Scorched Chute

During yesterday's recovery system deployment test I observed some scorching on the parachute. Today I got better pictures of the damage. Nothing that will keep me from using the parachute, but I definitely have to find a way to ensure it doesn't happen again. The last thing I need is for my rocket to come down with the parachute going up in flames.


Photo Album: 2010-10-23, Flying Colors

Flying Colors - Ejection System Ground Test

Today I finally got the recovery system ejection charge tested. I'd been concerned about the system deploying correctly due to how tightly it seemed to fit inside the airframe.

The first challenge to performing this test was the fact that while I'd managed to obtain a spent rear closure for my CTI Pro-38 motor case, I didn't have a forward closure to properly simulate the burn-out condition of the motor. The forward closure in these motors is part of the reload kit. Looking around my garage for something to fabricate a closure from I saw the can I'd been using to mix epoxy in for fiberglassing the airframe and fins. Fiberglassing the fins had in particular resulted in quite a bit of unused epoxy. I cut the can off the epoxy and then used a hole saw to cut a blank from the cleaner portion of the material. I mounted the blank on my hand drill and used this arrangement as a lathe to turn the blank down to the final diameter I needed. I also turned a shoulder on the part to insert into the front of the motor case. The hole saw left too large a hole through the blank, so I epoxied a washer with a small hole on the forward end of my pseudo-closure. I placed tape on the back of the washer before mounting it so that I was able to fill the central hole with epoxy on a second pass. Once the epoxy cured I drilled a 1/16" hole through the epoxy to simulate the hole between the delay charge and the ejection charge in the real motor. I applied double-sided outdoor carpet tape to the shoulder to secure it to the motor case once I had the ejection charge prepared.

I prepared a 1g charge of FFFF black powder by containing it in the tip of the thumb from a nitrile glove. I chose the thumb because I was able to obtain a large opening to pour the pre-measured powder into. Once the powder was in the tip the excess material was cut off. An Estes igniter was placed into the powder. One leg of the igniter was insulated with masking tape in advance of the insertion. Masking tape was used to gather the end of the glove tip together and tightly compact the powder. A drop of CA glue was applied to the opening to help insure it remained closed. The leads of the igniter were threaded through the 1/16" hole in the front of the simulated closure. The leads were restrained on the back of the closure by attaching them with double-sided tape after twisting them with the wires I'd be using to trigger the charge. More tape was placed over these weak unions to help insure they didn't separate. The wires had previously been threaded through the retainer ring, aft motor closure, and the motor case itself. At this stage the protective film was removed from the carpet tape and the simulated closure was stuck to the front of the motor case. Excess wire was drawn back through the motor and the rear closure attached. The assembly was then inserted into the rocket and the retainer ring installed. All that remained was to start the video camera recording, back off to a safe distance, and remotely trigger the charge with a 9-volt battery.

The photos and video show the results.


Video: 2010-10-22, "Flying Colors", Ejection Charge Ground Test


Video: 2010-10-22,"Flying Colors" Ejection Charge Ground Test (Slow Motion)


Photo Album: 2010-10-22,"Flying Colors" Ejection Charge Ground Test

Debut of the Dragon Fly

I finally finished the paint job on the Arreaux. I had it nearly finished and then screwed it up. It would have looked better than it does if I hadn't had to rework it.  I still have a bunch to learn about spray painting I guess.


Photo Album: 2010-09-20, Painted Arreaux

One Giant Leap...

...Rocketry order delivered, equals one small step forward for me. I ordered my Cesaroni Pro38 motor case, delay adjustment tool and spacers from Giant Leap Rocketry last week. The order was shipped last Friday, 3 days after I placed it. Today my order arrived. Everything looks great. My only complaint about the ordering process is a lack of transparency. After receiving confirmation for my order there wasn't any additional feedback. No order number for future reference, no shipment notice when the order shipped, or tracking information for the shipment. Since the order shipped USPS with delivery confirmation they could have at least sent the tracking number to me, though USPS doesn't show much in the way of information until after the package is delivered. I would certainly do business with Giant Leap again, despite my nit-picking.


Photo Album: 2010-09-13, CTI Pro38

Another Busy Weekend

On Friday evening and Saturday morning I worked on installing nuts for my railbuttons. I had gotten some special nuts from another local rocketeer that were supposed to embed in the wall of the airframe from the inside. Unfortunately they were not intended for use in kraft paper tubes and wouldn't seat. I ended up having to epoxy them into place which was rather tricky, since the forward nut was nearly two feet down the inside of my 2+" tube.

