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Introduction : This project has been completed already in the years 1984 / 1985, when I was still a young man. I had the intension of building my own designed steam engine for a model ship. A regular steam engine with crosshead-guides and Stephenson reversing control device, was too complicated to build, in lack of neighther lathe nor milling machine (still do`nt have….). So I decided to design a steam-motor with a minimum on moving parts, and yet powerful enough to propell an appr. 1100 mm long RC controlled ship model. And the driving challenge was also to see if I could do it anyway…… Current status : After some years of perfect performance, the boiler became a hair crack leakage in one or two of the inner heating tubes solderings, that unfortunately could not be mended without destroying the boiler. So neighther ship nor motor had been moved since. I wanted to rotate the motor the other day by trying to rotate the crankshaft but all was blocked somewhere, probably the pistons are sticking to the cylinder walls. Shall have to dismantle everything completely for overhaul, and build a new boiler if I want to have fun on that behalf again. Fortunately the was a raghther short little super 8 Kodak film made of the model travelling on the lake at full steam in those wayback years, the film in miserable quality, but at least a document of a successfully completed project. I`ll try to put that film in a little video here on MSW in this log later on. Some of the pictures I found fortunately in my photo-archive and scaned them in, and was myself surprised that I even had pics of motor complete, and boiler in the building stage. I thought this may be of interest for the one or other fellow builder here at MSW. The ship itself is still ready to be launched at any time, only the prop has a bit patina on it The ship Model-length 1090 mm Steam powered, gas fired, RC controlled, fictional version river tug “Lorbas” in nostalgic look Model Build year : 1984 / 1985 Ship is POB scratch design, self drawn lines, ply frames and diagonal planked with balsa stripes, Hull coated with glass-fibre rowing cloth and epoxy resin Removable deck housings and many maintenance opening hatches and doors, and ventillation openings for the boiler- and machine room large self made 80 mm 4-blade brass propeller RC control Simple oldtimer 2-channel radio-controller, Make “Robbe” and on the ship two-channel receiver and two servos (one for steam reverse valve, stop, foreward, aft) one for rudder port / stb. One power pack comprising 4 x 1,5 V mignon Batteries. I`m not allowed to use this RC equipment any more due to national postal radio frequency regulations The Engine Self designed Six cylinder Steam motor in Vee-6 design, for superheated steamflow, with direct piston rods to crankshaft, ball bearing crankrod head-bearings, each cylinderhead with common, horizontal working slide cam control bars, manifolds for steam inlet and steam outlet (reversible) Steam reverse valve (for swapping inlet / outlet channels with RC servo function. Motor designed for 2 bar constant steam backpressure when running at 200 RPM in direct (quick disconnectable) coupling to propshaft Idle unbreaked motor runs up to 3000 RPM, if control cam positions are set correct Model speed like modest walking pedestrian Lubrication by means of oiler-device in live steam line (high viscosity steam engine oil) Piston rings made of Teflon in circumferential pistenring grooves Manifold gaskets made from Viton O-rings (heat resistant) Elbow- and t-fittings and flanges silver soldered, tubes soft soldered in Materials: brass and stainless steel and commercial available bearings Six Cylinders 10 mm diam. X 10 mm strokelength Due to the six cylinder arrangement the motor is capable of starting rotation at any crank position The boiler It was my aim to create a powerful lightweight design for firing with butan gas burner and gas from commercial, exchangeable cylindrical cartridges that fit into the boat (like used for refueling cigarette lighters). Function: The boiler has one central flame-tube cross-spicked through with 6 smaller instant steam tubes that mount into the area of the upper steam collector dome. The hot gas of the flametube then reverses direction in the outer end-camber, that also contains the superheater tube coil and from there 13 heating air tubes lead back through the boiler, into the opposite chamber that takes up the chimney tube (inner liner of the ships funnel) The waste steam tube is connected to the inner chimney liner in order to burn out the micro-oil-fume of the exhaust steam in the upstreaming hot air together with the firing exhaust. (avoid lakewater pollution !) The safe running time with one distilled boiler-water filling is 20 minutes The boiler is capable of providing constantly 2 bar backpressure at ships full speed The boiler is equipped with a stand, wooden plank cladding, a blow off safety valve, a pressure gauge, a main steam valve, an oiling device, a water level indicator, a draining point, and a heat exchanger for pre-heating the expanding butan gas from the gas cartridge The boiler is mounted to a common aluminium baseplate that also takes up the motor mounting bracket and the burner mounting bracket. To fire up the boiler, the flame tube is heated with a external (more powerful) gas tourch outside the ship. When reaching 2 bar steam pressure the complete baseplate is set into the ship from above Materials: Boiler complete from stainless steel, silver soldered, pressure tested with 4 bar Enjoy...... Nils