All of my first jigs were just like Kang's simple dowel and sliding plank jig. The Science Olympiad kids I coached also made and used the simple dowel and plank jigs. However, as I built and covered wings with larger chords and wingspans, I discovered that I wanted stiffer rails and a more consistent way to slacken the film evenly along the whole length of jig. Thus, I used the turning of wingnuts to draw the "L" shaped rails together rather than just pushing in with my fingers.
One neat feature of the the Sanborn/Tyson jig is that it is easy to tighten the film if one outs too much slack in the film. I can loosen the wingnuts on my jig and pull back out but, although as precise as with the Sanborn/Tyson jig, it is not as "cool."
One other note. I find it easier and more consistent to cover using film that has been lightly "crinkled" by rolling it up once into a loose ball. This crinkling seems to help with the static cling and in getting fewer wrinkles in the finished wing/stab/prop. Some people, like Ray Harlan in his SO plane notes, say that the crinkling often makes for a better airplane, and some people say the opposite. Always being a doubting Thomas, I built two identical wings for my best LPP, one with crinkled film and one with non-crinkled film. The same plane with these wings exchanged flies the same times and pattern. One plane does not make for a good statistical sample but I think I will keep using crinkled film for the time being.
Leo
Leo
--- In Indoor_Construction_at_yahoogroups.com, "John Kagan" <john_kagan@...> wrote:
>
> --- In Indoor_Construction_at_yahoogroups.com, "Yuan Kang Lee" <ykleetx@> wrote:
> >
> > ...Others use simple box frames that are not even adjustable...
> >
>
> That's what I currently use. I slide the film in a bit on its chapstick adhesive to get some slack, but that's about it.
>
> It works fine. I am going to try one Sanborn's jig, though.
>
> Like most things, covering with thin film is difficult if you don't know how, and easy if you do. Use some kind of frame or jig to hold the film, mist or brush the adhesive, cut with a soldering iron. Easy peasy.
>
Received on Sun Apr 24 2011 - 18:33:50 CEST
This archive was generated by Yannick on Sat Dec 14 2019 - 19:13:46 CET