Walking Beam Stirling Engine Kit Assembly Instructions


Assembly Tips:

  • Warning! The engine contains sharp edges, handle with care and use appropriate personal protective equipment.

  • Keep all bearing points a little loose to minimize friction

  • Check for friction after tightening the screw connectors – they can sometimes twist when tightened and bind the parts.

  • The diaphragm should not be being stretched or compressed significantly, adjust it's connecting rod so that this doesn't happen.

  • The candle flame should be about 1 cm away from the base of the displacer cylinder.

  • Do not use intense heat sources such as propane, butane etc, as these will damage the engine.


Running the engine

Oil all of the bearing points regularly with a light machine oil.

Fill the cooling jacket with cold water

Light the tea light candle and place it underneath the displacer cylinder.

Wait around a minute for the engine to heat up.

Turn the flywheel counter clockwise to start the engine.

If everything has gone to plan, it should be running!

If not, check all of the bearing points for excess friction.

Try adjust the diaphragm, small adjustments in the tension of the rubber diaphragm can make a big difference to the operation of the engine.

Check that the displacer is being pulled up and down correctly. When the beam is at it's highest point there should be on a very small amount of slack in the wire ( 3 - 6mm). If it's being pulled tight, or there's a lot of slack in the nylon wire, make adjustments to it.

Wire parts assembly

Assemble the main connecting rod and crankshaft as shown below. The brass connectors should have small sections of heat-shrink tubing on either side.

Wire parts assembly

Tape the templates to the cardboard


1.) Cut around the templates and tape them to the corrugated cardboard.


2.) Pierce through all of the bearing points(marked +) using a drawing pin. Widen the holes using the 100mm bearing bar.


3.) Cut out the internal sections first. The slots should be matched to the thickness of the cardboard you are using.


4.) Cut out all of the pieces.


5.) Assemble the middle plate, baseplate, and side pieces as shown


6.) Check that the middle plate rests 100mm (4”) from the base plate.


7.) Glue the first diaphragm support piece into place. It should be level with the top of the cut out in the side pieces.


8.) Fit the displacer cylinder into place as shown.


9.) Glue the second diaphragm support piece in place, about 18 mm (1”) above the first one.


10.) Glue the diaphragm holder into place as shown.


11.) Pierce two holes for the bolts that hold the bearing bracket in place. Bolt one of the bearing brackets in place using a M4 x12 bolt, washer and nut.


12.) Fit the crankshaft in place. Thread it through the small holes, not the larger holes. Bolt the other bearing bracket into place.


13.) Screw one of the brass connectors onto a piece of 45mm bearing bar. Push the flywheel against the brass connector and glue the two together. Repeat for the other flywheel.


14.) Remove the flywheels and connector from the bearing bar and fix them into place as shown.


15.) Fit the diaphragm over the diaphragm holder. It should not be stretched tight.


16.) Glue the two beam support piece in place as shown.


17.) Glue the other beam piece on as shown.


18.) Widen the centre hole, so the beam will move freely.


19.) Cut two small 5mm (¼ “) pieces of spacer material. Push the beam bearing bar through the side pieces and through the walking beam, with the small spacer piece either side of the beam..


20.) Fit main connecting rod into the beam. There should be spacer material either side.


21.) Connect the other end of the main connecting rod into the crankshaft as shown.


22.) Cut the diaphragm connecting rod down to size and fix it into the brass connector on the main con rod.


23.) Fit the displacer con rod into place in the same way as the main con rod.


24.) Tie the displacer wire to the displacer con rod.

The nylon wire needs to be tied so that in moves the displacer up and down. Once you've tied the nylon wire on and got the movement reasonably close, it's easier to make small adjustments by bending the steel connecting rod so that it becomes longer or shorter.