The Wig-Wag Concept
The Wig-Wag Engine has been designed to be an easy introduction to model engine making for the beginner, and the vertical wig-wag is the starting model from which the Wig-Wag family is based upon.
Using a simple oscillating cylinder with a 15mm piston bore and a 30mm stroke, the engine runs very well at moderate and slower speeds, on both compressed air and steam, and is a pleasing engine to run and watch.
All the engines from the Wig-Wag family are built from aluminium, brass, steel and phosphor bronze bar stock which is readily available from metal stockists and model engineering suppliers, and does not use specialist castings or difficult to get hold of parts.
The majority of the engine parts are modular in their design, and are common to all the engines in the Wig-Wag family.
Start by building the Original Vertical Wig-Wag, and then choose to build one or more of the family.
Any hobby engineer with a modest workshop will find this an enjoyable build, and the construction covers most of the bases of model engineering such as turning, milling, threading, reaming and boring.
Drawings and Build Notes
Some of the downloadable drawings are complete as a set, others only detail the chassis specifications. There is a common components drawing (Drawing C) which should be used in conjunction with the basic chassis drawing. The generic 'build notes' word doc also accompanies the drawings.
The Original Vertical Wig-Wag Engine
This is the first engine that was made for the Wig-Wag family, and is a single cylinder vertical oscillating engine, which is easy to build and a great first engine for anyone wanting to start model engineering.
All the engines from the Wig-Wag family are built from readily available bar stock, and do not use special castings. The majority of the engine components are modular in design, and the dimensions are identical, allowing different designs of engine to be made which all have a common identity.
If you are new to building a Wig-Wag engine, then it is the ideal engine to start with and you can see an 8 part step-by-step video series on how to build this engine by following the youtube link below.
How to build a Wig-Wag Engine - Part 1 of 8
Original Wig-Wag Drawings & Build Notes
by David Gardener
The Horizontal Wig-Wag Engine Mk1
This engine uses a single cylinder design identical to the original Wig-Wag, but using a horizontal chassis layout. This was the original Mk1 chassis and has been updated to use the standard wigwag engine components detailed on Drawing C
Wig-Wag Horizontal Chassis
The Horizontal Wig-Wag Engine Mk2
This engine is Mk2 of the horizontal design, which follows a design which is more similar to the original wig-wag chassis. This uses the common components detailed in Drawing C.
The STRETCHED Horizontal Wig-Wag
This engine design was based on a concept by Chris Shanks.
It follows the format of the Mk1 horizontal Wig-Wag but has had the chassis stretched to create a longer engine. The cylinder has also been stretched to suit the design, and the crank disc increased to create a 42mm stroke length, to give a nice slow running engine.
The V-Twin Wig-Wag Engine
This interesting engine has a two cylinder arrangement set at 90 degrees to each other in a classic V shape, and uses a a pair of split crank connectors to connect to the crank journal, a brass crossover tube connects the two cylinders to distibute the air or steam input, and the engine creates a lovely twin cylinder sound when running.
The Twin Wig-Wag Engine
The Twin Wig-Wag engine is simply two vertical WigWags back to back, a slightly wider flywheel is used to 'fill' the extra space between the chassis which is needed to allow access to the spring tensioner. A shorter spring is also used to keep this compact. A straight brass crossover tube is used to connect the single air supply between the engines and the cranks are set at 180 degrees to each other
The Duplex Wig-Wag Engine
The Duplex Wig-Wag has a single chassis plate but with a cylinder on either side, the axle bridges across a dual crank to a support chassis for the flywheel. A copper tube connects both cylinder input ports and a single supply tube connects these to the air or steam supply.
The Triple Wig-Wag Engine
This engine is a lot of fun to make and a joy to run, having three in-line cylinders each on a standard vertical chassis, the 3-part axle shaft is interconnected using dual cranks between the individual engines, creating one continuous motion. The cranks are set at 120 degrees apart, allowing the engine to always be self starting.
The Inver-Wag Inverted Wig-Wag
This engine turns the WigWag on it's head, by simply inverting the chassis to place the flywheel at the top. It is a very simple chassis design which is easily made, and creates a lovely inverted WigWag engine
The Micro & Nano Wig-Wag Engines
The scale of the Wig-Wag engines have been reduced to half-size and one-quarter size to make the Micro and the Nano engines, both of which are fully functional and great fun to run. If anyone fancies a real challenge, then it would be great to see a one-eighth scale version one day!
The Drop Hammer
The Drop Hammer is the first 'accessory' I have built for the Wig-Wag engine series, and is designed in a similar style and an easy-to-build format. It can be driven by any of the Wig-Wag engines with the use of an 18mm drive pulley added to the Wig-Wag.
by David Gardener
The Wig-Wag Lathe
This miniature lathe is built in proportion to be driven by the original vertical Wig-Wag engine.
There are no drawings available as this was scratch built 'on the fly' from materials I had in my scrap box, but is a beautiful accompaniment to the wigwag series.
Click below to watch the video
More accessories will be added as they are built
These are concept sketches of Wig-Wag designs which have been created by David Gardener.
The beauty of the modular design of the Wig-Wag series is that any of the single engines can be duplicated to make a series, such as the 3,4,6,8 cylinder and so on
2 and 6 Cylinder
Wig-Wag V4 and V8
Wig-Wag Radial Engines
3 and 5 Cylinder
Ade Swash – 2021 Contact me at email@example.com
Many Thanks to David Gardener for the CAD drawings
Last updated 08/06/23