LOC Onyx - Experience?

LOC Onyx - Experience?

Post by Rocket Scot » Fri, 06 Oct 2000 04:00:00



I'm just finishing a LOC Onyx kit and was wondering if anyone had experience
with this particular model. In particular, I'm wondering about stability. My
Rocksim model indicates that the model is unstable using Barrowman and
marginally stable using the Rocksim static stability algorithm when using
the largest recommended power plant (G40-10). Any comments?

I will post the onyx.rkt file on abmr, if anyone is interested.

Scott

 
 
 

LOC Onyx - Experience?

Post by Greg Elde » Fri, 06 Oct 2000 04:00:00


I have one that I built stock.  I have flown it on F and G motors
without any problems.
Quote:

> I'm just finishing a LOC Onyx kit and was wondering if anyone had experience
> with this particular model. In particular, I'm wondering about stability. My
> Rocksim model indicates that the model is unstable using Barrowman and
> marginally stable using the Rocksim static stability algorithm when using
> the largest recommended power plant (G40-10). Any comments?

> I will post the onyx.rkt file on abmr, if anyone is interested.

> Scott


 
 
 

LOC Onyx - Experience?

Post by Woody Mille » Fri, 06 Oct 2000 04:00:00


Flew mine a number of times on G64-7's and it flies great.  Saw a cert with a
H128 (stock) Onyx, and it was flawless..

Added T-nuts for motor retention on mine, and fixed one Cat-O (the cat knocked
it on the floor, then jumped on it and broke a fin!)

The Onyx is what could be considered a "short-stubby" rocket, and rocksim at
times indicate these as unstable, since by there design can often be less than
nominal stable..

Quote:

> I'm just finishing a LOC Onyx kit and was wondering if anyone had experience
> with this particular model. In particular, I'm wondering about stability. My
> Rocksim model indicates that the model is unstable using Barrowman and
> marginally stable using the Rocksim static stability algorithm when using
> the largest recommended power plant (G40-10). Any comments?

> I will post the onyx.rkt file on abmr, if anyone is interested.

> Scott

--
Woody Miller
NAR 74701 Sr L2
SSS
EARS
----------------------------------------------------------------
Alpha 40 Project website: http://www.users.uswest.net/~woody8
Superstition Spacemodeling Society: http://www.sssrocketry.org/
----------------------------------------------------------------
 
 
 

LOC Onyx - Experience?

Post by Mark A. Dombrowsk » Fri, 06 Oct 2000 04:00:00


The LOC Onyx is a great little rocket.  We have flown ours on Fs and Gs many
times with no problems.  It was my wife's very first rocket, her second was a
LOC Warlock ;-)  Just hope you have a really calm day for the Gs

Mark A. Dombrowski

Quote:

> I'm just finishing a LOC Onyx kit and was wondering if anyone had experience
> with this particular model. In particular, I'm wondering about stability. My
> Rocksim model indicates that the model is unstable using Barrowman and
> marginally stable using the Rocksim static stability algorithm when using
> the largest recommended power plant (G40-10). Any comments?

> I will post the onyx.rkt file on abmr, if anyone is interested.

> Scott

 
 
 

LOC Onyx - Experience?

Post by Rick Polzell » Sat, 07 Oct 2000 09:23:14


I have built and flow 2. The first one on a G25 went horizontal at 100 feet
and disappeared over the horizon. The second one flew great twice on F20s in
VT with Jim Z. Unfortunately it still hangs in the tree that caught it.


Quote:
> I'm just finishing a LOC Onyx kit and was wondering if anyone had
experience
> with this particular model. In particular, I'm wondering about stability.
My
> Rocksim model indicates that the model is unstable using Barrowman and
> marginally stable using the Rocksim static stability algorithm when using
> the largest recommended power plant (G40-10). Any comments?

> I will post the onyx.rkt file on abmr, if anyone is interested.

> Scott

 
 
 

LOC Onyx - Experience?

Post by Jim Z in V » Sat, 07 Oct 2000 10:22:10


Quote:

> I have built and flow 2. The first one on a G25 went horizontal at 100
feet
> and disappeared over the horizon. The second one flew great twice on F20s
in
> VT with Jim Z. Unfortunately it still hangs in the tree that caught it.

