The “45” eZee Steam Engine

The “45” eZee Steam Engine

December 11, 2022 (posted)

The “45” eZee Steam Engine

This is a simple steam engine I made probably 15 years (or more) ago when I was learning to machine.  I think making a steam engine is a right of passage when learning to machine as well as being fun little projects to make. This particular steam engine was adapted from plans designed by Professor N. McMace from County College of Morris Engineering Tech Department back in 2005.  He describes this as “a simple oscillating steamer that is simple to build and does not require a lot of material. The “45” comes from the angle of the frame relative to the base.”  The plans for this as well as other easy stream engines can still be found at the e-Zee (Little) Steam Engines webpage.

I followed the plans for all the important bits but did change a few things mainly for aesthetics (such as the frame).

I polished up a few bits to give it some charm.

So spray paint was also used.


The Build

The basic plans.

Here are all of the parts for the Steam Engine.  From the top…  The Cylinder, Piston, Crankshaft, Frame, Flywheel, Spring, and Cylinder Bolt.

This is the frame of the steam engine and the main part that I changed. I started with a aluminum rod and machined one side completely flat and then a flat relief for the flywheel on the other side. I also machined a brass bushing for the crankshaft.

This is the cylinder side and here you can see the holes for the intake and exhaust.

One hole corresponds to the air intake which I machined a brass fitting for.

The other hole takes a 90° turn and exits out the bottom of the frame for the exhaust. (I flopped these holes compared to the design.)

Here is the cylinder… the large hole is for the mounting screw and the other hole leads to the bottom of the main cylinder hole for the piston.

This is the brass piston. (My machine work has since improved)

The piston then slides into the cylinder.

How the steam engine works is air comes in the top hole and into the cylinder which pushed the piston upwards which spins the crank shaft, as the crank shaft spins this causes the cylinder to oscillate until the hole in the cylinder aligns with the exhaust hole and the piston can then move back to the bottom for the next stroke.

Here we have the simple crank shaft.

I machined in a step so no washers are needed.

This is the flywheel.. basically the weight of the flywheel is what pushes the piston back down in the cylinder on the second half of the stroke.

It also has a small step in the back to eliminate the washer.

The last piece of the puzzle is the cylinder mounting bolt and spring. The spring basically pulls the cylinder block back against the frame to keep air from escaping when the timing holes are not lined up.

The first step in actual assembly is it insert the crankshaft into the frame.

Next the piston is slid into the cylinder and then connected to the crack shaft.

Then the cylinder can be aligned with the mounting bolt and fastened in place. (I used a little lock tight on the screw before tightening it.)

The flywheel is then secured to the other side of the crankshaft with a set screw.  The plans called for this to be press fit but I wanted to be able to remove it.  Drilling a hole in the flywheel may unbalance it but for what this is it should be to big of a problem.

The air line can then be connected.

I also machined up a simple pinch block that can be use to control the speed of the motor by squeezing the hose and regulating the air supply.

The other end of the hose attaches to this air hose fitting I machined up…

 I don’t have a steam boiler so compressed air is used to power the steam engine. The fitting is used to connect the air to an air compressor.  This type of regulator can also be used to control the speed over the pinch block.

The completed steam engine.

Here is some video of it in action. It has a bit of a wobble to it which it probably from the flywheel as it’s lose fit on the shaft. I’m sure my bench and the base are not level either so that doesn’t help. Overall it’s was a fun learning project all those years ago.


All Information, Pictures, and Material is copyright © 2022 by Stephen Thone and may not be used for any personal or commercial purposes without the consent of the author. All rights reserved. The Author makes no guarantees or warranties as to the accuracy or completeness of, or results to be obtained from accessing and using the Information herein.