Balancing the rhombic Stirling engine

[@MJohnRupert]

Happy to see frequent updates. There was a time we had to wait for years. Keep going!!!

[@myengines2443]

Thanks, as long as I get nice comments like this I am motivated to make more videos

[@Viper54K]

Honestly for me, I just enjoy the constant progress you make. I wouldnt mind seeing more videos like this.

[@myengines2443]

OK, thanks

[@petleh82]

I enjoy all development updates. Its very interesting and educational to se the steps taken. You make a very nice sterling engine.

[@myengines2443]

Thanks very much!

[@IronGoober]

I like all of the information in your videos. Results are nice, but sharing the journey is probably even more interesting/useful.

[@myengines2443]

Thanks, I hope to show more in the next time.

[@packacellgaming4847]

You know it's a good day when my engine's post a video

[@myengines2443]

Thanks a lot!

[@dieguerrero]

Please keep showing us these videos. They are extremely interesting!!!!

[@myengines2443]

Thanks very much!

[@MrCrazyChemist]

Nice to see another update, maybe first try heavier counterweights from lead castings to see if calculations match reality. Then try reducing weight in crank and other parts

[@myengines2443]

Yes, I will try a mix of both, heavier counterweights and reduce the mass a bit. Thanks for your comment!

[@Storhemul]

Very enjoyable video. Impressive work!

[@myengines2443]

Thanks very much!

[@Saheryk]

I don't know if I understood your question right, but I came to this channel to see your engine disassembled to the last screw and I'm not disappointed, so for me it wouldn't be boring.

[@myengines2443]

Thanks!

[@jameshendrickson3158]

Wonderful video. I really enjoyed how you explained the equations to balance the system.

[@myengines2443]

Thanks!

[@ntesla66]

The design process is extremely interesting to me. This video is awesome because you show how you got there, what is not optimal, and how you will move forward. Problems and solutions with the analytics to back it all up! What's not to love about it!!!

[@myengines2443]

Thanks for this nice feedback!

[@StanislavZachazevski]

Hello ! Just keep ot going. All new stuff on stirlings is interesting, and this one is especially. Could you comment a little on how hard rhombic is to build and assemble ? Do you need to fight backslash of gears ?

[@myengines2443]

The rhombic drive calls for precision machining and I had a bit trouble with the alignment of the cranks. If they are not perfect in phase the pistons don't run true. With backslash of the gears I hadn't any trouble as they only rotate in one direction.

[@StanislavZachazevski]

@@myengines2443 one direction - yes, but its delivers force to the flywheel and takes for one single rotation.

[@AlexB-j9n]

I'm learning so much watching your videos, keep going! BTW, sitting here tinkering on my own first stirling, I already upgraded my CNC for some metal parts. (unfortunately, 25 years of listing metal music didn't help metalworking) Seeing you starting the engine with the drill impresses me every time. I'm already happy if I can achieve 5% of your work!

[@myengines2443]

Thanks for your nice comment. Plz continue your Stirling building, I also began with just a very small lathe and milling machine. Its so much fun und progress will come soon. Plz show your tinkering and you will get much help from people all over the world. Its so motivating and the reason for me to make these videos. Greetings Ralf

[@AlexB-j9n]

@@myengines2443 A lathe will be definitely the next, but for now I will give a diaphragma design a try. As soon as I've something to show I will make a video, specially with infos about some pitfalls. Hope I find enough time next days, BTW marry christmas!

[@That_one_and_only_username]

Nice topic, nice channel, nice explanation, when a voice instead of the music! +1 sub

[@myengines2443]

Thanks alot for your comment, without criticism i can't improve The music was an experiment because i thought that all the theory would come across badly with language. If the music is annoying, I'll leave it in the future. Greetings Ralf

[@pieczona_cega5450]

idea: make go cart with Stirling engine

[@myengines2443]

Nice idea, thanks. But I think with its 300 watts of power performance will be mild.... Maybe some day.

[@matthewbeardmore]

Amazing work. Have you tried running an engine in reverse? I.e. drive it with an electric motor so it acts as a heat pump?

[@myengines2443]

Thanks, I haven't tried it but when I have time maybe I will do. It will surely produce a very cold top end.

[@camman58vlogs98]

Do you think it would be possible to make this into a Stirling cryocooler?

