I started work on my Sig kit that I got after Christmas. Going to build it a little different from stock since I want a bit more out of it than the run of the mill trainer.

The first thing I am doing is balancing the wing for stability in rolls. I spent about 30 minutes with a gram scale, the kind used for weighing food stuff for diets. I start with the ribs, weigh each one and group them according to weight. They run between .003 and .007 kg each. The ribs that land on the Fuse don't really figure in on this, so I dont weigh them. Starting with W4, and working out to the tip I go heaviest to lightest, with the final rib being on that is .005 kg. Reason for this is the last rib takes a beating, and while you dont want a lot of weight at the tip, you want a sturdy one.

Next I weigh each spar, LE and TE piece, then divide them up to be equal L>R, and then weigh the ribs in with each wing set. Once done, I then take the muffler and add it to the mix by weighing the right wing with muffler, then subtracting the left wing from right wing and then go through the spars and swap the difference. Once done the planes lateral balance should be close to perfect when completed, roll rates should also be equal in performance. I know, most will poopoo this move, Why waste your time, blah blah blah, but hey it has to be balanced one way or the other, why not from the start. Besides, with my luck I would wind up with all the heavy ribs on the outboard right wing and have to add 6 ounces of pennies to the left wing, which would suck if I have the covering on.

The mods I have in mind are few, but good ones. The first, it will be a tail dragger. Second I will be putting a bolt on wing instead of rubber bands. Finally the dihedral will be very shallow, something like 3 degrees as opposed to the 6 degrees of the kit. Dropping the difference from 3 3/4" to somewhere around 1 1/2" to 2". For power an OS 52 Surpass will be in the nose. I think I have a 12x8 prop for it, but cant remember off the top of my head the exact props I picked up for it.

If I get truely ambitious I may go for dual servos on the wings, but SIG had changed the kit to use center torque links instead of the bellcranks and pushrods of earlier kits. No horns sticking out of the wings, nice clean lines, but cant do flaperons for the fun of it with one servo. Would be pretty cool to have it just hover in the air with the ailerons hanging down.

The left wing has been built, lower, upper spars front and reat and TE are in place. The wing structure is solid, the design uses laser cut shear webs between the spars and ribs, and fit perfectly. So far every piece fell tightly into place, no trimming or sanding of any part was needed. I built the wing on a 3/8 Foam panel that is the type used for making Foamies, very dense, and flat, and had that taped down to my glass topped artist table. The wing came out nise and true, but after I took it off th e board I discovered the lower spar has a very slight bend to it that is only noticeable when you lay it down on the glass top. there is a 1/32" gap at the root. I can most likely get that out with the covering. I still need to attach the leading edge and W1 rib, but I first need to make a new Dihedral gauge with the 3 degree offset instead of the included 6 degree one, and also make new spar joiners out of plywood.

For the bolt downs, I plan to use dowels, so for the leading edge I am looking to cut back about 3/8-1/2" and insert 1/4" plywood at a slight angle, with 2 pins, and on the Fuse another 1/4" piece behind the windscreen ply so that when I insert the wing, the pins will be pointing up at a slight angle to lock the wing in place. Since the rear of the wing is angled down I most likely will put the bolt block in at a matching angle so the bolt heads lay flush with the wing, and will incorporate plywood in place of the balsa that currently goes there.

So far I am fairly impressed with the Sig kit, it goes together much nicer than the Top Flite P-51 GE I have going.

Pics soon as I take some.