# My first engine  Stirling 60



## Darren English (May 7, 2012)

After looking around the site, asking a few questions and searching the net I've decided to make J. Jonkman's Stirling 60 as my first engine.

Had a hunt around the workshop today and found some materials so I made a start.








this is the smallest lathe i have at work so this is what I'll be using for most of the turning work







This is what I'll be using for most of my milling










power cylinder after turning and with bore









My first finished components of the project, I'm getting a bit excited now! 

You'll have to excuse the large pictures, can't work out how to re-size pics in photobucket yet.


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## dgjessing (May 7, 2012)

Cool - I'll be following along. Stirlings require a very high degree of precision - don't settle for "close enough".


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## Darren English (May 7, 2012)

I'm not to worried about the precision element of the build, I'm quite used to working with tight tolerances (+- 0.01mm).
It's more that all my machinery is not that suitable for small parts. I'm looking around for a small manual lathe to help with this. 
Hopefully I can do some more later in the week when the bearings and test tubes arrive.


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## lazylathe (May 7, 2012)

Bought my ticket for the ride!!! Thm:

I love following along with any and all Stirling builds!

Andrew


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## Darren English (May 8, 2012)

Bearings and test tubes on order, should be here by the weekend.

You may have noticed that I'm making three of every component, I've decided that as i have to spend a lot of time setting up the machine I may as well make three. 
The first component takes hours, the next two a couple of minutes!


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## Ken I (May 8, 2012)

Darren English  said:
			
		

> I may as well make three.


If I had that equipment I'd make 5.

As my old auto-shop foreman used to say - "the might not be to the drawing, but they'll all be the bloody same !"

Just signing in for the journey - best of luck.

Ken


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## rhitee93 (May 8, 2012)

I'm tagging along on this one Darren. I don't know anything about Stirling engines, but I'd like to build one someday. This will be a fun one to watch and learn from. Thanks!


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## Darren English (May 9, 2012)

Ken,
I was going to make more but as this is my first engine I'm a bit worried about having loads of parts that don't fit!

Test tubes arrived today, all fifteen of them. I'm expecting to break a few. I have worked out how I'll cut them with my equipment and should be doing that this weekend.


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## rhitee93 (May 9, 2012)

If you have trouble cutting the test tubes, here is a method that works well:

1. score a ring at the cut line using a diamond wheel or other abrasive wheel.
2. touch the scored ring with something hot to cause the crack to propagate.
3. flame polish the cut end with a torch.

I've never made a sterling engine, but I have cut a lot of borosilicate glass tubing.


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## Darren English (May 9, 2012)

Managed to get the cranks turned and milled. 
I think they look quite good.

I have made a few changes. The diameter of the crank pin will be 2mm now as i had some 2mm 316 laying around I could use. The drawing calls for 1.6mm brass pins but I'm sure these will work fine.







Milling using a 1.6mm cutter, I also used this to interpolate the 2mm hole for the crank pin
If anyone is interested below is the coding I used for the hole

M06 T9;
S2500 M03;
G0 X0. Y-9. Z100. G43 HO9;
Z5. M08;
G01 Z1. F300;
G01 Z-3.1 F30;
G13 G90 Z-3.1 I1.199 F20 DO9;
G0 Z5.;



And here they are finished.


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## Darren English (May 9, 2012)

Brian, I was going to do something similar. Holding in a three jaw chuck in the lathe, make a score with the sharpest tool possible (probably a threading insert) then touch with a small hot flame. Watched a guy on youtube with this method and it worked very well.


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## rhitee93 (May 9, 2012)

Darren English  said:
			
		

> Brian, I was going to do something similar. Holding in a three jaw chuck in the lathe, make a score with the sharpest tool possible (probably a threading insert) then touch with a small hot flame. Watched a guy on youtube with this method and it worked very well.



Not a bad idea. Your are right in that you would want a sharp point. (No radius) 

If you have a hand held glass cutter, you could hold that in the tool post.


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## Darren English (May 12, 2012)

Bearings have arrived so I can take some accurate measurements and alter the drawings.

Well this morning I thought I had better have a go at cutting the test tubes. I have ordered 15 and only need 3 so plenty of spares.
The first one, done in a couple of minutes. Well this is easy, I don't know what all the fuss is about.
Glass now all over the floor! Six broken test tubes later and I have one more decent tube finished and one which will do for setting up and testing.
I still have a few left over, I'll save them for another project.








