Not a whole lot of gettin stuff done today, I think Tom and I both are starting to get the burn-out setting in. My work trip will be nice just to kind of get away for 2 weeks and get my mind clear of some things (not to mention make some money!).
Anyways, We replaced the wire nose strut for a 3/8" diameter offset Robo-strut. This fixed the lame duck nose gear, but with all the weight needed to get this thing to balance, its fully compressed. The plus, is we still have a bit of a positive AoA, so we are going with this setup for the initial flights. No pictures though.
We also did another CG check. We put everything in its respective positions and balanced it at the CG point (around 19" from the nose). We ended up with: two- 6s5000 lipo's, four- 4s4000 Lipo's, one- 3s2300, one-2s2300 A123, a 4cell 1500mah nicad, a 4cell 3300mah nimh, and a 9 channel Receiver. This is what it took to to get it to roughly the correct CG.. The total weight of all this stuff.. 31.XX pounds. So I suspect the flying weight to be 32-33lbs when all is painted and done.
With 4000watts available and 33lbs, that is 121 watts/pound. It may still fly with this ,but we are definitely doing a 12S jetfan 90 setup in the near future.
This also brings up a good point. We made up a CG doohicky (basically some pointed dowels mounted in a 2x4 that the center section can teeter on. The problem is, when you get it close to being balanced at the CG, depending on which end is lower (nose or tail) dictates if it shows as nose or tail heavy. For instance, without changing the position of anything, we can level the center section and it will sit there for a bit. But if when we are leveling it, the nose is slight to low, it will show as nose heavy, and vice versa if the tail is low. This is
without moving the position of Anything!
We really need a more reliable and accurate method of balancing this thing! I have a feeling that the Weight on wheels CG method is going to be the only way to accurately and reliably determine the CG within 1/16" accuracy. For those who don't know the W.o.w. method, it involves some measuring and weighting the weight at each axle, its essentially identical to how they balance full-size airplanes and VERY accurate.
So back to the work:
We got the upper strut door linkages built it. It involves some brass straps, 2-56 ball-links, clevis' threaded rod and a modified small control horn. Like I have said before, simplicity is the name of the game for these gear doors.
Then we did the closing and opening mechanism for the inner doors. The doors are pulled close via a piano-wire "lever" that is epoxied and glassed to the inner doors. The wires are visible under the center section when the gear is down, but the fact they are so simple to close and keep closed makes it worthwhile to me! To open the doors, we took some small piano wire and bent a torsion rod style setup. This is bolted the gear door spine and then the bends were modified so the doors would close completely, open completely and so that if one gear went up and closed the door before the other side, the other door would still close. It took about 30-45mins of fiddling with, but worked out great in the end.
And a little youtube video:
https://www.youtube.com/watch?v=4wmCN8DXeWQ