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Electric Stunt => Gettin all AMP'ed up! => Topic started by: Russell Bond on February 06, 2013, 04:08:21 AM

Title: "Too slow for proper governing?"
Post by: Russell Bond on February 06, 2013, 04:08:21 AM
Hi all,
Here's a question for you.......
I'm using a CC Ice 50, 930 k/v motor (10 pole) and 4s battery. (I'm using Set RPM)
The prop is the 13x4.5 thin pusher running at 9550 RPM doing 5.4 secs/lap. All good! (77% on the ESC)
I would like to try the JXF 13x6.5 thin 2-blade carbon pusher that just arrived from HobbyKing.
However, I had to set the RPM at 8700RPM and the ESC said "Too slow for proper governing".
At this RPM the lap times were a bit fast for me at 5.1 secs/lap.
Looks like I'll have to drop the revs to 8400 to get near 5.4 /lap.
This will put the ESC down to 67.8% where it says it's too slow.
Now I realise that when the ESC gets to 69.9% and it says it's too slow for proper governing that it will still work ok as it just doesn't stop working when it hits less than 70%.

My question is, how low can we go percentage wise on the ESC before it stops governing in control line mode?
Title: Re: "Too slow for proper governing?"
Post by: Dennis Adamisin on February 06, 2013, 05:23:06 AM
Hi all,
Here's a question for you.......
I'm using a CC Ice 50, 930 k/v motor (10 pole) and 4s battery. (I'm using Set RPM)
The prop is the 13x4.5 thin pusher running at 9550 RPM doing 5.4 secs/lap. All good! (77% on the ESC)
I would like to try the JXF 13x6.5 thin 2-blade carbon pusher that just arrived from HobbyKing.
However, I had to set the RPM at 8700RPM and the ESC said "Too slow for proper governing".
At this RPM the lap times were a bit fast for me at 5.1 secs/lap.
Looks like I'll have to drop the revs to 8400 to get near 5.4 /lap.
This will put the ESC down to 67.8% where it says it's too slow.
Now I realise that when the ESC gets to 69.9% and it says it's too slow for proper governing that it will still work ok as it just doesn't stop working when it hits less than 70%.

My question is, how low can we go percentage wise on the ESC before it stops governing in control line mode?

I have birds running as low as 60% (in Set RPM) that seem to work OK - I think your target RPM at 67.8% should be good.
Title: Re: "Too slow for proper governing?"
Post by: Russell Bond on February 06, 2013, 02:09:32 PM
Excellent, thanks very much.  ;D
Title: Re: "Too slow for proper governing?"
Post by: Dean Pappas on February 08, 2013, 07:45:14 PM
Hi Russell,
The lower you go, until the ESC refuses to govern any longer, the tighter and faster the RPM control loop can run.
I have always been an advocate of running with more "voltage overhead" for better control when maneuvers place a large transient load on the prop/motor combo.
The downside is additional ESC heating, but this is easy to check: if the ESC ain't too hot then all is well.

Regards,
  Dean Pappas