Fiberglass rod gear legs?

[scottessex]

Has anyone had any success with fiberglass rod gear legs?
I was wondering about the weight they can support and mounting info etc.
I have seen then on Challengers, and I think the butterfly gyro uses them.
Here is some prices. http://www.mgs4u.com/fiberglass-tube-rod.htm
I guess you would use a 4130 chroMo sleeve where it mounts?

[RayPierce]

Originally Posted by scottessex

Has anyone had any success with fiberglass rod gear legs?
I was wondering about the weight they can support and mounting info etc.
I have seen then on Challengers, and I think the butterfly gyro uses them.
Here is some prices. http://www.mgs4u.com/fiberglass-tube-rod.htm
I guess you would use a 4130 chroMo sleeve where it mounts?

Scott I think I've seen them on the BumbleBee Gyro. Sorry no data.

[Earthboundmisft]

Scott, Roy Davis has them on his 912 machine.
Definetly 4130 sockets.
The challange would be determining the geometry.
I always planned on an aluminum spring gear for my two place. (Grove)

[Boots]

The Honey Bee G2 uses them.

[choppergabor]

Or just follow my direction and use the Astro or Corvette composite leaf spring. Can't kill it!

[jcarleto]

I've built a few sets of gear for Vari-eze out of fiberglass. Lots of work, but really strong and light.

[dinoa]

Tapered T6-7075 rods in 4130 sockets are used in the Kolb main gear. I think only a Graphlite http://www.marskeaircraft.com/carbonrod.html poltruded rod sandwich lay up could be more efficient.

Dino

[Penguin]

The Honeybee G2 setup is very simple.
The problem with fiberglass, graphite and composite is that they are springs.
No damping.
So you're going to come back off the ground with app. the same energy you landed with.
Depending on surface, that may also be detrimental to takeoff.
So they are arguably better than a rigid axle with tire suspension.

[dinoa]

The only damping is tyre scrubbing.

Dino

[choppergabor]

Originally Posted by Penguin

The problem with fiberglass, graphite and composite is that they are springs.
No damping.
So you're going to come back off the ground with app. the same energy you landed with.

Larry you could not be more incorrect! As the landing gear stretches out due to its spring like nature the energy is being absorbed by the rubbing and dragging of the tires on the surface. It is not the most elegant way but very effective!!! Lots of airplanes use the same system very successfully. There is no such thing as coming back off the ground I have never seen a gyro do that, which had composite landing gear. I have seen rigid axles bounce as you had described though! So yes there is the built in damper by the outward motion of the tires.

[Vance]

Originally Posted by choppergabor

Larry you could not be more incorrect! As the landing gear stretches out due to its spring like nature the energy is being absorbed by the rubbing and dragging of the tires on the surface. It is not the most elegant way but very effective!!! Lots of airplanes use the same system very successfully. There is no such thing as coming back off the ground I have never seen a gyro do that, which had composite landing gear. I have seen rigid axles bounce as you had described though! So yes there is the built in damper by the outward motion of the tires.

Hello Gabor,

It is my understanding that the tire scrub system of dampening the energy doesn’t work well on wet grass or other slippery surfaces.

Most of us don’t land or take off on slippery surfaces so it may not be an important consideration.

Thank you, Vance

[choppergabor]

Originally Posted by Vance

Hello Gabor,

It is my understanding that the tire scrub system of dampening the energy doesn’t work well on wet grass or other slippery surfaces.

Most of us don’t land or take off on slippery surfaces so it may not be an important consideration.

Thank you, Vance

Hello Vance my friend. You are absolutely correct about that. The less friction between the tire and the landing surface, the less effectiveness of this simple system.

[Penguin]

Originally Posted by choppergabor

Larry you could not be more incorrect! As the landing gear stretches out due to its spring like nature the energy is being absorbed by the rubbing and dragging of the tires on the surface. It is not the most elegant way but very effective!!! Lots of airplanes use the same system very successfully. There is no such thing as coming back off the ground I have never seen a gyro do that, which had composite landing gear. I have seen rigid axles bounce as you had described though! So yes there is the built in damper by the outward motion of the tires.

Oops! My bad, Gab. Sorry I touched a nerve.
Based on your advise, I am removing the dampers from my 911 this weekend.
Relying on tire scrub, I'm gonna whip up on those boys at the track next weekend!

Coincidentally, another thread points to some thoughts by C. Beaty, in which he summarizes ... "A gyro ought to have a static deflection of ~4 inches which provides a ride rate of ~94 CPM; neither too harsh nor too mushy. Proper damping is a must." He further said "Springs by themselves are only a half measure; they need to be used in conjunction with hydraulic dampers to be fully effective. Otherwise, recoil (rebound) rears its ugly head." (emphasis added.)

http://www.rotaryforum.com/forum/new...reply&p=448676

OTOH, Mike (MissFit) corrects me that the Dom air shocks DO indeed have damping effect. One learns something most every day on this forum, which is why we like it.

[choppergabor]

Originally Posted by Penguin

Oops! My bad, Gab. Sorry I touched a nerve.
Based on your advise, I am removing the dampers from my 911 this weekend.
Relying on tire scrub, I'm gonna whip up on those boys at the track next weekend!

Now Larry Larry Larry.... I did not want to start a war here honestly and it is not about touching a nerve at all. It is simply about understanding the forces of gyrocopter during landing. I would not even be able to get into the same state let alone the same building with Mr.Beaty if the admission depended on smarts and knowledge. So please understand that this theory comes from a guy who speculates a lot and analyzes everything to the point where it becomes disgusting to some . Hard landing on a single spring loaded gyrocopter has the built in damper factor having the blades flap down at the very bottom of the bending action of the landing springs. The flap down action starts out delayed due to inertia and lasts longer for the blades to fully flap down than the landing springs. Therefore on the way up as the landing springs return to the original position you still have the downward force from your blades and that is right there your harmonic damper Voila! I might be wrong about a lot of other things but I do know that all the ELAs, MTOs, Magnis that have the single composite NO SHOCK system I YET have to hear a complaint about bouncing back into the air after a rough landing. Kai? Would you mind to chime in on this? Thank you. So take this with a grain of salt Larry since I know nuttin' and claim nuttin' mo than speculating. Airplanes bounce back because they don't have the flapping damper like gyros having the blade's inertia helping us during hard landing. DISCLAIMER: This is strictly my own speculation and it has no scientific value!

[NoWingsAttached]

Matt trimmed down the fiberglass axles on the Honey Bee that I purchased from him to stop the recoil bouncing he experienced on hard landings.