SpartanRC DS760 Gyro Review and Setup Vids

[noste500]

Got mine dialed in guys, Thats 3 of them earning their keep!!
Bounce back on one side has gone now that head speed is up and motor is not running too fat.

[Augman37]

Can't find V1.08 on the spartan site. Was it removed?

Can anyone tell me what the distance from their ball to their tail servo horn is on the TRex 500? I have mine at 7.5mm and I still have pretty strong bounce back. what are you guys running for this distance?

Thanks,
Julian

[TMoore]

V 1.08 is available via the firmware loader when you update the gyro as long as you are connected to the net.

TM

[Finless]

Well I apologize if someone thought I was outright blaming the gyro itself. That was not my intention. I must have something wrong because it's (the heli) having this problem, and I was only looking for help.

I did not have this problem with the GY770 that I took off of it. The stops with it were equally crisp in both directions. Headspeed, tail blades, battery, etc., are all the same. And yes my tail blades are on correctly.
Again, I was only looking for help.

I know some "people" will never get it... maybe I'm one of them. I'll bow out of this conversation and sit back and read as I used to do. Maybe I'll learn something.
It's crashed at the moment so any further changes will have to wait anyway.


Eeek JC.... I had not come back and read this post train. My rant was not directed at you. It was direct a page before or so from the guy that I found via PM had his tail on backwards.... Your post got intertwined man... No way would I suggest that you had this messed up as I know you and know you would have built your tail properly... Sorry if it seemed I was jumping on you!

Anyway might I suggest to folks having bounce back and not seeing the stop speeds changing anything that you try moving the ball out on your servo arm. I had to move out on my 600N. When the ball is too far in you have lots of resolution but lower speed. If you have changed to this gyro from another you cant assume the ball location on the servo must be at the same spot. You may have to change the location. Of course this will vary depending on different helis, head speed, tail blades used, etc.... Also If your too far out with the ball similar things can happen as now you have speed but no resolution. There is a happy spot with ball location. It's not hard to find but you have to try moving in or out.

Finally gain on this gyro does not work the same! Unlike some other gyro's you do not want to go up in gain until you wag then back off a few clicks. This gyro does not produce wag very easily! When I started I had my gain at 35% (about 75 in the DX gyro menu or 44 on the end points). It did not wag until I started doing backwards stuff. Also fast stall piro were jerky. Guys that are hovering or doing some simple forward flight may not realize the gain is too high. With this gyro you want to lower the gain as much as you can until the tail doesnt seem to hold then go up a couple clicks at a time until you feel it holding for you. High gains are not good. The goal is to get a lower number not go as high as you can. Too high a gain can cause a jerk or what some might see as a bounce when stopping piro's if the gain is too high. Mine on my 600N is now down to 24%!!!!!

BTW I may also add I do not like the Align batman blades for this reason. As many know the Align tail has some waddle in the tail grips and bearings. This slop seems to be amplified with the batman blades. Try CF's or even the KB tail blades.

Hope this helps,
Bob

[BruceW]

Just tried the new gain reporting feature in the latest configuration editor to read the gain as the gyro sees it in diagnostic polling mode. Very nice!

As mentioned before, the calibration factor of JR/Spektrum is about 1.4x of true gain. Since I run the gyro in 'gear' mode I have my endpoints set at 37% for HH which equals 27% as the gyro sees it. This should be a nice way for people to compare their gains without having to state their radio type and whether they're in gear or gyro sense mode.

Also, Angelos, I noticed that when I switch to rate mode the gain as read in diagnostic mode still shows positive instead of negative.

On another note: Is it possible to download and save the current firmware from the gyro as a binary file in case a new version ever cases problems? Or better yet, is it possible to download the actual binary file from SpartanRC? I know there is a lot of regression testing going on but I just sometimes like to know I can back rev a version if something happens. I noticed the firmware loader has the ability to read a file instead of just downloading from the web.

Thanks for the updates,
Bruce

[Angelos]

> Also, Angelos, I noticed that when I switch to rate mode the gain as read in diagnostic mode still shows positive instead of negative.

That's correct. It matches the gain graph in the user guide. Also if you have a Futaba radio the value you see in the gyro menu will be exactly the same as the one displayed by the software.

If there is ever a reason to roll back to a previous version we will make that version available. Yes, it is possible to choose a file for firmware update which is how we do the initial testing before making it available for automatic download.

