gyro401

[wiseman]

why is it necessary to set the gyro up in rate mode before setting in heading hold. im struggling with the rate mode on my 450 but it seems to fly quite well as things are in heading hold,

[cupracing]

If its flying nice, don't change anything.

[Pabs]

Rate mode allows you to set it up on the ground - trying to set up a gyro in HH on the deck is trickier (but not impossible)

[bolders]

Rate mode allows you to set it up on the ground - trying to set up a gyro in HH on the deck is trickier (but not impossible)

Not sure I understand this. setting in HH could not be easier and certainly less fiddly than setting rate. Just centre your slider make sure your endpoints and directions are ok and fly. Am I missing something .

to OP

IME there is no need to setup a 401 in rate. I have used several 401s on different helis (without rate setup) and they have always worked well. If you do not want to fly in rate mode then just leave it as it is and fly it

[coolice]

Hey.

From memory, the older GY series of gyros actually held better if setup in rate mode first before then switching into HH mode to fly. The current trend means no one really flies in rate mode, but only uses it to set the servo horn during the bench setup.
As already mentioned, if its currently working ok then leave it set as is. If however later down the line, as skill level increases and you start to see a holding problem, then perhaps spend some time setting rate mode before swapping gyros.
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[trillian]

IMHO if you don't intend to fly in rate mode then you may as well setup in HH. With the GY401 I always setup in HH and set the linkage for max travel in both directions because on the 401 you have only one travel limit and cannot set the limit for each direction individually, so you don't want to cheat yourself out of any available travel of the pitch slider. If you do find you must compromise in setting the travel limit when adjusting the linkage, bias it towards the direction that counteracts the rotor torque as you may need full pitch in that direction but will rarely need full pitch in the direction that goes with the rotor torque.

There are a lot of myths running around about how to setup the tail linkage and setting up rate mode etc. which are largely irrelevant with modern HH gyros.

[coolice]

Not sure I understand this. setting in HH could not be easier and certainly less fiddly than setting rate. Just centre your slider make sure your endpoints and directions are ok and fly. Am I missing something .

Hey.

I think he's referring to being able to set the servo horn easier in rate mode while performing the bench setup, as you'd never be able to accurately set the tail servo to neutral while the gyros in HH mode.
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[trillian]

Hey.

I think he's referring to being able to set the servo horn easier in rate mode while performing the bench setup, as you'd never be able to accurately set the tail servo to neutral while the gyros in HH mode.
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This is true in that while in HH the servo may not always snap back to the centre. What I do on the 401 is find what I think is most likely the centre (for example move the servo arm all the way to one side and then the other with the servo powered off and guess the centre). Then the fine tuning is done by looking at the travel limits and where the servo arm ends up once it's all powered up and linkage connected, you want the servo arm moving as close to the same amount in each direction to keep the geometry the same. On the Trex 450 you can also very easily get the linkage in the ballpark by moving the servo mount forward or back on the boom (and using the travel limit on the gyro) until you get max travel in both directions and then tighten the mount.

[coolice]

Hey.

You are best to set tail servo horns position in rate mode, its quicker and safer, as if you do accidentally move the model the tail servo will return to neutral.
Also to be accurate we need to bear in mind the GY401/601/611's are not modern gyros by todays standards and as such differ in how they should be setup to extract their maximum potential.

This is just one site which makes good reading on GY401 setup and makes reference to why setting in rate mode on this particular gyro is a good thing ;

My GY401 setup tips - RC Groups

The GY401/601/611 are not alone in this setup technique, the very capable CSM SL760 also demands being setup this way.
Bear in mind that the neutral position of the tail to hold against the torque will vary with head speed, so if you give it a go I'd suggest setting this position at the head speed you will be at the most.

However, if its working for you currently then leave it set. But to get best performance you will need to setup the gyro as described, but by that time in your flying career you'll probably want an even better gyro anyway ;-)
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[trillian]

The GY401/601/611 are not alone in this setup technique, the very capable CSM SL760 also demands being setup this way.
Bear in mind that the neutral position of the tail to hold against the torque will vary with head speed, so if you give it a go I'd suggest setting this position at the head speed you will be at the most.

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One big difference between the 401 and the others you mention is they can set a travel limit for each direction independently. For the others I agree that setting up with the centre at close to the degrees of pitch needed to hover in rate mode makes sense but setting a 401 in rate mode is going to effectively lose you a certain amount of travel as you're forced to set a limit that affects both directions (unless the airframe has a built in bias in the pitch slider). I think the instructions that suggest doing it that way for the 401 are very old now and assume some flyers were using it in rate mode. (quite a lot of Futaba's literature online is outdated and / or not explained fully, take for example the confusion that often arises over servos rated at 4.8 volts, etc. where they are basing the rating on sub-C packs )

[Gav]

Still got my first GY401, still a great gyro for basic and sport flying. Yup, just a single limit or travel adjust is a bummer though. I used it on a shuttle+2 and trex450. With it set to rate mode I would have the rudder servo centred and just try and hover with no rudder stick input. Land then slide the boom mounted rudder servo up n down the boom until the rudder was bang on and no rudder drift in the hover. lock the servo down then flick over to HH. Jobs a goodun.

cheers
Gav

[p4ddy]

But the limits would have been way off. I still have my first 401 & my second & still use them both, one in the 450 wolf the other in my Gaui 200 (currently in HK250GT)

[coolice]

One big difference between the 401 and the others you mention is they can set a travel limit for each direction independently. For the others I agree that setting up with the centre at close to the degrees of pitch needed to hover in rate mode makes sense but setting a 401 in rate mode is going to effectively lose you a certain amount of travel as you're forced to set a limit that affects both directions (unless the airframe has a built in bias in the pitch slider). I think the instructions that suggest doing it that way for the 401 are very old now and assume some flyers were using it in rate mode. (quite a lot of Futaba's literature online is outdated and / or not explained fully, take for example the confusion that often arises over servos rated at 4.8 volts, etc. where they are basing the rating on sub-C packs )

Hey Sheryl.

I do see what you're saying, but a 601/611 even with independant travel limits would still require less throw in the direction of the torque reaction, as the torque will help the tail rotate. The action of trimming the tail in rate mode helps balance the tail power inline with the torque reaction, by increasing tail thrust to push against the torque.

The bottomline is that both methods have been proven to work ok, but for the GY series it is advised that for best performance to setup in rate mode, teach the gyro its neutral position (toggle gain switch 3 times, ending in HH mode) then go fly in HH mode.

Written instructions can make an entirely new topic, remember they are written to help a purchaser setup their equipment properly. You can choose not to follow them, but when something doesn't work as it should (or fail if running a higher voltage than recommended by the manufacturers) then its down to user error. Hence why its best to tread carefully when using an item outside its recommended parameters. A good example is Align servos, we know they can work on straight 2s LiPo power, but they are not rated to and have been known to fail. Going against manufacturers advice voids warrentys as we know, the question is what ones can be rewritten and what ones are accurate as they are.
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[Gav]

But the limits would have been way off. I still have my first 401 & my second & still use them both, one in the 450 wolf the other in my Gaui 200 (currently in HK250GT)

But then i would readjust the limits :thumbup:

cheers
Gav

[wiseman]

thanks for all your advise,i will continue as i am and not read read to much on the rate mode thing, things are good for now,,,, cheers