LOC/Precision - Cyclotron

Contributed by Joe Balsamo

Construction Rating: starstarstarstarstar_border
Flight Rating: starstarstarstarstar_border
Overall Rating: starstarstarstarstar_border
Manufacturer: LOC/Precision
LOC Cyclotron
(Contributed - by Joe Balsamo - 01/01/02)

Single stage, tube-finned, 38mm rocket with a 3" BT transitioning to a 2.14" payload bay. The rocket is very suitable for Level 1 certifications.

3" LOC main body tube with 6 coupler tubes used for the tube fins. 38mm LOC Motor mount tube is held in place by two centering rings. The kit comes with a fairly long elastic shock cord, 2.14" payload tube section, plastic nose cone and plastic transition. I made some modifications to this which I will describe below.

The rocket is quite easy to build and the instruction sheet is fairly well written. I built it stock except for the recovery system. I don't like elastic shock cords. I no longer have an AT Sumo because the elastic shock cord broke during ejection. I have now replaced all of the elastic in my fleet with either Kevlar® or Kevlar®/tubular nylon recovery harnesses.

On the Cyclotron, I drilled out two 180 degree opposing holes each about 1/8" in diameter in the forward centering ring. I then strung a length of Pratt Hobbies 1/8" tubular Kevlar ® , both ends through the holes, knots tied about 4" from each end, then the ends epoxied to the motor mount. Thus creating a Kevlar® harness, the closed loop end now reaching just below the lip of the main 3" tube. Now, I can attach to this either tubular nylon, tubular Kevlar® or whatever. The Kevlar® may someday wear out, but it will take a very long time. Plus, I usually shove a small amount of wadding into the motor mount itself, so the brunt of the blast is taken by that.

I like SkyAngle chutes, so I ditched the LOC chute and recover on a SkyAngle 36. I use a Kevlar® chute protector to protect the chute.

I am also a big fan of the Aeropack system, so I included an Aeropack motor retainer on my Cyclotron. The bottom of the Aeropack is flush with BT.

The only other thing I can add is to make sure you rough up the body tube and the fin tubes, use a good quality epoxy and make all your fillets. Nothing is holding the fin tubes to the body tube other than glue, so this is key. I used a long wooden down to create the fillets once the tubes were attached to the body tube. LOC gives a good technique to build the fin tube structure, so I recommend using their technique.

I epoxied the bottom of the payload tube to the top of the plastic LOC transition and attached the nose cone to the top of the payload tube using a plastic pop rivet.

Finishing is typical of any kraft paper tube type rocket. Fill the spirals (I use Elmers Fill-n-Finish), primer the rocket, and paint.

In the case of this particular rocket, I decided to test out the new Dupli-Color Mirage color-changing paint. I get mine locally at Kragen, but AutoBarn on the web sells it as well. I chose the Purple/Green color as that seemed to look better (at least on the can top in the store) than the Gold/Magenta or Silver/Green. I used Fill-N-Finish and sanding until I got a fairly smooth surface. I then used Dupli-Color white primer in a couple of coats to get a near-glass smooth finish. I then applied the three-part Dupli-Color as per the instructions on the paint kit. First the flat black basecoat. Then the color changing paint itself. Then finally the clear coat. I really like how it came out and I get a lot of positive comments about my paint job, so it seems others do as well. I painted the inside of each of the tube fins with a simple brushed-on flat black enamel and the same for the bottom end of the rocket. I don't like bare areas on my rockets showing through and sometimes for certain acres, flat black painted on just works out real nicely.

Construction Rating: 4 out of 5

I've flown my Cyclotron a half dozen times now and it is a great flying rocket! Straight as an arrow and looks very cool as it blasts off. Most of the time, I try to remember to put a small amount of wadding up the motor mount tube before inserting the motor. I have forgotten a few times and no harm seems to have come from it. I use a Kevlar® chute protector and it seems to work just great. Motor retention is via Aeropack, as noted above, and I find that the transition fits into the body tube fairly loosely on my Cyclotron, so I use masking tape to attain a not-too-tight fit. My Cyclotron has flown on the AT H238, Pro38 G69 and Pro38 I170. Great flights, all of them.

As I noted already, I've completely replaced the LOC recovery system with my own. My system works flawlessly. It is the above mentioned tubular Kevlar® harness, attached to that is a 30' length of very heavy duty Kevlar® "mule tape". SkyAngle36 is attached to this via a kwik-link and I use a Kevlar® chute protector. All works great.

Flight Rating: 4 out of 5

This rocket is a great looking and flying rocket. The only area of change that I would recommend would be in the recovery system as I've already noted. Though I was already an L1 when I bought this kit, I feel that it makes a great L1 rocket. Also a good "small field" rocket with G size engines, but yet you can bust loose at larger fields with an I.

Overall Rating: 4 out of 5



J.b.b.j. (March 29, 2007)
I just bought the cyclotron. I love me some tube-finned rockets. The reviews were very helpful concerning construction techniques.I just knew that elastic shock cord was not going to make it. Great tips!

comment Post a Comment