|Jul 04, 2012, 06:37 PM|
ALZRC 3GY V2/Robird G31 Flybarless 3-Axis Gyro
Firstly, thanks to hk-parts for sending me this gyro to review. From what I've read about it so far, I'm excited to see how it goes.
It's very nicely packaged with a double box to keep the lid closed (click to enlarge):
What's provided in the box is very complete:
1 x 3GY V2.0 Gyro
1 x SRx1 (S-Bus/Sat lead)
1 x USB cable
1 x Screw driver (for adjusting the gains)
1 x Short extension lead
1 x Triple Rx cable
3 x Single Rx cable
4 x Double sided mounting foam
The gyro is very small, probably the smallest I've seen. It's smaller than the ZYX and the Hobbymate:
Gyro weight: 14.0g
With all Rx leads: 22.5g
The cables are very thin. Personally I would like to see heavier cables, more like the ones supplied with the Hobbymate and ZYX.
I find the label on the gyro very hard to read in some lights. They should have used a clear lexan, instead of the opaque one.
Another nice feature of this gyro is that you can have two satellites. This allows much larger helis to be used with Spektrum gear, without having to use a full Rx. Only one sat cable is supplied with the gyro, so you would need to purchase another SRx1 cable, separately.
I downloaded the PC application from robird's site: http://www.robird.net/G31/
Win XP: http://www.robird.net/G31/xG31.zip
Win 7: http://www.robird.net/G31/RG31.application
Once the app was installed, I connected the gyro to the PC's USB. That's one of the nice features with this gyro. It's powered from the USB, so no Rx power is required, and the gyro can be tweaked without powering up the heli (note the servos will not operate). I was presented with a gyro version and a serial on the welcome screen. My gyro had v0.97. The latest version is 0.97a, when I wrote this.
To upgrade the firmware, I disconnected the gyro from the USB and while holding the "Next" button, I reconnected the gyro. Normally a green light would come on but with the button held you get no light. Make sure you have an internet connection, then in the application click the "Online Update" button, on the main welcome screen. Accept the updated version and it will proceed to flash the gyro with the latest firmware. It was very easy, but I note there does not seem to be any way to go back a version, at this time.
Powering the rudder servo:
This gyro has a split servo power bus, to allow the cyclic and tail servo to run at different voltages. Because of this, if you are using a single servo supply and a satellite or S-bus, you have to link the aileron power to the rudder power. This is done by connecting one of the single plug cables provided between the SRx1 boards 3 pin connector and the SRx2/rud input. If you are using two satellites, then you must connect the cable between the SRx1 and SRx2 boards.
Mounting foam tests:
Thanks Kauaiguy: http://www.rcgroups.com/forums/showt...3#post22102262
New metal case and blue label:
Thanks IFHELI: http://www.rcgroups.com/forums/showp...&postcount=130
Much more to come...
Feel free to ask any questions you have regarding this review or any setup issue you might have. Setup is very easy if you have done another flybarless gyro setup before, but it can be a bit daunting the first time, so don't hesitate to ask anything, no matter how simple a question it might be.
Also please post in this thread any of your own flight videos using this gyro or someone else's flight video, and I'll link them in this first post.
If anyone else has a mini review of this gyro, or the same gyro with a different label, also feel free to post it in this thread.
