Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Hi,

An interesting project and I look forward to reading about its progress.  Bruce is right about trying to keep the weight down my Roadster weighs 2.24 kg very near 5 lb the three wheel version is a lot lighter at 1.74 kg about 3.8 lb.  Though their speed and ability to run continuously is about the same the lighter version certainly runs longer using the same amount of water.  Although there is independent springing on the front wheels it doesn't really allow the single driving wheel to reliably stay in contact with the ground other than on very flat floors.  If I modified one again I would look at fitting a solid front axle which was pivoted at its centre to allow the wheels to remain in contact the ground over reasonable undulations.

Take care.

Tony.

I have been enjoying having you in the thread Tony. I agree the pivot front axle will solve the lifting of the drive wheel issue. I live in the woods, so there is zero place on the property suited to run the Mamod Roadster, but I do have a Very smooth tennis court 10 minutes away. Before I try the swing axle, I may wind New Very Soft spring ( music wire guitar string) springs for the front. The Mamad stock springs look far to stout. Ideally the front springs would be perhaps more than 50% compressed with and empty boiler or maybe shoot for 95% compressed with a full boiler. This level of softness may allow me to run continuously on a premium surface like tennis court, but I will take your suggestion to heart as it would be nice to Not be confined to the tennis court only.

My "kit" shipped out this morning, I am eager to build it!