    Yup...2 excellent flights. Still in the tree....I visited it today.

Quote:


> > I'm just finishing a LOC Onyx ...............
> > Rocksim model indicates that the model is unstable using Barrowman and
> > marginally stable using the Rocksim static stability algorithm when
using
> > the largest recommended power plant (G40-10). Any comments?

    Short fat rockets don't require as large CP/CG margin as "normal"
designs do. There's a good article here that explains this:

    http://www.cmass.org/uploads/Robert.Galejs/sentinel39-galejs.pdf

Rocksim (I believe) says "marginally stable" at 1 caliber and "unstable"
below that.
--
Fly 'em high!

Jim Z in Vermont

(to reply by e-mail, remove the polite decline from my address)

 
 
 

LOC Onyx - Experience?

Post by BRMut » Sat, 07 Oct 2000 11:40:05


Hi Scott,
  34 of the 35 flights my Onyx made are at
http://members.aol.com/BRMutti/rockets/Onyx.html  Flight 35 was underpowered on
an F22 and hit the ground under power, totalling the rocket.  It was a good
flier the whole time.  I had to upgrad the parachute to an 18" one, and after
that change had no problems with fins breaking on landing.  I also ended up
epoxying an eyebolt into the nose after the plastic loop ripped off.  A fun
rocket, all in all.

Fly straight and true!

MikeyR

 
 
 

LOC Onyx - Experience?

Post by FREEDMIN » Sat, 07 Oct 2000 12:24:23


Scott:


Onyx with great success.  You can see pictures of it at www.varocketry.com in
the guest photos section.

VR,
Scott

 
 
 

LOC Onyx - Experience?

Post by Rick Polzell » Sat, 07 Oct 2000 04:00:00


Yup...2 excellent flights. Still in the tree....I visited it today

That's okay. LOC Onyx #3 is in the workshop and I will start it tonight. I
must really like this kit or something? Three, all in the same year.
Hmmmm... I am hoping that I'll get to paint this one. :-)



Quote:


> > I have built and flow 2. The first one on a G25 went horizontal at 100
> feet
> > and disappeared over the horizon. The second one flew great twice on
F20s
> in
> > VT with Jim Z. Unfortunately it still hangs in the tree that caught it.

>     Yup...2 excellent flights. Still in the tree....I visited it today.



> > > I'm just finishing a LOC Onyx ...............
> > > Rocksim model indicates that the model is unstable using Barrowman and
> > > marginally stable using the Rocksim static stability algorithm when
> using
> > > the largest recommended power plant (G40-10). Any comments?

>     Short fat rockets don't require as large CP/CG margin as "normal"
> designs do. There's a good article here that explains this:

>     http://www.cmass.org/uploads/Robert.Galejs/sentinel39-galejs.pdf

> Rocksim (I believe) says "marginally stable" at 1 caliber and "unstable"
> below that.
> --
> Fly 'em high!

> Jim Z in Vermont

> (to reply by e-mail, remove the polite decline from my address)

 
 
 

LOC Onyx - Experience?

Post by Rocket Scot » Sat, 07 Oct 2000 04:00:00


Thanks to everyone who related their experience with the Onyx. Mine is ready
to fly tomorrow at O'burg, although it will only be wearing primer. From
everyone's experience, I'll try it without additional nose weight first. The
instructions list a D12-3 as a recommended engine. Has anyone tried this
small of an engine?

Scott


Quote:
> I'm just finishing a LOC Onyx kit and was wondering if anyone had
experience
> with this particular model. In particular, I'm wondering about stability.
My
> Rocksim model indicates that the model is unstable using Barrowman and
> marginally stable using the Rocksim static stability algorithm when using
> the largest recommended power plant (G40-10). Any comments?

> I will post the onyx.rkt file on abmr, if anyone is interested.

> Scott

 
 
 

LOC Onyx - Experience?

Post by Rick Polzell » Sat, 07 Oct 2000 04:00:00


I don't know why they list the D12 as okay for this rocket. It is super
marginal and requires perfect conditions. You know, the kind of conditions
that don't exist outside the lab.