All the best
thanks ridge_racer: http://www.rcgroups.com/forums/showp...&postcount=550 (cyclic expo should have been -20)
thanks boredom.is.me: http://www.rcgroups.com/forums/showp...&postcount=574
Setup videos: (18 of them, skip videos 6 to 9 if you are not using S-Bus or a Sat)
Compass 7HV: http://www.rcgroups.com/forums/showp...05&postcount=4
Devil 450 Pro: http://www.rcgroups.com/forums/showp...7&postcount=11
Devil 450 Pro FAST: http://www.rcgroups.com/forums/showp...9&postcount=12
Trex 450 Pro, thanks zhnme523: http://www.rcgroups.com/forums/showp...postcount=1041
450 Pro, thanks ridge_racer: http://www.rcgroups.com/forums/showp...&postcount=561
Mini Titan 325, thanks IFHELI: http://www.rcgroups.com/forums/showp...2&postcount=68
Beam E4 with DFC, thanks Kauaiguy: http://www.rcgroups.com/forums/showp...6&postcount=48
Thunder Tiger X50E: http://www.rcgroups.com/forums/showp...&postcount=561
Kasama Dune 600, thanks SDHeliPilot: http://www.rcgroups.com/forums/showp...&postcount=726
Protos 500, thanks airbasher: http://www.rcgroups.com/forums/showp...postcount=1344
Older G31 with Tx programming: http://www.rcgroups.com/forums/showp...postcount=1154
FBL Servo arm lengths:
RobirdUSA distributor website
Thanks to boredom.is.me, IFHELI, ridge_racer for their contribution to this 3GY V2 thread:
Highlights from that thread:
IFHELI's fleet: http://www.rcgroups.com/forums/showp...9&postcount=38
IFHELI's performance page: http://www.rcgroups.com/forums/showp...5&postcount=70
Jombo's link to the Blackwidow thread: http://www.rcgroups.com/forums/showp...2&postcount=61
IFHELI's setup tabs: http://www.rcgroups.com/forums/showp...2&postcount=78
Some of the apps screen can't be seen: http://www.rcgroups.com/forums/showt...4#post22057954
This gyro is also know as the:
robird G31 (designer and manufacturer)
|Jul 04, 2012, 06:38 PM|
Installation, Setup and Test Flight
Out with the old (3GYS) and in with the new (3GY v2) in the ALZRC 450 Pro. Installation went well. I did my usual trick of putting dots on the Rx leads using a Vivid marker (1 = Ail, 2 = Pitch, 3 = Elev, 4 = Rudd), so when I feed all of the cables down to the receiver, I knew which ones went where. Note, make sure the lead with the 3 plugs on the end goes in the left most socket. Do not put a standard lead, with power and ground, into this socket.
The supplied leads are a good length and unlike the old 3GYS, I wasn't stretching the leads to the limit to reach the receiver.
I used Tarot ZYX foam to mount the gyro, as I felt the supplied foam was too thick and too soft. Also Kauaiguy's tests showed more vibration with the supplied foam, and less with a firmer foam. Update, it looks like the vib results attached, with this foam, are good.
I was pleased when I powered up the gyro and everything worked. I had already set up the gyro on the bench, connected to another receiver, but for some strange reason the gyro had lost my Tx reverse settings. I'm a little concerned about this, because I don't know what could have caused them to revert to not reversed. The tail limits were still at minimum, where I'd set them, and the performance setup values were also as I'd set them. Perhaps I turned them off for some reason, it was very late.
I've also strangely had the blue led momentary blinking off a couple of time and a twitch from the servos. I can find nothing mechanical causing this and I can't get it to repeat it by doing anything, i.e. stick stirring or bumping the heli.
The setup using the PC application is excellent. I couldn't ask for any more setup settings and the setup is very logical. There is enough information on each setup screen telling you what to do.
I had a dream setup up with most sliders at there default, and then left the heli running for half an hour, moving the sticks occasionally and moving the heli around. I've attached all of my setup screens.
Some things may still change in the performance tab. I've currently zeroed the expo, as I like to use my Tx expo for all of my helis, to keep it consistent and lowered the swash in/out to 200.
I've filmed a test flight at home. For a change I used the hat cam, so I could fly around a bit more. There were a couple of flights before this one where I adjusted the settings to get the feel I wanted. I must admit that I was disappointed when I first flew it. It was too loose and in banking turns it seemed to fall into it's own down wash.
I changed the swash in/out back to 255 and zeroed the pitch to elevator and cyclic to tail. I also adjusted the gain pots to 1 o'clock. It flew better, so I increased the gains to 2 o'clock. This felt much better.
The tail required a higher gain than I'm used to setting. I had to go to 42 (50 in the PC app) to get the hold I wanted. Other FBL gyros I have are set to around 28-32. It has a slight bounce on a hard stop nose left. I also increased the tail maxrate to 64. This gave me the same tail speed/feel as my other gyros, perhaps a little faster.
