Two-stage HPR design build

[SteelyEyed]

I have decided to secure the interstage coupler to the forward booster airframe tube with an anchor bulkhead. Pic 1 shows the booster av-bay bulkhead and the anchor bulkhead. Pic 2 shows how the two bulkheads engage. The anchor bulkhead will be epoxied in place within the forward airframe tube on the booster (as shown in Pic 3) and the three all-thread rods from the interstage coupler will stick through the anchor bulkhead and be secured with wing nuts...

 

[SteelyEyed]

Progress is slowing due to busy time of year, but here's a small update. Attached pic shows the large vent holes cut in the av-bay tube which opens up the "pressurometer" to the air volume within the booster tranition. I still need to determine the appropriate size for the static vent port holes (3 each) to be drilled through the airframe tube into the aft shoulder of the transition (which will expose the Adept22 to atmospheric pressure).

 

[sodmeister]

Wow ,you talk about nice clean work !! I love watching this thread ,many interesting and cool ideas to be had.

Cheers

Paul T

 

[SteelyEyed]

Wow, you talk about nice clean work!! I love watching this thread, many interesting and cool ideas to be had.

Cheers

Paul T

Thanks Paul,
Glad you're enjoying the thread. Many, of the "cool ideas" came from things I've learned surfing this forum (although, I have picked up a few things at launches, observing rockets built by others). That's what it's all about, sharing stuff we've learned with others.

Speaking of cool ideas, I figured out a nifty technique that allows me to easily secure my Garmin DC30 gps transmitter in the nose cone (removal is equally quick and easy). I've never seen it done this way before, although others may have already utilized a similar approach. Either way it's worth sharing. I'm going to do a short video rather than try to write it up (pics would work, but not as well). My son is coming over for dinner tonight, I'll get him to operate the camera and we will get it posted later tonight or tomorrow...

Bret

 

[sodmeister]

Now that sounds like a great idea.I look forward to seeing that ,as I`m sure do the others !

The best part for me about building rockets ,is the "tinkering" I get to do in my workshop.

I love tools !!


Paul T

 

[SteelyEyed]

I discovered this technique when I was working on my L3 project https://www.rocketryforum.com/showthread.php?t=6471. I cut off the base of the nose cone, because I needed the extra volume for storing the laundry. I found that there is a "lip" or a "ridge" around the circumference where the shoulder meets the base of the nose cone (that is created in the vacu-form process). It forms a surface on which a bulkhead can be mounted. For that rocket I installed a ring with t-nuts inserted on the back side of the ring, to which I screwed down a bulkhead with a U-bolt on it (and a Garmin DC20 was also mounted inside the nosecone). On this rocket I did it without any additional components, screws, t-nuts, etc.

As you will see on the video, this approach makes a quick and easy, tool free way to install and remove contents from within the volume of the nose cone...

[YOUTUBE]m3VBjEu3PWg[/YOUTUBE]

 

[SteelyEyed]

I forgot to mention the "obvious" in the above video. The most important thing to make this approach work, you must get the diameter of the bulkhead just right so it has a nice tight fit in nose cone when pulled into final position. It is nominally, the same OD as the shoulder of the nose cone, but should be a "hair" larger to get the desired tight fit.

Also, I mentioned in the video that the U-bolt was used to "attach the parachute," more accurately it's used as an attachment point for the shock cord (the main parachute will be attached several feet down the shock cord). So, the only "weight" that the bulkhead has to support is its own weight and that of the Garmin DC30.

 

[Aksrockets]

geinus!

 

[SteelyEyed]

geinus!

That's what I thought! I really like the way it works.

 

[tightwad]

Great build. Very high level of craftmanship. Are you planning to fly at night? I think with all that natural green glow, you wouldn't even need lights. By the way, thanks for glowing salmon, it makes it easier to catch. LOL Seriously, now, your build is very impressive. LOve to see it fly.

 

[SteelyEyed]

Great build. Very high level of craftmanship. Are you planning to fly at night? I think with all that natural green glow, you wouldn't even need lights. By the way, thanks for glowing salmon, it makes it easier to catch. LOL Seriously, now, your build is very impressive. LOve to see it fly.