I used a carbide threading insert to score a line then put a flame on with a micro blow torch, it worked, kind of!


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## Ken I (May 12, 2012)

A method I saw some time back - score the tube like you have done. Stand it upright and fill with water to just below the score - apply heat.
I saw heat applied by wrapping a couple of turns of inconel heater wire around the tube supplied with power from a variac / step down to get the wire red hot. This to cut a 1 gallon glass jug in two - go figure.

Ken


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## Darren English (May 22, 2012)

Not much progress.
Because i can only use the machines at work I'm a bit limited on time.
Anyway i have booked in a job this week that needs a M3 thread on a silver steel bar, so i can get on and make all the conrods which are the same design.


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## Darren English (Jun 10, 2012)

I've done something!!

After a few frustrating weeks not being able to any of my project I found some time






This is the crank assembly


The drawings say to make the main shaft from brass but I thought silver steel would be better.

The flywheels have only been turned so far. I chemical blacked them to see what they looked like but they need some milling detail, that will follow later.









Another change to the original drawings is the con rods. The drawing shows them as one solid part but I'm going to make them from 316 stainless rods (as shown) with brass connectors on the ends.


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## Ken I (Jun 10, 2012)

Nice to see progress - a bit here and a bit there and before you know it you're done.

Ken


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## Darren English (Jun 10, 2012)

I'm starting to build up a nice collection of parts now.

The next problem, my wife is 39 weeks pregnant so not sure when i'll get back to it. ???

Is there a record for the longest project?


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## Tin Falcon (Jun 10, 2012)

> The next problem, my wife is 39 weeks pregnant so not sure when i'll get back to it.
> 
> Is there a record for the longest project?



No worries. Take care of the family and be prepared to be distracted for the next 20 years or so lol. 

As for the build it will wait till you get back to it. This is a hobby it is for fun . No time limits no deadlines. 
Tin


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## b.lindsey (Jun 10, 2012)

Darren, congratulations on the soon to be addition to the family. As fun as this hobby is...nothing compares to the miracle of little ones....yours for now and someday as for many of us...grandkids. As Tin said, no deadlines here so take your time and enjoy the family. When you get back to the build...we'll be here to encourage and celebrate with you.

Bill


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## Darren English (Jun 14, 2012)

Thanks for the encouragement.

I have now made the support beams. I won't bother to post pictures of them as they are only basic.
Just 4mm dia silver steel cut with a hacksaw and sanded to length.


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## Darren English (Sep 8, 2012)

I'm back!  My son is now a couple of months old so I've managed to get some spare time and get back to the build.

Decided to mill the detail onto the flywheels. Sticking with the theme of this build I've changed the drawings to what I think will look best.







They still need a final deburr and not sure what surface finish to give them, maybe black chrome?


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## Darren English (Sep 11, 2012)

Has anyone else on here built one of these before? 

It would be interesting to see how someone else has gone about making it.


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## Ogaryd (Sep 11, 2012)

Hi Darren,
      I built a stirling 60 about 6 months ago. It's a little tricky to get it running on a tee light  candle. I had trouble getting the displacer shaft & bushing operating smoothly. I changed the power piston to graphite. From my experience reducing friction is the trick. I'd be happy to answer any questions.
                                                         Regards Gary


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## xander janssen (Sep 12, 2012)

Hi Darran and Ogaryd,

I got my stirling 60 running last weekend. Although machining was finished several weeks ago, I just would not run more than a few turns. 

Finding the problem took me a lot of playing around. The first problem was the friction of the displacer rod (polished silversteel) in the reamed brass bushing. I did not use cast iron as mentioned in the plans as I did not have cast iron at the time. When I enlarged the hole in the brass, the friction was reduced a lot without loosing the air-tightness, but now the rod was able to tilt in the bushing and the displacer started to touch the side of the testtube. Now the engine ran a few turns more than before but still not continously.

Finally I replaced the brass bushing by one made from teflon. The hole, through which the displacer rod runs, was drilled with a smaller diameter and 0.5 mm out of center to avoid the displacer touching the side of the testtube. Even with the reduced diameter of the hole, the displacer rod runs virtually without friction and the out of center gives another 0.5 mm clearance to compensate for the small amount of tilting of the displacer rod. Now the eninge runs pretty fast and continously using only a small flame as is should.

cheers,

Xander


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## Darren English (Sep 12, 2012)

Thanks for the tips. 

