[roc-chat] Re: How Much Extra BP for Shear Pins?
- From: "Lesnick, Mike" <mikel@xxxxxxxxxxx>
- To: <roc-chat@xxxxxxxxxxxxx>
- Date: Sun, 8 May 2011 10:55:38 -0400
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>
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>
To:
<roc-chat@xxxxxxxxxxxxx>
Date:
05/06/2011 06:21 PM
Subject:
[roc-chat] How Much Extra BP for Shear Pins?
Sent by:
roc-chat-bounce@xxxxxxxxxxxxx
________________________________
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
[mailto:roc-chat-bounce@xxxxxxxxxxxxx
<mailto:roc-chat-bounce@xxxxxxxxxxxxx> ] On Behalf Of
MonsieurBoo@xxxxxxx
Sent: Friday, May 06, 2011 3:17 AM
To: roc-chat@xxxxxxxxxxxxx
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 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
Follow us on Twitter! <http://twitter.com/fruitychutes/>
408-499-9050
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