PML Amraam 2

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A

Austin

PML Amraam 2 (build pics to be added soon)


Brief:

The PML Amraam 2 is a stand-off scale version of the original Amraam/Aim-120 used by both the U.S Navy and Air Force as a medium range air to air missile. The kit is a 2.1” model with a length of 43 inches and can fly on 29mm motors from F to H class.



Components:


The kit came in a bag and all the components were included. Kit design is actually very simple and straight forward; included were the nosecone, Quantum body tube pre-slotted for fins, G-10 Fiberglass fins, centering rings, 29mm motor mount tube, piston kit, 24” ripstop nylon parachute, tubular nylon shockcord and all the hardware. This is a superb quality kit, using the best components commercially available. The body tube is made of PML’s “Quantum” tubing, approximately 1/16” thick plastic, somewhat flexible/forgiving and smooth with no spirals. A quality set of decals also came with the kit, along with an easy to follow instruction manual. The instruction manual was very good and step-by-step construction went well.

Component Rating: 5 of 5



Construction:

Epoxy (15 minute) was used throughout the construction, which begins with the assembly of the motor mount. Make sure you use at least 80 grit sandpaper to rough up all surfaces to be glued. The motor mount procedures require you glue a ¾” wide black nylon shock strap to the side of the tube. I glazed mine with epoxy for added strength once the initial epoxy had set. IMPORTANT: Make sure when you install the motor mount in the body tube that you position the shock strap BETWEEN two fin slots, otherwise the strap will no allow one of your through-the-wall mounted fins to fit flush against the motor mount tube. This is noted in the instructions, but is in small text and it’s a point that you need to follow. Do not use the “scotch tape” method on the rear centering ring as they suggest. Trust me, the tape just breaks off. I installed the motor mount and the rear centering ring without tape, then, once the glue was set at the top, I used a metal ruler through the fin slot to push the lower centering ring back out. Much easier to do than tape.



Once the motor mount is complete, you need to glue in each fin. Use an alignment jig or measure to make sure each fin is straight and perpendicular. Also insure you rough up the outside of the motor mount and inside of the body tube in the area of the fin slots for filets or glassing later. Note, I used 80 grit sandpaper on all parts of the plastic Quantum body tube for roughing up an area prior to gluing. It has more bite than the suggested 120 grit and cuts deeper grooves for a good glue joint. Additionally, I roughed up the outer surface of the body tube from about 1” forward of the lower fin slots to the tail, as I planned on fiberglassing the lower fins for strength.

Lower fins are glued on next; I put a small amount of epoxy on the edge of a fin, then inserted it through the fin slot and allowed its own weight to hold it down on the motor tube. Once all four fins were glued, I cut 1 ½” wide strips of 2oz fiberglass cloth to the length of each fin, then glassed the space from the motor mount to the fin and inner body tube. Soaking the cloth in epoxy then folding it around a ½” wide stick allowed me to insert it into the tube, then the stick was used to make sure the cloth was pressed down on all surfaces. This added strength inside the body tube like you cannot believe, as I have had these fins break clean off in colder weather without glassing on this PML kits. I now glass all my fins and it pays off!!!

Next step is to glue on the upper fins, which went well. Once all 8 fins were glued, I fiberglassed the lower 4 fins using 1 ½ oz cloth and 15 minute epoxy. I ran the cloth from about 1 ½” up one fin, down and across the body tube and up the other fin about 1 ½”. FYI: using this method I have NEVER broken a fin out of the slot, as had happened before on PML kits as small as 2” without fiberglassing. If you fly on any kind of hard surface or in the winter, fiberglass your rocket’s fins.

Piston assembly is next on the list; PML uses a unique “piston” ejection system which is really slick and works well. You can prep a rocket in a flash without having to mess with wadding as the piston protects the parachute and shock cord from the heat of ejection. The piston assembly is glued to the other end of the ¾” black strap, which comes from the motor mount. Once assembled, I glazed the wood surfaces inside and out with epoxy. This waterproofs the wood and allows for easy clean up after a day’s flight.

Launch lug placement instructions are supplied in the kit, and the lug consists of a single ¼” brass tube. Make sure that you rough up the gluing area with sandpaper before mounting the lug. Next, I applied fillets to each fin side and the sides of the launch lug. I turned the rocket so lower fins were at a 45 degree angle, used masking tape to create a “dam” on the top and bottom of each lower fin, then mixed 15 minute and poured it in the area. Heating the epoxy in the microwave so it is hot and runs like water makes it easier to pour in the area and leaves nearly a sanding free fillet. I applied a small filet to each of the upper fins just for safety. The center fins actually never touch the ground on landing, so they have no stress applied, but the lower fins do make contact, so these filets are a good size.

Construction Rating: 5 of 5



Finishing:

White Krylon primer was applied prior to the first sanding and I used 100 grit to cut away any excess epoxy resin left from the fiberglassing and to blend in the cloth seams. Use an electric sander in the glassed area, which cuts through the epoxy nicely and blends glass seams well . A few more coats of primer were added, then I wet sanded with 220 grit, then 400 grit. Once primer was finished, the Quantum body tubes and fins paint like a dream!