[@myengines2443]

Sure, it will produce a very cold top end but I haven't tried till now, maybe sometime I will.

[@reinhardtburger7108]

I would just like to say I have been a long-time fan of your work, your engines are awesome. I really enjoy the machining videos and also the more problem solving ones too. I have one or two questions. 1) You are currently using cast iron sealing elements how is the wear on the cast iron (I know cast contains a lot of graphite so it has some natural lubrication) but could a aluminium still be used if you ad some form of custom wear ring make the ring out of cast but have it couted with Tungsten disulfide (WS2)? 2)Do you make custom piston rings, or do you buy it off the shelf?

[@myengines2443]

Hi, when the clearance is right I think the wear is not high but I have to make long term runs to validate this. Till now the engine has run with cast iron running gear only for a few dozen hours. Fancy coatings are surely nice but expensive a take a long time when you have to have it done. I turn and mill the piston rings from bar stock so they meet my needs and I can experiment fast with different geometries. Its always the best to make things by yourself as you get them fast and cheap and in the way you want them. I tried hundreds of different piston rings in the last years for example. Greetings

[@janlietaer9046]

top, the more updates, the better for me.

[@myengines2443]

Thanks

[@bxnjxmxn5727]

WIrd der Kolben geschmiert oder wie wird im Zylinder verfahren?

[@myengines2443]

Der Kolben läuft trocken um die Wärmetauscher nicht zu konterminieren.

[@StanislavZachazevski]

One more question on balancing - m6r6 is the sum for both sides ? Not for each side ? So each side must balance pair of conrods + half weigth of displacer and power piston + crankpin of course .

[@myengines2443]

Hi, m6r6 is for one side, for both sides you need 2*m6r6. Greetings

[@StanislavZachazevski]

@@myengines2443 happy new yeae. In book : The Philips stirling thermal engine: Analysis of the Rhombic drive mechanism and efficiency measurements On page 35 it states different. Half mass of piston and displacer + mass of 1 conrod for piston and displacer.

[@myengines2443]

I think you have a different edition of the paper, in my text page 35 deals with a different topic. Also the notation is different, the m6r6 I use is from the book of Hargreaves so maybe there lies the misunderstanding? m6r6 with half the masses is only for one side, with both sides you need the complete mass of the moving parts to balance the engine. Greetings Ralf

[@StanislavZachazevski]

@@myengines2443 Hello. Maybe. But i do make an test in freecad - i do have some code to calculate center of mass of body. If done by my book - it is always balanced and center of mass stays. If done rhombic mass at each counterweight - its points counterweight down. Tried this code on v twin - same as per book. Btw - could you share used bearing dimensions ?

[@ackbar8297]

Balancing is easy, just use 2 opposed cylinders. This makes sense since you want more power out than you currently get.

[@myengines2443]

Yes you are right, and it had been done in the past but it makes the engine double complex and expensive!

[@thermogenerale7483]

Hello, do you sell the construction plan for $100?

[@myengines2443]

Sorry but the engine has grown over years and I don't have proper drawings of all parts! Maybe one day I will make the work and draw all parts and give them to everybody! There is a link in the comments of the 3D printed engine with some files to download!

[@BokoMoko65]

Greetings, Earthling! I come in peace. Have you considered using AI to reshape the parts? Reduce mass, maintain strength. I think it's worth a try.

[@myengines2443]

Do you know a plug-in for cad programs which can do this? Especially for freecad or fusion360.

[@Saheryk]

Bibliography: The Philips Sterling Engine C.M. Hargreaves

[@myengines2443]

Its a wonderful book I read many many hours and still do often!

[@skylersmall6322]

Couldn't you use more cylinders or smooth it out? I've never heard of a 1 cylinder engine being smooth. Inline 6 it!

[@myengines2443]

Yes you are right, the more cylinders the smoother an engine will run. But just making a 1 cylinder engine is so much work that developing a multi-cylinder engine would not be possible for a single person just working in leisure time. The benefit of the rhombic drive is despite its complexity its absence of imbalance and piston side forces, if done right. Thanks and Greetings

[@thomaskung1865]

Your concerns about the total mass are not relevant so much: A) your Engine does not power a vehicle B) Metal price per kg is very low - except for Brass/Bronce.