bilberry
Maybe you could provide Richard with actual measurements from top to bottom and side to side on the firewall for Richard to compare his offset and cross lines to...just a double check.
STAB:
The Simla stab span was one of the "givens" contained in the World Engines ad description, that allowed us to reproduce the plan. None of the pictures show the stab very well, so I believe that Jeff used his experience to come up with an acceptable stab airfoil.
The original prototype kit had a problem with the stab rib lengths that Kevin and I discovered...they were not long enough. What we did was to alter the way the stab was constructed, otherwise we would have built according to plans. The plans show the stab and elevators are built all at once as a unit with long ribs, then the elevators are cut away with a scroll saw, or sharp Dremel knife. Jeff's King Altair kit is the same way based on the original King Altair plan. Doing it this way has some advantages...you get a uniform airfoil being the main advantage. Some may feel it is easier as well. That's a matter of opinion.
I found it easier to build the elevators SEPARATELY, and use small, thin wedges of balsa, (easy to do), between the top and bottom...that way you build DIRECTLY against the plan, and don't have to make allowances when cutting out your elevators for the trailing edge of the stab and leading edge of the elevators. That scrollsaw really helps when cutting out the elevators each time you hit a rib. Building the elevators separately is the more "conventional" way to produce these, and I'm more comfortable with that method...plus with the particular situation we found ourselves in, it was the
only way short of waiting for new stab ribs...remember the ribs weren't long enough!!
The plans show the trailing edge and stab LE going all the way out to the tip, with small pieces of balsa making the remainder of the tips. Again I found it easier for me to cut off the LE and TE where the tip starts, and make a one-piece tip...it's just me.
The stab ribs have alignment tabs on them making it easy to get a straight stab. I believe there is a hole in the stab ribs for inserting an alignment rod in if you so choose. The top side of the stab is sheeted right there on the board to further ensure that nothing gets warped. Once the top is sheeted you can flip the structure over and sheet the other side. Add your LE, bevel the LE of the elevators, and add the tips and you're ready for sanding. Be sure to add small pieces of balsa to support the hinges, (DuBro). For what it's worth, I also do the slits for the hinges before covering.
DON'T GET TOO FAR INTO THE FIN ASSEMBLY UNTIL WE TALK!!!
