After a very long thinking (!), I just bought this 1515 1Y sensored today, I hope it will works great and reliably for a long time.

let us know

For those who are interested (if any) in electrical parameters from this new motor, I've done some meseaures on my brand new 1515 1Y sensored (bought from amain, hope that it's not a fake !)

The motor is on my desk with no cooling and no pinion, and it is new. The esc is a brand new castle MMX (also from amain). These measures where done from a regulated power supply to get precise input voltage, current and wattage (dps3005 verified by myself for its precision readings) and a little oscilloscope to get the precise wave form on motor phases (to check the full throttle) and the precise frenquency to determine the rpm (freq/2x60 because of 2 poles pairs). The I0 is the current from the PSU minus the idle current consume by the esc (which is variyng between 150mA@8V to 75mA@24V). The motor power loss is then the PSU voltage by the motor I0. I don't use MMX logging to get I0 current because it not precise enough on such low current.


At 8V I0=2A power=16W rpm=17760 and kv=2220 (maxeff=93.1% at 56.6A)
At 10V I0=2.2A power=22W rpm=22140 and kv=2214 (maxeff=93.5% at 66.3A)
At 12V I0=2.4A power=29W rpm=26640 and kv=2220 (maxeff=93.8% at 75.9A)
At 16V I0=3.0A power=48W rpm=35460 and kv=2216 (maxeff=94.0% at 98.0A)
At 24V I0=4.0A power=96W rpm=53250 and kv=2219 (maxeff=94.3% at 138.6A)

I will do the measure at 20V soon.

The MMX logging of RPM is 3.6-3.7% more than my measures. Not too bad. Maybe due to it's clock without crystal oscillator. Dont' really know.

The motor heats up very slowly at 8V (takes several minutes to reach 50°C) but it's a different story at 24V, it's more a matter of seconds before it reach 50°C and before you can't hold it in your hand. And it is with no work done, just the losses. It's always a good idea to have a good cooling solution.

The next step is to mesaure precisly the Rm of each phase to see if the motor is well around 5 milliohms.

Question for patrick, are you sure your measure was at 24V ? Because your result seems very far from what I get (2.7A versus 4.0A).

Were you running sensored or sensorless? What phase advance were you using?

Note that you will see higher IO at higher phase advance.

Thanks!

Patrick

Thx for the answer. It was sensorless. I have tested both mode and no real differences between the two. The advance is set to low (0 to 5 if I remember well) with castle link.

And now here is the Rm for each phase (measured with precisely 5A passing through the phase and a millivolt meter on the motor solders)

AB=5.6 mohms
AC=5.6 mohms
BC=4.4 mohms

It's weird that there is so much difference between two phases, no ?

average of the three 5.2 mohms

I'm surprised to see THAT much difference, usually they are a little better balanced.

I'd honestly expect to see slightly lower (A) to (B) and (B) to (C) than (A) to (C).

B phase has a shorter run to the outside than A and C.

But, it's still within nominal.

Thanks!

Not surprising you didn't see a difference -- even in sensored mode, timing above a certain threshold is dominated by the sensorless routine. (which makes sense...)

You are probably close to the maximum 5 degree advance at 24V, so your rise in current is normal.

Thanks!

Patrick

Yes, my bad. the values are AB=5.6 AC=4.4 and BC 5.6

OK good to know. I will try with 0 timing to see what append and report here...

On the motor box I can read "revision date: 03/17" and "PKG: 6140-03-0401". Maybe it's not a genuine castle 1515 ? If it's the case it would be a very nice (and expensive ;) ) counterfact !

Could very good bearings (like boca ceramic abec 7 for exemple) reduce I0 losses and if yes in which proportions ?

For I0, I have tested at 0 timing. Same results at all voltage.

For phase Rm, I have double checked every of my measures of the new 1515 and all the results are good.

AB=5.6 mohms at solder tab 7 mohms at bullet
BC=5.6 mohms at solder tab 7 mohms at bullet
AC=4.4 mohms at solder tab 5.8 mohms at bullet

Just to compare here is the results for my old hpi alphastar 2350kv made by castle with shortened wires (old design without solder tabs)

AB=6.2 mohms at bullet
BC=6.2 mohms at bullet
AC=6.2 mohms at bullet

Perfectly equal phase to phase. I have to say that I am a bit desapointed by the result of the 1515 sensored. I will have to check how the coper wires are connected to the tabs, maybe a defect. How can I check if it's a genuine castle ? Amain is a reputable store, isn't it ?

Disappointed by what?

Those are excellent numbers. At 100A, the whole motor is only dissipating 50W.

The difference is simply that there are tabs -- and A & C phase have slightly higher resistance because they go farther around the rear of the motor, while the B phase terminates right at the terminal.

Perfectly normal. The motor phases are balanced, there's just some additional resistance on A&C for the tabs.

Thanks!

Patrick

OK, it's certainly perfectly fine. Do you if high grade ceramic bearing can reduce I0 in a measurable manner, or it's useless ? (and make it run noise free, the orignal bearings tend to make some noise at different rpm)

Ps: what is the toshiba mosfet ref used in the mamba monster X, if it's not top secret, TPHR6503PL ? just to know... And I promise, I stop bother you with all my questions ;)