Hey tightwad, welcome to the thread. Thanks for the positive feedback. No, I don't plan on any night ops with this bird. I assume since you live in WA that you are likely going to get to see this one fly (BTW, have we met?). Are you gonna be at FITS 2012? I will probably attempt to fly it there. If all goes well, I might get a chance to fly it at a March or April launch... we will see.

Bret

 

[sodmeister]

I forgot to mention the "obvious" in the above video. The most important thing to make this approach work, you must get the diameter of the bulkhead just right so it has a nice tight fit in nose cone when pulled into final position. It is nominally, the same OD as the shoulder of the nose cone, but should be a "hair" larger to get the desired tight fit.

Also, I mentioned in the video that the U-bolt was used to "attach the parachute," more accurately it's used as an attachment point for the shock cord (the main parachute will be attached several feet down the shock cord). So, the only "weight" that the bulkhead has to support is its own weight and that of the Garmin DC30.

Yes ,I saw the video ,but the pics you posted show the ridge inside the nosecone more clearly ,so I have a better idea of how the bulkhead fits in such a manner.

Only problem I have now ,is this urge to cut a nosecone apart ,so I may require some form of reimbursement LOL

Genius indeed !


Paul T

 

[bill2654]

Love watching your builds Bret. Very inspiring. Cant wait to see it finished.

 

[tightwad]

Hey tightwad, welcome to the thread. Thanks for the positive feedback. No, I don't plan on any night ops with this bird. I assume since you live in WA that you are likely going to get to see this one fly (BTW, have we met?). Are you gonna be at FITS 2012? I will probably attempt to fly it there. If all goes well, I might get a chance to fly it at a March or April launch... we will see.

Bret

SteelyEyed, I do not believe that we have met. Living on the coast makes it hard to meet other fliers and it is a long trip to FITS, but it is one of the launches I want to go to. Looking forward to more of your thread build.

 

[SteelyEyed]

Love watching your builds Bret. Very inspiring. Cant wait to see it finished.

Thanks Bill. More posts are coming, but I didn't get much done today.

Merry Christmas,
Bret

 

[SteelyEyed]

Most of today was spent doing fillets on the sustainer. I did get the ramjet intake tubes on it. I'm liking the way they look. Here's a peek... I can't pick it up to get some better pics cause that fillet is fresh.

Cheers,
Bret

 

[SteelyEyed]

Also cut a scrap piece of LOC 3" tubing and added a nose cone to the booster, so I can fly it all by itself...

 

[sodmeister]

While the old photon Probe is cool.....that is just too much ,can`t say too much about the design ,and the further along it gets the better it looks.

Are you getting tired of fillets yet ?

As soon as i get some projects off the build table ,I should like to do something with a transition ,as i have one in the parts box.....3" to 4" I believe.Perhaps the creative juices will flow over the holidays ,helped of course by a libation induced vision or perhaps good old fashion plagiarism

:snowman:

Paul T

PS -How long would you say the booster is ? (not a plagiarism directed question BTW)

 

[SteelyEyed]

While the old photon Probe is cool.....that is just too much ,can`t say too much about the design ,and the further along it gets the better it looks.

Are you getting tired of fillets yet ?

As soon as i get some projects off the build table ,I should like to do something with a transition ,as i have one in the parts box.....3" to 4" I believe.Perhaps the creative juices will flow over the holidays ,helped of course by a libation induced vision or perhaps good old fashion plagiarism

:snowman:

Paul T

PS -How long would you say the booster is ? (not a plagiarism directed question BTW)

Paul,
I'm just enjoying the process (it's therapy from the daily grind), not really getting tired of doing fillets... I'm getting pretty good at it though.

PS Reply: According to RS9 (with the nose cone included) the Booster overall length is 48.5 inches. That includes the two transitions. The 4" airframe is 24" long and (made up of 2 sections). Then there's the 5 inch piece of 3" tubing at the top, and 1.75 inch piece below the aft transition (boat tail). Given your penchant for firearms, I'm getting a vision of your next design.

