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[Nordsee]

Years ago I built a model of a Windermere steam launch which was a free plan in Model Boats Mag , I believe. It was fitted with a Unit Steam Engine which was adapted for this boat as a side wheeler. ( Cost about 60 pounds complete if I remember correctly!!) Anyway, made a nice boat, lots of fun, but the usual problem, no self start or reverse. Now, if you fitted a servo which would give the Flywheel a "kick" in the right direction, could this be used to restart a stopped engine? Would only need a simple friction pad acting on the outside rim of the Flywheel, has anyone done it? Are Unit Engines still available? I recall the Boiler hinged up to give better access to the Fire box where the solid fuel pellets went.

[kno3]

Hello, yes it's been done, most often with a small electric motor with a rubber wheel, being pressed by a servo to the engine flywheel just to start it.
Unit engines are still available, look here:
http://www.tonygreensteammodels.co.uk/acatalog/copy_of_Unit_Steam_Engines.html

[steamboatmodel]

With full size engine they used a smaller steam engine called a Barring Engine to move the main engine off dead spots.
Regards,
Gerald.

[kiwimodeller]

I have also seen it done with a small electric motor with an O ring drive to a groove in the flywheel. This had the advantage that if the steam engine stopped and would not restart the electric motor would still get the boat home. It did have a separate battery pack. I thought it would have needed a speed controller but the builder had just fitted a switch which was actuated when the throttle was put to full ahead and then the transmitter trim was used to give the servo a little extra travel to turn on the switch. Quite ingenious I thought.

[Gyula]

[kno3]

A picture is worth a thousand words! This drawing also shows how to set the device up to turn the flywheel for both forward and reverse (provided the steam engine has a slip eccentric or reversing gear).

[Nordsee]

Lots of ideas there! Would a simple engine like the Unit model also run in both directions?

[mogogear]

Lots of ideas there! Would a simple engine like the Unit model also run in both directions?

Nope - just one.....

[Circlip]

Would a simple engine like the Unit model also run in both directions?

 No, it can only rotate in one direction at a time  

 BUT, it depends which of the port holes you elect to feed steam into, so with a changeover valve and a barring engine (Motor) it could be run in either direction.

  Regards  Ian.

 Problem with trying to make a silk purse out of an oscillator is that of stalling it. OK theres the barring option, but a more refined way is to let the motor run in one direction and use a variable pitch prop for forward/stop/reverse.

[Underpressure]

 Problem with trying to make a silk purse out of an oscillator is that of stalling it. OK theres the barring option, but a more refined way is to let the motor run in one direction and use a variable pitch prop for forward/stop/reverse.

Or install a Kitchen rudder.


http://www.oldmarineengine.com/discus/messages/1/95580.html

[Circlip]

Yes, that one too U/P, but in the model originally mentioned, even using the latest micro servos, size may be a restriction?

  Regards  Ian.

[kiwimodeller]

I have recently purchased two Unit engines to have a bit of a play with simple steam engines. They do have the ability to run in either direction and can be controlled by a simple rotary reverse/throttle valve as used in small steam trains. I purchased one from Dream Steam but there are plans available if you want to build your own. This does not of course solve the problem of stopping at top or bottom dead centre and not being able to start. Even the two engines coupled together as a twin will not always start as they are single acting engines so they can stop with one at the top and one on the up stroke. This is where we came in and it seems an electric start would be the most reliable but it is getting away from the simple idea!

[Circlip]

Other option is a crash reverse gearbox but a bit violent if the O/P is thinking of a paddler.

  Regards  Ian

[Nordsee]

Yes, that one too U/P, but in the model originally mentioned, even using the latest micro servos, size may be a restriction?

  Regards  Ian.

It was about 1982, and the boat was , I believe, called "Nina" She was 3 feet long and 4 inches beam, plus paddle boxes. I installed 2 channel RC, with just a normal standard servo for steering. She looked and went very well, I fitted a false keel with some ballast as she tended to heel too much in turns.She was planned around the Unit engine, there was also a sister model with screw propulsion, also for Unit engines. I have the plan somewhere....

[Circlip]

It's the space required around the rudder post Nordsee for the Kitchen rudder system. One servo operates the rudder "Cups" to open and close them, but then, that whole assembly is mounted on a pivot and a second servo used to control the direction of point of the cup assembly.

 "Nina" was one of the giveaway plans, other one "Mabel"??

   Regards  Ian.