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EeZeBilts From Keil Kraft

A brushed 775 motor? Standard 'Johnson Can'. Cheap and powerful, for power drills - a bit more powerful than I am using. For cutting curvy balsa shapes, as aeromodellers do, it would be ideal. Most modellers cut shapes that are long and thin. The only problem for marine modellers is that we typically require shapes that are about 36"/1m long, while aeromodellers rarely look for aerofoils which are longer than 1'/30mm. And the longer the base of a , the more it will cost...

5 years ago by DodgyGeezer

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CNC boat kits...?

A strong magnet would work - but in fact I have found that: - cutting 1/16" and 1/8" balsa sheet - using a 0.5mm cutting tool and a 12v boat motor the sideways cutting forces are sufficiently small for a simple raised lip around the cutting table to hold the sheet in place. One difficulty with passing round files of 'cutting instructions' to people so that they can create their own kits is that the s are all different. They will all accept 'G-Code' of some kind, but that code effectively says things like 'Go to position 25"x2" and cut a circle radius 2 inches'. Now, if you have a machine that only has a 10" cutting bed, you can't do that. You have to reposition the part so that it fits onto your cutter. So I've passed a DXF file to Nick - this is a CNC file with the shapes drawn on it. He will have to take each shape and position it on his machine where he want to cut. I have designed my machine to be able to take a standard sheet of 4"x36" balsa, because I expect to do most of my cutting that way. If other people have cutting beds which can do this, i can pass them cutting files directly. Another difficulty with cutting everything out of a single sheet is that one part may fall out of the sheet while cutting is going on in another part of the sheet. The best way I have found to avoid this is to not cut completely through the balsa sheet - leave a small gap of about 5 thou. Then you can easily push the shapes out later...

5 years ago by DodgyGeezer

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Look for a simple balsa build

"........I have found that most old hand drawn plans are inaccurate......." I bow to your experience, of course! My rather more limited exposure to vintage model plans is that they are indeed inaccurate. Your points are all true, and on top of that wood and paper can shrink and warp over the years. I handled that on the initial EeZeBilts by providing a copy of the die-cut sheets as well as the 'improved' cutting lines, which were 'what I thought the designer meant'. It was still hard to be sure that I had got things right, because manual cutting from plans introduces more errors - but now that I have a that source of errors should be minimised. I originally thought that PDF format was a good one to use for distribution, since it was meant to be a 'facsimile image' - but I didn't realise that people can set their printers up to do all sorts of default formatting, which can alter sizes...

5 years ago by DodgyGeezer