I've lowered brake CCW slightly to see if it helps the bounce and increased pitch to tail slightly. I'll post new performance pages if I make any other changes.
Update (13 Aug 2012):
It's becoming evident that the cyclic MaxRate's are not like the tail. They seem to have less of an effect on agility (roll/pitch rate) and more effect on reducing damping, as the setting gets higher.
The other interesting thing is the same dampening also affects collective pitch. I have to admit that I was not fond of how this gyro flew until I increased the cyclics MaxRate to above 22, as I was noticing the slower reaction to collective pitch and cyclic, even when sport flying, making me feel disconnected with the heli.
If you're a beginner then it's probably a good thing, but I recommend as you progress to circuits that you try increasing the cyclic MaxRate's to avoid finding yourself touching the ground with a wind level changes or when doing a negative pitch decent.
If you're already doing sport or 3D flying make sure you increase the cyclic MaxRate setting to 22 or above. I'm using 26 for Aileron and 23 for Elevator. The maximum value is 27.
Tail CCW piro stop bounce is also an issue I'm having with this heli and gyro. I've even tried setting the tail up in rate mode and adjusting the CCWBrake, but it's still there. Reducing CCWBrake just makes it a slow bounce back and increasing it makes it a wag on stop. A pity the tail doesn't have more adjustments. These smaller helis can be finicky.
Update (27 Aug 2012):
I like the new v22.214.171.124 application and the way the gyro flies with the new v0.98a firmware. Robird's work on this gyro is definitely heading in the right direction. I've added the v126.96.36.199 screenshots with my settings for the ALZRC 450 Pro.
More tweaking and testing underway...
|Jul 04, 2012, 06:49 PM|
Even though IFHELI posted these in another thead, I'll post them again here, because it shows robird's efforts to improve this gyro and how well it already works in Gavin's flight video:
Note: For some reason the original videos are now private. It would seem that Gavin Broadbent will no longer be promoting this gyro.
Here's some other ones I've found of Gavin flying the robird G31:
Latest, thanks SDHeliPilot:
|Jul 04, 2012, 07:51 PM|
I think you will truely enjoy flying with this Gyro. I want another one so bad but I have an extra BeastX and ZYX-S sitting on my bench.
|Jul 04, 2012, 08:38 PM|
FYI, I've added a link to your video post in the 3GYS v1 thread. Are there any others you'd like me to add?
|Jul 04, 2012, 08:41 PM|
Joined Nov 2010
|Jul 05, 2012, 08:18 PM|
Interesting to see the 3GY is a little heavier than the ZYX. The 3GY weighs 14.0g without cables and 22.5g with all of the cables to connect to an Rx. The ZYX without the cables weights 10g and 18.4g with all of the cables to connect to an Rx.
I wonder what is the cause of the additional weight. Perhaps the additional hardware for the USB? The USB does have a metal socket.
Also interesting is that the 3GY requires an additional cable to connect to the Rx, as they have reserved one of the plugs on the cable with the 3 plugs.
|Jul 05, 2012, 09:47 PM|
This may explain why... LOL.... Copy from instructions.....
Fbl system self supports HV(High voltage), the voltage within 4.1V~9V is supported.
Tail servo, swash plate servo and USB has 3 separate power supply circuit. So that HV servo
and normal servo can be used together.
The swash plate servos [ServoLeft, ServoCenter, ServoRight] are powered by [Ail, Ele] such 2
ports, each port can afford 5A current, 2 ports can afford 10A for swash plate servos in total.
The tail servo is powered by Rudd port, which can afford 5A current.
USB will NOT power the servos, so that if you only connected USB, the servos won't move.
For the same reason, if you only powered the Rudd port, the swash plate servos won't move either.
|Jul 05, 2012, 10:05 PM|
That's a very nice feature and makes good sense, as to why they went with the additional cable.
Seems I should read the manual. I hadn't up until now, because I thought most of it related to the Tx programming.
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