Going for 100,000 Feet

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Look in the end of the PDF he posted above. Kurt
I assume you're answering me regarding the polyethylene tubing? I only see some reference to some hard plastic tubes, not polyethylene.

Regardless, my charges are virtually identical in appearance to Tony's with the exception of tube material, and will be oriented axially with the tube with the intent that they blow out the ends and pressure impinges directly on the nose cone bulkhead. My rockets are minimum diameter 38 and 54, and my altitude goals are a modest ~20,000 and 30,000, respectively. I don't have room for a bulkhead mounted charge so I really like the idea of a long skinny charge that can lay alongside the chute but not rupture sideways and risk damaging the rocket body which it would be in contact with.
 
I really like the idea of a long skinny charge that can lay alongside the chute but not rupture sideways and risk damaging the rocket body which it would be in contact with.

This is what I need as well.
 
Jim and Tony, have either of you tested with polyethylene tubing or the fiber reinforced vinyl tubing?

I’ve run a couple of ground tests with poly tubes and it works great. It’s stiffer and stronger than vinyl so less likely to rupture out the sides. I have not flown a charge with poly yet, but hope to do so soon.


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I've not played with any other "plastic tubing". I've just used normal vinyl. I chose it to help ease the violent nature of Jims metal tube. I've not had any of the vinyl tubes split. During testing I did have a couple spit the hot glue plug. To correct that, I now kinda pre-heat the vinyl tube with the tip of the hot glue gun (maybe even slightly melt it) and make the plug longer then I had been.

To mount them I doubled up a portion of the ebay lid and then added a pocket for one of the tubes. Then taped the back-up charge tubes to the primary tube...see photos.


Tony

tube1.jpg

tube2.jpg

tube3.jpg
 
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I like this, but it seems to me that it would be easier and lighter to run the charge assemblies down the inside of the booster and direct the charge toward the coupler bulkhead. The chute, chute protector, and shock would wedge them into position. No need to have the additional fiberglass.

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I've monkeyed around with the program and have simulated rockets that went ridiculously high. I don't know if it's a glitch in the system, but there seems to be a tiny sweet spot in rocket design that puts the Earth well behind the rocket, exceeding the requirements for an orbital vehicle. I don't know if it will work, but every one of the designs involved clustered O motors below a single O motor.
 
I've monkeyed around with the program and have simulated rockets that went ridiculously high. I don't know if it's a glitch in the system, but there seems to be a tiny sweet spot in rocket design that puts the Earth well behind the rocket, exceeding the requirements for an orbital vehicle. I don't know if it will work, but every one of the designs involved clustered O motors below a single O motor.

Bath salts?
 
I've monkeyed around with the program and have simulated rockets that went ridiculously high. I don't know if it's a glitch in the system, but there seems to be a tiny sweet spot in rocket design that puts the Earth well behind the rocket, exceeding the requirements for an orbital vehicle. I don't know if it will work, but every one of the designs involved clustered O motors below a single O motor.

If nothing else, your post gives me an excellent excuse to post a pic and video of my favorate rocket ever. This was Terry LeRight's Hercules - a work of art. Two N5800's airstarting two O3400's with an N2540 in the sustainer. Only one of the airstarts lit or it might have gone way high, and there were other issues. I wasn't far from it when it flew.

https://youtu.be/Xs3R-SN7Was

Sorry for the highjack, but every now and then this rocket just needs to be seen.

Jim
 
Sorry for the highjack, but every now and then this rocket just needs to be seen.

Jim
Thanks for that Jim! A lot of info can be found if you know vaguely what you're looking for, but sometimes there are things we just didn't know we needed to see. That thing is wicked.
 
If nothing else, your post gives me an excellent excuse to post a pic and video of my favorate rocket ever. This was Terry LeRight's Hercules - a work of art. Two N5800's airstarting two O3400's with an N2540 in the sustainer. Only one of the airstarts lit or it might have gone way high, and there were other issues. I wasn't far from it when it flew.

https://youtu.be/Xs3R-SN7Was

Sorry for the highjack, but every now and then this rocket just needs to be seen.

