Scratch Flying Carrot Original Design / Scratch Built

Scratch - Flying Carrot {Scratch}

Contributed by Bob Patterson

Manufacturer: Scratch
(Contributed - by Bob Patterson - 07/01/02)

Brief:
Home brewed rocket named after a 1st Grader's book of the same title. Said 1st grader built a Lego model, and dear old dad attempted to copy. Painted orange and green to resemble a carrot, with hand drawn black lines to mimic cracks found in a carrot.

Construction:
Tubing, main nosecone, and D engine mount are from Estes Designer's Special, other nosecones are from brother-in-law's scrap box. Kevlar® yarn from Pratt Hobbies. 1/4" elastic shock cord from Walmart (3 yards for a buck). Main tube is 1 3/8" diameter, smaller tubes are 1" diameter. Balsa cross pieces and fins made from scraps.

Assembly was a pain in the butt. Cross pieces were notched to provide a firm mount for out-rigger tubes. Cross pieces on ends have come off several times, and I expect to have to re-attach them after 1st flight. Instead of butt-gluing and filleting corners, may use some kind of hand-cut dado kind of a joint. Large fins were added to sort of look like carrot leaves, but mostly to increase fin area. Cross pieces also have a centering top glued on top and bottom for more security. Used Kevlar® yarn for shock cord attachment a la Quest rockets.

Finishing:
Paint is no-name orange (only orange could find) instead of Krylon, find that it peels rather easily. I am dissapointed in it. The green also blistered/orange peeled over the white base coat (also not Krylon), which detracts from the appearance. Live & learn - Krylon for me from now on.

Rocket PicFlight:
Launched the Flying Carrot this morning for first time. Fairly calm morning, light variable wind, few clouds. Loaded up the 'Carrot with C11-3 engine, packed up a homemade nylon parachute wrapped in Pratt Hobbies flameproof cloth, grabbed my Olympus DigiCam and had my son launch it. Caught the liftoff, and apparantly the rocket flew up and arced right over my head to a height of about 100 feet according to a knowledgeable bystander (who was walking with his dog and son and had flown rockets as a kid), then came down and popped the chute mere feet above the ground. No major damage, except for one of the side nose-cone tube assemblies breaking off at the glue joint (which was a constant problem during assembly also). Will glue back together, maybe get some kind of dovetail joint going there, and try with a D12 engine and see if that helps the lift off any ( going from a B6 to a C6 seemed to help the wife's Enterprise take off better) - or perhaps some nose cone weight - will check with local rocket club (www.cmass.org) and see what recommendations I can get.

Summary:
Pros - it looks kinda neat. Cons - outriggers not all that secure, may have to modify installation technique.

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