-Angelos

[helical]

Mine on my 600N is now down to 24%!!!!!

Hope this helps,
Bob

On my 600N, I have mine at 31% (Futaba) and was thinking about moving in on the servo arm becuase the instructions say that gain below 35% may require moving the ball in. So I guess there's no ill effect to having such a low gain?

[Pulento]

People fail to understand that the mechanical components of the tail are an integral part of the gyro's feedback path.

HFG,

Need your enlightment here, I'm an Electrical Engineer too but Automatic Control isn't my field. I know there is delay in my feedback path but I wonder why this delay is on CW pyros only.

I suppose that CW stops needs faster response since the main rotor turns CW also ?

If there is delay in the path, maybe a longer arm will help.

My setup is T600N @ 2000 RPMs with K&B 92mm blades, 14mm servo arm. 81/102 are the endpoints. ~8 degrees on center (no drift on rate mode). The gain is 70 at DX7 gyro menu (40).

I played with CW stop gain and increased until 130 and decreased the deceleration profile until 50 and noted a slight improvement.

I feel the slider smooth all the travel. What I did noted is a slight slop on the tail (every 600N on my field has it) but also my tail shaft has a small slop of about 0.5mm I mean the shaft can move 0.5mm (axial) inside the tail cage.

BTW, is nice to have people like Angelo and HFG who can teach us :)

[Pulento]

Anyway might I suggest to folks having bounce back and not seeing the stop speeds changing anything that you try moving the ball out on your servo arm. I had to move out on my 600N

Bob, how long is your servo arm ? I used 14mm since the manual states that is better to have the arm so the endpoints are near %100.

I'm running %40 gain so I like to compare arm lenght/gain since longer arm means higher gain.

[HFG]

What you are describing is not delay in the engineering sense. What your describing is different closed loop responses for positive tail pitch and negative tail pitch. Make sure your tail servo horn is perfectly centered, servos have a very non-linear response (its a sine function). The reason Angelos recommends the use of 8 degree during setup is an approximation to "cancel out" (still remember first year physics and net forces ?) the torque of the tail. Without this 8 degrees the gyro will have to have a fixed offset on the tail servo to counter this torque. So you may ask yourself why on earth should i care if they gyro will automatically cancel out the torque if i dont do it with the 8 degrees of pitch ! Well remember the servo horn follows a non-linear function, so any movement to the positive pitch or negative pitch will experience different closed loop characteristics. Moving the servo ball link on the horn will only increase the closed loop gain but it will do so in both directions. The reason there is a sweet spot between 13 and 17mm (those numbers are off memory) is to avoid 2 situations. First one is if the ball is less than 13mm, in this case the horn will have to move alot to move the same pitch which means you travel further along the non-linear response of the servo. The other case is greater than 17mm in which case the tail servo moves too little to accomplish the pitch in this case you will run into the resolution of the servo itself. The mechanics of the tail have to be setup so the gyro can perform equally in both directions.

[HFG]

P.S. Iam running 26% gain on my G5.

[Pulento]

:)

Thanks. Indeed I was thinking the same, that the 8 degrees was only an aproximation so I hovered the heli and set the link to have no drift in rate mode, it´s about 9-10 degrees now. And my arm is perfect 90 degrees.

I think that I have to play with the arm, our local pro has a Spartan and have 17mm arm and he said to me that last time Alan came to Chile he had about 15-16mm (was using the Align JR rounded horn).

BTW my bounce is little (about 6-7 inches) just that in these matters I like to fiddle and learn :D

[BruceW]

> Also, Angelos, I noticed that when I switch to rate mode the gain as read in diagnostic mode still shows positive instead of negative.

That's correct. It matches the gain graph in the user guide. Also if you have a Futaba radio the value you see in the gyro menu will be exactly the same as the one displayed by the software.

If there is ever a reason to roll back to a previous version we will make that version available. Yes, it is possible to choose a file for firmware update which is how we do the initial testing before making it available for automatic download.

-Angelos

Oh yes, I forgot about the gain being represented on the classic V graph. Thanks for the update, I'll probably update to 1.08 today even though everything is running perfect... just to be up to date.:)

Also, when do you plan on releasing an SDK or communication protocol details to talk to the DS760? Its nice to know that you plan on encouraging 3rd party development. Since you use a serial link through USB to communicate do you use RS-232/422, X/Y/Zmodem protocols, or something else for sending commands?

