tbzep
12-21-2012, 02:46 PM
I'm building a Midget and have come across an issue with the kit. It is very possible that I've screwed something up, but I don't see how I could have done it.
The kit is designed to use fishpaper engine blocks mounted flush with the top of the sustainer motor tube, and the other mounted flush with the bottom of the booster tube. I have done this.
When I install two shorty blanks included with the kit, there is nearly an 1/8" gap between the booster and sustainer. I've checked to make sure the engine blocks are flush. The sustainer motor mount is flush with the end of the reducer. The booster motor tube is exposed, so there is nothing that can be wrong with it.
Here's where I need help. Can somebody post the length of both your motor tubes, fishpaper engine blocks, and shorty blanks so that I can see if I've got something with an incorrect length? Also, please measure how far the shorty blank sticks out of the sustainer motor tube assembly. I'd be inclined to think I screwed something up during assembly, but this kit is simple and straightforward and I don't see how I could have done it.
I still plan to finish the kit and fly it. It won't be a problem as I'll just cut 1/8" off one of the motors/blanks to get a proper fit. I fly alone so I won't have any NAR conflicts with RSO's who want to argue I've altered the motor. I see no difference in trimming the end and peeling layers to get them to fit a tight motor mount. Safety Nazis just keep to yourselves. A razor saw isn't going to create enough heat to cause paper to burn and I won't be cutting into propellant.
The kit is designed to use fishpaper engine blocks mounted flush with the top of the sustainer motor tube, and the other mounted flush with the bottom of the booster tube. I have done this.
When I install two shorty blanks included with the kit, there is nearly an 1/8" gap between the booster and sustainer. I've checked to make sure the engine blocks are flush. The sustainer motor mount is flush with the end of the reducer. The booster motor tube is exposed, so there is nothing that can be wrong with it.
Here's where I need help. Can somebody post the length of both your motor tubes, fishpaper engine blocks, and shorty blanks so that I can see if I've got something with an incorrect length? Also, please measure how far the shorty blank sticks out of the sustainer motor tube assembly. I'd be inclined to think I screwed something up during assembly, but this kit is simple and straightforward and I don't see how I could have done it.
I still plan to finish the kit and fly it. It won't be a problem as I'll just cut 1/8" off one of the motors/blanks to get a proper fit. I fly alone so I won't have any NAR conflicts with RSO's who want to argue I've altered the motor. I see no difference in trimming the end and peeling layers to get them to fit a tight motor mount. Safety Nazis just keep to yourselves. A razor saw isn't going to create enough heat to cause paper to burn and I won't be cutting into propellant.