I have a very old, venerable Mikado Logo 500SE that has been flying since about 2009.
It has INOlab servos in and am trying to sort the Spirit W1 as perfectly as possible.
I have centered the servos and swash and have been trying to adjust zero pitch and MAX / MIN pitch.
I have a reasonable (0.01 +/-) zero, but my max and min give me +13 down to -16.
As far as I can tell my servos are set up properly, I am using old, crappy blades, which still fly ok (I am being sensible in mounting position of gauge), but am awaiting some newer expensive blades, I have zeroed my blade pitch gauge but will receive a new one, but this is one hell of a difference!
Are my INOLab servos just no longer up to the job in terms of accuracy or am I missing something?
Normal due diligence has been followed with pitch curves, servo arms, surface accuracy, etc., but this discrepancy is a little too large?
Am I missing something?
I am perfectly accepting that I may be doing something stupid, but this time I have not had too much to drink and am a bit flummoxed!
Andy
PS This helicopter has been flying with VBar, BD 3SX / Axon as well as now Spirit W1!
I have been flying RC helicopters since 1976 but am perfectly accepting that I have missed something here!
I am thinking that I have a poor pitch gauge and am trying to mitigate this, but am not confident in the uptodate reliability of the old servos!
Any insights? I would like to be as foolproof as possible to use GPS, etc.
Andy

Hello Andy !
If you have unequal pitch that means your swashplate is not in the middle of the travel path -
You have all servoarms at 90° ? If yes then you have to lenghen the length of the servo pushrods, if that is possible - then take an swash-leveler that the swashplate is in level - I have no idea how much this is but I would at first lengthen the pushrods +1mm for example. After that you have to adjust ad "midstick" that the blades have to have 0° ! Midstick is meant at subtrim (tuning) without gyro - shorten/lengthen then the pushrods to the bladegrips that you get 0° -

If you can not lengthen/shorten the pushrods in your heli I don't know because I don't have any Mikado, then you can try in subtrim tuning menue at pitch adjustment set there an check at the box pitch-adjustment - now you can all servos drive in the wanted direction by changeing only one servo data for example +-5...

Make sure that your values ​​change evenly, ideally you should write down the values ​​of the individual servos beforehand, then nothing gets lost -

One is the clean way, the other is the only possible way if you cannot change the length of the servo pushrods -
All the best with the adjustment!

I hope I haven't messed anything up now
If so, you will notice it yourself when you set it up - then sorry for confusion...


Best regards
Matthias

Hi Matthias,
Thank you for your reply.
I have adjusted pitch at mid-stick, not with servo rods to swash, but with pitch control links - 0 pitch confirmed. Total link length from servo arm to pitch control arm connection is the relevant dimension, whether this is adjusted up to swash or up to pitch control arms from the swash.
But this is the crux, range is not the same +ve to -ve after this adjustment!
The servo arms are level, but I will further confirm this with a pitch gauge - this is all that it can be now, I think, unless the servos are behaving abnormally. Maybe my by-eye measurement is not what it used to be!
RDLohr, I think used to have a servo arm gauge, but the orientation of the servos in this Logo 500SE makes the use of such a tool a little awkward.
Andy

After verifying the following:
-In diagnostics tab collective channel centers at 0% when the stick is in the middle. Use subtrim on the radio collective pitch channel if it is very far off.
-Collective travel is -100% to 100% when you move the stick to both ends. Adjust end points in the radio if it is not.
-Servo arms are at 90° angle to the swash links at zero pitch (subtrim tuning enabled). Put them on as close as possible and then use subtrim in the Spirit settings to get it exact.
-Only at this point adjust servo to swash links to level the swashplate, and finally main pitch links to achieve 0° blade pitch.
-Now verify 6° tuning value in the advanced tab is correctly set.

If +/- range is still uneven after checking all this (important: in that order), you can use servo travel correction in the Spirit settings servo tab. Make sure to tick the pitch adjustment box to correct all three servos together equally, so swashplate remains level.

Hi Mona, thank you for your reply.
I think I may have not made it completely understood? I have been setting up these types of units for many years with different radios.
This helicopter is being set up on a Spirit Wave radio with W1 unit.
I understand completely the process after servo centering and have followed these normal steps, but still have a discrepancy in range.
Although I have followed the due process diligently, the Logo 500SE has Mikado servo arms, which I eye-balled for centre, and I may have made a less than perfect job of this!
I have ordered some of RD Lohr's servo centering gauges, which I will try to see if they make a useful difference here.
I have not used the computer in this particular set-up, so no diagnostics page, sub-trim, endpoints, etc., purely Spirit Wave!
I don't even know if these pages exist if using the Spirit Wave radio on the computer.
I have of course used these on Jeti, Futaba, Spektrum, FrSky, RadioMaster, etc!
I think my problem has been a less-than easy to gauge servo arm in terms of judgement of centre by eye.
An inaccuracy of just a couple of degrees on servo centering could make a significant difference, but I have not usually had this degree of problem!
Maybe, I am just getting old?
Andy

Have a watch of these videos, Freddy shows you the adjustments i think you need....
https://www.youtube.com/watch?v=nzXaWchLtw4
https://www.youtube.com/watch?v=Cdu_2Vs6dI0

Sorry I did not notice W1, of course you don't need to do the first two steps. Spirit Wave still has subtrims to level the servo arms and servo travel correction to correct unequal throws. The software has received several updates already so it may use a slightly different term, but this is the setting you need if everything is mechanically correct.

Hello,

older Mikado models are known to have quite assymetric geometry because servo arms and their push rods are not in the right angle.
This makes travel in both direciton quite imprecise, especially with a bigger angles. There is basically no good way to fix it, it is just designed like that.
However it will still work well without any special adjustments.

You will only have to care about tail mechanics, because tail control system is made of plastic ball links that have very high friction. A ball reamer is required for this model for sure to achieve good performance results.

Please note 13° is already too much for this model, I recommend to stay at 12° max. On the other hand TAIL mechanics allows way too high angle so there it is also good to limit it to a reasonable good travel, but not too big to prevent belt slipping and tail blades stalling.

To set the model as precisely as possible enable Subtrim menu - all servo arms should be precisely at the center. If not, use subtrims to correct this.
Then adjust push rod lengths to set swashplate in the middle of its travel. And at the same time set push rod lengths to 0° - all this can be done preferably when subtrim menu is enabled. If you do this step correctly, extents of the travel should be as close as possible.
Still you will need to correct pitch difference with servo travel correction - this model will require it always.

_________________
Spirit System developer

Thank you Tomas!