The flying monkeys got me...

Helis and fixed wing

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Wednesday, May 31, 2017

HK EPP Sbach Bebuild

Finally decided I was ready to rebuild the HK EPP Sbach I crashed back in April. She became uncontrollable and she crashed. I have to suspect that it was the HK Orange Reciever-3 axis Stablizer as there really was no other reason for it to fly the way that it did. A few weeks later the Edge 540, also equipped with that receiver-stabilizer combo was delayed responding to an up elevator command and came in a bit hard. I don't know that I will trust these reciever ones anymore, and threw out the one in the Sbach. I will fly it without stablilization for now. I just hate to throw them away, but its not worth the worry.


I collected all the pieces and disassembled the motor box. Looked over what I had and started putting things together. I missed a few pieces that I didnt recognize just where they went in the puzzle, which lead to some sequencing errors, but I was able to get a nice frame together.



The gear hard point after the major pieces were CA'd in place.
Front.



Back.



Epoxied wood into the front frame of the gear hardpoint to add strength.
The front fuse frame is also drying but thin CA. 



The epoxied wood supports. I laid up a lot of epoxy behind the wood to strengthen the puzzle pieces. There was a center piece I missed. I will look tomorrow at dropping a piece in from the top, but I think this is enough support.



Since the back of the hardpoint wasn't so broken up, I only added support to carry energy from the hardpoint into the fuse. If this comes out again the aircraft will not survive.

Tomorrow I will work on getting the motor box onto the fuse. I am gluing the EPP where its cracked and split, but its going to need some more support, and I am not sure how I am going to paint it. Not sure if EPP can take rattle can paint? I don't have air paint... some research to follow. I am sure I can find some brush paint.

The gear hardpoint went back together better than I expected. I am a little anxious about getting it to fit its tear away points, and know in the end this repair is adding some weight that will affect its CG and flight characteristics.

Either way, we are on our way.

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