Jim

Two words... Suh WEEET!
That is one gorgeous bird.
 
If nothing else, your post gives me an excellent excuse to post a pic and video of my favorate rocket ever. This was Terry LeRight's Hercules - a work of art. Two N5800's airstarting two O3400's with an N2540 in the sustainer. Only one of the airstarts lit or it might have gone way high, and there were other issues. I wasn't far from it when it flew.

https://youtu.be/Xs3R-SN7Was

Sorry for the highjack, but every now and then this rocket just needs to be seen.

Jim

And once again I wish we had a thumbs up [emoji1303] button to like a post without commenting.


Steve Shannon
 
Once again it has been a while, but I am now active on building the second of the three rockets in this project. God willing, the creek don't rise, and I don't run out of money, I want to fly it this September at LDRS in Argonia. There is a 50,000' waiver there, and this rocket sims to about 40,000'. I will be communicating with the team there to gain approval for the flight after the build is farther along.

At long last, I settled on a fin design based primarily on ease of cutting fins of equal dimensions. I do not have a CNC cutter so I have to do it the old-school way. In old school, you have to accept that perfection or near perfection is extremely difficult to achieve. However, if you strive for "uniform imperfection" you can still cut several fins to the same dimensions. The secret is to reduce cutting to a minimum and avoid making individual cuts.

In this case, the fins were "stack-sawed" using a table saw. The process is relatively simple. stack all the parts with common angles together and cut them all in one slice so that whether exact or not, all angles fins are the same dimension ... They are all equally imperfect.

Since I designed both booster and sustainer fins to have the same angle from the leading edge of the root to the trailing edge of the chord, I did not have to worry about cutting different angles. That meant I could cut the leading edge for all 8 fins with just one pass through the saw and just cut off the excess portion on the aft end of the sustainer.

I wanted a spare fin for each of sustainer and booster so i needed 8 total fins.

First thing to do was to cut four lengths of G10 that were as wide as the booster fins were "tall." Next, all four strips were carefully and tightly taped together. Then, after measuring 50-60 times, I made the one cut diagonal cut. After that cut, I taped up leading edges of the sustainer fins, marked the excess portion to be cut off, then after measuring 20-30 times, cut off the excess. In six cuts, I had 8 complete fins.

My initial goal was for the sustainer chord edge to be 4" long ant 1.75" high. The booster chord edge should be 5" long and 2.1875" high. The sustainer was almost an exact match. The booster fins were all 1/8" to short at the chord edge, however the most important dimension, the height, came in at 2.1875."

I fed these new dimensions into the sim and my simmed altitude changed by a couple feet

Here is the latest design and flight simulations according to Open Rocket. OR does not have the capability of factoring in a VK nose cone. RAS Aero does, and it suggests a 40,000' max altitude while OR suggests 38,000'. Both are well north of the current TRA Complex K record.
Re 01.jpg Stack Sawing FIns.jpg Re 02.jpg
 
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Haven't seen you in a long time, dude. I was wondering what ever happened to this project!
 
Haven't seen you in a long time, dude. I was wondering what ever happened to this project!

Other things had to take priority. Our club hosted NSL 2018 and I am the treasurer. Lots of work on that ... little time to build and the time that I did have was spent on an upscale Estes Alpha done in original markings since Verne and Gleda were going to be there. The Alpha by the way was glorious. Flew on an AT L1040 Dark Matter. After NSL I was burned out a little and really didn't do much the rest of the summer. But now it is back to this. Really hoping to get out to Argonia with it. If I do, the Alpha will probably come along for the ride among other toys.
 

