johnsmachines

machines which I have made, am making, or intend to make, and some other stuff. If you find this site interesting, please leave a comment. I read every comment and respond to most. n.b. There is a list of my first 800 posts in my post of 17 June 2021, titled "800 Posts"

Tag: Stirling cycle

September 27, 2015

Koffiekop Engine

I have been busy for the past week or so making a Stirling cycle engine.  It is the Coffee Cup engine designed by Jan Ridders.  It is powered by the heat from a coffee cup of hot fluid.  Or an ice cube sitting on the top plate!

 

Page one of five of Jan Ridders excellent plans.

Page one of five of Jan Ridders’ excellent plans.

Most of the components of the coffee cup engine.

Most of the components of the coffee cup engine.

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100mm flywheel.

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Possible alternative flywheel, roughed out, I will see how it appears with a bit more finishing. Looks interesting?

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An experiment with engine turning on an aluminium surface, using a “Brownells Engine Turning Kit”, kindly loaned to me by Stuart.   The pattern is made with the spring loaded wire brush seen in the picture. I used this on the upper plate of the displacement cylinder.

Lots of tiny fiddly bits.

Lots of tiny fiddly bits.

The piston is made from graphite.  An interesting material to turn.  Surprisingly tough, accepting a 3mm internal thread.  And presumably self lubricating. Machining it produces black, pervasive dust.  SWMBO is not impressed, since my CNC lathe sits in our living room.   I might get marching orders for the lathe as a result of this one.

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September 19, 2015

Triple Rest

I have put the triple expansion steam engine build to one side for a while.  There are many parts made over the past year, but still a few to go, and I am taking a rest from it.

My modelling club is conducting a competition to build a Stirling cycle engine, and I have decided to make an entry.  It is the coffee cup engine by Jan Ridders.  It is an annual Stirling cycle competition.  I made an entry last year, but I couldn’t get it to work.  So I am determined to make this one work.

I am also using the Koffiekop engine project to become more familiar with the CNC machining processes.  So I am making as many components as possible using CNC.  For simple parts this often takes longer than using a manual process, but my CNCing is definitely becoming faster and easier, and crashes and tooling breakages are now rare.

The Koffiekop is progressing well, and I will post some pics and maybe a video when I get it working.

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