On Sunday I got back to work on the rocket and got the payload and nose cone mostly painted. I got the airframe primed. The photos show the airframe ready for painting, with bolts threaded into the nuts to keep paint from getting into them and tape over the bolts to keep them from being stuck to the nuts.


Photo Album: 2010-09-12, Vulcanite Airframe

Fin Reinforcement

I finished sanding out the fillets on the fins and decided to get going this evening on the reinforcement of the fins. I set up the airframe on my workbench and applied fiberglass to one side of one set of fins. This time I applied the epoxy before applying the fiberglass. I still had to apply epoxy to the fiberglass after I laid it on the rocket. Unfortunately I'm going to have more sanding to do as the epoxy has obviously settled into the area of the fillets. I'll also have to apply more epoxy to fill the texture of the fiberglass after the current round of epoxy has cured. I'll only be able to do one side of one fin at a time as I'll have to have the fin horizontal while the epoxy is curing. I'm going to first get the glass applied to all three sides of the rocket before I tackle this step. The thing I hate most about it is how wasteful it will be of my epoxy. I have to mix a full pump up and won't come close to using it all. I don't have any projects waiting in the wings that I can use excess epoxy on either. :-(


Photo Album: Tip to Tip Fins

Busy Weekend

On Friday afternoon I installed the centering rings on my engine tube. Since I plan to install an Aero Pack Engine Retainer I had to alter the assembly instructions slightly. The instructions call for the centering rings to be mounted 1/8" from each end of the engine tube, but the motor retainer requires 3/8" for mounting. I checked the fit with the rear centering ring moved 1/4" forward and found that that puts the forward edge of the ring right at the back of the fin slots in the tube, so proceeded to assemble the engine tube in this configuration. I then prepped the bad area of fiberglass on my payload bay tube for patching by sanding out the bad area and feathering out the surrounding area.

On Saturday I fiberglassed, patching my payload bay tube and adding a layer of the fiberglass sleeving to the engine tube between the centering rings. The primary motivation for adding the fiberglass to the engine tube is to account for the extra thickness of the airframe tube when mounting the fins. There is an added benefit in that the fiberglass should also strengthen the connection between the engine tube and the centering rings.

One of these days I will learn that fiberglass doesn't like making 90° bends. I cut the sleeve for the engine tube quite a bit longer than the tube in order to allow for fraying as I worked the sleeve over the centering ring and stretched it out on the engine tube. I thought I'd be able to bend the sleeve up along the centering rings. This proved harder than I anticipated. Once I had my epoxy applied I found that I couldn't keep the fiberglass in contact with the tube as it approached the centering rings. I had a length of the shrink tubing available that was the right length, but I couldn't see how I was going to keep it from contracting lengthwise while I shrunk it as the centering rings would keep me from holding it with my pliers. I decide that I had to try using the tubing anyway, as I wasn't getting what I wanted without it. When I tried to pull the shrink tubing on over the engine tube the fiberglass pulled off the engine tube and ended up a wadded mess inside the shrink tubing. I pulled the shrink tubing back off and straightened out the fiberglass. I ended up doing this twice as a second attempt yielded the same results. I finally resorted to cutting two lengths, each about 1" in length, from the shrink tubing and working them onto the engine tube. After sorting  out the fiberglass yet again I put one at each end of the engine tube and shrank them in place, using my stirring stick from my epoxy to push the tubing sections towards the centering rings as I heated them. I did a better job of this apparently at the forward centering ring than at the aft one. The finished product has a fairly tightly radiused curve in the glass as it transitions up onto the centering ring with the gap under the radius filled with epoxy. At the aft end the radius isn't as tight and there are areas that are not epoxy filled.

On Sunday I installed the engine tube in the airframe and proceeded to install the fins. I had to use my Dremel with an engraving cutter to cut out the radiused fiberglass at the aft centering ring in order to get the fins to insert into the slots. The poor bonding at the aft centering ring worked in my favor in this case, making it easy to remove the obstruction.

On Monday I used Loctite Repair Putty to form fillets between the fins and the airframe. I worked on sanding out the fillets, but ran out of time. More sanding tonight.


Photo Album: Fiberglassing 103

Sanding out the "bulge".

I sanded out the bulge in the fiberglass on the payload bay. Almost as soon as I touched it with the sand paper it disintegrated, leaving a nasty void in the fiberglass with epoxy underneath. Now I have to figure out how to fix it.


