IRIS Sounding Rocket - SCALE DATA !

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Part 7 . . . Last part . . . PDF Files & miscellaneous.

Dave F.

booster_bandw.jpg booster_color.jpg IRIS_017_xerox.jpg IRIS_018_xerox.jpg Iris-2-stage.jpg
 

Attachments

  • IRIS DRAWING.pdf
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  • iris_arc_1.pdf
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  • iris_arc_2.pdf
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  • IRIS_CENTURI_DATA.pdf
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  • 19640002804_1964002804.pdf
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Your pictures of the display at Goddard was a sad sight. Not maintained and hit too many times by lawnmowers thus the reasons for the cracks. Was an example of a spiral-wound motor casing. Was there a few times and got to launch with the local club onsite for MR demos for the public and visit the backroom of museum with curator. If I remember correctly there was an ASP at the road entrance to the museum
 
Warning thread resurrection ahead!

I am working on a BT-80 scale IRIS rocket. I am seeing some inconsistencies in the Nose cone. The drawings above are little hard to read an I may be misinterpreting some things. I am attaching a picture of my sketch of the nose cone in Solidworks. This is a mashup of two of the drawings above.
The nose cone tip (4 inches effective length) 1.684 diameter 10.8 degree half angle) and the main body of the cone. There is a slight problem on the tip. I get a diameter of 1.716 when the angle is 10 degrees 48 minutes ( .8 degrees). I am neglecting this for now. The big problem is in the main body.
I have the overall length of this part as 76 inches. the small end is 1.684 inches diameter. The location of the center and tangent point for the radius is 36 inches back from the small end. Radius is 305 inches. As you can see from the picture the 305 radius does not meet at the 1.684 diameter.
Where am I going wrong? Am I miss reading a dimension? It seems like the 305 radius should intersect the tip at 1.684 AND be tangent.
 

Attachments

  • Iris nose  cone CAD sketch.jpg
    Iris nose cone CAD sketch.jpg
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I would disregard the G. Harry Stine drawing, as it is a drawing of a model and not an original prototype.

I would also disregard the "IRIS" drawing, as it erroneously reports the diameter of the Nose Cone as 12.5", when it is 12" diameter. The first two images clearly show the 12.5" diameter "band" and the fact that the nose cone is, in fact, the same diameter as the main airframe.

That leaves Peter Alway's ROTW drawing . . . It is well drawn and cites sources of data ( including the Stine drawing, for some reason ).

NOTE : The Blueprint shows a Nose Length of 76" . . . However, upon closer examination, the Nose Cone Tip was not included in that 76" dimension.

When the 5.00" length of the Nose Cone Tip is added to the 76 the result is 81.00", 1-inch longer than the ROTW Drawing.

Looking at the "Nose Skin" drawings, it is clear that the contour of the Nose Cone becomes "parallel" at a point 56.00" back from the forward end, remembering that the 5.00" long Nose Cone Tip would need to be added, yielding a "curved length" of 61.00" and a "parallel" section, 20.00" in length.

We, now have the "dilemma of the extra inch" . . .

This is unconfirmed, but I believe that the base of the Nose Cone Tip may recess into the lower section when the Nose Cone is assembled, accounting for the "extra inch"

Dave F..

Nose Skin 1-2.gifNose Skin 2-2.gifNose Skin Extension.gifNose Tip Type B.gifNose Tip Type B.gifTube Weldment 1-2.gifTube_Weldment_2-2.gif
 
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Ahhh! 56 inches not 36 inches!.. That fixes the main nose piece issue.

RE: the nose tip: The overall length of the piece is 5 inches BUT 1 inch of that fits inside the main nose cone. Note that the diameter of the tip is 1.684 1 inch from the fat end of the part. That is the same diameter as the diameter of the big nose piece at the small end.
5-1 equals an effective nose tip length of 4 inches.
76+ 4 = 80. Problem solved.
 
You have the transition piece dwg sk4-22533. Is there a chance you have a drawing of the front part of the rocket tube that mates with this transition piece? This part mates with the nose cone on one side and I assume the rocket tube on the other.
I am trying to figure out the source of the 12.5 inch dimension at the nose cone/body junction.
What I feel confident about are:
1. OD of nose cone 12.162 inches. source: dwgs above
2. OD of transition piece 12.162. dwgs above.
3. OD of main body tube 12.00 source: Rocket data sheet in post 1 of this thread.

The 12.5 dimension is either a feature on the front of the main rocket tube or an error and the dim is really only 12.162.
 
You have the transition piece dwg sk4-22533. Is there a chance you have a drawing of the front part of the rocket tube that mates with this transition piece? This part mates with the nose cone on one side and I assume the rocket tube on the other.
I am trying to figure out the source of the 12.5 inch dimension at the nose cone/body junction.
What I feel confident about are:
1. OD of nose cone 12.162 inches. source: dwgs above
2. OD of transition piece 12.162. dwgs above.
3. OD of main body tube 12.00 source: Rocket data sheet in post 1 of this thread.

The 12.5 dimension is either a feature on the front of the main rocket tube or an error and the dim is really only 12.162.

