I am looking for some ideas on how i could make a model of a chair that I have designed to be manufactured by the deep drawing/metal stamping process. Any ideas?
I have a limited budget and limited time (isn’t that always the case?).
So far I am considering CNC cutting the negative of the seat (i have access to a 3axis CNC machine) and laying fibreglass over the ‘mold’.
Any other ideas? A scale model is not out of the question.
metal fabricators can make a soft tool and press the form - just depends on your budget and timeline.
If a scale model is not out of the question, then by all means, build a scale model. A model will require substantially less material to build; not necessarily less time however. Say, 1/8 scale. In 1/4 scale the niggly bits would be easier to achieve.
I think you are on the right track if you have the ability to CNC a “plug”.
I would suggest your build your model out of polyester/fiberglass - over a male armature. I say over a male because most people mentally “understand” working in the positive, rather than the negative. Depending upon how dimensionally accurate you need to be, allowances will need to be made for material thickness.
If you are comfortable working in the negative, you could CNC a female mold and it would significantly reduce the amount of surface finish work required. and no allowance would be needed for material thicknesses.
It will require a lot of hand finish work to made presentable, but dollar-wise you are looking at something like $50-75; a quart of resin, a square yard of cloth and/or mat, and a quart of polyester glazing putty (which is of a finer texture than reg. bondo).
Although polyester based resins shrink more than epoxy-base material it 1) is more readily available 2) cures quickly, and 3) maybe most importantly, easily builds upon itself (epoxies require that a cured surface be solvent wiped and/or mechanically abraded to ensure that subsequent layer adhere well).
ALTERNATIVELY: If a prototype vacuum former were available, and depending upon the complexity, and depth/width ratio of the part, you might be able to use your CNC capability to make a mold and draw ABS into it/over it.
send it to a metal fabricator.
if you just want to make one, cut, beat, weld and grind.