Photo Album: 2010-08-24, Patching the Payload Bay

Soller update

I sent an email this morning inquiring about the refund for the nitrile gloves I cancelled from my order. About 3 hours after I sent the email I had a reply stating the funds had been refunded to my credit card. They haven't shown up on VISA yet, but I assume it takes time for them to process the refund to my account.

Fiberglassing 102

So today was the day to strip the shrink wrap from the practice tube and see what I had. I'm not completely happy with the results. As you can see in the photos there are areas the appear to correspond with where I started heating the shrink wrap that are not bonded to the underlying tube. The areas are also rough when compared to areas further away, as if there is significantly less epoxy in them. My first impression was that I may have held my heat gun on these areas too long and somehow caused this.

With this information in hand I proceeded to glass the real airframe and payload bay tubes. I decided that the easiest way to do them would be to mount them up adjacent to each other on a single PVC pipe, with a small gap between them. I then slid the fiberglass on them and secured it. When applying the epoxy I again found myself working excess fiberglass down the length of the tubes. Apparently the epoxy is acting as a lubricant and allowing the glass to slide along the tube and I suspect even more importantly along the weave.

I made what I feel was a mistake when I started putting the shrink wrap tubing on. Without thinking about it I started sliding the tube on from the end that I had worked the excess fiberglass down to. As I was pulling the tubing up I started seeing the fiberglass come off of the airframe tube as I was obviously pulling slack up the with the shrink tubing. I stopped and pulled the shrink tubing back off and then pulled it on from the opposite end.

I made sure my heat gun was on its low temperature setting to ensure I didn't overheat the fiberglass, due to my impressions from the practice tube. I shrank the tubing without any apparent complications until I got down to the payload tube. There I had a bulge that I could not get out.

I hung the tube up and let it cure. I then grabbed the practice tube and sanded it with 80 grit paper to prep it for a layer of epoxy per Soller Composite's recommended process. With the tube prepped I applied the epoxy and hung it up to cure.

Next I took the coupler tube and used the fiberglass sleeve to line it. This proved to be somewhat tricky, as the sleeve's natural tendency is to contract, not expand (think Chinese finger trap). This proved to be a real problem after I applied the epoxy. I ended up working the fiberglass until the epoxy got very tacky in order to get it adhered to the inside of the tube. Any force that pulled toward the ends of the tube would cause the sleeve to contract and pull away from the tubing. The ends absolutely refused to bond, particularly the end where I'd started applying the sleeve and had come hard around the end of the tube. It finally got to the point where the epoxy was so tacky that attempting to manipulate the fiberglass any further was doing as much harm as good due to it attempting to adhere to my glove.

Late in the day I was able to use the coupler tube as a gauge and determined that I could strip the shrink tubing from the airframe and payload bay tubes. I was really eager to do this in order to see my results and investigate the bulge on the payload bay. As you can see in the photos the bulge is an area that is not bonded to the underlying tube. My conclusion at this point is that when I smoothed the fiberglass back out after pulling the shrink tubing on from the wrong end that I missed a spot. I thought I had it all, but the evidence speaks for itself.

The main airframe tube looks great. I applied scotch tape over the pre-cut fin slots in order to prevent them getting filled with epoxy. It looks like I left a scrap of tape on the tube, though I really don't remember it. I don't see this as a real problem.

I don't think I'll be able to repair the bulge on the payload bay tube. I do have a solution though. The practice tube has plenty of good sections, so if the original payload bay is unsalvageable I'll cut a new one from the practice tube.

Photo Album: Fiberglassing 102

Fiberglassing 101

Today, for the first time in some 30 years, I did fiberglassing. The last time was working with my Dad to do some body work on a rusted out fender and then he handled the epoxy mixing. Today was the first time I would do the entire process on my own.

For this reason I purchased the practice tube I previously spoke about and today it was time to glass it.

I'm using the West Systems epoxy and fiberglass sleeve sold by Soller Composites with the 207 hardner.

I started by borrowing a trick from Vern Knowles and using foam to make centering rings to mount my tube on a PVC pipe. I then slid the fiberglass sleeve down the tube and used masking tape to secure the first end to the PVC pipe. I then worked the fiberglass back along the tube to make it as snug and even a fit as I could. I used the masking tape to cinch down the sleeve on the second end of the PVC and then borrowed again from Vern. I masked off all but a narrow band of the sleeve and then applied the same 3M Super 77 adhesive he used to prevent fraying. I gave that a bit of time to set up then cut the sleeve off and finished securing the second end to the PVC pipe with more masking tape.

