MIRV Gryphon inspired

[BABAR]

2 fins on each sustainer.
Stability?

 

[GlenP]

This is the Seattle Rocket Works design, not mine, I am assuming that it will be a stable proven design. The number of fins is not as important as the total fin area.
https://www.oldrocketplans.com/srw/srwMG/SRW_MIRV_Gryphon.pdf
my body tubes are slightly longer, and I am thinking about adding a little more incremental nose weight to each sustainer, not too much, but in different amounts to slightly bias the acceleration of each sustainer.

EDIT-well the two-fins can be stable, but not necessarily straight. It will be drag biased, so they will turn, but they should be stable and arc away from each other for the fairly short duration of the mini boost/coast phases. Should make a nice Diamond Break flight path like this, I hope.

 

[GlenP]

After sanding those hybrid balsa/cardstock cones for a while, I decided to scrap them and start over. I just don't like how they each turned out a little different and don't match up as well as I would like with gaps between them. I ordered a set of BT-5 Estes nose cones, and one larger SEMROC balsa cone. I will try quartering the larger balsa cone to make the 4 sustainer cones and see how that works, if I can't get it uniform and fitting together properly, then I will just go with the individual nose cones.

 

[GlenP]

Is it okay to resuscitate your own thread? This was one of the rockets that has been in primer for a while, and I decided to start finishing it. Kind of inspired by the Red Nova. Two of the sustainers are still masked off and drying, but you kind of get the idea... Also, the decal scans were not that great quality, so I am redrawing my own.

 

[kuririn]

Cool, I was thinking about doing this for the longest time. I'd be interested in the details about your manifold/splitter. Is it made of wood? The Estes MIRV uses a plastic splitter.
The Thunderbirds call the maneuver where they split apart at apogee the "High Bomb Burst". Would be neat to paint the sustainers in Thunderbird livery and do that maneuver. Heh heh.

On a related note: at our weekly rocket club metering tonight I came up with a cool name for a rocket - The Slauson Cutoff. You have to be of a certain age to get the joke on these names.

As Art Fern would say: How do you get there? Take the Slauson Cutoff, and cut off your Slauson!

 

[GlenP]

First picture in the thread shows the receptacle for the sustainer motors, these are just short lengths of 13 mm motor tubes inside the main booster body tube which has an 18 mm motor mount. The 13 mm tubes are vented as is the outer booster body. I made a little cone to fill in the gap in between the four sustainer tubes to block the flow in the middle of the sustainer tubes. These were all hand rolled from cardstock, double ply. In the manifold area I just coated lots of white glue, but not sure how many launches it will last.

The original plans call for a sacrificial paper liner in the gap staged area.

My photo of the Diamond Break above is of the Blue Angels. Another cool paint scheme idea. I was thinking of going with red blue green yellow sustainers, but did not want it to look like a toy so much, even though that is basically what it is. A really cool toy that goes whoosh, whoosh, pop, pop, pop, pop. Instead of whoosh pop.

 

[BABAR]

First picture in the thread shows the receptacle for the sustainer motors, these are just short lengths of 13 mm motor tubes inside the main booster body tube which has an 18 mm motor mount. The 13 mm tubes are vented as is the outer booster body. I made a little cone to fill in the gap in between the four sustainer tubes to block the flow in the middle of the sustainer tubes. These were all hand rolled from cardstock, double ply. In the manifold area I just coated lots of white glue, but not sure how many launches it will last.

The original plans call for a sacrificial paper liner in the gap staged area.

My photo of the Diamond Break above is of the Blue Angels. Another cool paint scheme idea. I was thinking of going with red blue green yellow sustainers, but did not want it to look like a toy so much, even though that is basically what it is. A really cool toy that goes whoosh, whoosh, pop, pop, pop, pop. Instead of whoosh pop.

Looking forward to the rest of the build.
Assuming everything lights and delays of the sustainers are close, it should be
Whoosh
Whoosh
P-p-p-pop!

Followed by
Okay, whose got eyes on the booster and does anybody have a tally on all 4 sustainers?

 

[BABAR]

Hope for a windless day and a big clear launch site!

 

[GlenP]

Mainly just have to finish paint and decals, then ready for flight. I decided to go with the four separate plastic nose cones, I just didn’t like how the pieces of the larger segmented cone were fitting together with large gaps between them.

