Thread: Gyro Delay 101
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Old 04-25-2010, 07:32 AM   #14 (permalink)
Steve Evans
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Join Date: May 2007
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Interesting thread. Delay is something that most people just ignore.

I have found that a little delay makes a big difference on my 500ESP using a GP780, but setting it seems rather hit and miss given that it's set by rudder stick position during setup. Unfortunately whilst messing around with setting the limits on my 450SEv2 (also with a GP780) having moved the ball in one hole on the servo disc I managed to get the dreaded GP780 tail twitch/wag again! Arrrgggghhhh! This is even using PU gel to mount it. I coiled the wires to the gyro (see PHOTO HERE) to be absolutely sure there were no vibrations getting through there to no effect.

This morning I decided to try to be a little more accurate than "stick 1/8 of an inch right", convinced that I must have inadvertently reset the delay on the gyro. Judging the delay by stick position is, as mentioned above, a bit hit and miss, so I made use of the SERVO menu on my Futaba 8FG transmitter to display the exact stick position as a %.

First the GP780 setup on the 450SEv2. I tried 0% delay in small heli mode (stick left), This was very fidgety. The 0% in large heli mode (stick right) and the tag wagged like a dog. 10%L left was better, but still quite twitchy. 20%L and the tail was "soft" for want of a better word, and wandered around a bit. 30%L and the tail was really not very well controlled at all. This suggested that somewhere between 10 and 20%L was required, so I tried 15%L. Rock solid. The difference in stick position setting this was tiny; I'd never be able to repeat it without the % reading from the tx SERVO menu.

Then for the 500ESP. Again, I tried %0 in both small and large heli mode. Tail was better in large heli mode being more twitchy than waggy. At 10%R still wagged quite a bit. At 20%R solid as a rock. At 30%R "soft" and wagging.

It would appear that with the GP780 setting the delay to max as advised at the start of this thread won't work. You need to get the delay right or you don't have a chance of setting the gain. Also you NEED to use the accurate servo position display on your tx or you'll never get repeatable results. I've just been lucky hitting the right delay in the past, and then unlucky when the tail "lost tune".

I'll be interested to hear how picky the delay settings are on other folks helis using the GP780.

Steve
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Trex 450SEv2/HS65-MGs cyclic/Spartan Quark/DS520 tail
Trex 450ProV2 DFC/CGY750 FBL/DS410s cyclic/DS520 tail
Trex 500ESP DFC/CGY750 FBL/YGE-120LV ESC/DS510s cyclic/DS650 tail
Blackout 330/OpenPilot Revo with FatShark 600mW VTX, Futaba 8FG 2.4GHz
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