane. Thank you for the videos. Question. Do both the diaphragms (pistons) contribute power to the crankshaft? I know that the hot side develops pressure to move the diaphragm out. Does the cold side develop pressure or vacuum or is it acting like a displacer to get the air back to the hot side so the cycle can start again? You have put a thought in my head, but I need to know what the actions are on the diagrams. You’ve developed a lot of experience and knowledge with this type of Stirling engine, so hopefully you will be able to shed some light on my query. Regards. Stephen. New Zealand.
Hi Stephen, I'll be honest, I don't know! I think the hot piston is moved by most of the expansion force and the cold side by some of expansion force until the part of the cycle is reached where the internal gases are being moved from hot to the cold side and the internal pressure drops. Not sure if that answers your question but that's all I know. This seems to have always been the problem with stirling engines, know one really knows exactly what's going on inside : ) All the best, Shane, UK
you own a new sub , very nice idea to try get a design with membrane, u r trying get rid of the friction loss ^^
for normal people machining air tight piston is tricky .. and using car part with lub is not the best idea... membrane from home depot like kinda a good way , wath material is it? pound liner?
It is just normal black rubber, nothing fancy! I think it's natural rubber. I've heard that pond lining rubber is pretty good. The fabric is 100% cotton canvas painted with silicon sealant@@sunoncream1118
Wow very impressive Shane!
That’s awesome!!
Get a laser thermometer, they're cheap and accurate enough and even LIDL sells them (sometimes).
Oh yeah, flir camera, get a CAT S62 pro phone secondhand. The things are bomb proof and have a built in flir camera. I inherited my lads 3 yr old one and its still going strong, dead useful having a flir in your pocket that can record video and stills, and if you need to knock a nail in something, I recon you could use em for that too and not do any damage!
That's a good tip, cheers
Bit of a brick compared to a regular phone but a bloody cheap way of buying a flir camera that records video@@ShanePomeroy
Hi Shane, I have a question. Why did you close the valve after the air inside is already heated?
As I know, if you first close the valve and then light it, more pressure would build in the pistons and that creates more torque. Am I wrong?
Excelent design btw.
It can't be seen in the video, there is a one way valve underneath on the side that lets air in but not out, cheers
Well done! You might consider oiled leather for the diaphragm.
It is worthy of a go..., cheers
Could you explain the theory of how this works?
What us the long rectangular section that goes in the middle
from one end to the other?
What is inside the rectangular section?
Hi, the theory is the stirling cycle. There are plenty of explanations on the Web. The difference with this engine configuration is how it achieves this. Search alpha stirling engine. The heat exchanger tubes are empty
wow man!..
Dude, you have built a giant "essex hot air engine"..
And an engine without pistons...
nice job...I think this engine needs to be improved..
....and moreover, there is no bulky "displacer" inside..
You have to improve this.
She a real slapper. Enjoy!
if u want get rid of one of ur build i would be very happy to have one running in my sallon instead of the ventilated stove ^^ i run some solar pannel but not much on battery and the winter dont produce much , some 8hour time 500 watt would be plenty more power to feed my 12 volt line ^^
❤❤❤❤❤👍👍👍👍👍👍
It doesnt seem to be anywhere near as powerful as earlier versions. Where is this design process going?
If you can make this a low temp Stirling, that only needs warm water from a solar boiler than that would be a very cool thing to do also, no need for firewood anymore!😊
@@markgeurts258 You might want to consider the fact you cant get more energy out of a system than you put in...
@@manoo422There is a lot of energy available in let's say: 1000Liter of warm water (80°c)..
@@markgeurts258 It would probably make more sense to replace the solar panel with a PV panel and produce electricity directly.
it had be great to make a pulley lifting weight for know the force involved
also i noticed the stove design is all but pratical
the door too narrow and no evacuation grid at the bottom for let the ash fall
wonder why the heart cant be sized as standard log for cheminee warming
for the end i feel the word easy a bit overrated
Heh. It runs on first try.
You may use some sort of one way valve to bulge diaphragms to outside. And some rubber band between cylinders to negate extra work/not optimum buffer pressure.
Hi, I like your project.
I think this compression measuring device is dampening the power...Run without this please. thank´s!
Engine Keeper New Movie
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