PML Stratus

PML Stratus

Post by Mark Simpso » Tue, 21 Jul 1998 04:00:00



I'm in the process of building a PML Stratus and I'm getting to the
point where I need to decide if I deviate from stock or build it stock.
Here's the dilemma:
The Stratus is an altimeter deployment only near 38mm minimum diameter
high performance bird designed to go 12,000' on an I.  The problem is
that it is designed for single deployment at apogee.  Now, I'm not as
young as I once was and I have no desire to chase a 22 oz. rocket as it
drifts in under main chute from 12,000'. <g>  So, I've gotten a good
suggestion from Darrell to cut a small section of BT and use a floating
coupler that is blown out by the motor ejection charge, staying with the
payload section and then blows out, releasing the main chute by the
altimeter controlled charge.  Does anyone see any unforeseen  problems
with this scenario?  It seems too easy to be true, but I think that
it'll work.
A couple of questions remain before I start:
1. Will the rocket be structually sound enough under high G's with a
"floating" coupler?
2. The kit uses a piston for ejection which I'm assuming won't be needed
or wanted considering the modification. Correct?
3. Would the addition of a small, dummy payload section be a preferrable
option to the above?

Your comments are welcome.

Mark Simpson
NAR 71503 Level II

 
 
 

PML Stratus

Post by Sylvain Gagno » Wed, 22 Jul 1998 04:00:00


Hi Mark,

I believe this is a great idea. Though my experience is limited, that is
exactly what I am planning to do with mine. I am also planning on byuing a
replacement Cirrus for which I would like to setup the altimeter (Adept of
course) in the payload section to achieve similar results. These models are
otherwise not very "usefull". I also believe that though they are minimum
diameter or close too, they will need positive motor retention (I use screws
set under the fiberglass mat used to reinforce the fins) The only thing
missing at that point is a sonic locator small enough...

Good luck

Sylvain Gagnon, SiS

Quote:

> I'm in the process of building a PML Stratus and I'm getting to the
> point where I need to decide if I deviate from stock or build it stock.
> Here's the dilemma:
> The Stratus is an altimeter deployment only near 38mm minimum diameter
> high performance bird designed to go 12,000' on an I.  The problem is
> that it is designed for single deployment at apogee.  Now, I'm not as
> young as I once was and I have no desire to chase a 22 oz. rocket as it
> drifts in under main chute from 12,000'. <g>  So, I've gotten a good
> suggestion from Darrell to cut a small section of BT and use a floating
> coupler that is blown out by the motor ejection charge, staying with the
> payload section and then blows out, releasing the main chute by the
> altimeter controlled charge.  Does anyone see any unforeseen  problems
> with this scenario?  It seems too easy to be true, but I think that
> it'll work.
> A couple of questions remain before I start:
> 1. Will the rocket be structually sound enough under high G's with a
> "floating" coupler?
> 2. The kit uses a piston for ejection which I'm assuming won't be needed
> or wanted considering the modification. Correct?
> 3. Would the addition of a small, dummy payload section be a preferrable
> option to the above?

> Your comments are welcome.

> Mark Simpson
> NAR 71503 Level II


 
 
 

PML Stratus

Post by Darrell D. Moble » Wed, 22 Jul 1998 04:00:00


Quote:

> I believe this is a great idea. Though my experience is limited, that is
> exactly what I am planning to do with mine. I am also planning on byuing a
> replacement Cirrus for which I would like to setup the altimeter (Adept of
> course) in the payload section to achieve similar results. These models are
> otherwise not very "usefull". I also believe that though they are minimum
> diameter or close too, they will need positive motor retention (I use screws
> set under the fiberglass mat used to reinforce the fins) The only thing
> missing at that point is a sonic locator small enough...

Have you looked into the AeroPack motor retainers?  They are great!
They should work well on the Cirrus.
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