Thread: cnc router er

HI, i'm an ex boatbuilder now full time CAD operator so i might be able to help if your still interested.

Yep sure am! Do you do much in the way of centreboards and things? What I'm looking at doing is having made to plugs (half each) to make composite centreboards. The board restrictions are as followed

Chord - 290mm min (which is where I want to be)
Thickness at Keel line in down position 21mm min. to 26mm max.

If I work at a foil section of 9% (0009 naca section) I end up at 26.1mm.
I've tried and still trying to get some more information on alternative sections other than 0009, but it seems it is possibly the best option. Do you have any thoughts in that regard? Others such as a 63009 section have caught my eye.

Anyway the boards would be 290mm wide, 26mm thick, and approx 1000mm long. I have thought to shape the head of the centreboard in such a way that it is still supported in the case, but a cut out section as well to reduce some weight. The photo attached are some timber boards I made years ago showing such a cut out, actually this board is narrower, but its basically what I'm trying to achieve.

I'm not a pro builder, I do these things for myself mainly, just to learn something new, however I'm very familiar with fibreglass laminating and boats. I was initially thinking to route these from aluminium, but then found out the cost, so I'm looking at a much cheaper timber option now.

Let me know what you think.

Thanks

Matt