Bensen question

joeheli

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I was just curios. The cable that goes from the rotor head to the front of the gyro. Is that nessesary to have it? I have seen alote of Bensens with out it and the KB2 dosen't come with that cable. The problem is since I install the seat tank, now I hit my head with that cable. :mad:
 

Rick Whittridge

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Jose, You can take the cable off without any problems to the airframe. I believe Dr.Bensen used the cable for extra support when the gyro was used as a tow glider. Just make sure your gyro has a redundant mast([email protected] pieces)
 

gyromike

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Jose,

I don't have the cable on mine either.

When I fly my friends KB-2, I'm always catching the cable with my helmet.
 

scottessex

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I have been debating if I should take mine off or not on the new version.

The nice thing about it is that you can mount your yaw string to it, and use the yaw string as a reference point to the horizon. But My mast is taller that a standard bensen, so I don't bump my helmet on it.
 

joeheli

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I don't have a redundand mass. Mike and Scott do you have a redundand mass?
 

scottessex

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Yes my mast is 2 pieces of 1x2.

It stayed together and bent very nicely in the roll-over.
 

gyromike

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Jose,

I do have the redundant mast.
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Scott,

I attached a piece of 1/16th welding rod to the front of my boom, sticking straight up. I made a loop on each end, and one end attaches to the bolt at the end up the boom in fronm of my pod with the other loop for a piece of yarn.
 

Screw

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Screw-In

My KB-2 came with one however, I removed it because the cable was in the way of the rotor break.

Screw-Out
 

Gyroflyer

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I also took mine off the kb-2 but I thought it had something to do with if you crashed it protected you in some way. Something to do with the mast and blades. I know I read that in something but don't remember where. Might have been when I bought my Bensen 20 some years ago.

Mark
 

Doug Riley

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Mark, you're probably thinking of an article by Al Cudney in the PRA mag many, many years ago. Al was a sort of Bensen groupie, having worked for Bensen off and on. He had a regular column called "Logically Speaking." He said more about that little cable than most of us want to hear.

The main point was that the cable was necessary in towed gyros, because the propulsive thrust was applied at the far front end of the keel. The out-and-down pull of the rope applies a bending load to the mast and keel that was better carried by a straight-line cable right up to the rotor head.

The engine pushes directly against the mast, so there's no bending load on the keel in a powered gyro. The bending load on the mast is still there any time the rotor tilt exceeds the rake angle of the mast, such as in a flare. Hence the cable still gets some use if rigged on a powered gyro.

Al then went on to spin a bunch of tales (some merely humorous) about other benefits of the cable. One of his "serious" side benefits was that the cable would provide crash protection. Obviously, a cable doesn't carry crush loads, only tension loads. Crush, or compression, loads are what you get in crashes. The cable might help restrain a broken-off piece of mast and rotor head in the event of a blade strike -- but that's a bit far-fetched IMHO. Don't bet the farm on it.
 

Gyroflyer

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LOL!! Bensen groupie. I love it. Actually Doug, I think thats what I had read, something about restraining or pulling the mast/blades away from you if a blade strike occured.

Anyway, thanks for the info on Al Cudney.LOL

Mark
 

Doug Riley

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I think I lifted the "Bensen groupie" term from Chuck Beaty, master of the deadpan gyro wisecrack.
 

bogman

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Contact info on R&D

Contact info on R&D

Gary Hall mentioned at Bastrop that a company called R&D offers a electric starter kit for the Mac.

Does anyone know how to to contact them and has anyone tried this kit on a Mac?
 

BUD ONEAL

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I called the cable my "chicken wire" I refused to remove it for a long while untill Chuck Beaty and a few others told me of someone crashing and having the cable wrapped around thier neck. That did it for me,This was over twenty years ago and I still remember!
 
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