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Sunday, July 25, 2010

Broken Arreaux

I worked yesterday on painting my Arreaux. I assembled my improvised paint booth and applied primer and the first color coats, all in white.

My 3'x5'x7' improvised paint booth. Constructed from 3/4" PVC pipe and wrapped with a plastic drop cloth. The drop cloth is long enough to pull under from one end to the other to protect the floor. This will also serve (sans drop cloth) as the support for fiberglassing my Vulcanite.


While sanding primer coat on the payload bay tube I discovered damage that apparently occurred during its uncontrolled landing a few weeks back. It is very minor and won't prevent me flying the rocket. In a bone I believe this would be termed a buckle fracture, basically a compression of one side of the tube. Provided there are no repeats of the hard landing I don't expect it to ever be a problem.

The buckle is rotated towards the side and is pointed at by the arrow. Contrast with the equivalent area on top of the tube to see the difference.


The buckle parallels one of the seams in the tube's construction.

Thursday, July 22, 2010

Order Recieved

I received my order today from Apogee Components. It consisted of my practice airframe tube and Modern High Power Rocketry - 2nd Edition. There was a short delay in getting my order filled because Apogee was out of stock on the book. They did a good job of keeping me informed on the issue and when my order shipped. While I'd have liked my order to have shipped right away I have no complaint with how the situation was handled.

The book was highly recommended by several members of the local Tripoli chapter and has already started showing its value, providing some guidance on how I should fiberglass my fins. With this additional input I have finally made up my mind on how I want to proceed and must now select my fiberglass materials and get them ordered.

Hopefully in another week I'll be ready to start glassing the rocket.

Saturday, July 17, 2010

Stepping up to a High Power Rocket.




I've made my choice for the rocket I intend to use to my get Level 1 and Level 2 TRA Certifcations. I'm going to build an LOC/Precision Vulcanite H76 kit, with numerous upgrades. I'm following the upgrade recommendations that can be found on the Apogee Rockets web site in order to beef it up for flights on the J class motors.

I ordered the kit from Hobbylinc.com. The order was shipped within 1 day and delivered promptly via FedEx Ground, arriving in Idaho from Georgia 5 days after I placed my order. Kudos to both for fine service.

Since the first upgrade will be to fiberglass the airframe I'm also ordering an LOC airframe tube of the same dimensions as the main tube in the kit  from Apogee Rockets. This tube will be my practice piece before committing to glassing the real tubes from the kit. If it comes out good I'll have it available for use on a future project.

The packaged kit as it arrived.


The components of the kit laid out.

I shot an Arreaux into the air, it fell earth, I knew not where...

So my first step up from low-power rockets was an Aerotech Arreaux kit that I purchased at my local hobby shop. I built it this spring, which took far longer than it should because I lost a part and had to get a replacement from the manufacturer. Kudos to Aerotech for excellent customer service.

I finished the rocket just in time to take it, sans paint, to the final launch of the Spring season conducted by our local Tripoli Rocketry Association chapter. I hadn't even managed to acquire motors for the rocket before the launch date, so had to get a motor from another member for the maiden flight. I ended up getting a G80-10T. This is a single use motor from Aerotech. At the time I failed to realize that this was not one of the recommended motors for this rocket, having too short a delay on the ejection charge. This also represented the most powerful motor that can be flown in the Arreaux, which was hardly what I wanted to shake-down my build with. With some trepidation I proceeded to load the motor into my rocket. The launch was a success with the rocket climbing straight into the sky despite a moderate breeze. No weather cocking was observed and the chute deployed successfully. I happily recovered the rocket a couple hundred yards from the launch pad.

Jubilant with the success, I went in search of another motor to fly it on. Another member had an Aerotech G71-10R reload he was willing to sell me and a Rouse-Tech Monster Motor case he would loan me for the flight. This being the first time I'd flown a re-loadable motor I did the assembly under his supervision. I took my rocket to the pad and hooked up my first Copperhead igniter. Again my rocket flew off the pad straight into the sky, this time with a beautiful, bright, red flame trailing out the back. As it approached apogee all observers lost track of my rocket against the sun. No sign of the rocket was seen as it descended and I came to fear that my parachute had failed to deploy. I spent the next 3+ hours searching the desert for my rocket, but to no avail. Finally my wife was not feeling well, so I was forced to abandon the search.

Later in the week our club's "finder", Jim, went out to the launch site and searched for my rocket and the booster section of another rocket that had gone missing. After 8 hours of searching he gave up for the day, having found neither of the missing items.

Our finder went out again late in the week and put another 5 hours into searching for the two stray lambs. Again he met with no success.

I went out on the weekend and spent six hours with my daughter combing the area for my rocket and the booster section. Some of the search areas are heavy with cheatgrass which gets into your socks and shoes and makes walking an absolute torment. Again neither object turned up.

Our finder found he couldn't give up on our missing rockets and went out again the following week.  This time within a couple of hours he had found both my rocket and the stray booster section! After some 13 days exposure to the environment, a period which saw some serious T-storms roll though, my Arreaux was finally found. As feared, the recovery system had failed to deploy. The payload bay was only separated from the rear portion of the rocket by about 1/4 inch. Apparently the small piece of masking tape I'd used on the coupler tube to tighten this connection had managed to prevent the two parts from separating. Miraculously my rocket somehow managed to make an uncontrolled descent and land with no apparent damage. There are some water stains and other marks on the body tube, but otherwise my rocket appears ready to go again! I've cleaned up the tube with a light sanding to prepare it for painting and look forward to flying it again this fall when fire season is over and we can resume launching.

Thanks Jim!

My recovered Arreaux standing in my backyard.



Close-up showing the stains on my rocket.

First steps

I'm going to be building rockets with the goal of getting a Level 3 Tripoli Rocketry Assocation (TRA) certification. So far I've built several low power rockets and one mid-power rocket. I'll tell about the mid-power rocket in separate posts and track the construction and flights of my high-power rockets as I advance. Future posts will be tagged by model and name of the rockets so you should be able to restrict the viewed posts based on those tags.