EFL hub very loose

[vtown nick]

Ever since I converted my 500 pro to FBL it's had a cyclic wobble in a hover than no amount of tuning can get rid of. I tore it down just now to do inventory from last nights crash. With the Jesus bolt fully secured I can grab both blade grips and rock the head back and fourth on the main shaft. None of my other helis do this and the Jesus boot is firmly secured. The EFL hub has a cut all the way down the side for some reason and nothing clamps that.

I'm running the pro flybar main shafts but can't imagine the EFL shafts are different or are they?

[MGPTWEGB]

My first 250 did this....... the hole in my main shaft was worn badly..... It had also worn the expansion area where the main shaft went thought the head. ( not the hole in the head but the surface area where the main shaft makes contact with it. This happened from the wobble in head.... witch happened from the worn hole in the main shaft ????? Dunno but I found it by a preflight inspec

Both parts had to be replaced. I never knew what happened to make this happen as the head was tight when I installed it. The screw ( jesus bolt ) was still tight when I removed it.

[SumOFparts]

Which head are you using -

this one ?


http://grandrc.com/p6142/H50123-500-...duct_info.html

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If so more modern designs have gone to a jesus plus two bolts clamped to main shaft - and not the weak ass follower arm bolts either.....

http://www.ebay.com/itm/Tarot-Flybar...item3f26cf8999


Sure the align one works fine - until you crash on it a few times.......


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[vtown nick]

Originally Posted by SumOFparts

Which head are you using -

this one ?


http://grandrc.com/p6142/H50123-500-...duct_info.html

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If so more modern designs have gone to a jesus plus two bolts clamped to main shaft - and not the weak ass follower arm bolts either.....

Tarot Flybarless Rotor Head Parts for Trex T Rex 500 Helicopter RH50901 | eBay


Sure the align one works fine - until you crash on it a few times.......


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That is the original flybarless head, I have the EFL the follower arms don't clamp it down only the Jesus bolt. I have the better hub on my 450 and my 300 and it clamps down very nice I just wish the 500 fit tighter and there seems to be no way to make it tighter.

[SumOFparts]

Yeah I have the tarots and even the Vwin generic ones on several 500's- they all cramp down.

I recently got one of the original align efl ones in a box of 500 parts - was surprised to see no clamp on main....
Noticed a slightly twisted follower arm on it with its broken swash link - meaning the jesus broke and twisted these other pieces at some time in its history...

I may just sell or trade it off.

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[vtown nick]

Originally Posted by SumOFparts

Yeah I have the tarots and even the Vwin generic ones on several 500's- they all cramp down.

I recently got one of the original align efl ones in a box of 500 parts - was surprised to see no clamp on main....
Noticed a slightly twisted follower arm on it with its broken swash link - meaning the jesus broke and twisted these other pieces at some time in its history...

I may just sell or trade it off.

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I put mine down inverted and somehow a washout arm came off and got caut on something bending it all up and stripped a servo out. Pretty lame but the Jesus bolt didn't let go, maybe I'll go with the i2RC head block then.

[SumOFparts]

When I found that black plastic follower link was broke - wasnt even obvious - would of never seen that spit on bottom of that link if I wasnt messing with that slightly twisted arm.
When touched - it popped right off - so makes me wonder if that rocking in the head is causing over stress on the rest of head parts....wearing on the ball links....

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[Gladius]

+1 on the clamping head. Just make sure you tighten the two clamping bolts evenly. If you tighten one down before you start the other, it can clamp down unevenly, throwing your head out of balance.

[vtown nick]

I'm guessing the EFL head just doesn't crash well then? I did a full rebuild and dam near stripped the jesus bolt out and even used a new one. Still I can grab the head and rock it back and fourth on the new main shaft. I flew it anyways and it has a nasty cyclic shake that is worse than the last rebuild. I'm pretty bummed out with my whole EFL cost experience with the 2 crashes I have on it. I steered away from the DFC head because of crash costs!

[Russell Harding]

My EFL head was like that too. I tried pinching the head in a doorframe and it helped a tiny bit...

Flew okay despite the slop though (for me).

Good luck.

[Gladius]

Get yourself an RJX clamping head, and you'll get rid of that slop. You can get them pretty cheap at HK. Or you can pony up for the i2rc head, and never look back!

[Blayd]

Yeah, I have an i2 FBL head courtesy of a fellow member on here
From when I almost went FBL....it IS the bomb. ( Never went fbl... )
That and the atom 500 head is really nice as well.
I've never really been sure about the RJX heads.. My 700 came with a FBL RJX head, but like before, I'm not FBL, so I really dont know how good they are. People who fly them say they are better then the Aligns.

[Gladius]

My 500 came with an RJX head, and it is definitely better than the Align. I have not sprung for the i2rc head, since I have no complaints with the RJX head.

[vtown nick]

When ever I find a moment of free time I'm going to install the dfc swash and head and see how it flys. If all else fails I will totally go with the i2rc!

[tdeane]

Hi I just thought that I would point out this thread.

https://www.helifreak.com/showthread.php?t=394087

I was having the same head slop on my Trex 500 which I changed from the flybarred head to the FL head, and it turned out that my mistake was using the same jesus bolt through the head as before rather than a slightly shorter bolt (M2.5x16mm collared bolt). What was happening to me was that when the nut and bolt were tight, the nut was actually biting into where the screw threads ended and the collar began, so that it could not tighten the head onto the shaft, hence the slop. When I changed the bolt, voila, a solid head with no slop.

T

[Gladius]

That's a great observation. Thanks for sharing.