The Steamboating Forum

Just completed my CNC Grizzly mill conversion to 3 axis CNC. Took me a while to get it right! Currently holds to within a thousandth inch in XYZ. Video shows the mill CNC machining the rotor and the Turbine in a rough "proof of concept" rig running on compressed air and live steam. Turbine connects directly to a 24 volt motor used as a generator which is then linked to a matched DC motor. Avoids the gearing problem usually associated with turbines, but I really need a source of cheap, small 12-24 volt high speed, ball bearing supported, surplus DC model motors. Any leads?

Lots more design work to do as this configuration is a single phase impulse-reaction compromise. Probably switch to inside steam admission eventually since it allows more flexible reaction divergence. If you'd like, and a few folks are interested, I'll keep you up-to-date as the project evolves (probably slowly, since I have way too many projects). Intention is to run a steam/electric hybrid in a model boat with a constant output boiler. Excess power to be stored in battery with an electric motor running the prop. In that way, you can go till the fuel runs out and cruise home under electric power. Anyone out there got a good plan for the electronics package?

The turbine rotor is running well less than max in the videos because it's not well balanced. This is a jury-rigged test set-up, after all. The boat system could be set up to add some gyro stability to the boat. Any one had experience with gyroscopes in model boats.

For video copy the following into your browser: http://www.youtube.com/watch?v=2DfrJGTo8O8



See you at the dock. . . . Bilge Rat

All kinds of motors, low surplus prices: HERBACH & RADEMAN

Also, E-Bay usually has a good selection, especially if you shop for a period of time, they will even e-mail you when what you are looking for comes up.

For small power and high RPM, consider small timing belt drives, they are really quite tough and capable of high speeds: STOCK DRIVE PRODUCTS

Do you have any design data for your turbine, such as rated RPM, power, steam consumption, etc?

Very nice mill you have setup, makes it look easy, although, its always more complicated than it appears.

Fred: Thanks for the info. I'll keep an eye on Herbach & Rademan. They certainly have a nice selection of geared motors. My eBay explorations haven't yet produced any leads, but I'll keep looking.

I really want to avoid gearing or belts so that I maintain a direct link from the turbine to the generator, spin the generator as fast as possible, and to keep the system simple and compact.

I really haven't developed a test bed for measuring input/output, yet. I will, once I find the generator/motor combo I'll be using. The current gen/motor set-up isn't very efficient.

You are correct re. the mill. It's currently more complex than I'd like. It would be great to have a more integrated CAD to CAM software system. My current software set up AutoCAD > SheetCAM > g/m code editing and proofing > Mach3 and the mill, has too many steps, a steep learning curve and lots of opportunity for problems. It takes a long time to get the code proofed for milling. Since I'm really prototyping at this stage it takes time to make most modifications since I have to go all the way back to AutoCAD to make moderate changes.

I am very impressed with my SheetCAM software. Its developer, Les Newell from UK, is very responsive to his customers and is continually evolving his software (upgrades are distributed free to licensed clients). It integrates well with Mach3. The good integrated packages are too expensive for non-professionals. Anyone out there had any experience with cheap hobbyist-level CAD/CAM software?