Estes “Vapor” Review

Summary: In the variety of paths available to plot your Roadmap to High Power Rocketry certification, the Estes Vapor is a very low-cost first leg of the Journey.

The Vapor is a bit of an obscure model from Estes. It seems to have been made specifically for Hobby Lobby, or at least only offered by Hobby Lobby.

The Vapor is priced under $20, making it an extremely good value as a rocket to brush-up on your rocket construction skills.

At One Way Rocketry, we believe this is the perfect rocket for someone who has experience with Estes’ smaller, “classroom” rocket kits, and thinks they might have an interest in building High Power Rockets. This rocket will require building techniques not dissimilar to HPR building techniques. It will also require you to perfect your launch infrastructure, including designing, building, or buying your launch pad and ignition system. We can assure you the standard Estes launch system is woefully inadequate; with its four, “AA” batteries, you can count on no more than four launches. You will immediately begin planning the use of your spouse’s portable car jump-starter as a far superior source of ignition current.

Airframe

Made using two, 18 inch Estes ‘BT-60′ body tubes which are coupled to make three feet of airframe, the Vapor totals nearly 46 inches including its ogive-shaped nosecone. The BT-60s are similar to, but a little larger than, a LOC Precision 1.5″ body tube. The LOC body tube comes in 36 inches, but is the approximate cost of the entire Vapor kit. The two BT-60s are well-balanced with Estes’ “D” engines, which is the perfect engine for small park launches, and nearly guaranteed recovery. The Vapor’s length is a bit short when using the larger “E” engines, which should push the Vapor to nearly one thousand feet. A little extra weight in the nosecone is required to make it stable with anything larger than D engines. We don’t think of this as a flaw; a manufacturer should never presume to add weight to your rocket. To the One Way Rocketry edition Vapor, we added 10 grams of a two-part epoxy putty, and mashed it to the tip with a chopstick. This gives us more than one body-tube difference between the Center of Pressure and the Center of Gravity, as calculated by OpenRocket.

Assembly

We followed Este’s instructions for the most part. We did depart by utilizing epoxy as the glue. We also attached a cotton butcher’s string for its heat resistant properties to the engine mount. We then attach the nosecone and all recovery to this shock cord, similar to what would we do in HPR. The engine mount point will be much stronger than the little folded paper mount, as stated in the instructions. Further, we don’t want the mounting point paper-wad near the body tube opening to foul the deployment of the parachute, so having the connection far below the parachute is an improvement in reliability over the manufacturer’s design.

Engine & Mounting

The Vapor holds 24mm engines, but HPR engines start at 29mm, and go up from there. With the Vapor, we cannot become certified at HPR Level 1. But at One Way Rocketry, we will help you become HPR0 certified; and the Vapor is a perfect vehicle.

We were really happy to discover a threaded engine retainer is included with the Vapor. These are usually an upgrade in High Power Rocketry, and with the re-loadable engines in HPR a quick-change operation is appreciated. Further, with the many more reliable launches and recoveries you will be achieving in your aerospace engineering, we have no doubt you will benefit from engine retainers. No more friction fit engines that have to be pulled out with needle-nose pliers, usually pulling out the motor mount tube with it.

The Vapor also includes a “D” engine adapter. The “D” and “E” are both 24mm engines, but the “E” packs more power in by increasing length. The Vapor includes a little orange spacer for the shorter “D” engines. Try to watch for this orange ring, or assign someone to watch, during the launch.

Fins & Fin Alignment

The Vapor includes three, pre-cut balsa fins. They are thick, light, and somewhat fragile. They glue directly to the tube’s outside, which is small departure from the usual HPR “thru-hole” technique which mounts the fin internally, through the outer tube, onto the inner engine mount tube. At One Way, we used a Cricut Maker to form two jigs from cardstock to help with fin alignment.

