Gyrobee Keel

rcflier

Experienced Gyroplane Pilot
Joined
May 24, 2007
Messages
702
Location
Nexø (Denmark)
Aircraft
Auto-Gyro MTO Sport 914 (upgraded MT-03)
Total Flight Time
35 as PIC
Hi.

Should I cut the keel to normal length or wait until I have mounted the seat?
I have long-ish legs and I wonder, if I should adjust the pedal placement?

Cheers
Erik
 
I feel your gyroplane should be custom tailored to you Eric.

I would keep in mind how even small changes can affect many things and modify the plans accordingly.

It is much harder to lengthen a tube than it is to shorten it.
 
Don't cut the front off the keel tube. I've seen extended pedal and wheel placements on several 'Bees for long leggedly pilots, it is pretty simple to mount it out farther and greatly improves ground handling character.

One other thing: I will soon be replacing my front "Flintstones" wheel/braking with something a guy did on here years ago - putting a Razor scooter front wheel on it with disc brake :) My own electric Razor Scooter battrery pack gave up the ghost, and I always knew when this time came that I would be cannibalizing the scooter for the front fork, wheel and disc brake with cables and handle. CAN'T WAIT to get this mod done :) :) :)

If you are going to change anything on the Bee, like moving the nose cluster fwd, the nose wheel and brake is definitely something you want to upgrade - those Flintstone brakes go through tires at the rate of one every season, at the very least, and are very high maintenance. The money trouble you will save on upgrading this will pay for itself in the first year or two.
 
Hi guys - thank you for answering.

The piece I have for the keel is 59" instead of 48", so there should be legroom to spare. ;-)
I won't cut it until I know the length that suits me.

This afternoon I just had a flight in a UL Rans-S6. Very nice small sportscar-like plane, with gobs of power (912UL).

And it went well, much better than the first time. And I applied for two PPL tests of the eight needed.So now it feels like Im going somewhere.

I'll see, what I can come up with for the front wheel assembly. Oh, I have so many more questions.

Cheers
Erik
 
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Here's my setup. The pedals are on a welded pedestal, a bit above and forward of, the front end of the stock-length keel. The nosewheel is not linked to the pedals. Instead, you swivel it using a separate steering bar and scrub brake that I lifted from my old Bensen.
 

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Hi Doug.

I see you're using the Watson tail. But with some small plates at the end of the HS, it looks like.
Won't a T-tail work better with the HS near the middle of the propwash? And I really like the
Aviomania Gsa1 - so much like the Wallis gyros. And the Gsa1 tail makes me think of a Piper J3 Cub.

And you have't bent the undercarriage tubes. I have one spare to scrap, when I have to bend them.

I plan on buying the hardware pack, Wheel Group and tank at Starbee. But LEAF hasn't got the old seat anymore.
They have a plastic seat instead. Hmm. I won't make the seat supports until I have a seat.

Cheers
Erik
 
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Erik: Yes, it's not only a Watson tail, it's Doc Watson's original. I bought his partially-completed Aerotec 'Bee kit back from him, finished and flew it. I later sold the Watson tail group, though, and made a 1/4" marine-plywood tail set, a la Bensen. Same general layout as Doc's.

Doc's location for the H-stab is about right, in my opinion. At that height, it receives the fastest propwash, and also is less blanketed when the power is off than a centered H-stab. Centered H-stabs lose most of their power when the throttle is closed, since the stab is immersed in the turbulent air thrown off by the pilot and engine upstream.

No, I didn't bend my axle tubes. Bending structural tubes sets my teeth on edge. Forces work in straight lines, not around corners. The 'Bee's 1/8" wall axle tubing is so massive that it likely doesn't matter, but bent tubes are just offensive to the eye, IMHO. To avoid the bending, I made and sold a machined insert for the axle tubes that has the necessary angle between the (steel) stub axles and the axle tube built in. I don't know if Starbee continued with that particular part design.
 
Hi Doug.

Is the Watson HS really in the propwash? It just doesn't look that way to me.
I would like to build the Watson tail, as I can get the West Epoxy locally and the
rest from Aircraft Spruce EU. Although all that stuff adds up to a hefty sum.
Many years ago I took a short class in building theRutan way and I still have the
"book" somewhere. Maybe I could even call the local EAA chapter if needed.

Do you have a drawing of that axle tube insert, so I can make it myself?
I would like to avoid bending the axle tubes - it's just one more thing, that can go wrong.

Cheers
Erik
 
Erik: I haven't wandered about behind my 'Bee with an airspeed indicator, which is the simple way to check for HS immersion. The propwash is smaller in diameter than the prop itself, especially when the aircraft is static or flying slowly; the loss of diameter is as much as 1/3 of prop diameter, sometimes even more at full throttle and zero airspeed.

The Watson HS is fairly low because the tail tube is long and unbraced. A T-tail, for example, would impose more twist on the tail tube than is wise, IMHO.

What I can tell you is that, with -3 deg, incidence on the HS, it sure ACTS as if it's immersed. The Bee is slightly high-thrustline, yet the nose rises, instead of dipping, when you add power. That is normally a characteristic of a LOW-thrustline gyro, such as a Dominator. However, a negative-incidence HS immersed in the propwash can mimic the flying qualities of a LTL gyro. A bit of nose-rise with power increases is a good thing.

I'll scrounge around home for that axle-holder drawing. It takes a skilled machinist to make the thing, though.
 
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Here's the axle-holder drawing. the red squiggle indicates a setscrew, which secures the steel axle against rotation while you drill through the 1.25" axle tube, holder and steel axle on assembly. Any holes drilled through should be well inboard of the outer end of the axle tube and holder, lest the steel axle be weakened at a fulcrum point and be subject to breakage.

The vertical scribe line on the end aids you in lining up the holder so that it doesn't create toe-in or -out.

The wheel will still have a bit of camber, but nothing serious in my experience.
 

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Thank you very much, Doug.
Cheers
Erik
 
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