Originally Posted by
drac1
Matt, can you post a link to where you discussed taper sanding?
Do you bandsaw or hot wire the cores?
Do you make 2 cuts in the core to get the rib thickness or sand?
One more thing. Do you leave the foam block in while the ribs dry, and if so how do you stop the foam block from gluing to the skin and rib?
Might be a stupid question, but thanks anyway.
Scott,
Although I have taper sanded balsa sheeting for years, I think the first place I mentioned it is in this thread. Check back several pages.
The cores were cut by a guy close to where I live who had done a lot of work for Selig (sailplanes). He was a master at his CNC hot wire cutter. I had never seen such precise work by anyone else before. Unfortunately Les has passed.....but his work still lives and is a model for others with CNC equipment to follow.
Regarding the relief in the cores for the ribs, these required a single cut with a zona saw and then sanding on a flat surface. BTW- the wing core I am prepping was ready sheeted and with socket in place. Converting a fully sheeted and fully prepped core is a little painful because of the work that went into that to begin with, but if the tooling makes several much lighter wings, it would be worth the extra work. Not that the foam wing panel was heavy. It was a 500 sq inch panel less than 9 ozs. fully prepped and ready for covering. However, if my estimates prove correct, the same panel built up should be around 7 ounces ready for covering
Regarding whether to leave the foam stations in place while the glue cures, I suppose it is possible but much trickier. I use the foam stations only to position the ribs precisely, then remove the foam. Then I tack glue front, middle and rear with ca. Then I fully glue with thinned carpenter's glue (using a syringe).