Steam Spider
in collaboration with

Cheddar Plover

Tamiya junked tank


This project begin when I saw Joe's amazing leg mechanics at After talking shop and developing a friendship with Joe, he was kind enough to help me visualize this project - an 8 legged, full function R/C steam powered Robot.

It was a toss up between a twin engine design, or one powerful engine with clutch drive. I went with the single engine design, and searched high and low for the core parts.

The engine is a Cheddar Plover. Double acting duel cylinders, propane/butane mix gas tank and ceramic burner.  This engine / boiler is capable of much more power and pressure than other engines that I've work with before.

Next up was the need for a clutch drive system that could be adapted to this spider. I was lucky enough to track down a junked 1/16 Tamiya tank with clutch drive. These tanks are hard to come by, as they are no longer being produced with a single motor & clutch system.

After ripping out the clutch, I went on brainstorming and designing the spider with Joe. My part was making sure that the engine, boiler, clutch, R/C all work well together as a unit. Joe went on designing a crank driven legs system that will work well with this setup.

Sketch of the original Steam Spider design:

Original Sketch of the Steam Spider I

Tamiya Tank gearbox/clutch mounted to the steam engine. Servos installed & tested

Laser cut plastic chassis

In preparation for Robogames, The 3 layered plastic crank broke
during a test run, just a few days before the event! I ended up
hacking the core into a Steam Trilobite Tank at the last minute,
and won the Gold medal for Best of Show!

broken crank

Movie of Steam Spider I

Steam Spider II

Steam Spider II project took the opposite approach to Steam Spider I.
 Joe and I decided to Start simple, but make a flexible design to refine and build on
 top of. The idea is to use an affordable steam engine, Wilesco D14
(the same one used in the Steam Walker) and produce them as kits, or pre assembled for sale.
Construction should be pretty simple, similar to erector sets - no machining required, only basic tools.
There are many plans for upgrades and add ons on the Steam Spider II, but initially the
Steam Spider II will just be an 8 legged walking Spider, capable of walking forward or reverse,
with a built in whistle. Design and prototyping is in progress, and hopefully soon will
have a solid design that is easy to build, as well as simple and  fun to run.

Initial Steam Spider II sketches. Considering wide or narrow chassis

Steam Spider II Sketch. Original Wilesco firebox is redesigned

The "Woody" version. Wood lagging would help insulate from heat lost.
Firebox need to be sealed on top to not catch the wood on fire :)
Tubes on the topside of the firebox is designed for ventilation.

Joe's final Steam Spider drawing in 3D.  Holly gears! They are needed as these engines
 are very low powered, and requires a lot of gearing down.

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