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        Help! Timing Question

#1 Kevin Greene Jan 19, 2013 03:33 PM

Timing Question
 
I have a timing question---Normally, I rely on the instructions with a particular motor/fan for timing instructions...But when you are experimanting or going beyond the stock specs of a particular fan/motor---You are on your own...

I started up my twin 35mm F-15 on 4S...When I get to almost full throttle I get some surging of both motors...When I get to full throttle the surging stops...It seems as though I'm running into a timing issue at that particular throttle setting...About 7/8ths throttle...

The timing is set to low...Do I need to go to higher timing or do I have another issue???...ESC's are Turnigy Plush 12 amp units rated for 4S...Battery is 4S 25-40C NanoTech...

Kevin

#2 Odysis Jan 19, 2013 10:25 PM

May not be timing. I've run into the commutation limit a few times with these micro's.
What motor is it?

When you get to WOT, does the RPM increase from when it was surging, or does it just run smoothly at the same speed?

#3 stegla Jan 20, 2013 04:25 AM

I have a 1 cell indoor model with a 5g outrunner that makes strange squealing sounds at part throttle. I just fly it and try to ignore the noise.

I did have problems with a 24mm fan using the long-can 10mm eflite inrunner. It just misfired at part throttle settings. Nevertheless it flew ok!! However, the problem cured itself when I rearranged some of the gear to alter the cg??? strange!

Try a big battery to see if it is a LVC issue.

Steve

#4 Kevin Greene Jan 20, 2013 01:22 PM

Quote:

Originally Posted by stegla (Post 23868913)
I have a 1 cell indoor model with a 5g outrunner that makes strange squealing sounds at part throttle. I just fly it and try to ignore the noise.

I did have problems with a 24mm fan using the long-can 10mm eflite inrunner. It just misfired at part throttle settings. Nevertheless it flew ok!! However, the problem cured itself when I rearranged some of the gear to alter the cg??? strange!

Try a big battery to see if it is a LVC issue.

I'm using an 850mAh batt intended for the plane...I do know that twins can get into harmonic issues...I have the same motors/fans running in single engine planes with no issues like I'm having in the twin engine F-15...I could check the motors individually but that would mean removing shrink tubing and de-solding components...YUCK!!!...:mad:...

Kevin


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