nater Posted April 8, 2013 Posted April 8, 2013 Dag wanted to see some pictures of this build, so maybe others do too. I like rockets of all types, and got my first interest in rocketry by building Estes kits as a kid. Now, I have decided to step it up and build a fiberglass dual deploy rocket capable of flying on level 1 high powered motors. After a suggestion from another club member, I called up Wildman and ordered one of his kits. I ordered the Wild Child and he accidentally sent an Eagle Claw. No big deal to me, as the kits are similar. I decided against the split fin design of the Eagle Claw for my first HPR build, so I have something closer to the Wild Child as well as extra parts for another build! Working with fiberglass is new to me, but I it is much nicer than filling all the spirals on the phenolic tubing. The first step was to make a recovery harness and attach it to the nosecone with epoxy. The knot is tied on a piece of kevlar cord to attach to a quick link. On a larger rocket, this might not be strong enough, but this was just following the instructions with the kit. Next, some bulkheads were made for the AV bay. I might change out the eye bolts for forged ones, as I have been told that the force of the ejection charges can open them up. Due to the split fin design on the original kit, the body tube has some length I wanted to cut off at the bottom. This worked out great, because I needed a centering band for the coupler / AV bay anyway. A miter saw made quick work cutting the fiberglass tubing. Just remember to wear gloves and a respirator to avoid the irritation from the fine glass particles. The centering band was then epoxied into place on the coupler. The bulkheads pictured above will be held in with all thread rod and the mount for the electronics. Unfortunately for me, I was planning on using the Adept22 altimeter, which they quit selling right before I was going to order it. There are a few more altimeters in the same price range that should be released soon, so I will finish the AV bay once I have the electronics on hand. You will notice that one end of the coupler is sanded heavier than the other. I think the tubing for the payload section was cut from different stock than the booster. The ID's were a little different, so the coupler was just sanded down for a good fit. Next up was the motor mount. Again, the instructions for the kit called for making a Y shaped harness out of kevlar cord and securing it to the motor mount with epoxy with a centering ring slipped over for good measure. A loop was tied for another quick release. The fins were masked off, and a rounded shape was sanded into the leading and trailing edge. I thought about sanding a true airfoil shape, but the reality is this rocket will mostly be a park flyer and does not need optimum performance. The next shot is a dry fit with the fins taped to the motor mount in order to position the centering rings properly. The centering rings were then epoxied onto the motor mount along with the motor retainer and set aside to cure. Once cured, the motor mount was secured into the body tube of the booster section. The root edge of the fins were "double dipped" with epoxy making a quick and dirty internal fillet. I still need to mix up some filler, make the external fillets and paint the rocket. I wasn't sure what to do with the gap between the top of the fin and the fin slot. I don't know if it should be filled, or just pull the fillets over it and sand to a nice aerodynamic shape. I have an Aerotech 29/40-120 and 29 mm CTI cases for 3 and 6 grain motors. This is small for high power, and I doubt I will fly it on a 6 grain motor so I make sure to get it back. Open Rocket sims this to about 2000 ft on a G-80 and about 5000 ft on a small H, but I can't seem to get the program sim deployment at apogee. I keep getting a warning that the airspeed is too high at ejection, but I configured the motors with no delay and using apogee detection to pop the ejection charge. I must be missing something somewhere, but then it is free software too.
JFeve81 Posted April 8, 2013 Posted April 8, 2013 Nice rocket. I've got an Aerotech Initiator and a few G80 motors to fly her on. It's more a mid-level rocket and I haven't flown it once in the several years that I've owned it but it was a fun build. Hell I've got 3 Estes rocket that have been waiting to be built or finished in just as long. I had big plans back around 2004-2005 of building a big cluster rocket. Had a big cardboard tube I was going to use as a mold to lay some fiberglass on. Followed by a handmade nosecone and fins. From my mock-ups the finished rocket would have stood about 6.5 feet tall. Rocksim said it should of at least flown straight.
dagabu Posted April 8, 2013 Posted April 8, 2013 Only one work of advice from me Nate: A forged eyelet even 1/2 the size will be twice as strong as a closed loop eyelet and a series of aluminum washers instead or the smaller one you are using on the nut side will keep the bulkhead from "coneing" pulling the bulkhead away from the tube walls. Nice looking rocket, cant wait to see what your paint looks like. Are you thinking about a whistle fuel motor on this bad boy?
nater Posted April 8, 2013 Author Posted April 8, 2013 (edited) Only one work of advice from me Nate: A forged eyelet even 1/2 the size will be twice as strong as a closed loop eyelet and a series of aluminum washers instead or the smaller one you are using on the nut side will keep the bulkhead from "coneing" pulling the bulkhead away from the tube walls. Nice looking rocket, cant wait to see what your paint looks like. Are you thinking about a whistle fuel motor on this bad boy? Thanks for those tips, like I said, the AV bay is on hold until the electronics arrive. As for the motor, I really WANT to fly it on a whistle motor, but when I talked to our local HPR club about it, there was a big fat NO. They're affiliated with NAR, so it is commercial motors only at their events due to insurance. They do have some members that make large APCP motors and fly them with other clubs, so at least they are friendly towards experimental designs. For the paint, I like the sounding rocket look. I'm thinking a white body, with a silver tip on the nose cone, navy blue on the fins, nose cone and accents on the body. I know those colors will make it harder to track on a sunny day, but I like them. Edited April 8, 2013 by nater
dagabu Posted April 8, 2013 Posted April 8, 2013 (edited) Ask Danny Cregan if you can get clearance at PGI for a rocket shoot, you will be WAY under the FAA ceiling. Edited April 8, 2013 by dagabu
nater Posted April 9, 2013 Author Posted April 9, 2013 That's not a bad idea. I can't imagine a whistle motor that fits in a 29mm motor mount would go higher than some of the rockets we launch during the convention. My fiberglass rocket probably weighs less than some of the 6 lb motors with 8" and 10" shells on top too.
kpknd Posted April 9, 2013 Posted April 9, 2013 Looks good, like it could be made up as an ARCAS. G motor? Park flier? Must be a big park.
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