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View Full Version : ABS Plastics: Minimal armor to withstand shots?



Fanatic
11-11-2012, 06:34 PM
Basically I will be fab'ing my own frame/armor and I need an estimate of *mm of armor I need to withstand a normal shot. I'm assuming the majority of participants will be using defender guns still. Either way I'll have my printer soon and I'll buy a defender to test it out myself if there's no answer.

jwatte
11-11-2012, 10:05 PM
I'm assuming you're talking about airsoft shots, and not, say, a .22 rifle :-)

I think 1mm ABS would be plenty. The Defender style guns aren't particularly strong, and the 6mm BBs are made of soft plastic. They don't go through LEGOs, which are made of ABS plastic.

If you need a better number, then you'll just have to print a few gauges and test them yourself. Please post results if you do :-)

darkback2
11-11-2012, 11:51 PM
A number of people are using AEG based guns which are pretty powerful. I use 1/8 inch polystyrene for my body panels, haven't had any holes shot in them...but underneith is aluminum with holes drilled in it. I have found shattered bbs inside of Hikari's case though. I did a test fire with a defender gun at relatively close range...went right through some scrap plastic that I had around...punched a nice clean hole too. Remember if you are vacuum forming the plastic gets thinner where it is stretched...

Hope this helps.

DB

Fanatic
11-12-2012, 12:48 AM
1mm ABS would be plenty) Mmm thanks now I'll have a starting point. I hope to find the bare minimum to reduce frame weight.



I use 1/8 inch polystyrene for my body panels, haven't had any holes shot in them
DB

Do you happen to know if your polystyrene is GPPS(general purpose) or HIPS(high impact)? It'll give me more of a specific reference to imagine and compare.


While researching plastic strengths I stumbled on this site that rates them(I think) at the bottom of each info page.
ABS: http://www.ides.com/info/generics/1/Acrylonitrile-Butadiene-Styrene-ABS
PS: http://www.ides.com/info/generics/43/Polystyrene-PS

Apparently ABS has a score of 2x compared to PS in high impact resistance. 623 vs 330 respectively.
If this is true and 1mm ABS is plenty then DB can reduce his 3.1mm PS armor by 1mm. Haha of course we'll all have to field test it anyways.

gdubb2
11-12-2012, 11:13 AM
On "Maggot", the body panels are all vac formed high impact polystyrene. The thickest material I have used is .040 (1mm).I have never had a BB penetrate the panels. I also use .020 and .030, so I don't think it would take much to stop the BB's. Since vac forming does stretch the material, I don't think there is very much that is at full thickness.

This chart shows ABS as having almost 4X the impact resistance of Styrene.......Interesting..
http://www.curbellplastics.com/technical-resources/plastics-properties-table.asp

Good luck
Gary

darkback2
11-12-2012, 12:46 PM
So the original test was done on stuff from Fon's...I just repeated the test using the new stuff from mcmaster carr and didn't make a dent in it from less than a foot away. so I'm guessing Fon's stuff is general purpose, and I must have gotten high impact. Go figure...didn't know there was a difference.

elaughlin
11-12-2012, 03:55 PM
For the 3D printed materials I used from shapeways, I tried to make all the walls at least 2.5mm thick. I know I didn't see much action, but I faced Insanity Wolf and Godless Endeavour in some demo matches, whom both used the AEGs and I did not notice any damage let alone holes going through. I used the White Strong Flexible from Shapeways.

jwatte
11-12-2012, 04:25 PM
Shapeways WSF is actually Nylon 6/6, which is one of the toughest engineering plastics there is. I think you massively over-specced your armor :-) (The black and colored strong/flexible ones are Nylon, too.)
The main draw-back with Nylon is its water absorbtion, which is at least 10x if not more compared to PP or polycarbonate or UHMW or ABS.

Hmm ... maybe a water gun will slow them down ... ;-)

Fanatic
11-12-2012, 07:22 PM
Shapeways WSF is actually Nylon 6/6, which is one of the toughest engineering plastics there is. I think you massively over-specced your armor

Hmm according to gdubb's chart (http://www.curbellplastics.com/technical-resources/plastics-properties-table.asp) nylon 6/6 has a weaker impact resistance(1.2) than ABS(7.7) and HIPS(2.0)..elaughlin's 2.5mm armor might have been a right choice.....at least its score is super high for resisting being torn apart AND for being flexible.

And I'm guessing the AEG's are the strongest weapons used to date right? Just in case I want to get the strongest gun used so far to test out armor tolerances.

jwatte
11-12-2012, 08:59 PM
Just look at the FPS rating of the weapons/gearboxes. I think you won't find anything over 600 or so even for the highest end snipers, and more normal AEG ratings are around 400. The $20 mini-auto I've got just gets 160 or so. Still enough to fling a BB at a target :-)
Also, the internets claims that after a lot of use, the guns get weaker -- perhaps the springs wear down or the compression cylinders start leaking or whatever.

If you want the highest IZOD rating, you want LDPE, which is also lightweight as a bonus. It is plastic enough that it doesn't break during normal testing. It does, however, deform quite easily. That being said, a lightweight armor that goes all bumpy when you shoot it might actually look really cool :-)