Modification - Der Max Squared {Modification}

Manufacturer:

Modification

Contributed by Jim Bassham

Brief:
This is my twin-engine modification of Estes' Der Red Max kit for the EMRR "Twice the Thrust" Challenge

Modifications:
Construction started with the two motor tubes. I cut a slit 1/4" from one end of the tubes for the hook, held it in place with masking tape and glued the engine block in place above the clip. With the clips on opposite sides, I glued the tubes to each other using epoxy. While they were drying, I placed a length of Kevlar into the joint as a shock-cord anchor.

Once dried, I fitted the two tubes into the coupler. A couple strips of paper were required to get a tight fit that did not distort the coupler. I glued this assembly together using yellow glue. As this dried I stuffed paper towels, dipped in a 50/50 solution of yellow glue and water and then rung out into the cavity between the coupler and the motor tubes to block the ejection charge from blowing out the back.

I let this assembly dry over night and filled and sanded the body tube, nose cone and fins of the rocket. I used three coats of Elmer's Carpenter's wood filler on the fins thinned with water, and the same to fill the grooves on the tube. The nose cone required a few dabs of Squadron green putty to fill grooves.

I glued the modified motor mount with shock cord into the body with yellow glue. I placed the motor tubes flush with the back of the rocket.

The rest of the assembly followed the instructions from the Red Max kit.

I finished this Max yellow and applied the decals as usual. After everything had dried, I used a Sharpie to cross out the "Red" in Red Max and ink in a "2" above the "Max" to make the "Max Squared"

With the engines in place, I compared the balance point with the SpaceCad file I had created for this rocket, and felt the balance point was a bit too far aft, so i added plasticine clay to the nosecone (About a 1" by 1" by 1/2" piece) until the balance was about 1 caliber (body tube diameter) forward of of the CP.

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