Destroyerator Motor Mount Progress

I've slowly been making progress on the motor mount for Destroyerator's booster stage. Currently, several centering rings have been tacked in place with medium CA glue, and some epoxy fillets have been applied . I used Bob Smith Industries (BSI) 15 minute epoxy mixed with milled fiberglass for extra strength. Once applied, I used a plastic spoon to shape the epoxy into a fillet and then rotated the tube to prevent running and sagging until the epoxy set. In these pictures, the threaded rods are only temporarily slid into place.

I began fiberglassing the centering rings to the motor mount tube as well. I used "wedges" of 6 oz/sq.yrd. fiberglass to lay onto the rings and up onto the tube. This fiberglass will all be coated with West Systems epoxy once I have more. Right now it is just tacked in place with small drops of CA.

All centering rings will have fiberglass applied in this fashion on both sides, resulting in a very solid motor mount assembly.

Destroyerator Booster Work

I received some of the necessary items to continue work on Destroyerator. Most recently I received threaded rods, and corresponding nuts and washers, the Aero Pack 98mm motor retainer, and one of the Perfectflite mini timers.

 

The centering rings are drilled for the threaded rods. 2 have been laminated together, forming .5" thick versions for the aft-most, and forward-most centering rings. The aft centering ring was marked and center punched for the 12 cap screws that will hold the motor retainer in place. That ring is currently layered with 2 pieces of 10 oz/sq.yrd fiberglass cloth, and weighted with 50 pounds for a nice finish.

  I also figured out the final length of the rocket, which was based on how much length was needed in the booster for the recovery gear. The length will be 20.5 feet in the 2 stage configuration and 14.5 feet in the single stage configuration. 

I was originally going to use Positive Ascent's parachute and deployment bag in the booster. However, I will not be using the deployment bag. Instead, I will fold the parachute in a more optimal method for this larger diameter rocket, taking up only 9 inches of body tube. It will still be protected by Kevlar or Nomex heat shields.

The next steps for the construction will be mounting the Aero Pack retainer and cutting threaded rods.

Destroyerator Booster Construction

I now have some of the components to begin construction of Destroyerator's booster stage motor mount assembly. Below are a couple of pictures showing the size of these components compared to Positive Ascent. The blue tube is the 98mm  motor mount tube, just long enough for a full N rocket motor.