Well, Richard, I think this thread has been a total waste of time.
On Mon, Jan 30, 2017 at 3:45 PM, R Dierking <applerocketry@xxxxxxxxxxx>
wrote:
You have to do *some* thinking David. Sorry, remember it’s me and please
don’t kill me when you see me next.
*From: *David Smith <davew6dps@xxxxxxxxx>
*Sent: *Monday, January 30, 2017 3:43 PM
*To: *roc-chat@xxxxxxxxxxxxx
*Subject: *[roc-chat] Re: Prohibiting Metal for Nose Weight
Dierking said: "But, there is a significant difference between the
potential impact damage of an 8 lb. solid nose, pieces of metal, or 8 lbs.
of dirt/sand/water."
WHAT SIGNIFICANT DIFFERENCE?
You haven't made an actual statement of why "metal" is bad compared to
anything else!
Impact of eight pounds at a given velocity is the same, whether it is
rebar or a brick.
On Mon, Jan 30, 2017 at 3:28 PM, R Dierking <applerocketry@xxxxxxxxxxx>
wrote:
Funny. Good story too. But, not discussing bowling balls. Yes,
difference between getting hit with 8 lb bowling ball vs. 8 lb rocket nose;
not much!!! But, there is a significant difference between the potential
impact damage of an 8 lb. solid nose, pieces of metal, or 8 lbs. of
dirt/sand/water.
Also, we are discussing using metal (and in particular things that are
intended to be used for projectiles like bb’s and lead shot), vs.
alternative types of masses.
Richard
*From: *richsilv@xxxxxxxxxxx
*Sent: *Monday, January 30, 2017 3:08 PM
*To: *roc-chat@xxxxxxxxxxxxx
*Subject: *[roc-chat] Re: Prohibiting Metal for Nose Weight
People get strange things in their heads, don’t they…
I recall being very freaked out by the whole notion of a Bowling Ball
competition… I’m like thinking WTF I think I’ll go into town while they are
holding this competition…
Then I got to thinking about what’s in some of my rockets… And chatting
with others with larger projects… Seem to recall that the Gates Porthos had
more than 35 pounds of Nose Weight…
It took me a while to get over that…
And the irony of the situation was just too funny…. My wife and I used to
bowl in what’s called a Vegas League… Without going into a lot of details
about what that is… And we always flew to Vegas… Just consider that between
my wife and I we were bringing 3 or four bowling balls onto the Aircraft
(No, I was not going to let the Gorillas on the tarmac throw around my
pristine bowling balls…)… At the Safety check (this was well before 9-11)
someone got freaked “What, you cant take those on the Plane!”, “Why?” I
asked and the inspector couldn’t come up with much of an answer, but their
antics did finally get a manager over… The manager’s comment was (and I
quote) “What do you think they are going to do, roll the ball up the isle?”
To which there was a great laugh…
Then, when we get on the plane, I’m lifting these into the Overheads… and
people are freaking out (even though they were going be (largely) over my
head too…), a bowling ball up there? “What, you can put 70 pounds of
Purses, Laptops, Briefcases… But you are worried about < 4o pounds of
Urethane? But we complied and kept them on the deck… In those days, they
actually fit under the “seat in front”…
Mass is mass, don’t much matter what it is (as long as you have your
tetanus!) if its coming in ballistic, you’d better not be standing
underneath…
*From:* roc-chat-bounce@xxxxxxxxxxxxx [mailto:roc-chat-bounce@freeli
sts.org] *On Behalf Of *David Smith
*Sent:* Monday, January 30, 2017 2:04 PM
*To:* roc-chat@xxxxxxxxxxxxx
*Subject:* [roc-chat] Re: Prohibiting Metal for Nose Weight
Richard,
One of the main reasons for avoiding metal structural partd is so the
rocket is not conductive in the event of contact with electrical lines.
As for the hazzards of using BBs or hardware for ballast, I don't see
where an alternative is better. Mass is mass, metallic, ceramic, or
otherwise.
Do you have any examples where metal ballast caused damage or injuries
that woukd not have bee. the case with non-metal ballast of the same weight?
David Smith
Nar 78668, TRA 15803
Amateur Extra: W6DPS
On Jan 30, 2017 1:50 PM, "R Dierking" <applerocketry@xxxxxxxxxxx> wrote:
Next time the NAR and TRA safety rules are revised, there should be
something about what kind of nose weight should be used or how about
shouldn’t be used.
Don’t the codes already say something about minimizing the use of metal?
Why add it? There’s no good reason why metal has to be used; there are
other things that would work fine.
And, just to get ahead of the one response that’s going to ask if a
rocket with other types of weight could hurt someone just as bad. Yes, I
realize that. But, again, if you think through the various failure
scenarios, metal (bolts, lead shot, bb’s, what ever…) is a poor choice for
nose weight.
What other things could be used? Things that would be even better for
both safety and performance.
Richard Dierking
--
David P Smith
NAR 78668, L2
Amateur Extra, W6DPS
