First run with my 6s rigger and NEU 1527

[RaceMechaniX]

I would check the motor with another controller. If in fact you saw a spark come out from the end bell you have a shorted winding.

There are known problems using MGM controllers with Neu motors. I have demag'ed a 2215 using a 40063 within 30 seconds of dropping the boat in the water. Nothing wrong with that setup. Motor ran fine with a Schulze controller and the MGM ran fine with a 2028. Some combos just don't work. The 2215 and 40063 just did not work and the rotor was completely demagnetized within 30 seconds. The boat acted similar to what you described.

I can pull the motor apart and check for you if you shorted a winding or demaged the rotor.

Tyler

[RandyatBBY]

Did you look at the Steve Neu prop chart? It says to run a 1450 over that I would think would burn it up.

http://www.castlecreations.com/products/neumotors/nm_boat_apps.html

[Fluid]

Randy, the 1450 is listed as a starting prop. With a reasonable setup it should not burn the motor up in 30 seconds. ..

[RandyatBBY]

He said it was not going fast enough with a 1455 so he went to a 1457 on the second run and it stopped and sparks coming out of the motor. He did not start at a 1450.

I always start small and work up.

Any time I start big and work up the magic smoke will appear.

It all depends on a lot of different variables. How wet the boat is, how thick the water is/what minerals are in the water and so on......

[StevenBryant]

Randy the boat I rant his motor in has been setup and run with a Lehner 2250, it weighs 3.5kg with the NEU motor which is a very light weight setup for the motor. The boat runs very light on the water. The test lake I was at is fresh water fed from a river with little minerals in the water.

The first run with a stock 1455 prop was for around 30 seconds which I have on video if you would like to have a look, after this run I checked the data log and the max input current was 187amps and the max rpm 29,000. The cells motor and esc were all cool, based upon this info I decided to try the 1457 prop and as you can see in the video I was gentle on the throttle.

The spark occurred when I bench tested the motor at the end of the day to check the rpm data, I initially bench test the motor in the morning before going to the lake however I was sat facing the front of the motor so I would not have noticed any spark coming from the end bell, all of the data from the datalog seemed pretty good.



Sent from my iPhone using Tapatalk

[StevenBryant]

Thank you Tyler for your information, unfortunately the only other ESC i have that is rated over 180amps and is not a MGM 28026 is in my SAW mono soldered directly to the motor and i dont fancy having to remove it....

I'm considering taking you up on your very kind offer, i will PM about it later on about it.

Thanks

[oscarel]

I don't understand that datalog, does the manual say what the difference between input current, peak current, and pulse current are? I notice that input current, pulse current and input power are reasonably consistent throughout, but the peak current raises significantly in the highlighted area.

From MGM:

"peak current" means the phase current of the motor.
"input current" means the battery current.

[MarkF]

You said you were testing the RPMs of the motor in your garage. Not on 6s in an unloaded boat I hope.

Mark

[Fluid]

...The spark occurred when I bench tested the motor at the end of the day to check the rpm data...

I just don't understand all the "bench testing" folks insist on doing. It does nothing good for the motor, and a LOT of bad. An unloaded motor will heat up FAST since all the energy it receives from the ESC is converted into heat rather than into mechanical energy. Using full throttle unloaded can over-speed the motor, risking tossing a magnet or breaking a coil wire. In some long motors with 5mm shafts the shaft can whip around, damaging the magnets or windings. If by chance the motor is hooked up to the driveline during the "test" it can start to melt any teflon quickly.

What do you gain from this "testing"? Well, you find out if the motor runs in the correct direction. To find that out just takes a quick blip of the throttle, not WOT "bench testing" the rpm. The hobby would have much less trouble if folks eschewed constantly "bench testing" their motors. Test them on the water where it matters...



.

[StevenBryant]

I just don't understand all the "bench testing" .

Hi Fluid

If you read all of the posts you might understand why i bench tested the motor at the end of the day.......

After setting up the ESC for the motor in question i run the motor in a clamped jig in the workshop NOT IN A BOAT, the process i use is simple i throttle up to 50% and then too 100% bringing it straight back down too 0%. I do this to check the RPM data is correct, so to make sure i have the correct KV for the motor.

I do not bench test a motor constantly as you suggest, the motor are bench tested once before they are install into the boats and in 5 years of running BRUSHLESS FE the 1527 is the only motor i have run a second bench test on due to having the problems listed in the posts above.

The NEU 1527 1.5D with 8mm shaft is rated up to 60,000 rpm, i ran it up to 36,900 rpm for a fraction of a second, Also fluid remember when running boats they sometimes leave the water letting the RPM increase AS THE MOTOR IS NO LONGER UNDER LOAD.

[Fluid]

First, the bearings are rated to 60,000 rpm. No one at Neu would recommend running the motor that high. Folks with a lot of experience know this, re: MarkF's comment above.

Second, I was referring not to you alone in my post, as careful reading will divulge. Lots of boaters seem to think they have to "bench test", some for up to a minute. Bad idea. Too many posts ask "why does my motor get so hot when I bench test it?" A few questions usually discover the "bench test" was for 15-60 seconds.

Third, the momentary out-of-water prop is just that, momentary as in fractions of a second (check your logs). "Bench testing" for 15-60 seconds is far different.

It sounds like your own technique is fine, but you are definitely in the minority among "bench testers".



.

[StevenBryant]

Fluid if they do not recommend running a motor upto 60,000 rpm why do they advertise this, please check the link below, as you will see there is no staement about only the bearings being rated to 60,000rpm. Just to note i would never run any brand of motor anywhere near that RPM loaded or unloaded.

http://www.neumotors.com/NeuMotors/1500_series.html

I would be interested to know what the NEU 1527 1.5D motor is rated for Voltage and RPM if it is not what is on there website

My FE knowledge is very limited which is why i am on hear asking questions, however i have 25 years of racing Nitro boats, predominantly 21, 45 and 67 riggers and i have a huge amount of common or should i say uncommon sense...

Maybe i should have explained my bench test in an earlier post so there was no confusion.....

[Fluid]

It is common in the FE motor industry to advertise the maximum rpm a motor can survive, but this is usually just the bearing limit. Each manufacturer can say whatever they want, there is no real standard. Every Neu 1500 motor they sell (except the 1530 which is blank) has the same limit - which of course makes no sense from an engineering standpoint. If you multiply the "max voltage" times the Kv you will end up close to 60,000 rpm - but then this is never the case under load since pack voltage is reduced and the Kv always changes.

Besides the bearings, other factors which limit BL motor max rpm are shaft length, shaft diameter, magnet diameter, magnet glue strength and magnet wrapping.
.

[RandyatBBY]

Bench testing should not be used as the do to end all. It just a start. I did just the minimum. It is to make sure the motor runs and there is no squalling bearings. You do not over rev the motor on the bench or you will blow mag.

This is what I did not do. It is best to take a used motor apart and inspect everything before it is put under a load. If you are not qualified have some one do it that is. With the rotor out of the motor you can see the quality of the Kevlar winding around the mag. You stick your finger in the bearing and can feel the quality of the bearing if you know what your looking for. I would look at the winding and look for discolorations. If the bearings fail while the motor is running it will take out the winding's.

This is for fluid and no one else.
I have a old Ford motor that has not been ran for several years. Do you think I would take it out and thrash the heck out of it just because it ran fine ten years ago? No I would take it easy work my way in to it listen for noises and what I would rather do is tare it down inspect it.... fix the bad parts and move on.

[properchopper]

Hmmm....

http://www.hobbyking.com/hobbyking/s...rnigy_Thrust_S