Stuff about Arrow Gear Company

A few pics regarding Arrow Gear. They do heat treat. All ring gears are carburized and die quenched.

Weight Shift- CG Manipulation Rotorcraft Control

Photos coutesy of Steve Remington, Collect Air: All photos fall under the respective copyrights of  either Collect Air, Cessna, and/or Seibel Helicopters. No copyright infringement was intended with this posting. All due credit goes to one or more of the above mentioned entities.
http://www.collectair.com/cessna.html

There have been a number of perspectives with regard to weight shifting control for rotorcraft/helicopters  and even more concepts designed, patented, and attempted. Some successful and some not.
One in particular is a design by Charles Seibel. Seibel, a left field pioneer with respect to rotary wing aircraft, refused to let the "main stream" prevent him from building his platforms. Even when they laughed at him.

Seibel pushed forward and started to build his rotorcraft in his attic while working for Bell in New York and finally in his basement  when he moved to Kansas. Using Ford motor parts and scraps of aluminum, he built the S-3 in three different segments so it could be removed easily. What was most intriguing to me was when it came time to test the helicopter, Seibel fly it himself, though he had no license and no flying experience.
Seibel's design used weight shifting in the the form of moving the pilot's cabin forward, aft, and laterally thereby changing the CG, causing the helicopter to move in that direction.

S-3 Moveable Cabin/Weight Shifting Control

S-3 with Cyclic Control

Though the S-3 with weight shifting could fly and be controlled, it would at times tend to want to roll over in the event of a hard landing as outlined in the Collect Air web site. I believe that is the purpose for the lateral extending struts  seen in the first S-3 photo above.

The HIR design/patent, a 15 year old idea that I brought off of the back burner, started to take shape in 2005 in simple sketches. After I ran across the Collect Air web site, I thought perhaps that I was not crazy. Though my design was not a "linear" shift in weight like that of Seibel's design, could it still fly? Seibel's platform flew. After viewing the fixed pitch restrictions of both the Airscooter and GEN H-4 helicopters, I designed the HIR platform to utilize two separate airframes that worked "within" one another, incorporating the weight of the pilot which remains distributed equally between both airframes and with the added ability to tilt and reconfigure the airframes at will to vector the rotor disc thrust, yet all at equal moments and spans of motion. I must admit that the final draft was a result of attempting to solve a chain of set backs. I wanted a tilt mast helicopter, but then how would I prevent binding of push/pull rods or tubes, i.e. maintaining collective pitch? Further, if the mast tilted, how would I keep continuous power to the tail rotor? These two problems led me to design the morphing airframes, which then led to having to solve the unintentional collective pitch change as the airframes change configuration. That led to my designing it with a canted collective pitch stick.

There will be further trouble shooting and there are still hurdles to clear before I am satisfied. The trick is to find and learned the parts of physics and mathematics that are not yet known with respect to this concept of rotorcraft