Model Boat Mayhem
Technical, Techniques, Hints, and Tips => The "Black Arts!" ( Electrics & Electronics ) => Topic started by: thunderchild on April 02, 2010, 06:24:21 am
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Good Day All
New to the site and have few questions, hopefully someone can answer for me.
I've brought a hull and semi kit for a Bathurst Class corvette in 1/72 scale (31" (790mm) in length with a 5.1" (130mm) beam and should weigh 2.2kg). I would like to build her with twin engines and shafts. What size engines would be suitable, and how do you work out which engine goes in which boat.
(http://s4.postimage.org/pDwGS.jpg) (http://www.postimage.org/image.php?v=aVpDwGS)
If all goes well, the model should look like the one above
Thanks
Richard
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For scale speed 2 x 385 motors on 7.2 volts and a 3 blade 35mm brass props.
For more speed 2 x 555 motors on this set up.
How to work it out is a mixture of experience and looking at other instalations that work.
Unfortunately model boating isn't large enough to have motore specially made so we have to use motors produced for other uses.
Graupner motors are pretty good but can be expensive.
Bob
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Good Day Bob
Thank you for that information, I'll start looking for some 385 motors, as I would like scale speed.
Take Care
Richard
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If you were in UK I could recommend several sources, but no idea "down under" and the postage would be prohibitive.
Bob
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Your Bathurst is about the same size and power as a Flower at the same scale, which performs very adequately on one 15 volt 385/ 5 pole 400 running on 6 or 7.2 volts. I would look for a couple of 15 volt 285's and run them on about half that voltage.
Model power? Its a scale model, 1800 horse power at 1:72 works out at about 4 watts, less than 1 amp at 6 or 7.2 volts. Allowing for model prop shaft bearings not being as efficient as the real thing, same for props, and the efficiency or otherwise of the motor(s), about double that to 1 amp each, and you will be in the right ball park area with a bit of extra in hand "just in case".
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Thank you Malcolm
That gives me something to work with, this is the first time than I've tried building a scale model without all the build information supplied. The hull is of a good quality and supplied by aps models of NSW, and the drawings are good, but, some areas of them don't supply enough information (again I'm new to this sort of build, after the first, the next will be easy).
Thank you all for you help, and I'm sure that I'd be asking for more help down the line.
Richard