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How to choose the proper delay for RMS

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Jerry O'Sullivan

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Jun 27, 1999, 3:00:00 AM6/27/99
to
Adam,

There's a calculator on the Tripoli web page which estimates time to apogee
when you supply your rocket's diameter, weight, engine selection, and cd.
(You need to convert inches and pounds to metric). I found it useful for
selecting delays this weekend.

Hope that helps..

Jerry

>
> Are there any formulas or "golden rules" when it comes to choosing delays
(SML)
> for reloadable motors. I'm planning on launching a 7.5 inch diameter
(14#)
> rocket that I estimate will go ~1000 ft on a J350. i've pretty much
always
> stuck with the medium/10 sec. delay but am wondering if I need to use the
short
> delay due to the short altitude I'm estimating.
>
> Thanks,
> Adam

Bob Chmara

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Jun 27, 1999, 3:00:00 AM6/27/99
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I'd suggest modeling the rocket in RockSim.

--
Bob Chmara
NAR, HUVARS, TRA, Team1, L2, http://www.chmara.com/bt/rocketry
(remove SPAMFREE for personal replies)
Be careful whose advice you buy, but be patient with those who supply it.
Advice is a form of nostalgia. Dispensing it is a way of fishing the past
from the disposal, wiping it off, painting over the ugly parts and recycling
it for more than it's worth. -Kurt Vonnegut, From his 1997 commencement
address at MIT

Atom94 wrote in message <19990627215356...@ng-xa1.aol.com>...

Atom94

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Jun 28, 1999, 3:00:00 AM6/28/99
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BJamesjr

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Jun 28, 1999, 3:00:00 AM6/28/99
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>Are there any formulas or "golden rules" when it comes to choosing delays
>(SML)
>for reloadable motors.

I use WRASP. (I wonder how accurate it is.)

ROYNPATTI

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Jun 28, 1999, 3:00:00 AM6/28/99
to
I've found Rocksim to be fairly accurate.Your money will be well spent.
Roy Reedy
Nar#74750
Lvl 1

computer

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Jun 28, 1999, 3:00:00 AM6/28/99
to
You're right on the money Adam. For comparison, our stretched Minie
Magg is 6in dia and weighs in at 5.5 lbs dry. The J350m took it to
about 2000 feet alt. The delay was modified to 8 seconds instead of 10
and the chute (twice now) pops right at appogee. Your bigger bird
should be fine with a 6 sec (s) delay. With a J350 I wouldn't try to
drill it down to a 5.

Steve Bloom

Atom94 wrote:
>
> Are there any formulas or "golden rules" when it comes to choosing delays (SML)

Mark Simpson

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Jun 29, 1999, 3:00:00 AM6/29/99
to Atom94
Atom94 wrote:
>
> Are there any formulas or "golden rules" when it comes to choosing delays (SML)
> for reloadable motors. I'm planning on launching a 7.5 inch diameter (14#)
> rocket that I estimate will go ~1000 ft on a J350. i've pretty much always
> stuck with the medium/10 sec. delay but am wondering if I need to use the short
> delay due to the short altitude I'm estimating.
>
> Thanks,
> Adam


A 14# 7.5" diameter rocket appears to be a lob on a J350. I'd use a 6
second delay. A 10 second delay will be way too long for that
rocket/motor combo. Plug a 14# Bruiser EXP into WRASP and you'll see
what I mean.
I know because I've entertained using a J350 in my Bruiser EXP at one
time. It'll fly on a K550-10 at NYPOWER99 instead. ;-)

Mark Simpson
NAR 71503 Level II


Bill Sinkins

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Jun 30, 1999, 3:00:00 AM6/30/99
to
On Tue, 29 Jun 1999 19:07:44 -0400, Mark Simpson
<marks...@sprintmail.com> wrote:


>I know because I've entertained using a J350 in my Bruiser EXP at one
>time. It'll fly on a K550-10 at NYPOWER99 instead. ;-)
>

Fellow Sky-Buster Mark Sadowski is bringing his Bruiser EXP to
NYPOWER as well. He has a variety of big-ass cluster
flights planned. Maybe you'll wanna drag...

Bill


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