The Highlander 29 is a 3-inch diameter, 4-ft tall rocket fitted with a 29mm motor mount. I designed it as an experiment, using low cost components where possible. The body tubes are from a single Staples mailing tube (about $5) and the nosecone was 3d printed (about $1).
The construction is similar to the previous rockets that I’ve built and described. This rocket is intended for use with motors from F through H, making it a good choice for people going from mid-power to high-power.
The maiden flight took place at the ERC rocket launch in Calmar, on 19 Aug 2023. Powered by an Estes F50, the rocket reached an altitude of about 670-ft, followed by a perfect parachute recovery.
My friend Darcy (who 3d-printed the nosecone and gave it to me) took a video of the flight and was kind enough to post it on YouTube:
My first altimeter bay was so ugly that I couldn’t take a photo of it for fear of breaking the camera lens! The second attempt was neater, but it was difficult to position the “pull-pin” switches at the correct position within the bay. I needed a modular system, where the components could be aligned easily and reused in different sized bays if needed.
Altimeter Bay #3 (Front)
Altimeter Bay #3 allows me to swap components around among my 2.6″ and two 3.0″ rockets. The individual modules were each inspired by parts that others had posted online, but my ideas and design are original.
Altimeter Bay #3 (Back)
The middle module contains a single key switch, which takes up less vertical space then the “pull-pin” type of switch, and which can be easily adjusted up-or-down to line up with the hole in the altimeter bay coupler (not shown). This module could probably be modified to hold up to six switches in a 3.0″ rocket.
The top module can hold one or two EasyMini altimeters, while the bottom module holds a single 9v battery (there’s room for another).
Either of my first two altimeter bays should have worked fine, so why did I keep working away to develop this one? First off, I had not built any altimeter bays before and I needed to learn how it was done. I still believe that one learns by doing.
My experience with Altimeter Bay #1 taught me that component layout was important, and that more attention to detail was needed. Altimeter Bay #2 was much better, and after it was finished I could imagine how much better a modular component system would be. At this point, Altimeter Bay #3 is “the best that I can do” and is ready to be flight-tested!
The Edmonton Rocketry Club held a special, two-day rocket event in Calmar, Alberta, on July 15-16, 2023. There were various rocket competitions, but rocketeers could also fly model rockets in the “Sport” category (non-competition). Model rockets use commercial motors from the smallest A-size to the largest G-size.
Ignition!
My BT80 was ready for its maiden flight on Saturday morning, using a mid-power E16-4 motor. The first four attempts failed, because the Estes igniter would not ignite the Estes motor! Darcy saved the day by giving me a J-Tek igniter that worked perfectly. The rocket roared up to just over 500 feet, but failed to fully deploy the parachute. It “lawn-darted” in the tall grass, bounced once and came to rest with no damage at all! The kevlar shock cord had knotted up during deployment and tangled around the parachute, keeping it from opening. I removed the kevlar cord that night, and installed the nylon web shock cord from my Aerotech Mega-Initiator.
Sunday morning and the BT80 was ready for another flight, again using an E16-4 with a J-Tek igniter. It fired immediately on the first attempt, rose about 550 feet, had a perfect parachute deployment, and landed softly less than a hundred feet away. People actually applauded, which just shows that they know how frustrating rocket misadventures can be, and also shows that rocket people are better than normal people!
Now that I had a working rocket, it was time to put it to work. I put in an Estes F26-6 motor, which would send the rocket up over 1100 feet. I also added a Jolly Logic Chute Release, which I had never used before. The Jolly Logic is a small device that gets “hand-cuffed” to the parachute and holds it closed until the rocket descends to a preset lower altitude, where it then releases the parachute. This helps prevent the rocket from drifting too far away, especially when it is windy. I set the Jolly Logic to 500 feet. The rocket ignited and flew up to over 1100 feet, deploying the parachute at apogee (top of the flight trajectory). The Jolly Logic kept the parachute bundled up, but it still acted as a drogue and slowed the rocket down a little. Finally, at about 500 feet the Jolly Logic released the parachute, which opened and landed the rocket softly out in the dirt parking lot, about 800 feet away. If the parachute had opened at apogee, the wind would probably have carried it over the parking lot and into the residential or commercial areas of town.
All things considered, it was a great weekend! The next ERC club launch is scheduled for August 19, 2023.
I use a 3D-printer to create some of the parts for my rockets. The is a stepped lid to fit a BT80 coupler. Designed using OpenSCAD, so it can create lids, bulkheads, or centering rings in any size.
Setup for dual deployment using motor eject for drogue and EasyMini for main.
An altimeter bay is a removeable rocket compartment that usually contains electronic components used to eject one or two parachutes. All of the rockets that I have built relied on the rocket motor’s built-in ejection charge to deploy a single parachute at an appropriate time.
The wires from the altimeter to the electric match terminals must be long enough to allow removal of the bulkhead without pulling the wires loose.
The easiest dual deployment setup uses the motor to deploy the drogue parachute at apogee and an altimeter/computer to deploy the main parachute at a lower altitude. When done correctly, a dual deployment system brings the rocket down closer to the launch point.
2.6″ Avionics Bay Sled, 3D-Print design by Donald Gemmel. I cut out notches at either end to clear the inside parts of the eye-bolt hardware.
Redundant Rocket Altimeter Pull-Pin Switches, 3D-Print design by Anne Sos. Would be better to mount one switch “up” and one “down” to protect against g-loads. Difficult to align pin hole in altimeter band to guide holes in switch mounts.
The first altimeter bay that I built looked like it had been designed by Pablo Picasso, which is to say, there were no words to adequately describe it!
This altimeter bay uses several 3D-printed parts, fits together well, and is ready for testing. It fits into my BT80 rocket and I hope to test it at the next launch in Calmar.
Getting to this point was not easy, and I learned several things that had not been mentioned elsewhere, as far as I remember…
