vibe 90 and dx7 swash leveling problem

[whittm]

Just had a thought after what you just said to check, can I adjust sub trim equally until I get equal angles high and low stick in conjunction with swash mix?

Or, could I use travel adjust equally on the three servos to control how many degrees I get either side?

By the way, swash is level, wash out arms are level, as are the mixing arms.

Both blades are within 0.3 degrees of pitch to each other and the total runout with the fly bar locked is 0.4 degrees around the whole 360 degrees.

[trillian]

Just had a thought after what you just said to check, can I adjust sub trim equally until I get equal angles high and low stick in conjunction with swash mix?

Or, could I use travel adjust equally on the three servos to control how many degrees I get either side?

By the way, swash is level, wash out arms are level, as are the mixing arms.

Both blades are within 0.3 degrees of pitch to each other and the total runout with the fly bar locked is 0.4 degrees around the whole 360 degrees.

Yeah you can play around with a few different things just be mindful of how they can affect each other. It's more important to have the swash level all the way through the travel than it is to have exactly the same pitch at high and low stick (assuming they're not like massive different and you have plenty of collective in both directions).

I admit that there have been times when after adjusting all the linkage and servo arms and getting the swash totally level and then realising the pitch wasn't quite the same at both high and low stick, In my zeal to just finish it and fly I sometimes have elected at that point to just pull down one end of the pitch curves to shore it all up.

[whittm]

Ok, success with the head! 12 degrees pitch, 10 degrees give or take on cyclic, thanks. ..

I'm going to have a go at setting the gyro and the tail. It's a gp750 and it's obviously a dx7 transmitter. There are a couple of videos on YouTube discussing the setup. I haven't started looking at it in perfect detail yet as I want advice on what rates to set first.

Some people are suggesting rate mode in normal and hold and heading hold in stunt 1 and 2(. ..and yes I have realised, that any setting under 50% is rate mode and anything above is heading hold) others are setting heading hold, in various amounts in both normal, stunt and heading hold.

What do you guys reckon is the best way to go when it comes to heading hold and rate mode?

[whittm]

Also, the guy who built the heli,mounted the gyro sideways, should that makea difference?

[waveydavey]

Won't make a difference on orientation of gyro. Personally I wouldn't bother with a rate mode, can't see the point. You might get better performance from the tail by doing a rate mode trim of the control rod then switch to HH.

Well done with the head

[whittm]

So are you recommending setting whichever switch I choose, to alter heading hold, to rate mode temporarily just to set the travels on the gyro?

I did try that earlier. ..It did seem easier to set the limits, it seemed to give much smoother increments.

So is it a good idea in your opinion to have two separate heading hold settings for normal mode and flight mode? And if so, would you put it on a two position switch such as gear switch/aux 2/elevator etc. .. or would you set it up in automatic mode and have it on the three position flight mode switch for instance:

75% in normal mode
65% in flight mode 1+2

[trillian]

I always fly in HH and I have never needed a separate setting for different flight modes, I find the amount of gain that holds well without wagging and that's how it stays from then on. Unfortunately I have never used the GP750, my favs are the Futaba 611 and 601 and the Spartan.

Sometimes rate mode is used to setup the centre point where the tailrotor thrust counteracts the rotor torque in a hover. Having the rudder centre at that point can result in more even stops from pirouettes in both directions. I tend to just guess and set the rudder mid stick where there's 5 or 6 degrees of tailrotor pitch and since I don't do lots of piro moves this has always worked fine for me.

[whittm]

Hmm. ..think I need to, revisit centering the tail. ..Thanks!

[waveydavey]

I'm not to familiar with the Align gyros but I would centre the blades, fold them towards each other and adjust the control rod until they're in line. Do this in rate mode and the servo will centre, unless there is a centre position in the setup menu, make sure the servo horn is square etc. After doing this go through the tail limits in the menu and put into HH. Fly with it like this, change your servo endpoints to tune your left and right piro speeds and if you're stops aren't good then you may need to do a rate mode trim flight as above.

[whittm]

Ok, set the tail up as you described. ..perfect. ..no binding either side now. ..nice method! ;-)

Then I revisited my head. ..hmm. ..Since changing the percentages of the cyclic and pitch in the swash mixing screen, I took a look at the swash this morning.

I was shocked to see that the swash was no longer level...not good! I couldn't work out why. ..I had a long think about it and realised that it had something to do with the swash mix. ..I set those back to what they were and realised that the swash was now level.

I'm guessing this has something to do with travels. I don't want to do it without checking with you guys,but am I correct in thinking, that I will have to take the head off and adjust the elevator and aileron travels until the swash is level top of travel and bottom of travel, using a swash leveling tool to check it and then rebuild the head and check it all again?

[waveydavey]

Swash mix shouldn't cause any issues with swash centering. Did you use subtrim after to level the swash?

To get it right then yes you will need to remove the swash in order to check the interaction at top and bottom.

Edit : To get it right then yes you will need to remove the head in order to check the interaction at top and bottom.

[trillian]

Swash mix shouldn't cause any issues with swash centering. Did you use subtrim after to level the swash?

To get it right then yes you will need to remove the swash in order to check the interaction at top and bottom.

I think you mean removing the head, not the swash?

I think the thing to do is go in and set the subtrims back to zero and for the moment set the servo travel adjusts back to 150 (or 100, whatever the default is). Then get the collective range in the general vicinity and max cyclic throws using the swash mix. After that THEN go back and see what it's going to take to get the swash level at mid, bottom and top stick.

[waveydavey]

Yep, the head

[whittm]

Am I correct in assuming that it would affect it if the travels were incorrect in the first place?

[waveydavey]

No, the swash mix won't make this better or worse it will only adjust the overall range/rate