Servo & Swash Setup

Russell · Tue 03. Mar 2015 16:12:40

Been trying to setup a new unit using Jeti UDI, diagnose screen is all working correctly.
However i am not able to get the swash to move in the correct direction for cyclic, I can get the pitch to work ok, but not elevator or aileron.
In the software when i try to reverse only ch2 or only ch3, both get reversed together as if i was selecting the reverse ch2&ch3 option.
Also when adjusting the sub trim in the software for say ch2, both ch2 & ch3 move, and the same when i adjust ch3, both ch3 & ch2 move. Also the subtrim sliders go from -127 to +127, on both these channels i can only get movement from +80 to +127...not much at all, it is as if ch2 & ch3 are somehow mixed together.

Any suggestions on what I could try to get this unit working?

Tue 03. Mar 2015 16:18:44

Hi,

most probably your servos are connected not properly in the unit.

Make sure that elevator servo is in CH2 position, while CH1 and CH3 are aileron servos.

Russell · Tue 03. Mar 2015 21:20:55

Thanks
Yes I have the elevator servo in ch2 on the unit.

What else do you suggest I try?
What would be causing servos in ch2 and ch3 to be mixed together...it is as if the are on the same channel. ...

Tue 03. Mar 2015 21:45:12

What CCPM mix did you selected in the software? What is your helicopter?
If channels in the diagnostics tab are moving correctly (aileron/elevator), then there is no problem on the side of your transmitter/receiver.

Russell · Tue 03. Mar 2015 22:22:39

Std 120 deg on a Goblin 500.

It is running the latest software and firmware on the unit, and has been installed and re-installed several times yesterday.

Can the previous firmware be downloaded somewhere to try as I don't have a copy.

The only other thing I can think of is to try a pwm receiver.

But it is strange that the subtrim also doesn't work and will only move the servos 2 & 3 about 2 deg total movement, so setting them at 90 deg is not even possible.

Also servos servos 2 & 3 initially act strange on the pitch, it is as if they running V curve on the pitch, only after I enter the servo travel correction screen do they suddenly change to have a linear curve.

Tue 03. Mar 2015 22:35:51

Are you sure you have CCPM mixing disabled in your transmitter?
Is it clearly visible in the diagnostics tab, that for example elevator stick movement will change elevator bar only?

Old 1.0.25.1 version:

Windows - http://spirit-system.com/dl/settings/sp ... -win32.exe
OSX - http://spirit-system.com/dl/settings/sp ... .1-mac.dmg
Linux - http://spirit-system.com/dl/settings/sp ... ux.tar.bz2

Firmware:
http://spirit-system.com/dl/fw/spirit-fw-1.0.25.1.bin

Russell · Tue 03. Mar 2015 23:09:42

Yes Jeti DS swash is set to Mechanical.

And as you have stated in other posts Jeti works out of the box in relation to the diagnose screen, even though the receiver channel mapping is not matched to the RX output, and this i agree with 100%.

The diagnose screen is perfect.

Tue 03. Mar 2015 23:18:11

I am afraid but there could be only two possibilities.

Servo signal wire is shorted so signal for both CH2 and CH3 is shared. This can happen, when for example helicopter main frame is carbon and wires from both servos are partially cutted.
Something is shorted in the unit (CH2 and CH3 pins).

If you have multimeter it can be verified very easily.

Russell · Tue 03. Mar 2015 23:28:37

Well it is not the servo wires, they are brand new and not even installed, So I should check for a short between the signal pins on CH2 & CH3?

Tue 03. Mar 2015 23:32:47

If you can, it would be fine. You can measure it with multimeter (resistance measurement) and verify both signal pins. There shouldn't be any measurable resistance less than 30Kilo Ohms between these pins.
If there is short, then there could be resistance less than 2KOhms.

By the way, even new servos may contain shorts. Especially RJX servos are known for this. It is shorted by servo enclosure. Signal is on the metal shell so when the servo is mounted to carbon frame it is shorted together.