Thanks,
Bruce

[helis101]

I have a problem with this gyro i cant seem to get it not spin/hold i have the the gyro on my 700 nitro the wires from the gyro coming out the front. My radio is a DX7 i set up per finless video Left rudder input do i have to reverse gyro, put right rudder input so it holds?

[toaster12]

Well if you test the gyro sense and it is wrong then yes, use right stick during setup!

[TMoore]

I have a problem with this gyro i cant seem to get it not spin/hold i have the the gyro on my 700 nitro the wires from the gyro coming out the front. My radio is a DX7 i set up per finless video Left rudder input do i have to reverse gyro, put right rudder input so it holds?

It doesn't matter which way the wires come out of the gyro as long as the sensor is mounted correctly. What matters most is that you know which way is right and left for tail rotor and that the gyro is setup accordingly. Do you know which direction the tail rotor servo works for right rotation?

TM

[heliboy88]

Hi Angelos,

I've the Spartan gyro on its way now, and i'm gonna put it on the MSH Protos(425) heli, just wanna know if the hitec hs 5084 dig. tail servo( http://www.infinity-hobby.com/main/product_info.php?cPath=50_48&products_id=3122 ) will work with the Spartan, and should i set it up using the 9257 config.? Sorry if i didn't ask my question right cus i'm still waiting for the gyro(thus the manual).

regards,

[toaster12]

I have a problem with this gyro i cant seem to get it not spin/hold i have the the gyro on my 700 nitro the wires from the gyro coming out the front. My radio is a DX7 i set up per finless video Left rudder input do i have to reverse gyro, put right rudder input so it holds?

Best way to check direction is to forget about servo linkages and which way the hub moves.

All ways go by the leading edge of the tail blade (For those that don't know, leading edge is the edge that cuts into the air first or the fattest part of the blade!)

For all these the blades should be viewed from the rear!
For left turn, the tail goes right so the leading edge moves to the right, just like a screw it cuts to the right, pulling the tail that way.
So for a right turn the tail goes left and the leading edge goes to the left.

To check gryo direction (Programmed in the gyro) move the tail towards you and the leading edge should move away from you, move the tail away from you and the leading edge should move toward you.

This is not meant to be condescending in any way! I believe it is the easiest way to check the tail. Obviously if in the last part you pull the tail torwards you and the LE of the tail blades move torwards you then gyro sense is reversed and you have to use the reverse method of the Spartan i.e. use right stick instead of left!

With the gyro mounted at the front and the wires coming out of the front then yes I would reverse. It is in the same orientation as if it were mounted at the rear but moving in the opposite direction during yaw! Mine has the wires coming out of the rear and I use the standard setup (left input)

[MarkWebber]

Sorry if i didn't ask my question right cus i'm still waiting for the gyro(thus the manual).

You can have a look at the manual while you wait. It's available on the Spartan website. http://www.spartan-rc.com/products/ds760/ds760_user_guide.pdf

Though you're link doesn't say, I presume it would be a 1520uSec-333Mhz servo.

[heliboy88]

Hi Mark,

Thanks a lot for the heads up, in the link it's written as follows:

The extreme speed HSG-5084MG Digital Micro Tail Rotor servo is based of the HSG-5083 but utilizes a standard frame rate digital amplifier.

So does the so called 'standard frame rate' mean that it's a 1520uSec-333Mhz servo?
Sorry to ask again but i'm really a noob with electronics.
Also, thanks for the link to the manual, it'll take a good look at it before my gyro arrives.

regards,

[TMoore]

The 5083 works on the Hitec version of the Logictech 2100T gyro. It uses 900us centering. The 5084 is probably the more normal 1.5ms centering.

TM

[heliboy88]

Thanks a lot TM, just hope the Spartan is compatible with this servo too. Maybe Angelos can chime in and give some insights about this, and it'll be GREAT if he can give me some setup tips.

regards,

[MarkWebber]

For setup tips, I'd bet Angelos would suggest the manual as well as their FAQ page which you can check out here: http://www.spartan-rc.com/support.php
Quite a bit of good info there.

900 uSec, huh? That seems odd. But, I should think their "standard" comment would suggest 1520 uSec, as TMoore said.

[heliboy88]

Hi Mark,

Thanks a lot for helping. But does standard also mean 333Mhz? i've read the user guide of the gyro and saw there's a servo selection of 250Mhz, so what should be the standard one?

regards,

[HFG]

250MHz .............. try again :)