Vbar tail optimisers

[v58fuy]

Guys,

Can you help me out with a question.

I've been fine tuning my mini vbar on my Logo 500se, and got things pretty much ok on the cyclic side of things, but my tail optimiser values are 100 and 10 - what does his mean, and shouldn't they be closer to the same value like my cyclic.

David

[Andy from Sandy]

As the optimiser is supposed to equalise the piro rate in both directions a value of 100 could be an indication that it has maxed out and cannot get the job done. As a test try with a reduced piro rate value and see if the 100 value comes down.

I think they always are different because of working with and against the torque reaction.

[v58fuy]

When I mechanically setup the tail, I set the push rod length such that when servo at 90 deg, the pitch slider was in the centre of the tail shaft.

I have read somewhere that vbar wants an offset of the pitch slider when servo at 90 deg - never done this before, does anybody setup with an offset? And if so how much offset, and do you then limit the travel on one side.

David

[Andy from Sandy]

Various gyro manufacturers have you setup for a hands-off hover in rate mode. Similarly Mikado ask you to put in a couple of degrees of pitch to counter the torque. This just gives the system a head start in the correct direction. This does not fix your problem of equal piro rates in both directions until that figure of 100 is less than 100 though.

[Mystic3D]

No should not be the same as cyclic values.
Your numbers are kinda whacked , means too much travel in one direction and not enough on the other. Not a huge deal as VBar is compensating.

Set 8 deg on tail blades, make sure tail servo horn is centered, and adjust Endpoints in VBar for tail to get as much throw without binding


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[Andy from Sandy]

Set 8 deg on tail blades

This is not a Mikado requirement. They only ask for 2 to 3 degrees.

- the tail blades should have 2-3 deg against the torque in setup mode, stick centered

[v58fuy]

Guys,

I suppose you would class me as a 'good club flyer', and for me the heli fly's really nice.

I'm swinging 603mm main blades with 95mm tails, with the head speed governed to about 1850 rpm.

I had been running the optimisers since first setting up the heli a couple of months back, but read recently they should be switched off after a few flights - hence why I now have taken notice of the values for both cyclic and tail (cyclic approx 58/52, but tail 100/10).

The tail is currently set up, servo 90 deg tail pitch slider in the centre, then adjust the travel in the vbar to prevent binding at max stick throws.

If I introduce an offset, I can see how the optimiser value might come down to under 100 on one side - but would I need to the maximum throw on one side to prevent over driving the tail grips?

David

[Andy from Sandy]

Personally I cannot see the values changing. The optimiser is about equalising the piro rates in both directions. The offset is about giving the gyro the best chance to stop the kick when you do a punch out.

[bj660raptor]

Best way to explain it is the vbar and logo are like peas and carrots,meaning you want the numbers the same in both directions maxed out pretty much and that gives you your 3 or so degrees against torque.

[Kalpazan]

v58fuy, the tail seems to be weak. That 100 means Vbar is pushing the tail to its end and still cannot achieve good stop behavior. However you mentioned it flies well for you. If you happen to have different flying styles every time that could confuse Vbar optimizer. It is best to reset the tail values do few flight with only piros and tail stops and take a note of the values. If they are the same then you need better tail authority.