Thread: DS760 Messy Init

On power up, this will take the servo to one extreme - way beyond the limit set in the gyro.

Maybe one time in 4, it won't do this. Then it behaves fine. Inits cleanly, and holds the tail without drift. Servo end-points are fine in this case.

I've not spotted a pattern. Anyone seen this, and know what causes it ? Is it a fault, maybe ?

raise a ticket it sounds like it needs a service...

steve

When I set mine up I was told to make sure to set the correct servo type into the menu? Because if the frame rate etc is wrong strange things can happen including burnt out servo's so I was told by someone who did it.

Angelos and John of Spartan RC are great guys so drop them a line and they should be able to point you in the right direction.

Also might be worth looking at the FAQ page on there website as might fine the fault there Spartan RC

Martin

Originally Posted by scallybert

On power up, this will take the servo to one extreme - way beyond the limit set in the gyro.

That's what Futaba gyro's used to do when attached to JR servo's .............

The DS760 on my 450 does this too. Very annoying and can't be good for the servo

Are you using Spektrum radio? If so, did you set the gain to below 5% in each direction during binding?
I had some issues in the early days, very similar to the above and since doing the above get 100% service from the 760......

Edit,

Probably this!

i remember the old futaba gyros used to do this on power up if used with a #JR super servo defo not good for my tail servo

Yup, my JR 5700g servo did the same with my Futaba GY520

Originally Posted by Heliheaven

Are you using Spektrum radio? If so, did you set the gain to below 5% in each direction during binding?
I had some issues in the early days, very similar to the above and since doing the above get 100% service from the 760......

Edit,

Probably this!

Yes, that sounds like it. It's the tail servo on a T-Rex 450 Pro Combo. Align DS520. Bolleaux..!

[Yes, I bind at 4% to defer gyro init until the Rx connects.]

Did you rebind AFTER setup? If not try that.

This can sometimes be the cause of that.

Originally Posted by Jamin_00

Did you rebind AFTER setup? If not try that.

This can sometimes be the cause of that.

I'm a bit unconvinced of that. The defaults set at bind-time are gain 4%, and rudder (nominal) zero. I don't see why these should need to change, or change (except for pot error).

This (as you probably know) stops the gyro initialising until the Tx sends a 'proper' value on the gain channel, and therefore a genuine rudder zero is available (which the gyro takes as zero). You can see this working if you power up the heli before the Tx (default disclaimer and warnings apply...)

FWIW, the heli has been set-up on one DX8 and tested on another, so was re-bound. It's going to be bound back to the original Tx when I play around. If I suddenly see the problem go away, I'll have to have a re-think...

It does seem to be a case of how the whole set-up is powered up. ie whether the power connector goes in cleanly, etc. I'm going to try an S9257 and see how that changes things.

I have 4 DS760s, with Fuatab 9257, 9256, JR8900 and 8700 servos and DSX9 Tx.

None of them do this, ever. Never done the gain limit thing during bind either.

I always do the whole setup via the PC interface and they just work fine.

i had a JR 2700g do this with a Align GP780, and GP750

Re-bound to the DX8 that I did the set-up on. DS520 continued to be upset. In fact, so upset it seems to have stripped some gears... :/

Plugged in an S9257 from an in-progress FBL G5, it behaves fine. (As expected, since it now seems DS520s don't like the way Spartans don't send a signal until they're ready; and I've got S9257s on various G5s with Quarks & DS760s.)

The T-Rex 450 Pro now has an S9257 tail servo, and seems fine on the bench.

So I've now ordered a DS520 gear set, and an S9257. Unfortunately, the S9257 is about twice the price of a DS520 - and the (well-specced) InoLab equivalent has different fittings.

It would be good if Spartan put the workaround in a firmwear update.

Oh, another (bodgy) workaround might be to use a servo programmer to limit the DS520 travel - if you can.