suitable sidewheel engine

[bancroft]

 I'm starting on a new scratch built project and need some insight on a power system.The project is a sidewheeler with a length of 41.5"(105cm)and a beam of 6.5"(16.5cm).The wheels will be approx. 5"(12cm) diam.I know there are many commercial engines and plans available.Can anyone get me started in the right direction such as size of engine,drive method.I can build a engine if that is the option.I would appreciate everyone's experience.Is the power requirement the same as for a single screw vessel of the same dimensions?Are there any comparison charts available?
Rich

[derekwarner_decoy]

Hi PD’s….glad to see you made the trip across Rich

As I had mentioned …..there a countless articles on steam in our Archives & Links ….best start reading …but lets consider a hypothetical ’traditional’ scale hull…..not a racing vessel

Power requirements the same as a screw vessel?…..generally yes, but applied differently….for any given say 3’LOA x 6”beam vessel….guessing 15 kg? may require say 2000 shaft RPM for scale performance

A 3’LOA x 6”beam paddler vessel….guessing 15 kg?  may require 100 to 150 RPM paddle shaft  for scale performance

The French manufacturer ANTON [Fabrice Bretagne] quotes in his WEB site that a speed reduction……up to 8:1 is required for paddle applications…he is not talking about slow speed…but dictating that higher engine speed must be maintained & thus adequate torque applied to maintain the lower paddle shaft speed

Again either ANTON or JMC offer a listing of their respective engines to a recommended vessel displacements

Engine sizing will also be governed by the vessel beam….steam is complex…but a lot of fun…..Derek

[andy]

Hi,

a propelled model will need an engine with more revs, a paddlesteamer needs more torque and less revs. 100-300 revs is enough.
With the size of your model and the dia of the wheels I think you should look for a 2 cylinder engine with a piston diametre of about 15mm or more, maximum under 20mm. But that´s only a feeling.
My big paddler (see avatar) has 19mm+36mm diametre and wheels with 150mm dia. But this ist overengined. 2*20mm was enough, this is a 2m model with about 17kg weight.

Andreas

[bancroft]

Thanks for sharing your knowledge and experience with me.the more data I gain the easier thr project comes together.
Rich .

[R.G.Y.]

Rich, I have a paddler 59inches long with a twin oscillator 3/8 bore + 1/2 inch stroke, geared down 3to1. The model travels at a realistic scale speed. You will have to keep you engine small in your size model or the boiler will to big for the model or to small for a decent running time. have a look in the gallery go to members gallerys then look in R.G.Y.my photos. Geoff

[bancroft]

R.G.Y.
The pictures in your album help, especially the interior layout.Who's design are the engines?
Rich

[R.G.Y.]

The small engine in the Glen Usk is a Cheddar, I don't know if Stuart's have started to make this again as they have the rights. The diagonal paddle engine is a Westbury design.  The twin oscillator is my own. It is going in to a model of the Duke of Devonshire. look in construction on this site. for the boiler look in steam + boiler. just below this thread.
Oscillators are not difficult to make, I got all my knowledge from Stan Bray's book SIMPLE STEAM ENGINES. Geoff