Nose Skin Extension.gif
 
Yes, that is the transition piece I am talking about. The nose cone mates to the left side of section A-A.
I believe the main rocket body mates on the right side.
Do you have a drawing of the mating part?
 
Maybe my post belonged here...

I am looking to make a two-stage IRIS with both the 7x cluster as well as the Hydra 3x cluster variant.

There are some good photos of the 7x cluster booster version. However, the only pictures I can find of the Hydra 3x cluster version are the ones below. Does anyone have other pictures of the Hydra version (particularly of the nozzles on the booster)?
1690804362232.jpeg

1690804739012.png

1690804381121.jpeg

For the Hydra version (3x booster cluster) I am relying on dimensions in this document. Planning this for BT-80/2.6" main sustainer which makes the booster tubes BT-60 according to my calculations. I think making this for BT-80 and 2.6" tubes gives good options to go MPR or HPR.
1690804240420.png
 
Any chance you have ever come across a picture or more details on the motors / shrouds for the 3x cluster Hydra booster w/ the Sparrow motors?

Wondering what the shrouds should look like.
This may help ( a little ).

https://apps.dtic.mil/sti/citations/AD0431792

QUOTE :

"The Hydra-Iris is a two-stage system, employing a cluster of three Mk 6 Mod 0 Sparrow motors as a booster and an Iris sustainer that is capable of being launched from any spot on the oceans surface."


END QUOTE :

SPARROW DATA . . .

http://cv41.org/newsletters/V19I4.pdf

http://cv41.org/newsletters/V19I5.pdf



The SPARROW Booster . . .

1690836216438.png

1690836132006.png

1690836444964.png
 
This may help ( a little ).

https://apps.dtic.mil/sti/citations/AD0431792

QUOTE :

"The Hydra-Iris is a two-stage system, employing a cluster of three Mk 6 Mod 0 Sparrow motors as a booster and an Iris sustainer that is capable of being launched from any spot on the oceans surface."


END QUOTE :

SPARROW DATA . . .

http://cv41.org/newsletters/V19I4.pdf

http://cv41.org/newsletters/V19I5.pdf



The SPARROW Booster . . .

View attachment 595165

View attachment 595166

View attachment 595167
Thank you -- I was wondering if all the "Sparrow" stuff out there referred to the same motors...

I guess that there are no exposed shrouds on those models but many have boat tails. Not sure if the Hydra booster had boat tails / tapered shrouds or straight ones like the 7x engine cluster. It does look like tapered shrouds in the brochure depiction so I suppose that might be a safe bet to go with tapered shrouds / retainer caps.

1690847429268.png
 

This drawing seems to show an interstage coupler that with an enclosed connection from the booster to the nozzle of the sustainer. That's clearly not the case with all the other information that shows the 7- or 3-motor cluster boosters, which just have a cone and free air between them. Does anyone know what the source of the representation in this drawing is? It looks like a three-motor cluster, but is maybe even shorter than the 7-motor cluster that's documented.
 
This drawing seems to show an interstage coupler that with an enclosed connection from the booster to the nozzle of the sustainer. That's clearly not the case with all the other information that shows the 7- or 3-motor cluster boosters, which just have a cone and free air between them. Does anyone know what the source of the representation in this drawing is? It looks like a three-motor cluster, but is maybe even shorter than the 7-motor cluster that's documented.
19660081606 - Performance summary for the iris sounding rocket vehicle,1961

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Possibly. In all the other images/drawings, there's a body-diameter section that goes all the way to the back of the fins and conceals the nozzle. Then, the "crown" of the booster scaffolding frame abuts that. In this, it looks like the crown of the booster scaffolding seats where that cylindrical piece starts, and the tip of the booster's blast cone actually enters the nozzle of the sustainer. But then the whole assembly would have to be shorter, or the booster correspondingly longer. And there's no information about a different booster. So poor drawing seems like the best-supported answer, I guess.
 
Yes, that is the transition piece I am talking about. The nose cone mates to the left side of section A-A.
I believe the main rocket body mates on the right side.
Do you have a drawing of the mating part?

Late to the party on this question but I was also looking for better pictures of the connecting part between body tube and NC Extension. I found a couple of slightly higher-resolution picture of the IRIS at Goddard which shows the detail here a bit better (if you can turn on your LIDAR eyes to see through all the layers of paint may be able to figure out what those parts look like). Does anyone else happen to have better pictures of that transition/bracket section of the IRIS rocket?

1691265371862.png 1691265563332.png
 
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For some reason I cannot find the height of the sustainer fins on 3-fin IRIS Hydra version.

As far as I can tell the sustainer fins on the 4-fin IRIS version are 17.195" (43.67cm) tall [Based on 47.14" fin span and 12.75" airframe].

On the other hand, the only fin dimensions provided for the IRIS Hydra drawing indicates the fins are 35.6cm tall (but I assume these are the rear fins per the A-A notation).

Another way I can try to compute / check this -- the sweep angle for the IRIS fins is given as 45 degrees (in some of the scale data above). Given that the difference between the root length and tip length is 46.5cm for the IRIS Hydra sustainer fins, I could also assume the height of the sustainer fins are 46.5cm.

Anyone, have a fin height dimension for IRI Hydra 3-fin sustainer configuration or an informed opinion on this?

1691267204616.png
 
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