Nice to have some warmer painting weather, but now we are getting the April showers too.

 

[GlenP]

unmasked the other two sustainers...fairly clean mask line, just a couple of spots to clean up.

still not sure if I will add more color to the other white sustainers yet. Maybe just the nose cones or a couple of bands around the front end. Like a 1" yellow or blue, or metallic chrome stripe maybe?

 

[BABAR]

Very nice!
Looking forward to flight report.

 

[GlenP]

I decided to paint the two white sustainers to match the red/white sustainers. It will have a more consistent sport-type look to it that way, I hope. Color pattern was very much inspired by the Estes Red Nova, but the red/white portions are essentially reversed.

 

[BABAR]

Sounds great.
How about a splash of white or something to jazz up the booster?

 

[GlenP]

I am redrawing the decals and might experiment with the white background paper, still playing around with it. Might just do the fin tips in a contrasting color, don’t want to do too much.

 

[GlenP]

All four MIRVs loaded up. Will maybe add some black strips or metallic for trim lines.

 

[BABAR]

Slick!

When does she, oops, when do THEY fly?

 

[GlenP]

Next club launch is Saturday, weather looks promising so far. I have the engines for it. I guess the decals can wait. I am going to try to tape a short streamer to the booster’s central core dowel in between the sustainers.

 

[GlenP]

Wow, what a flight! Was maybe a little windy, and almost marginally heavy for the C6-0 booster, but it managed to get to a good altitude despite weathervaning a little bit off the rod. All four sustainers lit pretty much simultaneously and made a perfect diamond break. I tried to film it but it went out of frame during the boost, naturally. All four sustainers were recovered on the far edge of the field. The booster streamer did not unwrap from the core dowel, it nose dived on the dowel and it broke in two places, should be a simple enough repair. Was definitely an entertaining flight. Would be too heavy for a B engine in the booster. Will try to grab some still frames from my video.

 

[GlenP]

 

[GlenP]

booster on its way down dowel first into the dirt on the far right behind the pad.

 

[BABAR]

Congrats!

 

[GlenP]

It actually might not have weathervaned so much because I had leaned the rod away from us since I did not want staging, or mis-staging rather, to happen directly overhead. Would have been more impressive if it were straight up during staging. But since it had that flight path, all of the sustainers were on a similar course and landed fairly close to each other on the far side of the field. Will definitely fly this one again soon.

 

[stealth6]

Glen, nice job with this rocket and flight...I like it, and thank you for sharing it with us.

It brought back some memories for me. Specifically, a "MIRV like" project I built and posted here on the forum as my very first thread...WAY back when I was a fresh faced and innocent noob. That was a lot of time and rockets ago. Check it out here: https://www.rocketryforum.com/threads/multi-rocket-second-stage.21731/

s6

 

[BEC]

I think this was, by far, the coolest flight of the 38 that went up yesterday! I would love to see it fly again.

 

[GlenP]

Many thanks! Was really a great launch day, was glad to finally get this one in the air, and maiden flights of the 24mm (D12 & E12)Mean Machine and 29mm (E16) Prowler kit-bashed Screaming Eagle. Even got my mini-Max in the air for the first time, that thing really scoots off the pad, I didn't even catch it on video, was just a blur after ignition.

 

[GlenP]

Glen, nice job with this rocket and flight...I like it, and thank you for sharing it with us.

It brought back some memories for me. Specifically, a "MIRV like" project I built and posted here on the forum as my very first thread...WAY back when I was a fresh faced and innocent noob. That was a lot of time and rockets ago. Check it out here: https://www.rocketryforum.com/threads/multi-rocket-second-stage.21731/

s6

That is a cool cluster-stager. I wanted to avoid cluster ignition on the pad with this design, but that gives you lots more options for firing off those sidewinders, pretty clever design.

 

[Flyfalcons]

Of all the days for me to not bring a video camera........

Cool flight! Looking forward to seeing it go again.

 

[GlenP]

I lost sight of it on the way up and totally missed the staging in the video, but you can hear it! I first tried to track the booster on the way down, later the 4 sustainers fell on the far side of the field, just short of the tree line. Forgot that I had this video on my camera, just posted it.



@BEC “all down and on the field”