540 Nitro Governor Help

[Heli$]

Hi y'all, I'm new to the skookum 540 and I was wondering if there is a way to tell the governor that for every 1 revolution, the governor sensor will pick up 2 signals. I think I screwed up and installed the magnets the same way on the clutch bell! This would be so awesome if the software can do this so I don't have to remove a magnet and flip it the other way.

[RontaryUS]

I would re-install the magnets correctly. You could mathematically and theoretically divide the gear ratio in the software by 2 as a workaround but i do not recommend it, not sure of the potential downstream implications of doing this with the software algorythms...Get the magnets right!

[Heli$]

Ok, was able to get one of the magnets out that was epoxied in place. Not fun and didn't destroy anything on my new heli.

Thanks!

[RontaryUS]

I'm with you, hate removing magnets from bell...Glad you got it fixed.

[dcope17]

You could have just changed your gear ratio to accommodate it.
If you had 9, put in 18...

[Heli$]

I was kinda thinking like that but if both magnets had south poles up then the sensor wouldn't get any readings.

[gitbse]

Yea, it needs to be setup properly. You should be good to go now though.

Or just get a crankcase sensor. Much easier.

[Heli$]

I'm not sure the crankcase sensor works on YS 91srx.

[gitbse]

It works on any nitro that has a counter balanced crank. (all of them.) I have a 91SR, which is incredibly similar to a SRX.

[DCflyer]

Originally Posted by Heli$

I'm not sure the crankcase sensor works on YS 91srx.

It works. Works on my YS120 just fine.

[ticedoff8]

Originally Posted by gitbse

It works on any nitro that has a counter balanced crank. (all of them.) I have a 91SR, which is incredibly similar to a SRX.

First, the 91SR does not have the steel liner.
The SR-3DS and the SR-X motors do.

When I called YS in Reno, and talked to Richard, he told me that any of their motors that us the steel lined backplate should not use the backplate sensor. It would not be supported by YS.

If this works for you, be aware that it might not be reliable.

The SK gyro shows a toggle on/off as the sensor picks up a signal but no field strength.

The Futaba GV-1 gov has a field strength readout. The GV-1 shows the strength of the signal being sent by the sensor.
I could never get it higher than 80% or so with the Spektrum backplate sensor on my 91SR-3DX.
It "worked" in that it showed a reading on the GV-1.
But at speed, the gov would unlock and start seeking the proper speed.

But, I was getting 95% or higher with the magnets and it was locked in solid.
The "solution" for the 91SR-3DX was to use a 91SR backplate - no steel liner.

If it doesn't work for you, don't complain.

I use the Spektrum backplate sensor on my YS 60SR (no steel liner) but I use magnets on my YS 91SR-3DX and YS 120SR-X (steel liners).

Sorry for highjacking the thread.

BTW:
The easiest way to avoid the mistake of installing the magnets wrong:
* Take the magnets out of their package and stick them face-to-face.
* With a Sharpie (I use red) color the two outside faces of the magnets
* Install the magnets with the red side exposed.

Also:
Before you install the magnets into the bell / fan, drill and 1/64" hole through the magnet's cup in the bell / fan. This allows the air bubble to escape when you seat the magnets and it gives you a "back door" to push the magnets out if you need to a some point.

[sdunne]

Originally Posted by dcope17

You could have just changed your gear ratio to accommodate it.
If you had 9, put in 18...

Not a good idea!
If she throws a magnet your stuck on full throttle since it will try go twice as fast.

[ticedoff8]

Originally Posted by sdunne

Not a good idea!
If she throws a magnet your stuck on full throttle since it will try go twice as fast.

Good point.
Normally, if you lose a magnet, the SK "sees" no sensor input and goes to a "fail safe" throttle setting of 70% of total throttle servo position and sticks there.
It is a "limp home" feature without blowing up the motor.

But, if you have 2 magnets and a gear ratio programed into the SK that accounts for both magnets, then you lose one, the SK would detect this a 1/2 the programmed headspeed.
And it would try to adjust the throttle to get back to the proper headspeed.

I would think the engine would go to WFO. And shortly thereafter, explode.