I then mixed up the epoxy using the pumps I'd purchased to ensure the proper ratio of resin and hardner. To apply the epoxy I opted to just pour it onto the fiberglass and then use my gloved hand to spread the it along the tube. The only issue I had was when I was working at the end of the tube the fiberglass wouln't adhere despite having plenty of epoxy. Apparently I still had some slack in the sleeve that I'd not been able to work out during prep. I was not overly concerned about this as I intended to use heat shrink tubing to squeeze out excess epoxy and this would also have the affect of compressing the fiberglass against the tube while the epoxy cured, ensuring there would be no long term issue.

I did find that I'd mixed up more epoxy than I really needed and like my fellow local rocketeers I was trying to find something to do with the excess. Unfortunately I didn't come up with anything. It wasn't a whole lot and I'm not sure that using only 2 pumps of resin and hardner would have made enough epoxy.

The heat shrink tubing went on without any difficulty and performed as advertised. The tube is now hung (as recommended by Jon Soller) in the garage while it cures. Tomorrow I intend to strip the shrink tubing from it and dismount it from the PVC so I can glass the real airframe, payload bay, and coupler tubes. Fortunately the heat shrink tubes that were missing from my order showed up in the mail today.

Photo Album: Fiberglassing 101

Ordering Fiasco

I placed the order for the fiberglassing materials for use on the Vulcanite on July 28th or 29th with Soller Composites. (I can't tell from the receipt generated by Soller which day it was.) On the afternoon of the 29th I received an email from the sales department stating they were out of stock on the nitrile gloves I'd ordered and that they expected to have them back in stock on Monday (presumably August, 2nd) and asking if I wanted to wait for them to arrive. I replied that I would wait until they could ship the entire order. I was expecting an email to tell me my order had shipped on the 2nd. When I hadn't heard anything by the afternoon of the 4th I sent an email inquiring about the order status. I got back an email (with a time stamp more than an hour before I sent my inquiry) stating the order was still being held pending delivery of the gloves and they expected them to be back in stock later in the week. I again agreed to continue waiting. By August 11th I was tired of waiting and called them up and left a voice mail advising them to cancel the gloves and ship the order posthaste. I followed the phone call with a an email stating the same. That afternoon I got an email stating that my order was shipped and provided two tracking numbers. While Jon Soller had said it would only take UPS three or four days to get the order to me, it took the full week I had predicted, so I finally got the order on August 18th. I inspected the order and discovered that I'd only been shipped one of the three shrink tubes I'd ordered. I called and left a voice mail stating the deficiency. On the morning of the 19th I received an email stating that a package had been shipped via USPS priority mail, so I assume my missing tubes are on their way.

In the mean time Soller charged my credit card for the full amount of the purchase on July 30th, a charge that included the cost of the nitrile gloves. To date they have not applied the credit for the gloves, so I will be back on the phone with them on Monday.

Due to the quality of service I've received so far I really wish there were another vendor out there selling the fiberglass sleeving material. So far Soller is the only vendor I've found. I've also not heard any complaints from the other local rocketeers that have used their services, so hopefully my experiences are an isolated event.

I'm not a pin-striper!

I had the paint looking pretty good on the Arreaux, but had a couple things I wanted to try. The first thing was to use a gold leaf paint in an airbrush to apply a technique I've seen on TV to produce a scale like affect. I tried it on a practice tube first (an old wrapping paper tube) and found that the gold paint wouldn't work well in the airbrush. I scratched that plan. I also have a gold leaf pen that I wanted to do a pin stripe along the edge between the two colors already on the rocket. I made a horrible mess of things and am now in the process of sanding back down to a workable point. I'll then have to redo the original design that I was reasonably happy with. Since my fiberglass for the Vulcanite should be arriving this week and I really need to get that project moving I don't know when I'll get the paint finished on the Arreaux.  :-(

Slow Progress

The Vulcanite has been stalled while I wait for fiberglassing materials to arrive. I have been working on painting the Arreaux. I don't have photos yet, but I do have an image showing the paint scheme for the airframe. I'm not going to share the color scheme until I'm done. I have most of the painting done at this point, but won't get it finished until this coming weekend (I hope). The image includes cut-outs for the 3 fins (one split in two) and the two launch lugs. The centerline is just for reference. The dashed perimeter corresponds to the front edge of the airframe and the edges of the pattern where it meets when wrapped around the tube. The design is divided into 4 sections, as that is how many pages I had to print it on.

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.

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.

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.