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Originally posted by Cathar
This pushes the flanges out-wards, forcing them to bite into the walls of the middle plate holes thus holding them firmly in place.
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Wouldn't this create the potential for stress cracking? I did a quick search, and doing this might require annealing the piece to relieve the stresses. The annealing is very time consuming though, and appears to require fixturing similar to the mold itself. (To prevent the piece from warping?)
I'm not sure what the difficulty would be with casting the eyelets in. Maybe voids left in the piece near the eyelets, due to the poly carbonate not filling in as it flowed around?
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I may look into just doing integrated molded fittings and lose the brass barbs altogether and have polycarb straight-walled tubes coming out the top.
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One thing to keep in mind in designing molds is that all of the surfaces need at least 3 to 4 degrees of "draft". Meaning they need to taper so that the mold comes off the piece easily. "Straight" tubes might be problematic. And clamping tubing onto a tapered polycarbonate 'barb' might be a problem as well. The mold could be made such that it separates perpendicular to the axis of the barbs, and eliminate the need for the barb to taper, but that would leave the top piece having a 'wedged' bottom. Of course Stimpson makes much bigger eyelets too...
Can you get two different parts for that $500 minimum?
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utabintarbo, Since87, and bigben2k, if this works out, I owe each of you a free block.
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That is very generous of you. I'm hoping molding the parts works out.
