I’m going to use the ribs method of making a plug and I was thinking of making a large print of the outer perimeter on paper. Then I’d lay that paper onto cardboard or wood and cut. Rinse and repeat until I’ve got all my sections. Then fill sand etc.
The question I have is how does one get accurate cutouts when referencing a cad model?
you should use a plotter and mylar paper to print on to create accurate patterns. spray adhesive to your material and very carefully cut so you can still see the line, then sand till the line just disappears.
Why mylar? If you’re gluing it to the boards, regular printer paper works fine. Just spray some adhesive and apply the prints.
Trim to the line, and voila.
Just saw your PM too, but i would recommend sticking to this method instead. I don’t know any place that would be willing to set up their 5 axis for a free small job like this. It’s not as simple as throwing a block of foam on the bed and pressing “Go”.
Besides, most of the work will be in finishing the surface. Carving the shape is easy.
For what Canyon is doing im sure regular paper is fine, and I wont argue with that. However we used mylar because it would not be effected by humidity or from the spray adhesive, which can, if humidity is high, or fluctuates alot will shrink/ change dimensions slightly specially if the patterns are larger.
I changed the shape so only a 3 axis hot wire could do it but if I can’t find anything I’m going to go ahead with the ribs. There’s no way we could pay the even half the price for a mill or router so I made sure the shape didn’t need it. Nonetheless thanks for the response!
Canyon,
Basically I agree with what the others are saying, print onto paper, cut the paper to shape and stick to your wooden ribs and cutt out.
two other ways that I have used both in the past, first take section screen shots on your computer then using a overhead projector shine onto your wood, draw around the outline then cut.
Or my current favoured method is to take a screen shot, convert this image to a vector file then using a sticker cutting plotter you an end up with a vinyl sticker you can put onto your wood then cut out. I now prefer this method as you wont loose and details as you could by cutting your pattern by hand, That and the fact that I have a sticker cutter my self that can cutt upto 900mm tall. Im sure your college will have one of these in some department somewhere.
Use a jig saw to cut the ribs out, sand down to your final line.
Dont forget to ruduce the size of your ribs to allow for the thickness of your fibre glass/filler and whatever else is needed to finish your plug otherwise it will end up oversize.
My other tip is to put a drill hole reference on all your rubs in the same place, reletive to the centre line and height, so that you can then insert a tube to ensure that all the templates line up correctly and easily. Two or three of these would be great.
A student from my school wrote a script for easy sectioning of a part. I took these sections in Rhino and saved each one as an AI file leaving it full size. Now I can go to any graphics designer with no engineering experience and get these printed or plotted correctly. That was my primary concern, translating computer to real world. Thanks for all the tips!