(05/25/00) Recently BSD High Power Rocketry has started selling kits again and although they are a new name, they are not new to rocketry. BSD is run by Scott Binder who initially designed all of the Binder Design kits. So, now operating under BSD High Power Rocketry, Scott is offering several kits but one in particular caught my eye. The Diablo. It is what I call a "stubby" rocket, having less than a 10:1 length to diameter ratio. In the Diablo's case it is 8.25:1 being 33" in length and 4" in diameter.

See my 4" Stubby Rocket Comparison Page

The looks of the Diablo also caught my eye, being a short rocket, using three fins and the finish as displayed on BSD's website. Even though I noticed the finish, I never expected to get the decals displayed because many high power kits just don't come with decals. So this is a major positive for BSD's Diablo, because quite frankly the decals are what differentiate it from the looks of any other 3FNC rocket out there.

The Diablo includes a 17" long paper (LOC Style) glassine coated airframe. It is pre-marked for the three fin slots and the 1/2" launch lug. The plastic nose cone makes up the remaining length. There are three (3) 3/16" thick plywood fins that are pre-cut. There are also two (2) 1/8" thick composite centering rings (very smooth on one side and very rough on the other). The motor mount is 38mm and 8" in length. The recovery system consists of a 1/4" eye-bolt and a Quick Link that is combined with a 4-foot 1" wide nylon shock cord strap and a 10-foot 1" wide elastic shock cord. Lastly a 30" blue nylon parachute is added. Also included are 4 sheets of decals!

CONSTRUCTION:

BSD is trying to draw attention to their "best instructions available", so I should comment on those first. Other high power kits that I have built have had minimal, but usually adequate, instructions but were clearly written for individuals with quite a bit of experience. So, by initial comparison, BSD has put together a nice instruction booklet. Eight (8) pages of fully illustrated and photo-illustrated instructions taking the builder from an inventory to flying. They are well written and include helpful hints that can be applied to building any future rocket. Some of the hints cover successful airframe cutting for the fin slots, protecting your Fin Alignment Guide from glues, using fillers in fin fillets.

Each instruction step is clear and there are associate photo-illustrations to help "see" what is expected. This approach will allow even those with little experience to build the kit. The kit could be built by someone with just a couple of Estes' kits under their belts in my opinion. The instructions even "walk" you through the finishing steps thoroughly.

The motor mount is assembled using the two composite centering rings (I put the smooth side out). The upper centering ring is used to mount the 1/4" Eye-Bolt. The nylon shock cord strap is attached to the Eye-bolt using a Quick-Link. I drilled two holes in the lower centering ring to insert two t-nuts for motor retention later. I had to add a small spacer to keep the t-nuts flush with the exposed side of the centering ring.

Having to cut the fin slots into the airframe is always "extra" work, however, with the paper airframe it is not too bad. BSD had the lines pre-drawn so you just have to follow them. Once these are cut the fins are through-the-wall mounting and go all the way to the 38mm motor mount.

The cuts of the wood components were excellent. Perfect match for the three fins. The centering rings required very little sanding for a nice fit inside the airframe.

I replaced the the 1/2" launch lug with two 1/4" launch lugs (the instructions say to use at least a 3/8" rod). The two 1/4" launch lugs I used were from Budget Rocketry. They are plastic launch lugs with 45° cuts on both side and a slightly flattened back to allow for better adhesion. One nice thing about them, is even after the priming and painting they still accepted a 1/4" rod without having to clean out all of the over-spray.

One interesting little item that was noticed during the build of this rocket, was that the fins never lined up correctly according to the provided fin alignment guide. The issue was discovered that the pre-marked fin lines on the tube were about off on one fin. I noted that two seem to be 4 1/8" apart and then one was 4 3/8". No one can tell by eye, but when trying to line up two of the fins the third fin never hit the mark. Of course, I discovered this after I had cut the fin slots. I notified BSD and they assured me it would be addressed immediately.

For finishing, I didn't use anything to fill the spirals, nor did the instructions indicate it was needed. In fact, this tubing really doesn't have deep spirals at all. Therefore, I was successful in using several coats of Plasti-Kote Sandable Primer. The instructions are again very thorough in describing how to finish the rocket with several coats of primer, sanding, wiping down with a tack cloth and painting with light coats. I did one very heavy coat of primer and then focused on the spirals with a coat only aimed at the spirals. After sanding down the body was ready.

I used my normal method for finishing plastic nose cones which involves sanding with 150 grit sand paper until all shine is removed. The hitting it with a heavy coat of Plasti-Kote Primer to fill in all the scratches I made. I use several thick coats directly on the nose cone seam and then sand it back until the seam is filled. Once the seam is filled I change over to a 340-400 grit paper. I have never had nose cone paint chipping issues using this technique.

