Mike, Vern Knowels is a rocketeer from the northwest (Idaho) who has
an amazing website with all kinds of information. He chronicles his
building of several rockets and includes a wealth of information about
things like this. He also explains how and why which I find very
helpful. I recommend you give his site a visit...but plan on staying
awhile! Oh, he also has some great videos and pictures.
Www.vernk.com
Sent from Yahoo! Mail on Android
------------------------------------------------------------------------
*From: * Lesnick, Mike <mikel@xxxxxxxxxxx>;
*To: * <roc-chat@xxxxxxxxxxxxx>;
*Subject: * [roc-chat] Re: How Much Extra BP for Shear Pins?
*Sent: * Sun, May 8, 2011 2:55:38 PM
Thank you to all who helped with comments on BP & Shear Pins. Another
question:
QUESTION - Does anyone have a formula for the "air sampling hole" or
Static port hole (not sure what the correct name is) for the altimeter
bay?
Mike
Michael Lesnick
Axiom Healthcare Group
18135 Santa Lauretta Cir
Fountain Valley, CA 92708
714-594-5720 - Office Phone
714-323-5968 - Cell
714-968-7076 - Fax
MikeL@xxxxxxxxxxx
*From:*roc-chat-bounce@xxxxxxxxxxxxx
[mailto:roc-chat-bounce@xxxxxxxxxxxxx] *On Behalf Of *Gene Engelgau
*Sent:* Saturday, May 07, 2011 6:34 AM
*To:* roc-chat@xxxxxxxxxxxxx
*Subject:* [roc-chat] Re: How Much Extra BP for Shear Pins?
Hi all - IMHO it is a mistake to not use them symmetrical. So 1 pin
is out. But more than that number spaced evenly around the airframe
is good. Of course smaller airframes like 54mm would need only 2 2-56
nylon. Large 7.5" maybe 4 4-40 nylon screws.
YMMV...
-G
On Fri, May 6, 2011 at 9:26 PM, Chris J Kobel <Chris.J.Kobel@xxxxxxxx
<javascript:return>> wrote:
I've successfully used the following relationship on over 75
successful dual-deploy flights. I believe it was provided by someone
on roc-chat years ago (Dave Flynn?)
E-charges: BP(g)=.00051 x Length(in) x Force(lb) x (Peak Alt
ASL/10K+1) with an eject force somewhere between 100-200 lbs
Notice the equation is altitude corrected, as your "actual" ejection
will not occur at the same altitude as your ground test. (Hopefully)
Notice also that body tube diameter has been canceled out of the
equation during the math.
2-56 nylon bolts for shear pins; 35 lbs shear force each; 100 lbs
w/o pins, 200 lbs with
I often (mostly) use non-symmetric numbers of 2-56 shear pins (ie. one)
Chris Kobel
From:
"Lesnick, Mike" <mikel@xxxxxxxxxxx <javascript:return>>
To:
<roc-chat@xxxxxxxxxxxxx <javascript:return>>
Date:
05/06/2011 06:21 PM
Subject:
[roc-chat] How Much Extra BP for Shear Pins?
Sent by:
roc-chat-bounce@xxxxxxxxxxxxx <javascript:return>
------------------------------------------------------------------------
All,
One more question about shear pins.
If I use 2 or 3 2-56 nylon screws for shear pins, how much extra
Black powder do you think it would take to ensure the nose separates
from the airframe?
Mike
Michael Lesnick
Axiom Healthcare Group
18135 Santa Lauretta Cir
Fountain Valley, CA 92708
714-594-5720 - Office Phone
714-323-5968 - Cell
714-968-7076 - Fax
MikeL@xxxxxxxxxxx
*From:*roc-chat-bounce@xxxxxxxxxxxxx <javascript:return>
[mailto:roc-chat-bounce@xxxxxxxxxxxxx <javascript:return>] *On Behalf
Of *MonsieurBoo@xxxxxxx <javascript:return>*
Sent:* Friday, May 06, 2011 3:17 AM*
To:* roc-chat@xxxxxxxxxxxxx <javascript:return>*
Subject:* [roc-chat] Happy 50th anniversary of Alan Shepard's first
Cornwallis, Yorktown, 1781 ;-)
Cheers
Mark L
In a message dated 5/6/2011 1:07:17 A.M. Eastern Daylight Time,
ecartis@xxxxxxxxxxxxx <javascript:return> writes:
Rick "I mean, who *hasn't* beaten the French?" Dickinson
--
- Regards
Gene Engelgau
KI6IBL, NAR 86770 / TRA 12243 - L3
http://fruitychutes.com <http://fruitychutes.com/> - Consumer
Aerospace Recovery Solutions
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