N5 - Inflight failure - Preflight check warning!!

[Britflyer]

Best of both worlds ?? (as suggested by David):

Vibe 50 Collar Link


Paul

[v58fuy]

Had a bit more of a thought about this last night.

Now think the simplest way to add security, would simply to use 2 std collars without the need for loctite or anything - this would effectively double the frictional surface area, thereby requiring double the force to overcome friction, this should be ample.

The beauty of 2 collars is that there is no damage to the main shaft at all, and that they can easily be removed when taking the main shaft out.

David

[Britflyer]

By way of update. The final parts I need to repair my model arrived today.

Thanks to SynergyRC, Climb-Out, Matt, Roger and Ade.


Cheers

Paul

[debrooker]

I think i may add an extra collar, I have a spare collar from my R50 Titan SE which looks perfect (if has two M3 grub screws at 90 degrees) which should add security

[ROSSCO]

If you check your collar it should'nt be an issue, i've checked my collar and only one side has been taped and it is an easy fix with a 2.5mm drill to remove the threads if needed. It can even be done by hand so that you don't make a mess of the collar.

My collar has been holding great so the standard collar is fine if the threads are where they are supposed to be. Fitting an after market collar with grub screws for securing will make removing the mainshaft a real PITA!

[debrooker]

Just checked mine, and it has taps both side, so have drilled the front side with a hand drill. Doesn't look possible to double up the collars either as you will interfere with the elevator shaft.

So will have to hope this collar holds.

Also should I be loctiting the bolt, as the manual doesn't mention it (my gut feeling, being metal on metal is yes)?

[v58fuy]

Yes you want to use loctite on the clamp bolt - make sure the bolt is good and tight without stripping the head of the bolt.

David

[ROSSCO]

The standard collar will be fine, a second collar is not needed provided it can do its job and clamp up which is where the checking of the collar and de threaded the bolt head side of the collar.

Yes, the bolt used in the collar will require threadlock, i just used blue threadlock on it and its enough to lock the bolt in place.

[Droid]

My N5 is still in transit, however I will be checking that collar, i don't want a repeat of my early N9 experience!!!!!

Support seems to be more open and upfront now mind!!!!

Obviously don't have the model to check but is there any way of adding a bolt up the bottom of the mainshaft like the Vibe 90??

[ROSSCO]

If you have one of the latest kits it should have been sorted, my N5 was one of the first batch and i didnt have any issues with anything in the kit or the collar which hasn't slipped or anything, although the collar issue was hit and miss as to whether you got one of the faulty collars or not but i have built one from the latest batch and the collar had been checked at the factory. The spares are also coming checked.

With the collar, just a simple check to make sure it is correct and bolt it up and go!! No belt n braces needed!! Mine is bone stock and it's awesome!!..The only changes i made were to use some M3x10 Button head bolts to pin the boom supports as on the N9 and also charge the star locking washer on the tail slider assembly as per experience with the N9 but the ones supplied with the N5 Kits seem to be much better but i changed mine just to be safe.

I have to agree there, with Matt Boto's at the helm of Synergy not only is the support first rate but you also get direct support and advice from the designer!!

[moyesboy]

Why do our helis need a locking collar? there is a bearing eather side of the main gear on this heli which has a jesus bolt through it. So there can be a sleeve tube to fill the gap to the upper bearing. Then the shaft is fixed axially. Perhaps it would need fiddly shim washers too becuase of how accurate the space between the bearing blocks is. however even if there is 0.5mm of movement - it can't actually go anywhere unless there is catastophic jesus bolt failure (It can happen, perhaps more rare than slipping collars though!). Usually jesusbolt failure is catastrophic if the heli is right way up! (on the 600n you can fit an extra collar under the top bearing block to save you)

By the way, you don't want the collar placed above the top bearing (like a 600n) because the swash hits it when it tilts on full negative - maybe the n5 needs all that space too. I put the locking collar above the bottom bearing on my 600n and put up with the shaft damage -I've always got it through the bearings so far.

I was thinling to fill the gap between the main tail gear and the bottom bearing with a spacer ring on my 600n - but then the negative loads axial loads would be on the smaller bottom bearing...

[00boto]

Hey guys,

The reason the collar was slipping was two fold.

1. Collar was tapped all the way through which would not allow the collar to actually pinch the main shaft. This was simply a mass production mistake as the prototype was perfect. Once this was fixed the collar would only slip a fraction, not enough to cause a problem

2. The collar is anodized which hardens the surface of the aluminum. If you take a piece of sand paper to the inside of the collar in order to break the anodize coat, your collar won't even slip a tiny bit.

These collars are used on many helicopters including electric which produce double the power and still hold perfectly.

Hope that helps and thanks for the enthusiasm guys!

Matt

[Droid]

Am I right in assuming this collar is like the HYPER collar i have fitted to my N9??

[00boto]

Very similar with one big difference in that on a 12mm shaft you have more area to grip the main shaft making the collar operate better. Also on the N9 you have the crown gear stopping any upward movement. The Hyper collar may very well be susceptible to slipping if the crown gear wasn't in place.

Thanks,

Matt

[Droid]

Very similar with one big difference in that on a 12mm shaft you have more area to grip the main shaft making the collar operate better. Also on the N9 you have the crown gear stopping any upward movement. The Hyper collar may very well be susceptible to slipping if the crown gear wasn't in place.

Thanks,

Matt

Good point, overlooked that of course the N5 is a belt drive!! Well at least i won't have to worry about keeping the crown gear mesh snug on the N5!!