By the way, you guys are coming up with some wild ideas!!! In the future I’d love to try some of em out but at this point Im so sick of materials testing!! I just want to build the airplane
Doc,
I always like your drawings. 
I like the device also. Especially, if it’s being used to measure multiple points thoughout the range of a test. As far as measuring the clay/wax/playdough/floam goes, should be pretty staight forward. We know there are digital calipers available. Use the depth probe feature of the calipers. After a test, lay a bar across the end supports, measure the distance from the top of the bar to the top of the deformed clay, deduct the thickness of the bar and you’ve got the distance the bottom of the test specimens moved.
I like the critical path approach to a defined goal. That’s fancy talk for the keep it simple principle. For a simple maximum deflection under a single impact, this should provide a decent relative comparison of materials.
I was just thinking about rebound and resistence of the “Conical Maleable Displacement Indicator”. More fancy talk for clay cone. Providing a fairly tall cone is used, the amount of rebound resistence of the clay should be more or less equal among all tests. The taller the cone, the less the deflection variation between materials will influence the rebound.
Say one material deflects 1/4" and another 1/2". That’s a difference of 1/4". If a 1" cone is used it is compressed at least 25%. A 2.5" cone, 10%. A 5" cone, 5%. The less the cone is compressed the less the resistence and I assume less rebound.
Okay, I just realized I’ve got to get on with it and disengage this obsession. I’m done. This can make you crazy.
Not Play-Doh, nor (I think) Floam. This stuff came as a brilliant white powder to be mixed with water. It resembled gypsum, but acted like some kind of cellulose product (but I’m guessing the baking part rules that out). A whole bag of the powder (mebbe .3 cu ft) couldn’t have weighed more than a few ounces. When mixed, it had barely enough resiliance not to slump under its own weight. After some web searching, I think I have confused the characteristics of two materials: Sculpey, which is an oven-bake clay of modelling clay consistency; and Crayola Model Magic (or more likely some cheaper generic equivalent I had found), which is a light, soft powder mix that air dries. Model Magic does take 24 hours to dry, which should give adequate working time to the kind of experiment we are discussing.
-Samiam
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By the way, you guys are coming up with some wild ideas!!! In the future I’d love to try some of em out but at this point Im so sick of materials testing!! I just want to build the airplane
Rats! Just when we beginning to think you had real geek potential :->
-Samiam
Sam,
Yah, I think the crital property is resilience. You need something maleable, but with little elasticity. You don’t want it to rebound after impact. I think the density or stiffness can be compensated for by size/shape of the Conical Maleable Displacement Indicator.
C’mon, give me some geek props for Concical Maleable Displacement Indicator! You know, the CMDI. We can talk about what material we’re using for our CMDIs. “how tall is your CMDI?”, etc.
Oh Dang! I said I was done with this topic.
Nevermind what I said above. I’m done.
Geek props? You came back for more… 'Nuff said - you’re in :->
-Samiam
I know you are a geek -
I thought you knew as well
CDMI is classic -
It must have been born out of those late nights at the blue daisy, or when you were dropped on the head as a kid -
go figure, it always comes back the the concrete!
later
fff
landloked in fabu vegas
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CDMI is classic -
Thanks Frank,
Now everybody knows I was dropped on my head 