While you don’t need a jig to help with fin alignment, it certainly nearly guarantees alignment, and thus straight launches. If you do glue them by hand, make sure to put a perfectly plumb line on the body tube, using the doorframe technique mentioned in Estes instructions. Then align the same edge of each fin directly on the line. Try to glue only one fin at a time, and let it dry in the perfect position for at least a couple hours before attempting another; let it “rest” overnight if you can stand it.

HPR fins attached to the outside of the body tube is an advanced technique, even for HPR. It allows the engine to use the body tube itself as the engine mount. This technique carries with it many dependencies of other advanced techniques. It will usually will require fiberglass strengthening of the fins to the body tube, or metallic airframes, to achieve the strengths needed for MACH 1 and above. Thick balsa is not usually used in HPR; the fin would be torn off by the extreme acceleration. And while a balsa fin could be used in HPR as a base to which one might adhere advanced materials with epoxy, such as aramid, carbon, or other fibers, One Way Rocketry still recommends always using a stronger finstock like G10 fiberglass, for all HPR.

We have created a Fin Alignment Guide for Cricut machines. Use your Cricut machine to cut this shape out of two differentpieces of cardstock, then use those for alignment.

Estes Vapor Fin Alignment Guide Cricut Project: https://design.cricut.com/landing/project-detail/5ee2d85c10f9b0028451575c

Recovery

There is no way we, at One Way Rocketry, are going to settle for the “Flatsickle” parachute included by Estes with the Vapor. Actually, they call it a “Parasheet”, and it succeeds in keeping the cost of the kit down, and will function if you cut the spill hole out as indicated on the plastic sheet; and add a fishing swivel. It will probably need to be replaced within a few launches, but can get you started. If you decide to use the Parasheet, make a copy of it right away out of any kind of plastic sheet you have handy. Make a couple backup copies. You can use any kind of tape to strengthen shroud line attachment point. You can use dental floss, Dyneema/Spectra line, or upholstery thread, as a high-tech upgrade to the lines, but keep in mind that cotton is more heat resistant than synthetics.

Since One Way Rocketry can design and hand-build our own parachutes from advanced materials, we had to choose the most expensive option for our Vapor rendition. Since money was no object, we chose the One Way Rocketry Ultra-Parachute (UP-18). At five times the price of the rocket itself, the UP-18 is an 18 inch diameter annular ring style parachute with large spill hole, and pull-down apex. To say it is lightweight is an understatement. Weighing in at just a few grams, it feels like those thin little bags at the produce section of the grocery.

The UP-18 utilizes a Dyneema composite fabric that weighs in at only 1/3 of an ounce per square yard!

The shroud lines are Dyneema braided line, at 60 pound breaking strength each. These are tied with an anchor knot to each of the nine gores, or panels, each with a 1/4 inch seam, hemmed with T70 UV-resistant polyester thread. To say this is High Strength is an understatement. For testing the UP-18, we had an executive run the hallway with the UP-18 in tow. Due to the strange eddies inside a hallway, the UP-18 tried to grab a quickly passing door frame, to which it became immediately attached, and pulled violently from the executive’s hand, stopping nearly instantaneously. Sure enough, the UP-18 was nearly unscathed; the same could not be said for the Parasheet, which would have torn, stretched, and knotted itself permanently, destroying the connection points.

Launch

OpenRocket Simulation

One Way Rocketry uses OpenRocket to simulate launch conditions, and ensure safety and recovery of every launch. It also allows us to add our own parachutes, and track any other customization we make to the rocket, such as adding weight to the nosecone, or fiberglass to the fins.

We have attached the output of OpenRocket for the Estes Vapor – One Way Rocketry Edition:

Conclusion

At One Way Rocketry, we think you have no where to go but UP! Go and grab two of these babies from Hobby Lobby (not on Sunday!) and start building. Maybe follow the instructions perfectly for the first one, then build the second with your own “improvements”. The Vapor is really a perfect size and shape, and works well with the “Big Little” engines, D, E and beyond. You can use the Estes standard 3/16″ launch rod kit, also at Hobby Lobby, which technically can support HPR rockets, but we suspect you will want to build a little better launch system than a simple iron rod.