Gyrobee Builder Support and Ideas

There are a number of things that could be done to make life easier for Gyrobee builders, not to mention interesting ideas yet to be tried. Below you will find a sampling.

When Don and I started on the Gyrobee project, we had to feel our way, one step at a time, without even knowing if the concept would work. Now that the aircraft is flying, there are a number of things that builders or suppliers might do that would make life easier for those who also want to build one. Here are some that come immediately to mind.

Machined Parts Sets. The Gyrobee doesn't require a lot of machining, but there is some, including the nose block, the shock-strut end fittings, the saddle fittings, and the stainless-steel mast/keel cluster plates. Virtually any machine shop can make these pieces, but they are definitely most expensive when they have to be made one set at a time. Someone with the skill or the right connections, or even an established manufacturer, could make them in larger quantities for sale, as sets, to builders. If anyone does, I'll point you to them here on this page.

Tail Group Components. The most visible aspect of any open-frame gyro is the tail group - the vertical fin/rudder and horizontal stab. I have seen Bensen's that were built like a watch, but the whole impression was spoiled by the use of plywood plates for the tail group components. That is why I selected the KB-2 tail group from Ken Brock. These components are light and beautifully built and that gives an impression of quality to the entire airframe. Unfortunately, after the blades and the engine, they represent the most expensive individual components on the whole aircraft. The price is right in line with their quality, but some builders would like to save a little money and here is one place it could be done.

What would be ideal is a combination horizontal stab and fin/rudder that would mount all the way back on the tail boom. The fin/rudder should have about the same total area as the KB-2 unit, but the horizontal stab could be significantly larger. There are many ways to approach the problem - wood framework with a thin plywood skin, composite, or even an aluminum tube framework with a dacron fabric web (like many fixed-wing ultralights). It needs to be reasonably light, strong, and it has to look decent! Anyone is free to turn themselve's loose on this little design problem. If some of you come up with good solutions, I'll post them here!

Raw Materials and Hardware "Kits". One of the tedious aspects of any project of this sort is the fact that you end up ordering materials and hardware from lots of different suppliers and, since you order in small quantities, you pay a premium price. Since the materials and hardware used in the Gyrobee are common to most other gyros, one or more suppliers or manufacturers may elect to make materials and/or hardware kits available. One very attractive option would be a complete airframe materials "kit", with all the proper pieces of tubing and angle stock cut to length, but not drilled or finished. If any one elects to make such sets available, I will post the information here.

Conventional Kits. As I indicate in the documentation package, I have no objection to anyone making kits of the Gyrobee available for sale, as I have no commercial intent with respect to the design. If kits do become available, I will list the contact information here, provided I am satisfied with the quality of the components and the ability of the supplier to deliver in a timely fashion!

There are definitely things I would like to do in future versions of the aircraft, if nothing else, just to see how well they work. If I do implement any of them, I will also put together documentation to allow retrofitting to existing aircraft, as well as implementation in original construction. Some of these ideas are listed below:

Tuff Wheels. The original Bumblebee (Martin Hollmann's design, from which the Gyrobee was derived) used 20 inch "Tuff Wheels" (these are made of Zytel, not cheap polypropylene). I saw these wheels shed tires in some of the early ultralights, due to excessive side loads when landing in cross-winds. This was my primary reason for going with conventional wheels and tires in the prototype. After eight flying seasons with the Gyrobee, it is clear to me that a gyro will never have the side-load problems of many of the fixed-wing ultralights, making the large-diameter wheels worth another look. If they prove tough enough - and I think they are - it would eliminate the need for the bend in the main axle strut and would provide excellent rough-field performance.

Seat Tanks. In my humble opinion, no seat tank is as comfortable, or feels as secure, as a fiberglass bucket seat with a good seat cover. However, seat tanks are convenient and some of them are pretty nice. As noted in the documentation, this will require some work to safely integrate the seat into the airframe, but I am looking at that issue.

Electric Prerotation. The model engine prerotator we are now using is one of the lightest and most effective prerotation system you can have on a gyro. The only real drawback is the hassle of starting them (especially with a tall mast) and the exhaust mess they leave on your blades and airframe. The big project this winter (1997-98) is to work up an integrated system using electric model aircraft motors - almost certainly 25's or 40's from Astro-Flite. The big challenge is the commutator in the head to feed the voltage to the motors at relatively high current (50-75 Amps!). Provided the problem can be solved, the result will be no-mess prerotation with a simple ON/OFF switch next to the seat!

Overhead Stick. While the overhead stick has largely gone out of fashion in gyro circles, it is still the simplest control system you can have and it has other advantages as well. It is light, has no "slop" to interfere with precision control, and the control ratios are highly favorable. The "problem" is that movements are opposite those of a conventional aircraft control stick. In fact, they are identical to the control inputs used for weight shift fixed-wing ultralights and trikes. Having flown such machines for many years, I can tell you that it is a very easy and natural way to fly and I have never experienced any confusion in moving from one system to another. I intend to develop an overhead stick option for the Gyrobee, if only because I want to try it! The throttle, instrument panel switches, and Digipod LCD instrument display will all be integrated into the T handle. Once it is all working, I will post the documentation, even though I expect most of you to stick with the conventional option (pardon the pun!).

Engines. I am always on the lookout for new engine options and will keep you posted!