Need some Gyroscopic assistance

Need some Gyroscopic assistance

Post by Chris Taylor Jr » Tue, 16 May 2000 04:00:00



I need help on making a gyro stabilized rocket

Not interested in totally stable, Just Roll Stability

I will assume I can design it to be Fin stable to counter the Precession
that will result from just one gyro.

I assume I just mount it so the gyro's spin plan is parallel with the length
of the rocket ?? (side ways ??)

Any Ideas ??

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http://www.nerys.com/myjeep/
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Need some Gyroscopic assistance

Post by Kevin Re » Tue, 16 May 2000 04:00:00


Chris,

The easiest roll stability using gyroscopes may well be to use
"rollerons". These are flaps outboard on the fins of the rocket, each
with a spinning disk that hangs out into the airstream to drive its
rotation. If the rocket rolls, the precession on the spinning disk
drives the flap out into the airstream with a force proportional to
the rotation rate. As the rocket corrects, the flaps move back into
place.

This scheme was used in early air-to-air ordnance, most notably the
AIM 9: the electronics weren't fast enough to guide in pitch, roll and
yaw, so the design engineers replaced electronic roll control with a
purely mechanical system.

On Mon, 15 May 2000 02:48:58 GMT, "Chris Taylor Jr."

Quote:

>I need help on making a gyro stabilized rocket

>Not interested in totally stable, Just Roll Stability

>I will assume I can design it to be Fin stable to counter the Precession
>that will result from just one gyro.

>I assume I just mount it so the gyro's spin plan is parallel with the length
>of the rocket ?? (side ways ??)

>Any Ideas ??

>--
>This post was spell checked please forward all spelling complaints to
>www.microsoft.com
>-----
>Trust me you can Mail me without Mods

>Chris
>http://www.nerys.com/rocketry/
>http://www.nerys.com/myjeep/
>---
>---


 
 
 

Need some Gyroscopic assistance

Post by Jon3854 » Tue, 16 May 2000 04:00:00


Quote:

>Chris,

>The easiest roll stability using gyroscopes may well be to use
>"rollerons". These are flaps outboard on the fins of the rocket, each
>with a spinning disk that hangs out into the airstream to drive its
>rotation. If the rocket rolls, the precession on the spinning disk
>drives the flap out into the airstream with a force proportional to
>the rotation rate. As the rocket corrects, the flaps move back into
>place.

>This scheme was used in early air-to-air ordnance, most notably the
>AIM 9: the electronics weren't fast enough to guide in pitch, roll and
>yaw, so the design engineers replaced electronic roll control with a
>purely mechanical system.

>On Mon, 15 May 2000 02:48:58 GMT, "Chris Taylor Jr."

>>I need help on making a gyro stabilized rocket

>>Not interested in totally stable, Just Roll Stability

>>I will assume I can design it to be Fin stable to counter the Precession
>>that will result from just one gyro.

>>I assume I just mount it so the gyro's spin plan is parallel with the length
>>of the rocket ?? (side ways ??)

>>Any Ideas ??

>>--
>>This post was spell checked please forward all spelling complaints to
>>www.microsoft.com
>>-----
>>Trust me you can Mail me without Mods

>>Chris
>>http://www.nerys.com/rocketry/
>>http://www.nerys.com/myjeep/

To further describe them (I used to load these things in the Air Force), the
rollerons are notched, like a thick (.25" or so) table saw blade.  

Keep in mind that the rollerons need to be spun up prior to launch (on
Sidewinders, the airflow over them while in flight spun them up) and need to be
on really good bearings.  There is an article in an old HPR magazine where
someone used this method to provide roll stability.  They had air nozzles that
went up into the trailing edge of the "flap" containing the rolleron.  This had
the dual purpose of getting them spinning and holding the flap at a neutral
position at launch.  The flap also needed to be damped so that it wouldn't move
too far one way or the other.

Hope this helps a bit more.

John O'Donnell NAR 60742 L2 CSAR Sec #113

 
 
 

Need some Gyroscopic assistance

Post by Chris Taylor Jr » Wed, 17 May 2000 04:00:00


actually an EXCELLENT Idea !! (I might just have to make something along
those lines) but I need a Single internal Gyro for Scale Reasons

I want to make Mauls Camera Rocket with an at least semi functional Gyro
inside to simulate HIS use of the gyro to keep the camera pointed in the
direction desired to ahve photographed.

--
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Chris
http://www.nerys.com/rocketry/
http://www.nerys.com/myjeep/
---
---

Quote:
> Chris,

> The easiest roll stability using gyroscopes may well be to use
> "rollerons". These are flaps outboard on the fins of the rocket, each
> with a spinning disk that hangs out into the airstream to drive its
> rotation. If the rocket rolls, the precession on the spinning disk
> drives the flap out into the airstream with a force proportional to
> the rotation rate. As the rocket corrects, the flaps move back into
> place.

> This scheme was used in early air-to-air ordnance, most notably the
> AIM 9: the electronics weren't fast enough to guide in pitch, roll and
> yaw, so the design engineers replaced electronic roll control with a
> purely mechanical system.

> On Mon, 15 May 2000 02:48:58 GMT, "Chris Taylor Jr."

> >I need help on making a gyro stabilized rocket

> >Not interested in totally stable, Just Roll Stability

> >I will assume I can design it to be Fin stable to counter the Precession
> >that will result from just one gyro.

> >I assume I just mount it so the gyro's spin plan is parallel with the
length
> >of the rocket ?? (side ways ??)

> >Any Ideas ??

