2 Pole Motor Timing

[SweetAccord]

If that DF value was right with 8XL the formula seems right. I come out to 7.5 and rounding to the ESC's closest setting that would be right, interesting.

[Punisher 67]

If that DF value was right with 8XL the formula seems right. I come out to 7.5 and rounding to the ESC's closest setting that would be right, interesting.

Can you break that down , I can't seem to get that using your formula.......... We were using 4 cells or 15.0 volts

[SweetAccord]

Can you break that down , I can't seem to get that using your formula.......... We were using 4 cells or 15.0 volts

An 8XL is 2048kv 4 pole? 4S is 14.2 but you stated 15v.

So 2048x15x4/20=6,144. So that is close to 7.

[Punisher 67]

An 8XL is 2048kv 4 pole? 4S is 14.2 but you stated 15v.

So 2048x15x4/20=6,144. So that is close to 7.

A Feigao is a 2 pole motor , maybe there is still something missing in the formula... to do this properly there has to be an input for amperage used . A brushed motor will literally use double the timing with twice the load for spark-less commutation

[SweetAccord]

A Feigao is a 2 pole motor , maybe there is still something missing in the formula... to do this properly there has to be an input for amperage used . A brushed motor will literally use double the timing with twice the load for spark-less commutation

Right, but at the same time I don't want to discredit this formula as yet. The value is then 3072. So it may mean the 8XL should be set to 3º-4º to be safe but 5º-7º is optimal and that setup being at 7º was selected to get more speed?

Maybe this original thread needs to be re-opened to get more clarification where the formula originated from:

http://forums.offshoreelectrics.com/...1760kv+running

[Punisher 67]

That formula is for what frequency to run your ESC at and seems to have nothing to do with timing

[785boats]

I don't think that the formula has anything to do with timing. It is for calculating the PWM for various motors. Totally different to timing.
If anyone can find a formula for timing I'd love to see it.
Ken.
I find it interesting that you find 7 degrees the optimum in your DF 29.
The one I set up (now sold) with exactly the same motor & ESC ran better for me on 15 degrees. Also exactly the same setup in a 32" hull on 15 degrees.
But I will say that I had no eagle tree to get the real numbers. Just a temp gauge & a battery monitor, & a gut feeling too I guess. Temps are 45C-50C after a 5 lap heat.
The difference would be the prop I guess. I run an X440/3 blade on both setups. This prop I find really lets the motor sing. So maybe a higher revving & slightly less loaded motor likes a little more timing.
Out of interest, what prop are you using?
Cheers.
Paul.

Edit. Punisher. Seems you posted the same thing while I was typing mine.

[SweetAccord]

Then I'll just stick to the general rule since there is no formula.

2 pole motors should be set to 1 - 10 degrees, 4 pole motors 5 - 15 degrees, and 6 pole 10 - 20 etc etc.

Thank you all for contributing.

[Punisher 67]

There is a formula , just finding it is going to be the challange.............

It will not be as clean cut and dried like your first formula , This one will involve the ohms resistance in the windings and a lot more complex math . The math for brushed motors is not that easy

[SweetAccord]

Well I found the solution. Play with timing, watch the temps. I guess we all need to wait when boat ESC's will get advanced enough to have what the car guys have on their ESC's like the Novaks called Dynamic Timing Advance. Why don't boat ESC's have this?! May be time before it gets into the boating scene.

[martin]

What PWM should you use if esc only has 8k & 16k & motor works out at 12k.k using this formula. Martin.

[SweetAccord]

What PWM should you use if esc only has 8k & 16k & motor works out at 12k.k using this formula. Martin.

8KHz is for Low RPM and Low pole count motors, where as 16KHz is for most out runner motors.

[sailr]

Our Tenshock 2 poles are set at 5-8 degrees.

[SweetAccord]

Whoever creates Dynamic Timing Advance for a boat ESC will make some money!

[sailr]

The owner of Hifei, Zenith Peng, is the best esc engineer out there. If anybody does it, he will. Maybe I'll drop him a note suggesting he work on that!