Do not forget to place the metal strap inside rubber "C" channels, Virg
On Fri, 10 Mar 2006 16:27:20 +1000 "Robin Wills" <[email protected]> writes: > G'day Don. > > While I haven't retro-fitted wing tanks (yet) I will be doing so in > about 4 weeks time. This is due to me taking a wood saw to my wings > after a minor mishap in which the retracts folded up on landing on > a > strip that looked smoother than it was. (And yes, I did lose the > prop, > although the engine was stopped, thankfully). > > Anyone want a Revmaster? Am going to a Jabiru now I have an excuse > to do > so. > > My plan of attack is to install 3, 4 or 6" Aluminium or PVC tubing, > as > found on travelling irrigators and the like on farms. My > measurements > are that a 2m length, 4" in diameter, gives me 15.7 L total, or a > smidgen under 1 hours flight time a 2m length, 6" in diameter gives > me > 35.3L or 2 hours flying time. Ergo, 2x6" and 1x4" 2m lengths gives > me > 172.6L of fuel, or around 10 hours flying time. With that kind of > range, > if you so desire, you could only go with the 2x6" tubes and about 8 > hours flight time. > > I would be mounting this in 1 of 2 ways. 1. install a wear strap > around > the tubing at the ends, and cut suitable holes in the inboard and > outboard wing templates, as well as through the foam ribs. This > should > give the tubing plenty of support. Use the manifold at either end > to > provide lateral restraint. Or 2. install 6" fore and aft of main > spar > and 4" for of rear spar, with suitable brackets. For those who know > someone in a warehouse, that steel strapping they use on pallets > and > such would be nearly perfect, if you could find a way to ensure the > little clip will not wear loose over time (tack weld?). > > Disadvantages of this setup are a few. No internal baffles, so fuel > surge in uncoordinated flight will become an issue. The requirement > for > fuel boost pumps now that I no longer have a header tank. Devising > a > suitable filler neck for the round tubing, although this shouldn't > be > that hard. > > Benefits of this setup, again, are a few. A dirt cheap, simple, easy > to > make fuel tank that gives the airplane the legs to outlast your > bladder. > If you install the tanks for and aft of the main spar, and you hit > "something" then the 6" tubing will provide a measure of impact > protection, and worst case scenario, may hold the wing shape long > enough > to get you on the ground, versus having a slab sided leading edge. > (But > how often has this been the cause of the crash? Once? Never?) > > While I have not measured the weight of the tubing, yet, I believe > it > would be a small penalty over the existing header tank, and at the > same > time, give me longer legs for the KR. (Oshkosh here I come?). > > Drawings and costings will be up on my webpage sometime soon. > > Cheers, > Rob. > > Robin Wills > Second Person, Pacific National > KR-2 VH-OMV, Ser# N111 > > [email protected] > > > > > _______________________________________ > Search the KRnet Archives at > http://www.maddyhome.com/krsrch/index.jsp > to UNsubscribe from KRnet, send a message to [email protected] > please see other KRnet info at http://www.krnet.org/info.html > > Virgil N. Salisbury - AMSOIL www.lubedealer.com/salisbury Miami ,Fl