> >--
> >This post was spell checked please forward all spelling complaints to
> >www.microsoft.com
> >-----
> >Trust me you can Mail me without Mods

> >Chris
> >http://www.nerys.com/rocketry/
> >http://www.nerys.com/myjeep/
> >---
> >---

 
 
 

Need some Gyroscopic assistance

Post by Dave Urbane » Wed, 17 May 2000 04:00:00


Quote:

> actually an EXCELLENT Idea !! (I might just have to make something
> along those lines) but I need a Single internal Gyro for Scale Reasons

> I want to make Mauls Camera Rocket with an at least semi functional
> Gyro inside to simulate HIS use of the gyro to keep the camera pointed
> in the direction desired to ahve photographed.

That would be a WAY cool project.  As I understood it, the rocket body was
free to rotate, but the gyroscope kept the camera pointing in the same
direction because the camera was mounted on a vertically rotating frame.
The gyroscope, also mounted to this frame, kept the camera facing the
direction same way no matter which way rocket's body spun on it's vertical
axis.

Why not simply build it the way Maul built it?  Get a relatively heavy
gyroscope from a toy story and mount it on a rotating camera frame inside
the rocket body.  Keep the frame really low mass, so the gyroscope can do
it's job.  Spinning it up  might be a trick, but that would be so cool to
see.  Are you planning on putting a camera in the rocket?  I would suggest
a really low mass camera too.
--
===========================================================================
"Some guy hit my fender, and I said to him, 'Be fruitful and multiply',
but
 not in those words." -- Woody Allen
     __

     /_/

http://public.surfree.com/urbanek


 
 
 

Need some Gyroscopic assistance

Post by Tom » Wed, 17 May 2000 04:00:00


Rollerons. Like the Sidewinder uses. You have free-pivoting elevons on
the base of the fins. At the tip of this, 3/4 imbedded in the elevon
tip, is a sawtooth-shaped disk free to spin. Looks like a little
sawblade or milling blade.. 1/4 of the diameter sticks out into the
windstream with the teeth pointed forward. The disc gets spun up really
fast as the rocket accelerates and the wind picks up. If the rocket
begins to roll, the precession force on the disk pushes the elevon into
the direction of the roll thus damping it. The faster the rocket goes,
the more massive the roll damping.
Quote:

> I need help on making a gyro stabilized rocket

> Not interested in totally stable, Just Roll Stability

> I will assume I can design it to be Fin stable to counter the Precession
> that will result from just one gyro.

> I assume I just mount it so the gyro's spin plan is parallel with the length
> of the rocket ?? (side ways ??)

> Any Ideas ??

> --
> This post was spell checked please forward all spelling complaints to
> www.microsoft.com
> -----
> Trust me you can Mail me without Mods

> Chris
> http://www.nerys.com/rocketry/
> http://www.nerys.com/myjeep/
> ---
> ---

 
 
 

Need some Gyroscopic assistance

Post by Kevin Re » Thu, 18 May 2000 04:00:00


If you have the room inside to do it, having a frame and track inside
the body may be the ticket to do this.



Quote:

>> actually an EXCELLENT Idea !! (I might just have to make something
>> along those lines) but I need a Single internal Gyro for Scale Reasons

>> I want to make Mauls Camera Rocket with an at least semi functional
>> Gyro inside to simulate HIS use of the gyro to keep the camera pointed
>> in the direction desired to ahve photographed.

>That would be a WAY cool project.  As I understood it, the rocket body was
>free to rotate, but the gyroscope kept the camera pointing in the same
>direction because the camera was mounted on a vertically rotating frame.
>The gyroscope, also mounted to this frame, kept the camera facing the
>direction same way no matter which way rocket's body spun on it's vertical
>axis.

>Why not simply build it the way Maul built it?  Get a relatively heavy
>gyroscope from a toy story and mount it on a rotating camera frame inside
>the rocket body.  Keep the frame really low mass, so the gyroscope can do
>it's job.  Spinning it up  might be a trick, but that would be so cool to
>see.  Are you planning on putting a camera in the rocket?  I would suggest
>a really low mass camera too.
>--
>===========================================================================
>"Some guy hit my fender, and I said to him, 'Be fruitful and multiply',
>but
> not in those words." -- Woody Allen
>     __
>     \ \_____

>     /_/

>http://public.surfree.com/urbanek



 
 
 

Need some Gyroscopic assistance

Post by Alan Jon » Fri, 19 May 2000 04:00:00


Rollerons only provide role rate dampimg, not roll stabilization.



Quote:
>Chris,

>The easiest roll stability using gyroscopes may well be to use
>"rollerons". These are flaps outboard on the fins of the rocket, each
>with a spinning disk that hangs out into the airstream to drive its
>rotation. If the rocket rolls, the precession on the spinning disk
>drives the flap out into the airstream with a force proportional to
>the rotation rate. As the rocket corrects, the flaps move back into
>place.

>This scheme was used in early air-to-air ordnance, most notably the
>AIM 9: the electronics weren't fast enough to guide in pitch, roll and
>yaw, so the design engineers replaced electronic roll control with a
>purely mechanical system.

>On Mon, 15 May 2000 02:48:58 GMT, "Chris Taylor Jr."

>>I need help on making a gyro stabilized rocket

>>Not interested in totally stable, Just Roll Stability

>>I will assume I can design it to be Fin stable to counter the Precession
>>that will result from just one gyro.

>>I assume I just mount it so the gyro's spin plan is parallel with the length
>>of the rocket ?? (side ways ??)

>>Any Ideas ??
>>Chris
>>http://www.nerys.com/rocketry/