Deadguy
Well-Known Member
Wow.. this topic took off.. hang on a sec.. let me help.
We do our vacuum-formed helmet in 5 pieces..
#1 The top
#2 The Jawline (from Cheekbox to Cheekbox)
#3 The Visor
#4 left rear half
#5 right rear half.
Here's an early version we did.. you can see the sections and the rivets. Later we painted the rivet heads. It's funny how people don't seem to care about the rivets being there. As a perfectionist myself, it's hard to be ok with it, not to mention how our pieces didn't overlap real good at that point in development.
Every piece is designed to overlap into the next piece around the edges.
That means that making a head, and then cutting it up isn't enough. You need to make the head, carefully cut it up into sections, and then build-up the sections so that they include smaller versions of any features that are in the surrounding pieces.
We decided to rivet everything into place after putting on the basic paint (spray paint).
In Florida glues don't always work real good, but there ARE plastic glues that you can use to make seams go away.
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BE CAREFUL, your vacuumform molds cannot have undercuts on them, or you will either destroy the mold while getting off the plastic, and/or lose the mold when the plastic wraps around it and hardens. Look up undercuts.. be SURE you know what they are, and then avoid them like the plague. I've wasted so much hard effort on pieces that had undercuts and were basically useless.
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Don't use cardboard for molds, it won't survive the vacuum process, and actually the hot plastic might make it get crispy and start doing weird things.
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Another way to move the plastic is to use a heat gun on it.. the problem is that it's hard to get the plastic to do what you want, like get into corners and stuff, and stretch consistently, etc, to avoid wrinkles. It's better to use the heat gun to reshape parts, like the angles of bends, or size of curves, etc, rather than trying to do complex pieces with it.
---------
Ovens.. we took apart two ovens and a friend of mine is an electronics guy.. we made a big steel shell and hung down from the ceiling and had the wiring guy install the heating elements, and then layered the outside of it in insulation. We sized it to handle 4 x 4 sheets of plastic, but for armour you rarely need more than 3 foot.
Frames.. we cut out MDF wood and then hinged one edge, and put screws through it with wingnuts on. Don't be staple freaks.. there's NO need for it.
Replace frame parts when they get overcooked. stay away from plywood unless you're using it for the top face of your frame, or you'll have major air leaks.
We do our vacuum-formed helmet in 5 pieces..
#1 The top
#2 The Jawline (from Cheekbox to Cheekbox)
#3 The Visor
#4 left rear half
#5 right rear half.
Here's an early version we did.. you can see the sections and the rivets. Later we painted the rivet heads. It's funny how people don't seem to care about the rivets being there. As a perfectionist myself, it's hard to be ok with it, not to mention how our pieces didn't overlap real good at that point in development.
Every piece is designed to overlap into the next piece around the edges.
That means that making a head, and then cutting it up isn't enough. You need to make the head, carefully cut it up into sections, and then build-up the sections so that they include smaller versions of any features that are in the surrounding pieces.
We decided to rivet everything into place after putting on the basic paint (spray paint).
In Florida glues don't always work real good, but there ARE plastic glues that you can use to make seams go away.
---------
BE CAREFUL, your vacuumform molds cannot have undercuts on them, or you will either destroy the mold while getting off the plastic, and/or lose the mold when the plastic wraps around it and hardens. Look up undercuts.. be SURE you know what they are, and then avoid them like the plague. I've wasted so much hard effort on pieces that had undercuts and were basically useless.
--------
Don't use cardboard for molds, it won't survive the vacuum process, and actually the hot plastic might make it get crispy and start doing weird things.
--------
Another way to move the plastic is to use a heat gun on it.. the problem is that it's hard to get the plastic to do what you want, like get into corners and stuff, and stretch consistently, etc, to avoid wrinkles. It's better to use the heat gun to reshape parts, like the angles of bends, or size of curves, etc, rather than trying to do complex pieces with it.
---------
Ovens.. we took apart two ovens and a friend of mine is an electronics guy.. we made a big steel shell and hung down from the ceiling and had the wiring guy install the heating elements, and then layered the outside of it in insulation. We sized it to handle 4 x 4 sheets of plastic, but for armour you rarely need more than 3 foot.
Frames.. we cut out MDF wood and then hinged one edge, and put screws through it with wingnuts on. Don't be staple freaks.. there's NO need for it.
Replace frame parts when they get overcooked. stay away from plywood unless you're using it for the top face of your frame, or you'll have major air leaks.
