Page 1 of 7

Gov 1.3.1 Goblin 700 Gasser

Posted: Sat 24. Oct 2015 14:12:03
by Scott H
Hi All,

I have a Goblin 700 gasser with a rpm sensor on the main gear (one magnet north is up and one magnet north is down). I have no control of the throttle speed when the governor is engaged (idle up 1 and idle up 2 see no variation when switched).

Normal throttle curve is 0,25, 36
Idle up 1 is 42%
Idle up 2 is 58%

On the Spirit software i see requested rpm as 0 in normal mode, idle up 1 832, idle up 2 1161.
Max rpm is set at 2000 rpms
Dividing sensor is 1
Gear ratio is 1
spool up is very slow
Throttle frequency is set to 60hz I have a S3071hv Futaba servo.
Response is set to 3 (i've bounced around here in trying things, 7 was the highest I've gone)
holding power is set to 1 )I've bounced around here in trying things, 3 was the highest I've gone)

When the governor is engaged telemetry readout on the Jeti shows 2034 rpm

Spirit Serial number 55-70-c0-60-3f-2
Banks are not assigned to a channel

Any assistance in helping resolve why I have no control over the throttle, and it's seems to be too high would be appreciated.

Re: Gov 1.3.1 Goblin 700 Gasser

Posted: Sat 24. Oct 2015 14:30:53
by ZeXx86
Hi,

you can try to set Sensor Divider to 2.

When you see 2034 rpm on Jeti is it corresponding to the real RPM? Have you any tool for the measurement?

Re: Gov 1.3.1 Goblin 700 Gasser

Posted: Sat 24. Oct 2015 22:33:50
by Scott H
Okay I measured the rpms with a tachometer pointed up at the blades (in a holder on the ground). I stood close enough to read (about 10 feet).

When throttling up in Normal, I'm at 1300 rpms or so before I hit idle up 1. when I do switch to Idle up 1 the rpms go to 2030 or so. (They should drop to 800ish (that might be a problem. Perhaps I should set the throttle curve to idle up 1 at 1400rpms so it's higher than transition speed. )

I also redid the readings with the sensor divider at 2 and it made no difference to either the readout on the jeti or the actual tach on the ground.

Re: Gov 1.3.1 Goblin 700 Gasser

Posted: Sun 25. Oct 2015 18:27:01
by Scott H
I did a few flights today and tested having the throttle percent in idle 1 to higher than the take off throttle. Take of throttle resulted in rpms in the 1300's and the I set Idle up 1 to over 70% which I calculated to give me 1400rpms and Idle up 2 to 80% which should have been 1600.

Still when I switched from normal to idle up 1 the rpms jumped to 2034. Tach on the ground agreed with the readout on the transmitter.

So much for that theory

Re: Gov 1.3.1 Goblin 700 Gasser

Posted: Sun 25. Oct 2015 19:11:45
by Malc1
Does look very familiar this.

Re: Gov 1.3.1 Goblin 700 Gasser

Posted: Sun 25. Oct 2015 20:32:42
by keithw123
Gear ratio 1...?

Re: Gov 1.3.1 Goblin 700 Gasser

Posted: Mon 26. Oct 2015 3:51:13
by Dawiev
keithw123 wrote:Gear ratio 1...?
RPM sensor reads of the main gear.

Re: Gov 1.3.1 Goblin 700 Gasser

Posted: Mon 26. Oct 2015 15:35:03
by Scott H
Zex,
I get it that you are out of options to help me on this and it seems there's a fault somewhere. A thought just occurred to me is it possible this is ExBus related? Should I rewire to UDI and test again?

I like having the option to adjust in the transmitter, but I'd rather have the gov working.

Scott

Re: Gov 1.3.1 Goblin 700 Gasser

Posted: Mon 26. Oct 2015 20:08:15
by Dawiev
Subscribed with a lot of interest and concern .......... !

Planning to maiden a G700 with TRM 300 this weekend. Align sensor reading of the main gear and split to feed TM1000 and Spirit Pro.

Re: Gov 1.3.1 Goblin 700 Gasser

Posted: Mon 26. Oct 2015 20:52:16
by Malc1
I am also using Jeti ExBus with similar problems.