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Old 05-08-2014, 12:32 PM
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Default Rotor Head...how do I know?

Is there a way to look at my Air Command Rotor head and by looking at it know it is put together correctly? I mean NOT UPSIDE DOWN. This concerns me since Steve Weir's accident last year and especially since I have encountered so may issues with my gyro since I purchased it.

I would appreciate any and all advise. I just want to make sure.

The bearing seems to be quite, smooth and tight but that is all know.

Thanks

Mark
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Old 05-08-2014, 12:56 PM
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Default

In my opinion an important thing is make certain that the main rotor bearing is retained from slipping out of the bore on both sides. Generally there is a step in the block on one side and a plate on the other. Sometimes it can be done with two plates. Either way the outer bearing race should be retained in both directions.

From your pictures I cannot see if there is a step in the block to retain the bearing.

I feel this is important enough to disassemble the rotor head to see how the bearing is retained and make certain it cannot escape out of either side of the bore when everything is assembled.

Regards, Vance
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Old 05-08-2014, 01:06 PM
Alan_Cheatham Alan_Cheatham is offline
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The rotor head appears to be assembled correctly, at least as far as the bearing block/ teeter tower orientation.

On that Aircommand head the holes in the bearing block are not drilled on the blocks centerline but offset toward the top of the block. When bolted together, if the block were up-side-down the bottom of the towers would project below the bottom of the block and there would be a gap between ring gear and block instead of gap between ring gear and towers.

In this way you can't install the block wrong side up as you would not be able to properly bolt the ring gear in place without it being obviously wrong.
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Old 05-08-2014, 06:18 PM
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Default Thank you.

Thank you Vance. I always value your knowledge and input. If I had more experience I would take it apart and put it back together. I feel I need to wait for a time with hands on with some one who knows.

After reading Alan's reply I believe this gives me everything I need to know for now. I went and took a look at my rotor head it is exactly as he described it should be.

Thank you Alan. I feel confident that my rotor head is in proper working order and will have the guys and ROTR verify that.

So nice to have this access to so much help.

Mark
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Old 05-09-2014, 05:42 AM
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MadMuz,

When Steve died I first thought he had the bearing in upside down, like you mention...bit instead he had the bearing block upside down, as we all now know.

The slots for the resessed bolts sure seem to reduce the cross-section. What's left about 1/8" thickness?
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Old 05-09-2014, 06:00 AM
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Mark, your pictures are showing the top of the rotor head, you need to look at the bottom. It is very easy to see if it is installed properly, when you look at the bottom the block, make sure the hole in the block is smaller than the bearing.
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Old 05-09-2014, 06:55 AM
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You can read about it here, also has a report with pictures.

http://www.gyrosaway.com/newsletters/2013-12-LSRC.pdf
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Old 05-09-2014, 10:01 AM
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http://www.vxb.com/page/bearings/PRO...ONTACT/Kit8357
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Old 05-09-2014, 10:26 AM
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I feel the need to chime in here and say a big "Thank You" to Alan for posting those detailed pics..... really helps a newbie like me take what is written and truly understand based on the pictures.

Thanks again!!!
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Old 05-09-2014, 12:11 PM
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isn't the load being applied to the bottom of the bearing race,the rotor is pulling the race of the

bearing up and the load will be on the bottom side of the race and upper side of the inner cone.

best regards,eddie.....
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Old 05-09-2014, 01:58 PM
Alan_Cheatham Alan_Cheatham is offline
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Quote:
Originally Posted by eddie View Post
isn't the load being applied to the bottom of the bearing race,the rotor is pulling the race of the

bearing up and the load will be on the bottom side of the race and upper side of the inner cone.

best regards,eddie.....
The bearing balls can only carry the axial load from rotor thrust by being in compression between the bearing races so only one row of balls, the top, is carrying the axial load. This is why, if a bearing with a loading slot is used, the slot should be at the bottom of the bearing block.

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Old 05-09-2014, 02:08 PM
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thanks for good the explanation.

best regards,eddie.....
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Old 06-27-2014, 10:56 AM
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Default General RotoHead Re-Work

Group,
I have recently purchased a Barnett Rotorhead from a fellow member.
NICE piece of work! Mr. Barnett was a talented craftsman and machinist. I am bringing it back from long sleep and have ordered a new bearing (Nachi 5304ZZ). Original? was a ND5304(ZZ type), which was made in the USA by New Dimensions Bearings, now kaput. Looked and felt good and was well lubed, but caution abounds.

Question: Quite a few fasteners on the head, most under load stress rather than shear. I need to decide to go ahead and replace all or? The 'Jesus' bolt will be replaced, just wondering about the rest? Magnafluxed the spindle and looks great; I would hope so being 4130 steel!

Slight surface corrosion but overall they look good when given a bath`. Will use new locknuts (MIL spec expanding nuts rather than nylock.

Comments please.
Thanks,
Chris
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  #14  
Old 09-03-2014, 08:46 AM
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Nobody has mentioned the type of bearing, I one of my machines I used twin tapered roller bearings. Both outer tracks,fit in recessed bores so it is impossible for them two move.With no central spacer. Another type of bearing is angular contact, but they can fail, if worn or out of adjustment. IE early VW front wheel bearing. They are improved, with a central spacer. It must be an exact fit however.
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  #15  
Old 09-29-2014, 02:36 AM
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Why don't you use tapered roller bearings, that way you can adjust the preload.
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