Here's a picture of the first D12-3 launch of the 3" School Rocket, before the chrome trim was added. The picture is from the December 5th N.E.F.A.R. launch. Boost was arrow straight all looked good until ejection.
The Kevlar loop broke through the upper centering ring and the rocket came down in two parts.
This was a fluke - how could a shock cord break through a 1/8" thick plywood centering ring?
The nose cone descended on the 18" parachute and landed softly. No damage to the nose cone.
The body tube nosed in and hit the ground!
I thought the tube would be crimped and probably beyond repair. THERE WAS NO DAMAGE to the tube, except for some very light scratches. This is a strong tube, it looks to be about 1 1/2 times the thickness of a BT-60 with a .070" wall.
Looking inside the tube with a flashlight, the centering ring had broken through between the two tie-down holes. I had hoped to fly it again with an E9-4 but couldn't with the needed repair.
I called Bill at BMS and told him what happened. He agreed that the ejection charge had to of been a strong one. He didn't have this problem with his prototypes. While this pre-production model had a lightweight ply centering rings, the production kits will get heavier plywood centering rings.
I used an Estes style tri-fold mount for the repair.
UPDATE: The 3" School Rocket has flown a few more times with the E9-4 engine. It gets to a good, but manageable altitude, perfect for demonstrations. Slow off the launcher on the longer burning E9. This model is now a favorite, I have to buy more engines!
Again, this kit retails for $14.95!
At 28 3/4" tall it's almost 10" taller than the Estes Big Daddy - at half the price!
This one is highly recommended. You'll find it on the BMS website, CLICK HERE
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