LOC/Precision - Expediter {Kit} (PK-72)

Contributed by Dave Fountain

Diameter: 4.00 inches
Manufacturer: LOC/Precision
Style: Sport
(by Dave Fountain) 

[Picture]As everyone knows I like altitude and big rockets are no exception so I was rambling through the LOC catalog looking for a bird for my level two attempt at SOM 4 and I came across the Expediter. I liked it because it resembled an ICBM (inter continental ballistic missile, i.e. a Minute Man) so I bought it. The Expediter consists of a 4.0 inch booster that contains a single 54mm motor mount reduced to 3.10" and is 61" tall and is recovered by a single 48" parachute. 

To build the Expediter I constructed the motor mount using 30 min. epoxy and installed a recessed kaplow mount to retain the motor which required me to modify the fins a bit. Next I constructed the fin tabs which was the hard part. The big gripe I have about this kit is the FIN TABS which requires separate tabs to be glued to the bottom of the fin root which is very weak, to fix this I glued the tabs as to the instructions on wax paper and installed 3/4 oz. fiberglass on both sides of the tabs, this greatly increases the strength of the tabs. 

Next I installed the motor mount in the tube with 30 min. epoxy followed by the fins. Note: install an eye-bolt to the motor mount to attach the shock cord. Whatever you do, DO NOT USE THE STOCK SHOCK CORD MOUNT, IT WILL RIP OUT OF THE ROCKET CAUSING IT TO GO SPLAT on the hard surface which is not funny. 

Next I built the payload section by the instructions with epoxy. 

Finally, I painted the entire rocket with Rustoleum paint.

Its first flight was at SoM-4, the flight was picture perfect with no nose weight. The motor I used for the flight was an I357-m which produced a perfect, straight as an arrow, no roll flight which was recovered very close to the pad. The next planned flight is on a J350 . . . can you say Mach! One suggestion: relocate the shock cord mount to the center ring because the tube mount is not strong enough to handle the load.

Flights

Comments:

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D.R. (November 26, 2001)
I got one of these as my second HPR kit. I beveled the edges of the fin tabs and the tab extension thingys to get more glue surface area. I left the back centering ring out and filleted the heck out of everything. I found that the shock cord mount is quite suitable for this rocket, as it hasn't failed on the 2 dozen flights I've had with this rocket. The best motors for this rocket are I211-M and J180-M. This is how I did my Level 1 cert and Level 2 cert, in the same weekend! I love this rocket.
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P.C. (November 4, 2005)
The expediter no longer has 2 piece fins (which I found to be a real turn off) I asked why LOC did it that way and the reply I got basically said they did that for packaging reasons! So the fins are now 1 piece through the wall to the motor mount - good stuff! So I decided to buy one. It's a great kit - it's BIG and looks brutal yet it's an easy build. I don't like the shock cord mount so I'm putting a piston in mine with the piston strap fixed to the motor tube. Motor retention is using my standard motor retainer (http://waro.iinet.net.au/parc/motorretention.htm). I have been very happy with my LOC kit's and can't wait to launch this thing!
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L.B.B. (July 20, 2007)
I made some extensive mods to my Expediter. First, I cut the lower airframe to allow for an anti-zipper design. Each airframe piece was then glassed with one layer of 5oz fiberglass. I added a longer motor mount to handle anything up to a 54mm 1756 case and added a third centering ring. Used an Aeropac motor retainer. The fins seemed a little thin for a rocket that can take a J or a K motor, so after attaching them, I filleted the inside of the fin can and then added expanding foam. The outside fin fillets were made with a layer of 5oz fiberglass that covered about half of each side of each fin. Vent holes were drilled and the sections of the airframe attached using 20min epoxy or small machine screws. I also added rail buttons instead of the launch lug. The entire rocket came in weighing about 5.5 lbs. Overall a great kit with plenty of flexibility to customize as you see fit.

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