[dcaranci]

Hi all,
I'm setting up the tail rotor, servo, and gyro on my new Raptor 30 and need a little advice.
I'm following Michael Prewitt's advice on his web site "raptor technique" as much as possible, but not sure about this part...

I'm using an XP8103 radio, and 401 gyro. Ok, it's not a 401, its the G011 but it's basically exactly the same thing, just cheaper.

Anyway, using his instructions, I set the servo travel on the radio to 100% in both directions, then limit the travel with the dial on the gyro. Ok, but when I do this I end up with only about 70% of the stick on the transmitter being used. Beyond that, obviously the gyro is limiting the servo rotation (as expected) and further stick input does not have any effect.

My concern is that doing this, I will have a very sensitive tail rotor to my commands, plus I have a fairly large "dead ends" at the limits of the stick movement.

Would it not be better to limit the servo on the transmitter instead of on the gyro? This would allow a less sensitive tail to the stick movements, and able to use all of the available movement on the stick, which my intuition tells me is better, but there must be a reason for not doing this.

Anyone out there have any guesses? What is your setup like?

Thanks for the thoughts...
D

[marcham]

I have not tried the Walkera gyro, but I can try to help you out anyway.

Stick travel is not = tail travel.
Stick travel = piro speed.

The objective is to find a ball placement on the servo arm that allows you to keep the gyro travel setting as close as possible to 100%, without exceeding it. Ideally, you can set your ATV / end point adjustment for the rudder channel to it's max value 140? 150? and work the dual rates from there.

Without independent Left / Right travel limit, you piro rate will be limited in one direction.

There is some good info on this on trextuning.com, well worth the read. Also of interest is the Bob Finless video on the GY401 setup, which can be found with his TRex 450 videos on helifreak. Here's the TRex tuning bit:
http://www.trextuning.com/modern-gyros.php

With gyros, like anything else, you get what you pay for. The less expensive gyros typically drift with changes in temperature, do not filter out vibration very well (especially in the case of this gyro that was designed for electrics, not glow). All in all, it should be manageable unless you're doing crazy stuff.

[dcaranci]

Originally Posted by marcham

I have not tried the Walkera gyro, but I can try to help you out anyway.

Stick travel is not = tail travel.
Stick travel = piro speed.

Ok, please excuse me as I'm relatively new at this...
But how can they be different? In my mind, piro speed = simply pitch of tail rotor blades which = servo travel which = stick travel.

Obviously I'm missing something, but I'm not sure what...

I'll check out the references you pointed me to when I have a little more time this evening.

Thanks for the help and advice, it's very appreciated... but I'm a little confused still.

D

[dcaranci]

Ok, so I just took a read through that link and wow it's much more clear now. I actually do understand it now....

Sounds like even though on the bench the servo does not travel any further when it hits the limit at say 60% stick, there will still be an affect when it is in the air and the gyro is actually measuring the turn rate.

Anyway, long story short... I understand now.

Thanks again RCC and thanks MARCHAM!

D