CNC tail failure

[bearwood]

This is shades of the TREX450 tail problem. You never stood behind one in a hover unless you wanted your eyes parted. They modified their tail hub....

falconea45 This is not the Gaui tail rotor, it is the Sonix (HDX 550)!

There are plenty of good tail rotors out there -just the SONIX brand isn't one of them!

Very happy with my Raptor tail rotor and plenty of others are using the Trex 600 with good results.

[hobbytrade]

what is right what is wrong with ,pp all know about

[bearwood]

[QUOTE]what is right what is wrong with ,pp all know about/QUOTE]

And who might you be HOBBYTRADE?

What is right - not a lot because it breaks!
What is wrong - it breaks, look at the photos, they both failed in the same place.

Can someone translate what "pp all know about" means!

[hobbytrade]

I have business with SONIX item ,I try to contact factory improve Rotor hub with a Trust Bearing..
for my experience sonix product sweet price and good cnc finished ,all joint with bearing for tail system ..
BTW
I have a question The Sonix Rotor hub made by steel #304,and stock ep550 Raptor tail rotor made by aluminium ,which strong ?
pp =(people)

[mjdee14]

I have business with SONIX item ,I try to contact factory improve Rotor hub with a Trust Bearing..
for my experience sonix product sweet price and good cnc finished ,all joint with bearing for tail system ..
pp =(people)

From What I have seen the sonix tail for the 550 is a POS...

The bolt holding it together was so small it is a wonder they don't all blow apart.

For $15 teh stock Trex 600 unit is 100 times better than the Sonix. Sonix should be ashamed to sell a unit like that. i was lucky I didn't use mine and helidirect took it back.

A nice shinny piece of metal is no good if your going to loose your heli using it.

I have the Sonix tail gearbox and lever, and that seems OK....I also bought the Sonix tail slider and that didn't fit very well or slide easily until I had to reem it out to fit the shaft.

Sonix has a long way to go with quality control and I most likely will not be buying any of their productsin the near future.

JMHO

[mysticmead]

which is stronger steel or aluminum? well, that all depends on the quality of steel and aluminum. it also depends on the quality of the manufacturing. it appears that the quality of manufacturing is in question with the Sonix parts. adding thrust bearings to the hub might not be what is needed. what is needed is making the part better so it doesn't break apart while the heli is spinning. not only is the part breaking like it did putting the heli at risk, but more importantly it puts the pilot AND anyone standing around the heli in danger. personally, they could make the part better, they could add thrust bearings, but I would never fly those parts on my heli just because it has been proven to fail and could fail again and I won't put myself or others at risk.

[bugdozer]

From looking at the pictures of the hubs that have failed, it looks like the hole for the tail blade-grip screw was drilled too far down the shaft, weakening the point where the shaft and hub meet. If this hole was shallower and the screw shortened a bit, this would leave a solid shaft up into the first bearing, strengthen the failure point. I am going to check the depth of the hole on mine this weekend and see what's up. If it is too deep, I may drill and tap the hole all the way through the hub and use a longer screw. That should help.

[mysticmead]

I don't think even a longer screw would help. the metal the screw is going into is to thin at that point. now if they were to not drill and tap all the way down the shaft, then yes that would correct the problem.

[bugdozer]

Yup, that was my idea. Drill and tap through the hub and use screws that end just before entering the shaft hole in the hub. This way the screws go past the failure point, into the hub.

[mjdee14]

still a :BSS

[bearwood]

The Sonix Rotor hub made by steel #304,and stock ep550 Raptor tail rotor made by aluminium ,which strong ?

304 is Stainless and that does not mean it is stronger. Shiny yes, strong no.

I originally thought drilling and tapping further into the hub and using a longer screw would help but in hindsight I don't think it would help. It needs a redesign of the hub to make it like a Raptor (Pt No PV0499 sus tail hub) or the Trex 600. Something with some substance to it! As Mystic said it is too thin.
I'm with mjdee - the Sonix unit is a POS.

[odieser]

Check out the Helidirect postings they now have a upgrade hub that comes with new bearings that are going to be available for customers of this tail.
Mark

[neohp]

finally. But how much money and risks we had to wait for that to be done......

[mjdee14]

Check out the Helidirect postings they now have a upgrade hub that comes with new bearings that are going to be available for customers of this tail.
Mark

do you have a link for that....I looked but couldn't find it.

Thx

Mike

[helvetic]

do you have a link for that....I looked but couldn't find it.

Thx

Mike

http://www.helifreak.com/showthread.php?t=66951