Chris, have you considered spruce for the boom arms? This was/is the go to timber for spars in fixed wing RC aircraft.
Hi Marschy,
I'm using pine for the arms. As I understand Spruce is just a type of pine (norway pine?)...... Yes it is very strong, flexible and nice to work with, I did look into it but it's limited in supply options from what I can see. I think this is only the 3rd time I've taken an arm out and they are cheap. I get 3 arms to a 1.2m length for around $3. Plus with timber this cheap I can change the length around and get a completely different feel for it. I've using 40cm long arms so that I get a nice stable flight. I could shrink this down to 25-30cm and get a much more nimble machine. As a plus any broken arms are used to construct my landing gear :-)
It was a hard crash, I was going about 35km/h and it fell from about 4m up...... I'm surprised I didnt damage the plywood frame that I've got. I don't think spruce would hold up to that either.
Sadly I had to leave some of the balsawood in place, they hold the music wires in place on the pine parts. Tried to cut small bits of ply, not an easy task...... I was looking at it last night as I started to fix it all and decided I was going to revamp it so it's modular like my electronics tray (I love nylon bolts, great for attaching stuff and not paying the weight penalty). But that involves moving where the music wire is currently placed, so that will be a weekend project (after I get flying for an hour). I have it mostly reassembled, I just need to bolt the camera tray back on (plus the cameras) and cable tie the ESC and motor back on. So all toll this this accident cost me about an hour or two of my time. The mount for the GPS is now reinforced, I'll be pissed if I break it now......
I think I've added about 20g of weight to it by replacing some of the balsawood with pine but it will be much stronger.
So i've been looking at the footage from last Friday and reviewing the logs.....
I'm still not sure what happened though.... When it was flying I thought I saw the right motor separate from the airframe, however on the video footage I can clearly see that the right side just randomly went up, and it flipped over, almost back into a level position and then straight into the ground. I cannot see the motor come away in the footage but it was separated from the frame when it hit the ground. RC in on that channel shows no command for that. Also the rollin log entries show no change but the roll certainly changed, so it didnt intend it that is for sure. I'm wondering if a cable tie broke on the motor mount and it was wobbly?
All the footage I used was from the ground, the SD card on board were corrupted due to a loss of power. My bad, I forgot to hit stop recording before I pulled the power plug.
Would love to know why, sometimes having the data logs can be helpful other times they still leave you scratching your head.
Chris