I was thinking of using Nitronic 60 for the bush and 316 stainless for the displacer rod, the reason for this is I have lot's of it laying around. A few of my customers use these in combination as bearing materials but not sure about the friction levels.

Gary, graphite for the power piston is a good idea.


Xander, I hadn't considered using any type of plastics. Certainly worth considering.

One thing that I am doing is increasing the length of the displacer bearing by a couple of mm. I'm also thinking of making the displacer with Ali instead of brass to reduce the weight. Both of these are to try and stop the displacer from tilting and putting pressure on single points in the bush.

Did you both use a brass pin as a pivot for tumbler plate? I'm a bit worried that it will wear out quickly so was thinking of using bearings.


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## Darren English (Sep 15, 2012)

I started on the platform pillars today.  I didn't have much time so they are not finished. I need to turn them around, face-off and drill and tap M6.


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## Darren English (Sep 22, 2012)

Have now ordered some small (2x6x3mm) bearings to fit in the central pillar which will support the beam rather than just using a brass pin that the plans call for. 
I'm also planing to use the sides of the bearings to add support to the beam.


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## Darren English (Sep 22, 2012)

I was hoping to finish the support pillars off today but my 16C collet holder cracked almost in half.... doh


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## Darren English (Sep 29, 2012)

A bit of progress.

Bearings arrived, they are on the small side!








Decided to do the main cylinder. For the tuning I used our Mazak SQT lathe, it has conversational programming which is great to use and very quick.


After creating the program you can check the shape and tool paths before cutting anything







After turning and before parting off






Milling the support pillar holes






Aligning the part before milling the top detail in






And finished






I then test fitted the power cylinder and test tube


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## 110samec (Sep 29, 2012)

The flywheels look a bit like car wheels  Are you using CNC? your progress so far looks great


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## Darren English (Sep 29, 2012)

Thanks. Yes all my machines are CNC.


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## robcas631 (Sep 30, 2012)

May I ask where you bought the bearing from?


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## Darren English (Sep 30, 2012)

Hi Rob I bought them from here


http://www.technobotsonline.com

I've been trying out a few different suppliers and these are the cheapest


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## Darren English (Nov 17, 2012)

Managed to get a free hour or two so got back to the engine.

I've finished the platform pillars, they just needed facing off to length and a 3.3mm hole drilled. I tapped them M4 by hand.
I would normally do the tapping on the machine but I've had a nightmare job this week with deep hole M3 taps snapping and couldn't face the prospect of breaking any more!


In the chuck before maching.






And after






I also made the flywheel support pillars. The process is the same as for the platform pillars just a little bigger and made from brass. 
I changed a few dimensions to give a bit more rigidity.





I got in some 2mm diameter silver steel for the tumbler arm bearing pins, couldn't quite believe how cheap it was .59p (about one dollar) for a 12in length.
These I just cut to length with a hacksaw and belt sanded the ends.


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## Darren English (Sep 27, 2013)

Hi guys.
A little more progress.

I made the bases. In the original plans they are made from wood, I'm taking a different direction.
I'll wait until the engine is assembled to show you, this is mainly because it might look rubbish and I'll have to change it!

I've also made the displacers. I've made these from black Acetal. Nothing complex just a radius one end and threaded the other. I'm using Acetal because I had some off cuts laying around and it is lightweight.

Can't upload pictures at the moment as computer is down, bit of a pain doing it through my phone.


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## jwcnc1911 (Sep 27, 2013)

Great looking build!  I'm a hot air fan myself.  I'm looking forward to seeing this build come together.

However, with a max temp of 180°F I don't think acetal will take the internal temp.  Supposedly a tealight candle has a max flame temp of 1400°F and a usable heat of about 590°F to 650°F in your application.

Just something to think about.


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## Darren English (Sep 27, 2013)

I had considered the heat. The temperature of 180F relates to keeping the materials mechanical properties, it's melting point is a bit higher.
I also figure air should be circulating around the engine keeping temperatures down, I'll give it a go and see what happens.

It's a good point though.


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