I picked a Rustoleum Metallic paint. Copper! It came out very nice (to me).

I then applied the provided decals. I must admit this was the toughest part of building this rocket. They are self-adhesive vinyl. There was a silver, black and maroon strip, black DIABLO lettering and silver BSD lettering. In addition, there was silver, black and maroon fin decals.

The most trouble I had was lining up the strips since they come in two pieces and are to overlap where they meet. It was challenging to keep them evenly spaced and I would like another chance at it, but once these decals are down, they are down for good. Another little difference was how my fin decals had to go on. Although similar in looks, they did not match the picture. I even had to cut the bottom of the silver ones to match the angle of the fins.

After the decals were complete, I hit the entire rocket with coat of Rustoleum Clear Coat.

All in all, despite my minor difficulties in striving for perfection with the decals, I have a very nice looking rocket!

Overall, for CONSTRUCTION I would rate this kit 4 ½ points. Instructions are indeed excellent as advertised. The components are of good quality. A solid recovery system and most important for that distinguishing look . . . decals.

FLIGHT/RECOVERY:

Download RockSim file here! This file is set up with a 29mm adapter. Remove it to use as a 38mm kit. The weight is setup for with the 29mm adapter.

BSD indicates that the Diablo can be flown on as little as an F25, but recommends a G35 for the first flight. It also recommends the following 29mm motors: G80T, G64W, H128W, H180W and the following 38mm motors: H123W, I154J, I161W and I211W. Here are the altitudes that Apogee's RockSim says it will get. Simulations are based on the actual weight of my finished Diablo which was 34½ ounces. BSD indicates that the finished and ready to fly weight is between 28 to 48 ounces.

For my first flight I choose an EconoJet G35-4. After making a 29mm adapter and prepping a motor retention clip I was ready.

The instructions indicate how to pack a chute and also suggest wadding material. I used a Large Pratt Hobbies Nomex® Heat Shield which fit perfectly. I attached it about 10" above the body tube on the nylon strap. Most of the shock cord and parachute fit within the Heat Shield fully protecting them!

After testing the field out with a couple of smaller rockets, I set up the Diablo for her maiden voyage.
5, 4, 3, 2, 1 . . . roar! Nice and loud EconoJets!

It was a relatively slow lift off and a nice and straight flight. She still had a bit of steam left upon ejection but it was a good match. The parachute deployed quickly and she descended. Descent rate was on the slower side but still good. It looked like it was going into a tree but missed, only to hit pretty hard on the edge of the road. The brunt of impact was taken by the EconoJet thankfully. It was chipped and cracked, but no damage to the Diablo except for a couple of small paint chips at the bottom edge.

So, that was great fun, let's use the other G35 in the EconoJet pack! Re-Prepped and started the countdown . . . 5, 4, 3, 2, 1. No roar this time, just one big POP!

The motor blew apart sending the nozzle somewhere and also cracked the motor at the propellant and delay charge.

No damage to the rocket, but no second flight for the day either.

For FLIGHT/RECOVERY, I would rate this kit 5 points. This is only based off of one flight, however, it was super straight and recovery was perfect. I will fly her again on G's and once I find a bit larger field, I have an H128 with Diablo's name on it! After those flights, if I feel any different about flight and recovery, I'll update the review.

UPDATE: Well, I was able to put the Diablo up again. This time on a G64-7. This motor is a good match for this rocket! Excellent "straight-as-an-arrow" boost, with a picture perfect ejection at absolute apogee. It was wonderful! Flight hit the 1000 foot mark. I reefed the parachute to ensure a faster descent this time. The rocket landed in a very shallow stream, but I was there within seconds to retrieve it. No damage.

Overall, the Diablo is a very nice "stubby" rocket that is built with good quality of parts and truly has some of the "best instructions available". I would recommend this as an excellent Level I certification kit because even on an H128 she will only fly to about 1500 feet. One can certainly enjoy the entire flight at that altitude. My level 1 certification went to nearly 3000 feet and that was just too high for me to enjoy the entire flight (as you can tell, I'm not an altitude junky, I like to stay under that 2K ceiling). I give the kit an OVERALL rating of 5 points.

We now include our own motor retention system in the Diablo kit at no extra charge! The system is essentially two T-nuts that are built into the aft centering ring during initial construction. Two 6-32 bolts hold two clips that retain the motor casing in the rocket. Can be retro-fitted to already built models, too! Great review, thanks! - Scott Binder (BSD High Power Rocketry)