4/15/2012  Construction Begins

Drilled the upper centering ring and epoxied it to the motor tube last night.  All 3 rings are too big for the motor tube, so I used masking tape to make shims in order to keep it centered.  I’ll pull the tape out after tack gluing and make a full fillet on each side of the ring.  Mask looks dorky but glass dust is worse.

The final plan for recovery harness back up is to attach about a 3 foot section of ¼” Kevlar to the u-blot shown below with a quick link that will attach to the eyebolt in the motor.  The thing I didn’t like about using a small string or something else to keep the eyebolt from unscrewing is that different size motor (ie different case lengths) would require different length material.  It seemed too awkward to be tying off to the motor once loaded into the rocket.  With this method, the tie off kevlar is long enough to drop through the motor tube and attach to the eyebolt before loading the motor.  And with 3’, it’s long enough to accept the biggest motor that the booster will fit.  I know it’s probably overkill, but I’m sure it will be a really nice back-up that will never be needed.

It should be understood that this very simple "back up" plan for recovery harness attachment has been stewing around in my head for literally months.  I just can't seem to get comfortable with a single forged eyebolt in the forward closure.  The thought of it unscrewing on descent was driving me nuts.  While I don't really think that will ever happen, I feel much better about the whole setup now.