 

[SteelyEyed]

Still doing fillets today... But, I also completed another step. I used GLR expandable foam to attach the av-bay tube inside the transition. I chose to foam it in rather than epoxy it, because in the event that this bird does not drag separate and I choose to ignite the sustainer stage (which will certainly cause separation), it will likely damage the plastic transition. So, with the foam, if I want to replace a damaged transition all I have to do is run a knife blade around the inside circumference of the transition to remove it. Then scrape off the excess foam and foam on another transition. Just planning ahead. If you look carefully at the pic below you can see the foam in the annular space between the av-bay tube and the transition.

 

[SteelyEyed]

Filleting, filleting, filleting... Only 2 more fillets left to do. While they are setting up, I thought I'd post a pic or two.

And while I'm at it, Merry Christmas TRF!

Bret

 

[dixontj93060]

Filleting, filleting, filleting... Only 2 more fillets left to do. While they are setting up, I thought I'd post a pic or two.

Amazing fillets! I guess practice makes perfect, huh?

 

[sodmeister]

Filleting, filleting, filleting... Only 2 more fillets left to do. While they are setting up, I thought I'd post a pic or two.

And while I'm at it, Merry Christmas TRF!

Bret

When you measure your fillets in linear miles , you know you`ve done a lot !

Merry Christmas Bret !

Paul T

 

[SteelyEyed]

Amazing fillets! I guess practice makes perfect, huh?

Thanks dixon. Yep, I've had 40 years of practice, practice, practice...

In fact I've been practicing a new fillet technique using JB Weld and milled fiber (that particular project is still a secret). Mike Fisher says his JB Weld/fiber fillets have survived Mach 3. A good target to shoot for...

 

[SteelyEyed]

When you measure your fillets in linear miles , you know you`ve done a lot !

Merry Christmas Bret !

Paul T

Thanks Paul. Did you get your "non-plagarism" design worked out? I'm interested in what you're thinking regarding fins on that one...

 

[sodmeister]

Thanks Paul. Did you get your "non-plagarism" design worked out? I'm interested in what you're thinking regarding fins on that one...

No sir ,not yet.The old rockerty workshop is busier than Santa`s right now.Hopefully I`ll get a bunch of stuff done during the holidays ,as I have the week off.

As you know ,scratch building takes a lot of time ,what with cutting tubes ,fins and such.I also make my own centering rings, so that takes time also (not because I`m cheap ,I just like to tinker in the old woodworking shop and make my own parts where I can)

Regards

Paul t

 

[SteelyEyed]

I finished all the fillets and continued to progress a bit in the last few days. On the sustainer, I installed the 10 series airfoil rail guids from SC Precision (https://www.scpconcepts.com/). I like the look...

 

[SteelyEyed]

Here's a few shots of the sustainer. I still have to build the av-bay (and figure out how I'm going to seal it and secure it in place). I'm not going to start on the av-bay (much), until I receive the new Raven Power Perch and the Missile Works WRC+ (that could be February). I really need to have both of those in hand so I can figure out how much space I need and how I want to squeeze them into the av-bay along with with dual RouseTech CD-3 hardware. There's still a lot to be done in terms of paint prep (aaaargh). The thought of paint prep usually leads to me think about something more fun, like starting another project (it' a long winter)... Hmmm, maybe another sustainer to go with this set.

I like the look of this sustainer. I might just have to build a bigger one of these down the road (I'm thinking 5" airframe and 98mm MMT).

 

[RedMaxFlyer]

I was glazing over this thread for weeks looking at the original title and thinking it was another basic two-stage build thread... then I saw who started it.

Great build as usual. I can't wait to see this one fly! Altitude-wise, will it be flying from the racetrack or the away cell?

 

[SteelyEyed]

I was glazing over this thread for weeks looking at the original title and thinking it was another basic two-stage build thread... then I saw who started it.

Great build as usual. I can't wait to see this one fly! Altitude-wise, will it be flying from the racetrack or the away cell?

RMF,
Greetings and welcome to the thread. I could keep it under 8K ft with motor selection, and fly from the racetrack. With the largest motors I can stuff in it, it sims to 13K ft. I'm thinking it will likely be an "away cell" flight when I go two-stage. I plan to fly each (booster and sustainer) by themselves first and make sure they are individually flightworthy and all the electronics work as planned. Then I will go for two-stage flight. If all goes well it will be flying at FITS 2012.

Bret