Futaba GY 520

[Heli-RND]

http://manuals.hobbico.com/fut/futm0810-manual.pdf

有manual，但係好似 得個細字，同無溫度補償....

[tgo]

Hi Man,
Where you got the information "無溫度補償" ????

Originally Posted by Heli-RND

http://manuals.hobbico.com/fut/futm0810-manual.pdf

有manual，但係好似 得個細字，同無溫度補償....

[Heli-RND]

Page 4 ....

• Always allow the gyro to adjust to the surrounding environmental temperature before flight. A large temperature change during use will cause drift and other operational issues.

[tgo]

So have to wait for the Gyro to adopt the surrounding temp = no temp compensation... Oh.. I See.. This is the first time I learn about this...

A large temp change during use will cause drift, but I don't understand how this is possible... Flying from one side at 25C to another side at 0C and the tail drifts, is this possible? During the flight, the ambient temp change is just limited, right? I used to fly Futaba gyro from 401 to 601 to Spartan and never experience a drift suitation ! I know you are selling Spartan so you're more concern about this, because you SAID Spartan spends a lot of time in temp calibration, if this is true, they sucks......

Originally Posted by Heli-RND

Page 4 ....

• Always allow the gyro to adjust to the surrounding environmental temperature before flight. A large temperature change during use will cause drift and other operational issues.

[Heli-RND]

TGO,

You are correct about the ambient temp change .... reverse engineering on the Spartan copy cat ..... PG 800 shows the clone does not have this function, I do have one that really drift after one or two flights, not to the left (nose) as usual but to the right and even worse and worse within the same flight ...

Spartan does spend at least five hours for test and calibration (for ambient temp change)on individual product. I have 401 and it does not drift in flight... and there is not such a comment in 401 manual (as far as I can remember ...) but if Futaba makes such a comment in the 520 manual ..... this may be really true that the ambient temp does affect the performance since this unit is so small and heat generated is very close to the .... may be sensor or other component that can not handle temp change.

Please note that in the same page, there are other comments not usually seen in any other gyro manuals, such as ..... those I highlighted in the following.... do we see this very often in other manuals?????
Why are they here when a lot of those should be very easy to be solved... why is it here? You know what ... all those looks like disclaimer to me, sounds like Fubata knows these would be the problems...

BEFORE EACH FLIGHT:
• Always check the transmitter and receiver battery voltage to ensure they have enough remaining capacity to complete the flight.
• Verify that the gyro is operating correctly. ( BY HOW?)
• Verify that the gyro compensates in the correct direction before flight. If the compensation direction is incorrect the model will pirouette uncontrollably, at a very high rate. (ONCE WE SET UP A GYRO GOOD FOR THE FIRST TIME, DO WE REALLY NEED TO DO THAT EVERY TIME? YES WE SHOULD BUT DO WE SEE THIS COMMENT OFTEN? MAY BE I DO NOT REMEMBER)
• Verify that the gyro is operating in the desired mode. (SO WE CAN NOT SWITCH BETWEEN MODES IN FLIGHT WHEN EVEN A 401 CAN DO)
• Verify that the gyro mounting pads are in good condition.
• Verify that the gyro wires are not contacting the frame of the helicopter.
• The servo type parameter within the GY520 must match the type of servo you are using. Incorrect setting may damage the GY520 or the servo, possibly resulting in a loss of control during flight.
• Only use the GY520 with a 2.4GHz system such as the Futaba FASST™ system, or a PCM system. Use with a FM system is strongly discouraged since interference can cause serious operational problems. In addition to this the latest high performance tail rotor servos generate electrical noise which may also cause interference to an FM receiver. (THIS SHOULD NOT BE DIFFICULT TO BE FIXED BUT WHY IS IT NOT FIXED?)
• Always ensure that there is some slack in the gyro cables to help maximize performance. Always use the supplied gyro mounting pads to attach the gyro to the helicopter mechanics. Do not use a strap that encompasses the GY520. This may affect the overall performance of the gyro.
• Always allow the gyro to adjust to the surrounding environmental temperature before flight. A large temperature change during use will cause drift and other operational issues. (AS DESCRIBED BEFORE)
• The GY520 uses a conductive resin case to prevent electromagnetic interference. Do not allow anything to touch the gyro case as it may cause a short circuit.
• If you are switching between Normal Mode and AVCS Mode in flight, please keep in mind that you must have the gyro re-learn the center position after making a trim change within the transmitter. To memorize the new center position simply flip the gain switch on the transmitter three times between Normal Mode and AVCS Mode within one second. The tail rotor servo will center indicating that the new center position has been memorized. (??? CAN NOT SWITCH BETWEEN MODES IN-FLIGHT?)
• When the GY520 is used in Normal Mode, tail rotor compensation or revolution mixing must be used within the transmitter.(NOT SEEING THIS IN OTHER MANUALS??? DO I???? WHY IS THIS A BIT COMPLICATED WHEN I THINK THEY CAN BE FIXED EASILY?)
• When operating the gyro in AVCS Mode, all tail rotor compensation and revolution mixing must be disabled and any tail rotor offsets for flight modes must be disabled.
• When the GY520 is operated in AVCS mode the tail rotor servo will not center when the stick is released. This is normal operation for AVCS mode. The servo may also move to the extent while the model is being carried out to the flight line. Before take off, you must center the tail rotor servo by moving the tail rotor stick full left, then full right, back to full left and then allow the stick to center within one second. You
can also visually center the tail rotor pitch slider by using the tail rotor stick.
• Do not drop the GY520 onto a hard surface or subject the GY520 to a strong shock as this may damage the sensor. ( HUMM, THE SENSOR IS SO VOL UNABLE, SK 360 CAN TAKE UP TO 5000G OF IMPACT AS SKOOKUM DESCRIBED) Always use the supplied mounting pads or the Futaba replacement mounting pads available from your local hobby dealer.
• Always exit programming mode before attempting to fly the model.
• Do not use any type of priority mixing or gain reduction mixing on the GY520.(NOT SEEING THIS IN OTHER MANUALS??? DO I????)


I don't know, may be I am a bit bias to Spartan since I sell Spartan but these comments (disclaimers) .... may be Futaba is so keen on the size so they decided to sip those functions to make it so small....

[Heli-RND]

Originally Posted by tgo

.... because you SAID Spartan spends a lot of time in temp calibration, if this is true, they sucks......

Not really, this is because the gyro is a lot smaller in size than GY 401 and heat is trapped inside the case (GY 401 has "ventilation" via the toggle switches, case is not completely sealed)

[tgo]

Let's have some maths....

base on GY520's manual, the gyro consumes 40mA = 0.04A, If my system use 6V, the maximum power conusmed by the Gyro is 0.04A x 6V = 0.24W. So, what do you expect a 0.24W device can raise the temp in a sealed enclosure like the Gyro? just 10 mins time ....

Originally Posted by Heli-RND

Not really, this is because the gyro is a lot smaller in size than GY 401 and heat is trapped inside the case (GY 401 has "ventilation" via the toggle switches, case is not completely sealed)

[Heli-RND]

tgo, not for argue sake but that is what listed in the manual

[tgo]

And you can find some similar statements in 401 and 611 manuals too.... But I don't see how this affects the flight performance.

Originally Posted by Heli-RND

tgo, not for argue sake but that is what listed in the manual