Light Gray Glossy Krylon paint was used on the body tube and fins, which left a nice and smooth surface to apply decals. The nosecone was done in Krylon Flat White. I used Testors Gloss Navy Blue, Gold and Yellow for the ½” stripes and used a piece of Monokote self stick Chrome for the silver section. Once all decals were applied, I used TopFlite Clear Dullcoat for the flat military look. Do not use Testors Dullcoat; it leaves dirt and fingerprints like crazy which cannot be cleaned. The TopFlite can be found at any R/C hobby shop and is waterproof, alcohol proof and cleans easily. When applying the dullcoat, you must use light “dusting” layers; the Testors stripes you painted will orange peel if you put it on too thick. I had to re-do my yellow stripe for this reason, learned my lesson, and the rest of the rocket came out great. Just use light coats and it will dullcoat fine.

Finally, shock cord and parachute were attached per the instructions. Don’t forget to tack glue your knots with a drop of epoxy. I did purchase and add a 1” steel link so I could easily remove the parachute from the shock cord.

Finish: 5 of 5






Flight:

My rocket weighed in at 27.2 oz, about 3 ounces heavier than the manufacturers indicated weight. I can account for the extra weight though and attribute it to glassing and fillets. Note that the CG was checked with the motor installed prior to flight to insure proper CP relationship.

Note that this article was written nearly a year after the build process, so all tips on fiberglassing were the result of my experiences.

This was my first High Power model and I planned on using it for my Level 1 TRA certification. I had to sand the outside of the piston so it slid easily inside the body tube, so make sure you fit the piston to your tube before flight. Also note that the Quantum tubing, as nice as it is, does shrink in diameter under colder temperatures. This is not a problem if you prepare for it. Also, drill a 1/8” pressure relief hole in the body tube below the nose cone seat and always check node cone tightness. My A2 has just recently been permanently retired due to a nose cone popping off in mid-flight under H power…a sad sight indeed. The good news is another A2 is on the bench now and nearing completion.

My first launch was on a H128W with a medium delay. The rocket was preped and motor installed. I did purchase and install the PMR motor retainer prior to it’s first flight and recommend this to everyone that builds the kit. Also, when loading the motor case, do NOT use all the black powder ejection charge. The piston ejection system actually requires less ejection charge and PML includes a chart for reference when loading the charge.

The rocket was placed on the pad and then came the moment. The Amraam 2 took off the pad like a bullet, extremely fast, loud and very straight. It was an awsome launch, with the sound and white smoke billowing out the tail, I knew I was hooked in this hobby for good! It was a bit windy and very cold, around 25 degrees, but the model kept it’s track to apogee. Estimated altitude was around 2700 feet.


Recovery:

The parachute deployed at apogee and the rocket appeared to land just fine, but landed nearly ¼ mile away thanks to the wind, so the long walk was on. I trecked through the frozen plowed field and when I approached the rocket, I was delighted to see it appeared to be in good condition. However, when I picked it up, I saw the bad news; it had landed just right to where the lower fin NOT facing up had broken clean out of the model, along with part of the body tubing between two lower fins. I found the fin on the frozen mud about six feet away and made the slow depressing walk back. The prefect was all ready to sign my L1, but I stopped him and showed him the damage. This was a two day event so there was still tomorrow…..

I rushed home after the launch was over and began fiberglassing and repairing the lower section using methods I had learned and used for years with R/C aircraft. By the next day the Amraam 2 was ready for a second attempt, Still in white primer where the glassing was performed, I preped it once again, but with a little more experience and confidence this time. It was another beautiful launch, amazingly fast, straight and with good deployment. This time the wind was down and it landed only about 150 feet away; it was still a cold 22 degrees though but I thought it just HAD to hold up this time. Note that at those temperatures, the ground is like concrete and Quantum tubing does become brittle. I approached the rocket and was ecstatic to realize my glassing job made the rocket strong as steel and it landed without a scratch. I got my Level 1 TRA cert that day and since then, have been glassing all my kits. Maybe it’s overkill, but my new rule of thumb has since been “Stronger is Better”…especially with HPR. The Amraam 2 has had many low and high power launches on it since, prior to it’s “final” launch.

Flight/Recovery: 4 of 5



Summary:

The PML Amraam 2 is a superb quality kit that flies like a dream! I do highly recommend you glass your fins though, especially for cold weather flying. Also, do not forget that a pressure relief hole needs to be drilled in the body tube and isn’t documented. I have learned much since my first Amraam 2, a kit I will remember a lifetime, as it has opened up the entire world of High Power Rocketry to me. The new replacement A2 currently in the build stage has all the tricks I have learned since then on building strong incorporated in it , as I wish to keep this one for quite some time. In summary, if you want a great kit at a good price for HPR, this one will do the job for you and make a fine addition to your fleet!


Overall Rating: 5 of 5
 
I bought one my self and it was quite a nice looking rocket i loved the look and design of the coupler. The epoxy getting to the right amount and spreading was my only problem but overall i would rate a 9 i loved the quantum tube now thats what all rockets need to be made ot of, im thinking of ordering from PML it shouldnt be that expensive
 
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