Seaking 120A ESC, what should my timing be?

[MassiveOverkill]

So I have a CF2812 3300KV 8 magnet pole, 12 coil brushless on 2200 mAh 3S 30C batteries. What should my ESC timing be?

Pics:

Left motor is a standard CF2812 brushless. Right is Joysway frankenbrushless that I can't find anywhere. They removed 6 magnets (14 on left, 8 on right) and beefed up the gauge of the windings:



Motors put back together:



Windings of the stock Joysway Frankenbrushless:

[MassiveOverkill]

OK guys, I got my Seaking 120A ESC installed and man this thing jumps out of the water!! I've only done short 1-2 minute runs and the motor is running really hot. The driveshaft is pretty friction-free, but as I said in the other thread, a little heavier than teh stock drivetrain. I went from a 30mm prop to 32mm. I guess I could go back but I don't think it's the prop.

I've tried 3.75, 7.50, and 11.25 ESC timing and she still runs hot. If it's a timing thing, it should run cooler the lower the timing I use right? Cooling tube spits out a nice stream of water.

What do you think, try 0 degree timing? BTW I'm glad I got the programming card.

Oh, it's weird hot the motor responds to timing. When I had it at the most advanced of 11.25 the drivetrain sounded like a bumble bee, whereas the lower the timing I used the smoother she ran. I think I just answered my own question but would like more input.

Thanks.

[photohoward1]

Outrunners always run Hot. When you say hot? What temp? Outrunners also like a high degree of timing.

[MassiveOverkill]

Well the 'hold your finger for 5 seconds' test failed. Keep in mind that once I got my bearing situation resolved the motor on the stock ESC ran very cool to the touch immediately after the run.

Also keep in mind that my outrunner has about half the magnets it would normally have.

[Rumdog]

It has half the magnets....
So, what?
The timing probably isn't the issue. It's a cheap, tiny motor that can only be cooled with a cooled mount. As stated, outrunners run hot. Way hotter than a jacketed inrunner. Thing is, they can handle the heat.

[MassiveOverkill]

It has half the magnets....
So, what?
The timing probably isn't the issue. It's a cheap, tiny motor that can only be cooled with a cooled mount. As stated, outrunners run hot. Way hotter than a jacketed inrunner. Thing is, they can handle the heat.

What you mean this?!



FYI the motor ran cool on the old ESC and drivetrain before the stock ESC blew. It now has a new ESC and Octura drivetrain. You didn't even read my last post did you?

[Rumdog]

Yeah. That mount is what I mean. They don't do much for cooling. I'm willing to bet that the excessive heat is caused by your new drive setup.

[MassiveOverkill]

I had to ditch the new compression collet as it was too heavy and unbalanced. I drilled out my old brass collette to accomodate the larger .130 flexshaft as well as put some hot glue at the bottom of the motor so it mates with the plastic and vibrations are much less now.

Old collette was only 7 grams, new one was 12.

I'll restart ESC timing trials tommorrow.

[LiPo Power]

Go back to 30mm prop and see...
Its possible the little extra on the prop is installing enough load to get the motor wormer...

[MassiveOverkill]

I'm not ruling that out, but I'm going to check that as a last resort. I think the vibrations the Octura motor coupler was creating was the main culprit. I'll know tonight after work.

[lectriglide]

Outrunners also like a high degree of timing.

+1. Generally outrunners like 15 - 30 degrees of timing. They don't run worth a flip at less than 15.

[MassiveOverkill]

+1. Generally outrunners like 15 - 30 degrees of timing. They don't run worth a flip at less than 15.

And this is why I brought up question on the number of magnets or poles, which was shrugged off like it didn't matter:

http://www.rcgroups.com/forums/showthread.php?t=1408488

A default CF2812, which has 14 pole magnets would normally like to see 15-25 degrrees of timing, but mine is only an 8 pole motor, which puts it in one timing class lower.

[siberianhusky]

I think you may need to do something about the rest of the vibration, something in there is out of balance and this WILL cause inefficiency in the driveline.
" and vibrations are much less now. "
Should be smooth and vibration free.
A 2mm increase in prop diameter is a MAJOR change in load as well. So this could very well be your problem. You'd be very surprised if you saw the difference a 2mm change in prop size makes to amp draw if you had a data logger.
Last time out I put a slight cup in the tips of a prop and the amp draw went up almost 15 amps average for the run. A 10 amp increase would be massive for that little motor.
I have the headroom in that setup so 15 more amps was nothing to worry about, the motor and esc are more suited to each other amps wise also.
Your motor is seriously the weak link in your setup, you could over amp that motor and the esc wouldn't even get warm until the windings of the motor short!
Since the esc is basically bomb proof for that motor you have to be careful not to go too crazy on the props so you don't over amp the motor.
In short I'd solve the vibration issue so it runs smooth, go back to the 30mm prop which you know ran well and try medium timing to start, if things are ok bump it up to high and see what happens in a short run. Once you have the timing set try the 32mm prop and see how hot that gets in a minute of running.
You changed a whole pile of things at once so the problem could be with any of them or a combination.
Make one change or adjustment only then run the boat and see if that made it better or worse. Same way full size race teams track down problems on race weekend.

[MassiveOverkill]

Well removing the vibration means getting another motor, which means modifying the motor mount to take a standard outrunner. The vibration is there with just the original collette and has been there since the boat was stock. Even without the collette, the motor has minor vibration at certain points in the RPM range. It's not bad and doesn't persist throughout the entire RPM range. I guess I could try balancing the can, trying to determine what I could use that wouldn't fling off at 30K RPM....I guess I could use epoxy.

The existing motor mount is rather weak, which is why I've shored it up with hot-glue because the bottom of the motor mount is just free-hanging, and now it's at least mated to the hull. That alone has made a difference in vibration. I'll do a few short runs to make sure the heat problem is gone before I accept the hot glue as a long-term solution.

[martin]

Are you getting this vibration running the motor out of the water with no load on the motor. Outrunners will vibrate a lot more than inrunners if run with no load on the prop. Are you getting noticable vibration when the boat is in the water with load on the prop.