JR G770 Gyro Setup Videos + some new 101's

[Finless]

OK sorry for the delay on these vids.... I have been needing to get these videos done for a while ( 2 months and sorry for the delay) but I also like to fly and didn't want to mess with my flying helis to do it! Well time to belly up and just do it... Believe it or not I still haven't decided which heli to install the this gyro on but it WILL be a 50 sized heli since I got this gyro with the 8900G servo.

OK so after reading all the forum posts about setup, the misconceptions, debates, etc..... I decided that some ground work needed to be done to explain some things FIRST before going into gyro setup. BTW the discussions were helpful as they made me think a little as to the different way JR describes how to setup this gyro and why they want you to do it that way. It's not magic or rocket science but has some good ideas and merrits.....

So I decided to do some 101 videos explaining Dual Rates and Expo, what they do, and how to set them up. I tried to keep this generic in explanation so it can apply to other radios like Futaba OR use with Cyclic, etc... This hopefully will set the knowledge base before we go into setup of the gyro. If you don't need this stuff well.... then skip it.



So first up is an Overview of the JT G770 gyro:
Video Link ->JR G770 Overview and video plans (28 Megs)

Now to start the basics that I think need to be understood in order to understand why you would use Dual Rates and Expo setting up this gyro. The are also generic enough to use for anything (like expo on cyclic).

Dual Rates 101
Video Link ->Dual Rates 101! (71 Megs)

Exponential 101
Video Link ->Exponential 101! (45 Megs)

How to setup Dual Rates and Expo on the X9303 (most radios like Futaba can also use this)
Video Link ->Setting up Dual Rate and Expo on the X9303! (50 Megs)

How to setup Dual Rate and Expo on the DX7
Video Link ->Setting up Dual Rate and Expo on the DX7 (65 Megs)

OK sorry for the LONG delays! Here we go

This is pretty relevant only to my Compass Atom 500 build so watch if your interested. I did a pretty unique install
Installing the 8900G in a Compass Atom
Video Link ->Installing the 8900G in a Compass Atom (45 Megs)

Initial setup of the gyro, radio, and tail servo centering
Video Link ->Initial Gyro and tail servo setup (45 Megs)

Setting up the tail and limit pot. I also do some rambling about servo ball position, wag, and bounce back.
Video Link ->Setting up the tail and limits (52 Megs)

Setting up rudder and gyro correction direction
Video Link ->Rudder stick and gyro correction direction setup (42 Megs)

Dang it! More of my ramblings! I had to do another 101 video! This is about TRUE gyro gain vs what your radio settings are!
Video Link ->Gain 101! The difference between what your gyro gain is and what the radio shows (80 Megs)

OK here are the 2 radio setup videos. First one is on setting up Piro Rate using end points and dual rates per the manual. Second video is setting gain. Both show use of a X9303 and DX7.

Video Link ->Setting Piro Rate with a X9303 and DX7 (77 Megs)

Video Link ->Setting gyro gain with a X9303 and DX7 (58 Megs)

Flight tests. This is my 3rd flight after getting the heli trimmed and G770 gyro tweaking. In the video you will see a wag in some turns and piros. My gain was still too high at 19% true gain. I lowered it to 22 in my X9303 end point which is 15% true gain, and now no more wag or jerky piros. 15% may sound low but thats what it took. Tail still holds on hard punch outs, etc. DO NOT worry that your gain on this gyro is too low! My SolidG is this number on my logo500 too....

Anyway here is the video:
Video Link ->Flight Testing (64 Megs)

OK so thats it! I hope these all helped you. I tried to be as detailed as a could and maybe rambled too much? In the end the gyro is easy to setup but I took this opportunity to make some 101 videos in the process.

Also all... there is a good setup guide and a post here on HF discussing this gyro and setting it up. Worth a read even if you watch my vids.
https://www.helifreak.com/showthread.php?t=78591



Enjoy,
Bob

[Sircrashalott]

The How to setup Dual Rates and Expo on the X9303 link is not working

[HoffY]

Very nice Finless! Top effor mate! Been waiting for this very patiently and i thank you for your efforts.

[chrisag]

Bob, check link on How to setup Dual Rates and Expo on the X9303

Nice videos. Another homerun.

[madmick]

Hi Bob the Video Link ->Setting up Dual Rate and Expo on the X9303! is not working

[ZiD]

guys.. use your heads

http://video.helifreak.com/?subpath=...=dualx9303.wmv

quick fix before bob get it fixed..

good videos btw!!

[Finless]

OK link is fixed.... sorry about the typo

Bob

[main rotrz]

hey, Bob great video cant wait to see gyro setup , with the dx7 you were talking about not having the left and right dual rate to adjust speed of rudder to compensate for engine tork .Cant you setup rudder to throtle mix to increase the engine rpm to the rudder inputs?Just wondering if that will work.One more question is buying a new radio jr 9303 worth it, if i have the dx7?

