Flight Log - 2012-06-10 - Rich DeAngelis's Interceptor

 The Interceptor: This rocket kit is the new release of the Estes Interceptor. It flies on 18mm B and C motors.  This kit was modified with an ejection-gas baffle and Kevlar shock cord mount, and an Iris Altimeter Payload Section. After 6 months, it's finally ready. Construction went well, but painting using bargain-price Home Depot paint resulted in "orange peel" finish, which had to be sanded off - TWICE, and re-applied. The paint then reacted with the primer (SAME BRAND!!) and crinkled and cracked the finish. Re-sanded again and then used the expensive but acceptable Testors paint for $5 per 3 oz can. Clear-coat, decals, then 3 more clear-coats and finally it's done. With the generous glue, extra paint and the added electronics bay, she weighs in at 164.5 grams (5.6 oz.) and is 3.2" longer than stock. I'll plan to use the shorter ejection motors than recommended, just in case it's a little too heavy. Typically for me, this model only passed a string-stability test after I added 17 grams of nose-weight on the base of the nosecone. (Am I doing them wrong??) We'll see how well she flies, but she sure is a pretty gal!

 We DID see how she flies, and it wasn't pretty. This model is grossly overweight.  The baffle (10 grams?), payload section (19 grams), and the heavy nose-weight (17 grams) makes this too much for even a C6-3 motor. I'm going to send this up on a D10 just to see how well she can fly. Then I'm going to have to take out that nose-weight and see if it's stable enough for flight, I expect it to fly better that way. If it does not and it is destroyed, at least I'll have that one good D-flight to remember.

 With the Apogee (Aerotek) D10 motor, this model has flown This rocket has flown higher than the St. Louis Gateway Arch, the Singer building in NY, NY, and the Chicago Temple Building.

 I won't want to fly this on a regular basis using the $10 apogee motors though, so instead I hatched a plan to add two small A10-3T boosters on the back, for a total impulse with a C6 motor of 26. The parts for the "solid-rocket-boosters" were obtained from two Estes 220 Swift rockets. I'm waiting to see how well it will fly without the nose-weight before proceeding with this plan. It would be my first cluster rocket project.

Flight Date: 2012-06-10
Rocket Name: Interceptor
Kit Name: Estes - Interceptor {Kit} (1250) [2008-2011,2019-]
Flyer's Name: Rich DeAngelis
Motors: C6-3
Launch Site: Halifax, PA
Actual Altitude: 158.00 Feet

I lightened this model by about 15 grams by taking out the nylon parachute and using a lightweight plastic parachute, saving 6 grams, and by removing about 9 grams of nose weight. It was a very calm afternoon so I wanted to see if this model can fly economically with a C6 motor and remain stable with less nose weight.
Peak acceleration was 4.6Gs, good enough to get it off the launch rail cleanly and going up. The motor burned for 2.1 seconds and averaged 1.2 Gs for the burn.  Top speed was only 52 mph. It did turn into the wind about 30 degrees or more.
Again the ejection delay was too short – only 2.7 seconds – and the parachute started to deploy at only 147 feet. 7/10 seconds later, after climbing an additional 15 feet it reached its apogee of 158 feet.  The parachute deployed well and the rocket came back at 10 mph for a soft touchdown after a 13.6 second flight. Because of the curving trajectory it landed far, about 250 feet from the launch pad.
I am not so impressed with the Interceptor’s performance on the C6-3, I don’t believe removing the extra 8.3 grams of nose weight will give me much better performance, but I'll try that anyway.  Instead I am going to move ahead with my plans to attach two 13mm A10 boosters to this rocket for a 3-engine cluster, sort of like a JATO assist.  That will certainly make this model something unique!

StageMotor(s)
1Estes C6-3

 

comment Post a Comment