Author Topic: Lehmann Stirling Engine  (Read 1089 times)

Online yogi

  • Full Member
  • ****
  • Posts: 369
  • Duncannon, PA USA
    • Yogi's Workshop
Lehmann Stirling Engine
« on: December 20, 2018, 10:20:20 PM »
In this series I will be documenting the build of a Lehmann Stirling engine from plans by Ernst Vogt.

The project was started 20 years ago. But as so many things in life, priorities change, and so this project ended up being mothballed shortly after I started building it. It was safely stored away all this time in my brotherís workshop.
During a recent visit to my brother and family, I decided to resurrect this engine and take it home with me to continue and finish the engine.

Iíll start this build log with an overview of the parts that I have so far.

The main cylinder housing is made from 100mm square tubing, and is mostly completed. Whatís missing is the cylinder tube. I had one made, but for some reason it ended up being not round and needs to be remade.







The hot end:







For the flywheel, I got some help from my other brother (I have two). At the time, he was working on a large multi task machine, and he machined the flywheel for me. It is not completely finished yet, as it needs to be bored out and the outside diameter finished up.





The big pieces together gives an idea of the size of the engine.



The two part cast iron piston:







Bearing blocks:





Some brass parts. The oil cups are not finished and I might remake them anyway. Not decided yet.



The coolant reservoir:







Iíll be spending some time to work myself back into the project. Iíll also be inspecting the parts and start to plan how to proceed with the build.

I hope youíll be along for the journey and stay tuned for more.

Yogi


Offline tvoght

  • Full Member
  • ****
  • Posts: 916
  • Indiana
Re: Lehmann Stirling Engine
« Reply #1 on: December 20, 2018, 10:33:03 PM »
A very interesting project. I will be watching.
--Tim

Offline Ye-Ole Steam Dude

  • Full Member
  • ****
  • Posts: 1084
  • Deep East Texas on Sam Rayburn Lake
Re: Lehmann Stirling Engine
« Reply #2 on: December 20, 2018, 10:41:01 PM »
Hello yogi,

That is a great looking engine and will be following your build.

Have a great day,
Thomas

Offline 10KPete

  • Full Member
  • ****
  • Posts: 1526
  • Nordland, WA, USA
Re: Lehmann Stirling Engine
« Reply #3 on: December 20, 2018, 11:27:07 PM »
 :popcorn: :popcorn:

Pete
Craftsman, Tinkerer, Curious Person.
Retired, finally!
SB 10K lathe, Benchmaster mill. And stuff.

Offline Dave Otto

  • Full Member
  • *****
  • Posts: 3469
  • Boise, Idaho USA
    • Photo Bucket
Re: Lehmann Stirling Engine
« Reply #4 on: December 20, 2018, 11:37:37 PM »
Cool project Yogi, I'm looking forward to following along.

Dave

Offline crueby

  • Full Member
  • *****
  • Posts: 7701
  • Rochester NY
Re: Lehmann Stirling Engine
« Reply #5 on: December 21, 2018, 12:18:18 AM »
Thats quite an impressive engine, looking forward to seeing you finish it up.


 :popcorn:

Offline b.lindsey

  • Global Moderator
  • Full Member
  • *****
  • Posts: 12839
  • Dallas, NC, USA
    • Workbench-Miniatures
Re: Lehmann Stirling Engine
« Reply #6 on: December 21, 2018, 12:52:31 AM »
Looks like you got more than a good start on it, however long ago it was. Nice looking project!!

Bill

Offline Dave Otto

  • Full Member
  • *****
  • Posts: 3469
  • Boise, Idaho USA
    • Photo Bucket
Re: Lehmann Stirling Engine
« Reply #7 on: December 21, 2018, 01:20:27 AM »
I remember from one of the GEARS shows a a few years back one of the guys displayed a similar engine, maybe it's the same engine that you are building?

Dave
« Last Edit: December 21, 2018, 01:32:42 AM by Dave Otto »

Offline PJPickard

  • Full Member
  • ****
  • Posts: 126
Re: Lehmann Stirling Engine
« Reply #8 on: December 21, 2018, 02:28:01 AM »
I will be following for sure...where can one get the plans?? I've been interested in this engine for  a while.

Paul

Offline Ian S C

  • Full Member
  • ****
  • Posts: 1015
  • Stirling Engine Maker Darfield Canterbury N Z
Re: Lehmann Stirling Engine
« Reply #9 on: December 21, 2018, 02:31:35 AM »
Looks interesting Yogi, I'll be watching this one.
ian S C

Online yogi

  • Full Member
  • ****
  • Posts: 369
  • Duncannon, PA USA
    • Yogi's Workshop
Re: Lehmann Stirling Engine
« Reply #10 on: December 21, 2018, 02:13:55 PM »
Thank you guys for the kind comments, and following along.  :cheers:

Dave, that engine seems very similar as it's a Lehmann type stirling, and about the same size. I see enough difference though, that I can tell it's not the exact same version.

Paul, it looks like the plans are still available: http://dampfmodellbauer.de/webshop/product_info.php?products_id=39

Yogi

Offline Roger B

  • Global Moderator
  • Full Member
  • *****
  • Posts: 3704
  • Switzerland
Re: Lehmann Stirling Engine
« Reply #11 on: December 21, 2018, 05:36:03 PM »
That's quite a size  :) I will be following along  :ThumbsUp:  :ThumbsUp:  :wine1:
Best regards

Roger

Offline fumopuc

  • Full Member
  • ****
  • Posts: 2262
  • Munich, Germany, EU
Re: Lehmann Stirling Engine
« Reply #12 on: December 21, 2018, 08:22:58 PM »
Hi Yogi, what is the future job of this engine ? To open and close your garage door ?
Kind Regards
Achim

Offline PJPickard

  • Full Member
  • ****
  • Posts: 126
Re: Lehmann Stirling Engine
« Reply #13 on: December 21, 2018, 09:44:06 PM »
Yogi,

Thanks, it's funny I spent a LOT of time looking for plans for Lehmann and never found that link. Now to see if I can figure out how to order from there.