[SeanOC]

been looking forward to a 770 vid for a while now, thanks Bob!

[Finless]

Originally Posted by main rotrz

hey, Bob great video cant wait to see gyro setup , with the dx7 you were talking about not having the left and right dual rate to adjust speed of rudder to compensate for engine tork .Cant you setup rudder to throtle mix to increase the engine rpm to the rudder inputs?Just wondering if that will work.One more question is buying a new radio jr 9303 worth it, if i have the dx7?

Huh? Your misunderstanding. The dual rate will be used to control PIRO rate e.g. how fast the heli will pirouette when you move the rudder stick to one side or the other. It has nothing to do with how well the gyro will hold the tail as throttle is increased!!! So no you would not want to do any kind of rudder to throttle mix if that is what your thinking?

Bob

[huskynox]

Hi Bob. To go a little off topic here (770), I have an expo question.... Do you use the CCPM expo option on your X9303 in the swash menu, or do you leave in inhibited?

Some guys say they like it and some don't. Pinecone says he likes it. Just wanted your opinion?

I understand it's trying to get rid of the collective speed at 'zero' stick due to the arc the servo arm goes thru (faster in the center then at the end points), so that your collective is more linear. This is similar to what JK was trying to do with his long servo arm setup on the Trex 500, correct?

[Finless]

See this post by JKOS and trust me he knows what he is talking about:
https://www.helifreak.com/showpost.p...27&postcount=8

If you use subtrim to 90 your servos then leaving on "Swash exp" causes interaction issues with servo movement. The software for exp swash does not seem to account for subtrim and thus you get end point and overall servo movement differences.

I have tried it with it on and off and in the end really didn't notice enough difference to care if it is on or off. Because I do use subtrim on some helis (the 450 for instance since you cant drill your own holes), i just leave it off.

Bob

[Tommy Wagner]

Bob

so with the 770 if you add more expo it will make the tail less sensitive at center?
i have 3 of these gyros 1 is kinda bouncy at center should I add so expo to it?

[BenHeli]

Another set of excellent instructional videos. Thanks Bob. Am going to view them a few more times before getting down to business with the 9303 I just bought.

[mapleleafs]

great videos Bob...

[Jamesppp]

Bob,This vid is right on time! My 770/8900 combo just arrived on the big brown truck this afternoon...along with a TT E-620 Raptor kit to go with it.

[Kratos]

OMG! The light bulb has turned on and it is finally clear to me! If you are are noob or semi noob or just dont get the meaning of dual rate or expo, you must watch these videos! Thank you Finless, I just needed to see it instead of talking about it. The only glitch I may have is that I am using the DX6. It does'nt have all those adjustments available. There seems to be no menu mode that lets me adjust expo for the rudder. The only menu functions, that are tied to the rudder, are; sub trim,travel adjust and servo rev/norm.
But I will try to work with what I have and now that I "see" how it works, I have a better understanding of what I'm messing with instead of just changing the values and seeing what happens.

[mapleleafs]

i find it funny how alot of pure heli pilots do not know what dual rates and expo is.....maybe some guys outa buy a plank or two!

[SeanOC]

Originally Posted by mapleleafs

i find it funny how alot of pure heli pilots do not know what dual rates and expo is.....maybe some guys outa buy a plank or two!

I was thinking the exact same thing when watching the 101 vid's but I guess if you haven't flown airplanes it makes sense.

See guys... you can actually learn something from flying planks!

[stoatnchips]

Bob, this set of vidz has landed just in time.... I was about to give up on my 770 on my 450 and get a spartan instead!!! I've tried several different types of Gyro foam/gel, servo horn hole distances and radio settings with no real success... Its either not locked in or wags at about 15% using Travel adjust on the gear channel... Anyway I look forward to seeing the next videos; thanks!


As far as this D/R issue is concerned on a DX7, maybe i am missing something but i do not see it as being a problem??? Its more like the correct way of doing things as i see it. As you say in the video, Dual Rate is just a "gain" function that is overlaid onto the End Point (Travel Adjust) settings. So 80% D/R will be 80% of the left End Point setting and 80% of the right setting.

So first step should be to set L & R End Points to say 120% and 95% to get equal Piro rates in each direction. Then the programmed D/R setting will just reduce/increase both of these figures by the same ratio for each given flight mode; so maintaining an approximatley equal piro rate Left and Right for any D/R setting.

I guess in the case of the DX7, you need to use a conbination of both Travel Adjust and D/R to achieve different piro rates vs flight modes, while maintaing L&R consistency .... where as on the JR unit you only need to mess with D/R settings to do the same thing as both directions can be set independantly.