I was attempting to fly my Aerotech Sumo today on a Aerotech G35-4W. When the launch button was pressed there was a loud pop and that was all. At first I thought it just spit the igniter but when I went to remove the motor, about the back 1 inch of the motor came out with the propellant grain. The rest of the motor is further up the motor tube. It being a standard Aerotech kit, it has the Aerotech shock cord holder at the top of the motor tube so I really can't use a stick to push the rest of the motor out. Any one run into this and what did you do to remove the motor?
Then contact Aerotech, or whatever they're called now they may have an easier solution.
If I'm reading your post correctly, the full grain came out? If so my concern would be the BP charge possibly still being there. I can think of several methods of sending a dowel or stick up the aft end to pull it out. Providing you don't have BP or APCP in the way, sand the side and epoxy a stick to it then pull. Make a sort of 'T' or upside-down 'L' which will catch the top edge of the motor and allow you to pull it out (or use a long carriage bolt).
My next thought was a pipe extractor which is sort of a hex bar with an offset wheel to catch the pipe. I can't find a photo, so if you don't know what it is, nevermind.
I did turn up a pipe expander:
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made me think of the way drum sander arbors work. Perhaps one of those could catch the motor and expand enough while not expanding the motor case to hold it in place.
If the grain and BP are still in place, there are several methods I would try to remove them, but wouldn't suggest them to others. Kevin suggested the screw method, perhaps a long brass one.
Yes, the back 1 inch of the casing and the full grain came out It also looks like about another 4 inchs of the caseing is further up the tube. I can't see the top of the casing with the ejection charge
G35W Econojet Consumer Notification AeroTech has identified a higher-than-normal failure rate on certain batches of G35W Econojet motors. The lot codes affected are:
011213
002693
001914
Customers with motors displaying these lot codes are requested not to use them, and to contact AeroTech for disposition and replacement instructions. AeroTech apologizes for any inconvenience this has caused its customers, and will honor all G35W failure claims in accordance with our Warranty Policy.
I had the exact thing happen to me. Previous posts speak about the problem with G35s. The screw would probably work, but what I did was put a little epoxy on the end of a wooden dowel and set it in the end of the engine. Let set and voila!
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