First Stirling Engine Complete and Running Properly with new video!

[NickG]

Hello everybody,

I just thought I'd post up latest developments with my Stirling engine. In my last post I said I was going to leave it there and learn from my experiences, however, now I am delighted to say that I have got it running properly! It was really annoying me knowing that it was so close to running so I decided to dedicated another day to it, turns out it only needed half an hour!

Anyway, it sounds obvious but what I did was submerge the whole displacer, displacer cylinder and hot cap assembly in water whilst blowing into the transfer tube. This revealed a massive leak around the hot cap screw thread!

I reassembled the engine with a lot more ptfe tape around the joints and could feel straight away that there was a small compression / suction when turning the engine over by hand.

I put water in the jacket and lit the small spirit burner, the engine was trying to go after just a few seconds with just a slight push of the flywheel. After about a minute it was running nicely, all be it quite slowly, but I think that's due to the tiny dimensions of the engine & excess friction. I just did another test and with fresh cold water and a full spirit burner. It ran for 8 minutes and the limiting factor was the spirit burner running out of meths, I knew it should have been bigger as soon as I made it! It also ran faster this time, however, in that video you could hear me shouting at my two and a half year old son to stop trying to spin the flywheel in the opposite direction!

Anyway, the main thing is that it's running and I can move on without it bugging me all the time! My wife will certainly have seen a step change in my mood this afternoon, can't wipe the grin off my face! ;D

I won't copy in the pictures of my engine again, they can be seen in my other post here:

http://www.homemodelenginemachinist.com/index.php?topic=2380.15

Here is the new video:



Finally, I would like to give thanks to forum member who helped trouble shoot, especially Marv. Also, Jan Ridders whose help has and will continue to prove invaluable.

Cheers,

Nick

 

[rake60]

SWEET!

Congrats on the engine being a runner.
I'm grinning watching it and had nothing to do with it!

Rick

 

[Bogstandard]

Very nice indeed.

Success comes to those that persevere. It took a bit of time, but you got there in the end. Well done.

John

 

[NickG]

Thanks guys, very pleased with the outcome! In the past I have lost patience quite easily with projects. I think being 10 years older helps, but also having a place like this to air your ideas and problems is the biggest help / inspiration.

Nick

 

[mklotz]

Nick,

Congratulations and well done! There's nothing like getting an engine to run but it's even more satisfying when "getting it to run" requires doing some detective work. [I should know. I've never built an engine that didn't run but I've built plenty that didn't run the first time they were powered.] That detective work is an important learning tool that ultimately will make you a much better model engineer.

Now's the time to get out your shop notebook (third most important tool in the shop) and record what you've learned. While you may think you'll remember, I can speak with authority to the fact that lessons like this slip away over time. Most hot caps are made with an integral flange and bolted to the cold cap - often with an insulating washer between them. This makes a better seal than a threaded connection and prevents heat migrating from the hot end to the cold end.

If you are using a threaded fitting for a pressurized connection, look into getting some sealing compound that will withstand heat. I use Loctite (565 IIRC - I can check if you wish) which will withstand live steam, but there are probably other choices.

 

[NickG]

That is a good idea, recording what I have learnt, sure I've forgotton some of it already but it will come back to me if I have a think exactly what I did making each component.

In future then it may be prudent to record a log of what happens whilst building the engine, along with any troubleshooting at the end!

Thanks again for the tips.

Nick

 

[robert1352]

Very nicely done!!!! :bow:

 

[Twinsquirrel]

Very smoooooth!

 

[Brass_Machine]

Niiiice!

Eric

 

[CrewCab]

Well done, runs nicely 8)


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