AeroTech DMS 54mm Motor Thrust Ring Advisory

[CATO]

11/4/2015
AeroTech DMS 54mm Motor Thrust Ring Advisory
Dear AeroTech/RCS Dealers and Customers,

It has come to our attention that there have been two (2) reported instances of the factory glued-on thrust rings of 54mm DMS Disposable Motor System single-use rocket motors breaking off the motor casing during flight. One was a K535W, and the other was an L1000W that was flown at the recent Midwest Power launch. This usually results in the bare motor flying through the rocket and into the air, often in an unstable and unpredictable manner.

Customers are requested to NOT fly 54mm DMS motors using only the factory installed thrust ring and to take one of the following steps before flight to mitigate this problem:

1. Tightly wrap two layers of 1” wide masking tape around the thrust ring and motor case junction, and tightly friction fit the motor into the motor mount tube with masking tape. Using this method, the flyer should still be able to make use of their rocket’s existing motor retainer system.

2. Tightly wrap a layer of 1” wide masking tape around the motor case immediately adjacent to the thrust ring, to a thickness of 1/16”. Install the motor in the motor mount tube and tightly wrap 2 layers of masking tape around the motor and motor mount tube or motor retainer junction.

3. Remove the glued-on thrust ring and tightly wrap a layer of 1” wide masking tape around the motor case, flush with the nozzle end of the case, to a thickness of 1/16”. Install the motor in the motor mount tube and tightly wrap 2 layers of masking tape around the motor and motor mount tube or motor retainer junction.

4. Use a motor block within the motor mount tube that will transfer the thrust of the motor to the airframe and prevent the forward movement of the motor within the tube. Install the motor in the motor mount tube and tightly wrap 2 layers of masking tape around the motor and motor mount tube or motor retainer junction.

Two of these methods can be viewed on a YouTube video posted at:



AeroTech is continuing to examine and evaluate the situation and is actively working on a solution that we believe will conclusively solve the problem in the near future. Until then, new production 54mm DMS motors will be shipped without thrust rings and customers will need to apply their own tape thrust rings or use a motor block per steps 3 or 4 above. We are sorry for any inconvenience this may have caused for our dealers and customers. Your understanding and patience is appreciated, and we thank you for your continued support.