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My biggest apprehension of this and the next build is the transition. I have to buy a perfectly good nose cone and cut the tip off. If I cut too far, it is ruined. Lots of sanding if I don't cut far enough, but it is a better alternative. Still have to be careful because it is easy to sand too far as well. Very fine line. This is what I ended up with with a full-length coupler shown for demontration only.
Re 03.jpg

The actual 38mm coupler tube will extend 1.5" from the transition into the Interstage Coupler. THis leaves 3" to pack in a 8"{ drogue chute and some shock cord, which will be glued in place instead of bound with eyebolts to save space, weight, and better balance the overall rocket. The droge coming out of the forward end will also cause the booster to come down in a more vertical position which should reduce drift and also make it easier for the booster main to deploy. I am using DD deploy for the booster because its apogee alone sims to 7,000'.

This is the overall configuration of the Interstage area.
Interstage configuration.jpg
 
You should come up to Geneseo for NYPower.
On my list, but it is hard with two small kids. It either turns out to be an expensive whole family vacation, or else I have to leave them with my wife for the weekend. My kids are always reminding me how they see me as it is.
 
Something just occurred to me about efforts to ignite all the BP charge at 40,000'. Seems that a magician's flash paper used as wadding would help burn all the BP. Wrap the BP and the tip of the e-match inside it, then add additional paper as packing in the 3" charge tube which would create a fireball that any unspent BP would fly through. Any thoughts?
 
Back to the transition. So I got the cutting part done, but that was the least of my worries. How do I align it so that the sustainer stands straight up from the booster instead of off kilter. So I stood the thing up and tied to eyeball it, and realized I would never get close. I would need some way of holding it in an aligned position for at least 3 hours until the RocketPoxy sets.

Then a brilliant idea farted out of my head. The aft end of the transition is the same diameter as the booster. I happen to have 2 x 54mm CRs with 38mm holes They were designed for cardboard tubes, but a couple masking tape wraps around a FG tube and I could make them as snug as a bug in a rug.
Re 05a.jpg

First thing I did was cut a 1/2" long section of 38mm tube and glue it to the aft end of the coupler that comes out of the sustainer. This will hold the coupler in place if the transition is positioned upside down. I also get an ample amount of epoxy in place inside the transition to keep it in position after it sets.
Re 05b.jpg


I positioned the two CRs around the leftover 38mm tube. Then I glued the coupler into the transition and positioned it on top of the 38mm tube.
Re 05c.jpg

Next, I positioned the coupler and transition into the 38mm tube and slid it into the 54mm airframe until the mid-to-aft section of the transition was snuggly wedged into the 54mm tube. Then I tightly taped a couple pieces of angled aluminum around both the aft end of the transition and the 54mm tube.
Re 05d.jpg

Now the aft end of the transition is lined up with both the 54mm airframe and the angled aluminum, and the 2 CR's holding the 38mm tube holds the forward end in place. Once the rocketpoxy sets, I will pull everything apart and cut off all but 1.5" of coupler from the end of the transition. Leaving the excess coupler on until everything sets helps to better keep everything lined up.

Heat the Rocketpoxy up with a light to speed up the curing process and wait.
Re 05e.jpg

And since I have a little RocketPoxy left over, glue the sustainer fins to the airframe. I use a lot of old school techniques because of budget and space. However my son 3D-printed a set of fin alignment guides that are excellent for this project. I'll take any technology I can get, but in the meantime, I'll go old school when technology isn't available or too expensive.
Re 06.jpg
 
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Now it is starting to look like a rocket. All major cutting and parts assembly is done. From here the process slow down a little. Need to fillet and T-to-T fiberglass the fins. Then lots of sanding. I an going to make internal motor mounts out of FG. They will be thinner and lighter than aluminum. Space inside is a premium for recovery and other electronics.

Still this went together a lot quicker and a lot more smoothly than Do, the first rocket in this project, and I am hopeful that it will continue to progress just as well.
Re 08a.jpg Re 08b.jpg Re 08c.jpg
 
If nothing else, your post gives me an excellent excuse to post a pic and video of my favorate rocket ever. This was Terry LeRight's Hercules - a work of art. Two N5800's airstarting two O3400's with an N2540 in the sustainer. Only one of the airstarts lit or it might have gone way high, and there were other issues. I wasn't far from it when it flew.



