Phil Croucher Posted May 19, 2004 Report Share Posted May 19, 2004 Hi guys - we have this thing that is OK when loaded but spins like mad otherwise - aside from putting a mesh in at the front (there is one at the back), which I have already mentioned, does anyone else have any ideas? cheers Phil Quote Link to comment Share on other sites More sharing options...
Bladestrike Posted May 19, 2004 Report Share Posted May 19, 2004 Tie a tree to it. Quote Link to comment Share on other sites More sharing options...
407 Driver Posted May 19, 2004 Report Share Posted May 19, 2004 Fins ! You gotta have Fins...just like a Simplex or Isolaire seeder...or a Cessna 337 push/pull. Please send me $500 for the Consulting fees Quote Link to comment Share on other sites More sharing options...
Randy_G Posted May 19, 2004 Report Share Posted May 19, 2004 Fins ?? You mean like a 1950's, 60's Caddylac ??? Now you know why them things were so stable in the yaw axis. Cheers Quote Link to comment Share on other sites More sharing options...
Blackmac Posted May 19, 2004 Report Share Posted May 19, 2004 Two sixty MPH windsocks, one on each corner. Quote Link to comment Share on other sites More sharing options...
Rotorhead Posted May 20, 2004 Report Share Posted May 20, 2004 In the past with similar loads I have had pretty good luck with making the lines on the leading end a bit longer. It may not take much, but could make a difference. But definitely, 407 Driver's fins will make all the difference in the world. RH Quote Link to comment Share on other sites More sharing options...
Outwest Posted May 20, 2004 Report Share Posted May 20, 2004 Rotorhead is on the right track. This whole spinning load problem was explained to me many years ago by a aerodynamic engineer. Of course most of it was greek, but the jist was that it all had to do with mass. What happens is that when it is empty and with forward speed the load swings aft. The mass shifts and then wants to swap ends. When that happens the mass shifts and it starts it all over again. 407's solution will work, but what will happen is that the fins will have to be of sufficient size and have sufficent arm to counter act the effect. Akin to a tail rotor, you don't solve the problem, you just work against it. Changing the cable lengths will solve it. Of course then it will not fly level when full, which may be unacceptable. Cheers Quote Link to comment Share on other sites More sharing options...
Rotorhead Posted May 21, 2004 Report Share Posted May 21, 2004 I first discovered this when flying snowmobiles around a drill camp. My old buddy, Darrel Adzich, told me that if the straps are longer on the ski mount than the ones on the aft bracket, it would fly into wind at about 45 Knots nicely (without having to remove the windshield). A few years later, I observed another pilot sling a sled in a level scenario and the windshield flew off within an eighth of a mile from departure, due to the spinning expected. This same technique works well with lumber or drill steel too. You can use the same length of straps, just do a double choke on one end and that will change the effective length. RH Quote Link to comment Share on other sites More sharing options...
Phil Croucher Posted May 21, 2004 Author Report Share Posted May 21, 2004 Thanks for that!! Phil Quote Link to comment Share on other sites More sharing options...
Rotorhead Posted May 21, 2004 Report Share Posted May 21, 2004 ... just do a double choke on one end ... I re-read that this morning, and I should have said "do an extra choke on one end". Lumber and drill steel should always have at least two wraps when rigging the load with the straps. RH Quote Link to comment Share on other sites More sharing options...
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