futuba gy701 help

[hobaoe]

Hello. Is there any online calculator for the gy701? I need to type in som gear ratios to see wich pinion i can use.

[BustedRaptor77]

Originally Posted by hobaoe

Hello. Is there any online calculator for the gy701? I need to type in som gear ratios to see wich pinion i can use.

The 701 works backwards of this you just enter your gear ratio after selecting the pinion.

Is this a nitro aircraft or an electric? I don't think there has been a firmware update to the 701 to govern an electric so you would just use it as a tail gyro. Although you there are ways it could probably be done it wouldn't be very straight forward. If you are trying to calculate this on an electric google Mr. Mels calculator. If it is a castle ESC use the link below.

http://www.ecalc.ch/helicalc_e.htm?castle

[BustedRaptor77]

In theory if this is an electric you may be able to use the magnetic sensor on the main gear and set it to 1:1.

[hobaoe]

its for a helibug gasser, so i need to know wich pinion i need for the rpm i want

[BustedRaptor77]

You would either use something like a stator gator or find a spot to mount the magnetic pick up.

All you are doing is setting the ratio at the point of measurement to the head speed. IE if you installed it on the fan that is attached to a nitro engine you would enter that the fan spins 9 times for every 1 RPM on the head (made up example).

So the head speed doesn't involve any calculation in the GY701 other than you need to enter what it is to govern the head to the desired speed.

[BustedRaptor77]

In other words you need to find out what gear ratio you should be running based off the engine you have. This has nothing to do with the GY701 other than where you measure the RPM.

[BustedRaptor77]

PM Carey Shurley. He is the grand poo bah of all things gasser related he can explain anything you are looking for and then some. He uses Futaba equipment and is a really nice guy.

[hobaoe]

oh, ok,, i have only used the esc on my electric helis, and when i set on the governor mode, i almost always have to change pinion to get the higher headspeed that i want, because of the headroom the esc requires. but the gy701 also need some headroom? how many rpm headroom does it need?

[BustedRaptor77]

Originally Posted by hobaoe

oh, ok,, i have only used the esc on my electric helis, and when i set on the governor mode, i almost always have to change pinion to get the higher headspeed that i want, because of the headroom the esc requires. but the gy701 also need some headroom? how many rpm headroom does it need?

It is completely different on a Nitro or a Gasser because it is just controlling a servo. You still need to figure out the gearing but it is based off what engine and pipe you want to use so that you don't overheat the engine.

On an electric the overhead is so that the ESC isn't having to work as much because the motor spins at a fixed RPM based on the volts applied from the battery.

Gasser/Nitro makes power
Electric Consumes power

[hobaoe]

now i understand
thanks for the help