RE: Towing a flag/banner
Hey guys,
Just wanted to follow up on my help request...
I installed a tow release hook through the landing gear mounting block/landing gear (just forward of CG) on my UltraStik 60 and set it up with a micro servo so that I can release whatever I'm towing with a flip of a switch. Works great!
I set up my 2 1/2' x 4' flag with a 1/2" dowel for a spine, and used a 9/16 nut epoxied to the bottom end of the dowel for a weight. I set up my bridle so that the tow ring is about 40/60 off center, with the ring toward the top. I used a 24' towline with 3 #64 wing rubber bands for a shock absorber.
Well, yesterday evening was the moment of truth... Flight Test.
We laid out the towline to the left of the airplane on the runway, and my buddy Steve held the flag for launch. Remember, this is a US flag, so it CANNOT touch the ground... it has to be held. I taxied out onto the runway where we had laid the end of the towline, got on my belly and hooked it up to the towhook, ran up the engine, and asked Steve if he was ready. He said he was as we both ensured that there was nothing for the towline to get snagged on, and we both gave the thumbs up. I dropped the flaperons on the US60, and set full throttle. The takeoff roll was about 6-8 feet, and it was airborne and climbing at about a 60 degree angle. As the towline followed the airplane, it eventually played out and snatched the flag from Steve's hands, and it was flying! It initially was flying horizontal, but as the weight took over, it was soon flying vertical. The whole setup works wonderfully! The airplane is very controllable (especially after you raise the flaperons... the first flight I forgot to raise them after takeoff in all the excitement, which made it a little "interesting") while towing the flag, although you can definitely tell that there's some drag back there!!
We did 3 flights with it, just to practice picking up the flag on takeoff, and catching it after release, and each and every one went smoothly... never even had to think about cutting the flag loose to save the airplane, for any reason. The releaseable towhook works great... I used a Hitec HS81 servo with a piece of #4 steel rod (a leftover smooth end of a 4-40 threaded rod) through a 7/16 dowel rod that I drilled lengthwise for the steel rod. I made a wedge shaped cut in the dowel with the band saw to make a "clevis", and the steel rod is the pin. Flip a switch, the "pin" retracts up into the top of the dowel, and whatever you're towing is released. Pretty foolproof, works great, lasts a long time!
I'll try to get some photos of the flag in flight next week as well as some photos of the release mechanism, since we all know a picture is worth a thousand words.
So, just wanted to give you guys who helped me out a big THANKS!!