www.TK560.com

[Steve Lunn]

Hiya

I'm completely new to vac forming and i'm in the process of making my first table but i was wondering about the formers.

I make a lot of reproduction armour and i was wondering if the same armour could be used as a mould if closed off properly at the edges, eliminating undercuts. It would be in steel, minimum of 1.2mm, probably 2mm

I'm only thinking of using 2mm or 3mm sheet HIPS, so i guess nothing heavy duty.

Any thoughts??

[taurus66]

Well 2 or 3mm HIPS is pretty tough to form , trust me, personal experience , but not a lot of experience...lol I just built my own table, just doing to fine tuning of the heating to get it right.

But i am sure you will find it as much fun as i have so far.
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One day i may win the lottery.. In my dreams that is..

[Steve Lunn]

I must have been lucky on my small scale tests then lol.

I've had successes with doing small pieces... just 12" x 18" tests making shoulder armour in 2mm/3mm, but i want to up it to being able to do breastplates since it's the biggest thing i'll ever need to do.

i'm fortunate that i have an oven that's controlable to +/- 5 degrees and a vac tank/vac pump as they're used in what i make at the moment so it's probably helped me a lot having the equipment handy in making the first pieces, but i can see it becoming much harder as i scale up to using 24"x36" sheets as they won't fit in the oven lol

It'll certainly make life easier if i can use metal patterns as i can rattle those out quite quickly.

This is kind of what i'm looking to make in HIP... it's the steel stuff i make and why i'm hoping metal patterns will work

[kayaker43]

Hollow backed molds are always bad idea if you have a strong vacuum system. Take 15 lbs and multiply it by the surface area of your metal part. You can see that even a small 10x10 area would generate 1500lbs of crushing force.

You can see a large car fender I made from 3/16 plastic on my website

http://www.build-stuff.com/1002plans_proto-form.htm

I closed all sides with steel and back filled it with rigid expanding foam. It still crushed slightly because the foam compressed a little. Whatever you fill it with has to be fairly substantial.
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Doug Walsh
www.build-stuff.com
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