Thanks for the help!
Paul

Offline tvoght

  • Full Member
  • ****
  • Posts: 916
  • Indiana
Re: Lehmann Stirling Engine
« Reply #14 on: December 21, 2018, 10:51:19 PM »
I don't think anyone has posted a link to this video yet:

<a href="http://www.youtube.com/watch?v=mgIkP0eCKlo" target="_blank">http://www.youtube.com/watch?v=mgIkP0eCKlo</a>

--Tim

Online yogi

  • Full Member
  • ****
  • Posts: 369
  • Duncannon, PA USA
    • Yogi's Workshop
Re: Lehmann Stirling Engine
« Reply #15 on: December 21, 2018, 11:17:12 PM »
Thanks guys!  :cheers:

Achim, that or maybe power the shop...  :Lol:

Tim, thank for posting the video. That an exquisite model. Here another video of a beautifully completed engine:



Yogi

Offline toolznthings

  • Full Member
  • ****
  • Posts: 426
  • Kent,Ohio
Re: Lehmann Stirling Engine
« Reply #16 on: December 22, 2018, 01:41:25 AM »
Busy  :cartwheel:  :ThumbsUp: :ThumbsUp:

Nice project !
Thanks for the visit !
Brian

Offline PJPickard

  • Full Member
  • ****
  • Posts: 126
Re: Lehmann Stirling Engine
« Reply #17 on: December 22, 2018, 02:27:25 AM »
If you search youtube for "Lehmann Stirling engine" you will find a bunch of nice models. The Lehmann is one of my favorite hot air engines. I look forward to seeing this model develop!

Online steamer

  • Global Moderator
  • Full Member
  • *****
  • Posts: 9890
  • Central Massachusetts, USA
Re: Lehmann Stirling Engine
« Reply #18 on: December 22, 2018, 02:30:01 AM »
Nice looking project Yogi,   Propane fired?

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline ShopShoe

  • Full Member
  • ****
  • Posts: 312
  • Central Iowa, Central USA
Re: Lehmann Stirling Engine
« Reply #19 on: December 22, 2018, 01:34:08 PM »
That is a very interesting Engine.

It is pleasing to watch and I am impressed with how quietly it runs.

Thank You for posting.

ShopShoe

Offline bent

  • Full Member
  • ****
  • Posts: 314
  • Wet side of Washington State, USA
Re: Lehmann Stirling Engine
« Reply #20 on: January 02, 2019, 08:58:57 PM »
Very cool looking engine, and a nice size.  Wondering what the purpose of the flyball governor is and what it adjusts (if anything) to regulate speed?

Online yogi

  • Full Member
  • ****
  • Posts: 369
  • Duncannon, PA USA
    • Yogi's Workshop
Re: Lehmann Stirling Engine
« Reply #21 on: January 03, 2019, 03:09:17 PM »
Thank you guys for the kind comments! It's very much appreciated.  :cheers:

Dave, yes, the plan is to have it propane fired.

Bent, the governor will open a valve into the displacer cylinder and relieve air pressure from the engine, regulating the speed.


Yogi
 

Offline Craig DeShong

  • Full Member
  • ****
  • Posts: 378
  • Raleigh,NC. USA
    • Lauson small engines
Re: Lehmann Stirling Engine
« Reply #22 on: January 07, 2019, 09:57:28 PM »
I've sidelined a few projects over the years myself, then returned to them and thought, "Why did I ever put this aside, it's pretty far along and it's going to be really nice to finish it".

I'm thinking this is one of those projects too.  I'll be following along.  :popcorn: :popcorn:
Craig

Online yogi

  • Full Member
  • ****
  • Posts: 369
  • Duncannon, PA USA
    • Yogi's Workshop
Re: Lehmann Stirling Engine
« Reply #23 on: January 09, 2019, 12:31:30 AM »
Craig, thanks for checking in and yes, it's definitely good to be working on this project again...

To continue, I'll be making the cylinder. I made it out of 1144, and has a 50mm ID, 62mm OD, and is 194mm long when finished.
The challenge on this part, is for the tool not to chatter in the long bore. To rough out the bore, I used a carbide insert boring bar and roughed it out from either side. To finish, I used a HSS boring bar, to be able to take light cuts, and was able to accomplish it without chatter.

Taking a finishing cut, using a 1" boring bar with a HSS bit. The stick out on the bar is 8 inches.




The surface finish from turning alone was really nice already, as shown in the picture below. To make it even better, I used a small break cylinder hone. This took only a few passes to finish.




The cylinder is installed in the cylinder housing with Loctite 609.




The honed cylinder, even though the surface finish isn't showing up well in the picture (in reality it's better than it looks).





Thanks everyone for following along, and stay tuned for more.
Yogi


Offline b.lindsey

  • Global Moderator
  • Full Member
  • *****
  • Posts: 12839
  • Dallas, NC, USA
    • Workbench-Miniatures
Re: Lehmann Stirling Engine
« Reply #24 on: January 09, 2019, 01:46:32 AM »
Very nice finish on the cylinder. Still watching along even if quietly Yogi.

Bill