Sorry for the highjack, but every now and then this rocket just needs to be seen.

Jim


Doubly sorry about the hijack but Jim's post doesn't show the art form at it's best. Terry is an amazing master at building this stuff. He picked it up in no time, like skipping a smooth rock on calm water. I should add, This entire rocket was scratch built. ALL of it.

For anyone who wants to flip through the construction photos.
https://s273.photobucket.com/user/pyramid12/library/Hercules?sort=6&page=1
 
Sweet rocket. Now back to this project.

Deployment:
I have a Raven 3 altimeter which will serve as the sustainer's DD system and igniter for the sustainer motor. I am hoping that this time I can run flat wires internally to the motor from the AV bay instead of externally as I had to do with Do...the first rocket. It is going to be difficult in a 38mm tube to add redundant electronics and second high altitude BP charge setup. Since there is a fourth charge available on the Raven, I will add another charge that will ignite at 18K-20K feet on the way down. The apogee deployment will be a streamer so it is more likely to survive a high speed deployment.

The booster's AV bay will be in the transition. A 38mm bulkhead fits on the forward end of the coupler tube sticking out of the transition and a 54mm bulkhead will attach to the coupler out the aft end. I will use a Perfect Flite MT4 Timer in the booster AV bay to set off a small separation charge when the booster motor burns out. Since the booster's apogee is projected to be 7,000' itself, it needs to have a dual deploy system as well. The drogue chute will rest in the interstage are between the transition and the aft end of the motor. There will be a bulkhead to both protect the chute against the separation charge and also serve as the drogue chute bay. Because of the weight of the booster compared to the transition, I will deploy an 8" drogue chute out the nose of the transition. The booster will essentially fall "standing up" which should prevent drift. The stratologger will deploy a 30" main out the aft end of the transition at around 700'.

The downside of having a CTI 38mm rocket is that the nozzle serves as the aft closure and thrust ring, I will need to sand most of that off so the nozzle can fit into the interstage coupler. Since this is a TRA flight, I can do this. If it were NAR, I'd have to leave it alone even though I am doing nothing with the nozzle itself.

AMW ProX has forward closure adapters with threaded ends on them specifrically for CTI 38mm and 54mm motors. I will use these to mount to internal motor retainers. I will fabricate the motor retainers with a bulkhead which the cloure adapter will screw into attached to a section of coupler that will serve as a motor block. That will help save the length of the rocket. If Rocketpoxy can hold surfac-mounted fins on a rocket moving at Mach 1, it should be able to hold a FG coupler in place as a motor block inside a FG tube.

There will be a 70CM BRB GPS transmitter which will send location packets in real time enabling me to track the sustainer to apogee. It will be located in the nose cone. Here's a close-up of the booster separation and deployment setup.

Interstage configuration.jpg
 
The downside of having a CTI 38mm rocket is that the nozzle serves as the aft closure and thrust ring, I will need to sand most of that off so the nozzle can fit into the interstage coupler. Since this is a TRA flight, I can do this.

Does this tactic still count for the TRA altitude commercial records? Do I need an L2 to do this or does TRA not view it as a motor mod even at L1? Just a fellow TRA member kinda curious. I would love to do this to a CTI 24mm thrust ring for uh reasons someday. It sure beats machining a new aft closure.
 
Does this tactic still count for the TRA altitude commercial records? Do I need an L2 to do this or does TRA not view it as a motor mod even at L1? Just a fellow TRA member kinda curious. I would love to do this to a CTI 24mm thrust ring for uh reasons someday. It sure beats machining a new aft closure.
Definitely not. Modifying the motor from its as-certified condition makes it Research by definition, and inelligible for commercial record attempts.
 
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