HUH? With full forward elevator the swash link disengages the anti-rot bracket - MD6

[Tomy.]

I am going through the final steps of the mechanical setup of my new MD6 and I found a very strange thing. The first picture below says more than a 1000 words. This is with 14 degrees pitch and max forward elevator (cyclic set to 14 degrees max as well). Servos are not "pegged" and stalled in this position and swash has another 5-8 degrees play so this is not a terminal state for the head.

This looks pretty dangerous, I would certainly hate if the swash came disengaged mid flight. Is my setup "unique" somehow or this is the end result of some "elaborate, careful" engineering? Anyone else seen this? Is there a fix out there for this "issue"?

Thanks!

[ChuckL]

Honestly I never saw this when I owned it however I never even came close to putting that much cyclic on it. I would guess closer to 10 but really don't remember, however after I flew it I had to turn it down even more to make the Ikon and me happy with the feel. When I turned it down I just reduced it a couple clicks at a time so I really don't know where I ended up but visually from what I can recall it looked like about half what you have.

[mdhelicopters]

This may be unique to your setup. The first picture doesn't appear to be at 14 degrees pitch and the same for forward elevator, if so, the rear servo arm would peg against the anti rotation bracket and the swash would be higher up on the main shaft.

Can you take another photo of only max collective with no cyclic input and from a little further back to be able to see the head and servos?

[rfauske]

It might be the image but it also looks like the ball links would hit the swash because of the large cyclic movement.

Have you tried more normal values like 12degrees collective and 10 cyclic?

[Tomy.]

just to clarify, this happens with -14 pitch and +14 elevator, that's why the swash is on the bottom with the aft side all the way up. 14 degrees collective and cyclic setup worked fine for me in the past on the Compass 6HVU and the Fusion50 with no issues with low headspeed (1850-1950). Yes, the pitch can be lowered and I can change the setup but it does not change the fact that in my opinion the pin should not come out of the bracket in any position, so something is weird with my setup. I'm fairly sure this is not how this heli was designed :-).

The aft swash pin is 18.5mm long without the threaded part, is that the expected length?

[mdhelicopters]

Ill double check mine, but I don't think ive seen the pin come out of bracket.

[darkfa8]

I can check my pin length too, but I'm sure Matt will beat me to it.

Either way, you must have binding in the rest of the system with that much cyclic throw. I wouldn't be surprised if the elevator horn is hitting the bottom of the anti-rotation bracket.

In looking at the manual page 16 - since I'm at work, the swash pin doesn't stick through the bracket much.

Just because you ran 14* on other models doesn't mean you can or should on a different model. Instead, max out your collective pitch range if you must, and go with 8-12* of cyclic range and make sure there is no binding at the extremes.

Also make sure your servo to swash links and swash to main grip links are the correct length so as to produce 0* pitch at center stick with the cyclic servos horse at 90* or perpendicular to the main shaft.. Again, Matt and I can check ours since it's not listed in the manual (BUT should be!).

[ChuckL]

I can guarantee that pin is the length that it came in the kit, it was never shortened unless MD changed the pin at some point it is the normal factory length. That is a huge amount of cyclic, when I got it dialed in it was well below 10 degrees cyclic which made it still extremely fast but smooth. My initial starting point was about 10 and the cyclic felt jerky and kinda robotic. I would estimate when it was dialed in for me the cyclic was about 8 and I had it set at 13 degrees collective.

[Tomy.]

No worries Chuck. I figured out a way last night to have the anti-rotation bracket reliably lean forward a bit so the top is now 32mm from the main shaft, the bottom is 34mm and the bracket holds the pin all the way through the pitch range. Even if the amount of pitch that was required for the pin to disengage could not happen in the air, I feel much more comfortable flying knowing that this cannot be a problem in flight.

[ChuckL]

Well good you came up with a solution, I actually went and looked at some of my other helis and none of them actually came out of the guide but my Whiplash Nitro was close enough that with stresses inflight it probably would be able to if that much throw was actually used.