Del's Quiz Question!

It appear that you, Del the cat, have done it! The saying used to be "keep your powder dry", but now that appears to be changed to "keep your quiver dry".

I cannot imagine a U.S. Navy Seal needing that silent weapon, having swam ashore underwater, only to find the quiver leaked! <string of expletives deleted>, next entire section of tirade redacted by NSA, etc.

Do you use any form of glue to make the tube? Is it standard weight printing paper? What about card stock? What about paper impregnatum polycarbonatum?

There are papers that can be bought for writing in wet or underwater conditions, maybe that is even a good choice.

I do not currently have audio working on my office computer (no tirades from boss), so did you say the nock fractured?

It was just made up out of ordinary grade printer paper rolled to make a tube, glued with a little pva glue.
It was the only way I could demonstrate to the idiot that he was talking nonsense. He was one of those irritating individuals who knows all the theory but has no feel or concept of the order of magnitude of the forces involved... he was insisting that the mode of failure would be Euler buckling, which is somewhat unlikely seeing as how it isn't constrained at either end... he was basically full of excrement and wouldn't admit he was wrong even with the demo' ! Mind he did go quiet
del

o, haven't you patented it del? That's a good toy to sell, when you make it with plastic. That's genius.

I thought you were the boss.

Del: I didn't understand what you meant by, " Bolt ". I went to Google and I see that a bolt is approximately 16" in length, while an arrow is 22" or greater.

Google didn't say what it is called for an item that is greater than 16", but less than 22".

I can't answer your question, but seeing the video I have to wonder if the foam block hanging from the string has a relationship to the ability of the Bolt to being penetrated and the depth of penetration.

How far did the foam move ? How much kinetic energy was transferred ? Have you received the same results when the foam target was afixed to a stable mount.

And what was the effect on the Bolt, was it a single use item or was it reusable ?

I deliberately set the foam up to swing, as the bolt may not have survived impact. The argument was about if it would survive being launched, so I wasn't interested in anything else.
"Bolt" is just the term for the crossbow arrow, length isn't necessarilly a factor, in fact some archery organisations have silly rules about length like they have to be at least 12" long which is stupid when you consider that commercially available arrow shafts are 32" long and it is economical to make 3 bolts from each shaft!
Rules are often made by idiots.

This post from my blog may answer some of the other questions, as I did extensive tests using the same bow pistol.
http://bowyersdiary.blogspot.co.uk/2011/11/mass-velocity-and-energy.html
Del

Usually rules are made by the kids that did not get along in school, and could not or would not stand up for themselves?

Impressive stuff, (nice shooting BTW)

Cool video.

(I'll have to listen to it when I get home.)

A high speed video would be ideal but I understand the cost limitation.

I wonder if and how a paper bolt shaft plays into the archer's paradox?

There is no Archers Paradox with a crossbow as the bolt does not have to flex around the bow, all the forces (if it's made correctly) are in a straight line.
A similar, but scaled up paper arrow wouldn't survive being shot from a longbow, it would prob' just fold in half.... actually, it would certainly fold in half!
I've had arrows snap due to the flexing as they are loosed from a flight bow. (Ouch)
Del

Yes, that is an ugly, ouchy thing to happen. I like things to travel in a straight path, if available. parabolic is OK, too.

Nice job, Dell. I'm going to resist the impulse to call you a paper pusher. Keep up the good work.