Quote:
> Thanks to everyone who related their experience with the Onyx. Mine is
ready
> to fly tomorrow at O'burg, although it will only be wearing primer. From
> everyone's experience, I'll try it without additional nose weight first.
The
> instructions list a D12-3 as a recommended engine. Has anyone tried this
> small of an engine?

> Scott



> > I'm just finishing a LOC Onyx kit and was wondering if anyone had
> experience
> > with this particular model. In particular, I'm wondering about
stability.
> My
> > Rocksim model indicates that the model is unstable using Barrowman and
> > marginally stable using the Rocksim static stability algorithm when
using
> > the largest recommended power plant (G40-10). Any comments?

> > I will post the onyx.rkt file on abmr, if anyone is interested.

> > Scott

 
 
 

LOC Onyx - Experience?

Post by Ted Newcom » Sat, 07 Oct 2000 04:00:00


A member of our club flew his Onyx (renamed "Plum Crazy") on a D12-3 for his
first flight.  The conditions were absolutely perfect...but...the rocket was
clearly under powered.  Ejection occurred just before we thought "lawn dart" was
going to be its new name.  Consider the E motors...and if you really want to see
it fly, a little nose weight and an F20 will make her hummmmm!
Enjoy!

Quote:

> Thanks to everyone who related their experience with the Onyx. Mine is ready
> to fly tomorrow at O'burg, although it will only be wearing primer. From
> everyone's experience, I'll try it without additional nose weight first. The
> instructions list a D12-3 as a recommended engine. Has anyone tried this
> small of an engine?

--
Rev. Ted Newcomb
Trinity United Church of Christ
Mount Bethel, PA  18343

http://www.trinityucc.net
http://www.thehungersite.com
NAR# 77750 L1
ICQ# 4580073
~~~
"Some people come into our lives and quietly go.
Others stay for a while and leave footprints on our hearts
And we are never the same."
- Eleanor Roosevelt
 
 
 

LOC Onyx - Experience?

Post by Alex Merica » Sat, 07 Oct 2000 04:00:00


Quote:

> instructions list a D12-3 as a recommended engine. Has anyone tried this
> small of an engine?

Once.  Never again!  Granted mine is a bit heavy, with fiberglass reinforced
fillets.  The D12 was an exciting flight to put it mildly.  It went up maybe
50 or 100 feet then when horizontal.  I now use mainly econojet F engines
on mine. E's might work ok.

--
Alex Mericas
NAR 62956 Level 2
President, Austin Area Rocketry Group

 
 
 

LOC Onyx - Experience?

Post by Jim Z in V » Sat, 07 Oct 2000 04:00:00


    I don't know why the D12 would be recomended......it sims on the wRASP
software to only 140', with an off the rod velocity of only 28 ft./sec. (and
that's with a 5' rod!) Danger, Danger Will Robinson!!
    An E15-4 looks like the way to go for a first flight.....600' with a 40
ft./sec. velocity off the rod.
    Does the Onyx come with an adapter for 24mm motors? Doesn't it have a
29mm mount?
--
Fly 'em high!
--
Jim Z in Vermont

(to reply by e-mail, remove the polite decline from my address)


Quote:
> Thanks to everyone who related their experience with the Onyx. Mine is
ready
> to fly tomorrow at O'burg, although it will only be wearing primer. From
> everyone's experience, I'll try it without additional nose weight first.
The
> instructions list a D12-3 as a recommended engine. Has anyone tried this
> small of an engine?

> Scott

 
 
 

LOC Onyx - Experience?

Post by Chuck Walde » Sat, 07 Oct 2000 04:00:00


Don't believe it.   I launched mine once with a D12-3 and it flew so low that it
hit the ground before the delay popped the chute.
 A D will lift it off the pad but it won't go much higher.

The good news is that the rocket is sturdy enough to survive such a low flight.
An E engine is about as low as I would go with this one.

Chuck Walden
Vice President, Savannah Area Rocketry Club
NAR Section 613
planetwalden at sprintmail dot com
Savannah, Georgia
NAR 75273 L1