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View Full Version : My motor is "squealing", any ideas?


Forge
04-11-2009, 10:41 PM
Guys,

I have a small Scorpion 2215-22 motor that I am ready to maiden on my P-51 Mustang build. When I power it up, it's a bit jerky on the start and will stick and squeal unless I push the throttle up to around a 1/4 power.

Once it starts to spin it runs smoothly and I can power the motor back down to a spinning crawl, which then runs fine. The numbers on my watt meter seem fine.

Something seems a miss, any suggestions or trouble shooting tips? I hate to get this airborne to find a problem at the wrong time. ::o

I know this is a motor build forum, hopefully I'm in the right spot, I thought some of you guys might have some insight.

Thanks!

Forge

firemanbill
04-11-2009, 10:43 PM
Check your solder connection between the ESC and motor. I have had a bad/loose joint cause that jerkiness on start up. When one of the three wires isn't making a good connection it throws off the ESC timing causing that.

Forge
04-11-2009, 10:49 PM
Bill,

Thanks for the suggestion, I'll double check all my connections, and post up how it goes. :<:

Forge

Louis
04-12-2009, 12:33 AM
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Forge
04-12-2009, 01:38 AM
Louis,

I am using a Castle, Thunderbird 36amp. Probably overkill for my motor, battery set up. I have the instructions, but I don't really see a way to adjust the timing. I'm not all that versed in electric motor set up.



Bill,

I checked all my connections and everything appears normal. When I take off the prop and the prop adaptor, the motor seems to turn over more smoothly from the start, but still hangs up a bit. With the prop on it's more "sticky" to turn over when you first apply power.

i looked into all the vents in the motor to make sure I hadn't sucking in any screws or metal against one of the magnets (had that happen once ::o )

Like I mentioned, once I get the motor moving it runs smooth, just bugs me that it hangs up to start.

Thanks

Forge

groundrushesup
04-12-2009, 02:58 AM
Louis,
I am using a Castle, Thunderbird 36amp. Probably overkill for my motor, battery set up. I have the instructions, but I don't really see a way to adjust the timing. I'm not all that versed in electric motor set up.
Bill,
I checked all my connections and everything appears normal. When I take off the prop and the prop adaptor, the motor seems to turn over more smoothly from the start, but still hangs up a bit. With the prop on it's more "sticky" to turn over when you first apply power.
i looked into all the vents in the motor to make sure I hadn't sucking in any screws or metal against one of the magnets (had that happen once ::o )
Like I mentioned, once I get the motor moving it runs smooth, just bugs me that it hangs up to start.
Thanks
Forge

I have a Scorpion 3014-22 swinging a bighonkin' 13x4.7 SF prop on my DWFoamies BAF Juka that squeals a tad before it gets going - almost as if the initial burst of current is out of phase - but it runs great.

My particular ESC does not allow different settings for timing - I've got probably 2-3 flight hours on the motor so far (ESC is a E-Flite 40a ESC V2) and I have never had a problem (other than losing an aileron servo arm on consecutive snap-roll # 5 :p> Luckily there was a nice cushy tree there to help out). I've run it with my EagleTree expecting to see a massive dead-short at the very start of the run because of this but it was actually minimal. I am thinking about asking Lucien from Scorpion about it - maybe he can provide some insight as to if this is okay or not.

GRU

firemanbill
04-12-2009, 03:02 AM
It could be a timing thing, didn't think of that. My big Waco motor had an issue that was resolved by switching the timing.

If it runs ok once it's going I'd say you have nothing to worry about.

Louis
04-12-2009, 04:39 AM
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Larry3215
04-12-2009, 06:58 AM
The squealing on startup is normal for Castle esc's. They have a special startup routine where the PWM pulse is in the audible range durring the first second or so untill the motor gets spinning. Thats what the squeal is. Nothing to worry about.

Also, in general Castle controllers dont start well if you "sneek up" on start up. In other words, dont sloooooowly creap up with the throttle stick. Just start the motor. If that works ok then you are fine.

Serious stuttering is something else and 99.5% of the time is caused by a poor conection between the motor and esc or a short in the motor itself. It could be a bad or loose connector, mismatched connectors, broken motor wire or cold solder joint. Cold solder joint or bad connectoion is the most likely.

Not all conectors work well together even if they seem to go together ok. If your motor came with one brand of connector and your esc came with a different brand, they may very well not make a good enough connection even if they plug together.

You cannot check solder conections by looking at them. You need to re-melt each solder joint on each connector and allow them to cool again without moving the wires. Any slightest jiggle will cause a hi resistance cold solder joint and cause the stuttering.

Check those things and let us know.

Good luck!

Forge
04-12-2009, 12:27 PM
Guys,

Thanks for all the input. I appreciate the advice.


Larry,

I think I will try to re-melt my solder connections and see if that helps. Won't get to it until later this week.

Thanks

Forge

Glacier Girl
04-15-2009, 04:40 AM
Forge, something else, actually two things. #1 With Castle it's a good thing to buy the programming cable, and use their update site. Makes changes a lot faster, and you can go in and change just one thing, not having to run thru the whole set up like you do when programming with the tx.
Also all the updates to the programming of the esc's software are there, you can try changing the software to a newer or sometimes even an old one to correct problems like this. I had to do it on a CC 10 when running a Little Screamers motor, as the new software version caused the exact problems you got, old software corrected this.

#2 rare but it does happen. If the bell or bell adapter to the shaft is slipping it will cause same conditions, even cause the motor to try and run backwards. I've personally had this happen on a Turnigy motor.

Easy to check. Take a marker and draw a line down the shaft, adapter/bell, parallel to the shaft. Spin up the motor till it acts up.

Shut it down and see if the line is still straight across all parts. If it isn't somethings moving that's not supposed to be.

Can be something as easy as loose set screws on the bell to shaft point.
Bad is a pressed on bell/adapter. Usually means the splines on the shaft are stripped or the bell/adapter stripped out on the press joint.

Forge
04-20-2009, 02:14 AM
Glacier Girl,

Thanks for the illustration. I was away on vacation in FL the last few days, so I couldn't reply till now.

To test out the motor, I took a 20 amp e-flite ESC and hooked that up instead of the CC ESC that I had on the plane. It worked a little bit better, but still hung up a bit on throttle up, so I don't think it's my wiring or ESC.

I didn't want to do it, but I unmounted the motor, took off the set screws on the shaft and opened the motor up. It looked fine, (although I'm not really sure what to look for :eek:), but the windings looked fine, no broken leads, and no debris inside the case. (I did repair my T-28 motor once which had broken lead wires, so I kinda know what to look for)

I did decide to test fly the motor on a new build on Friday and everything did work our fine with the flight. I guess I will just live with it and hope it doesn't crap out on some flight. :<:

Thanks again for everyone's input.

Forge

kyleservicetech
04-22-2009, 02:08 AM
forge
Take a look at my wattflyer thread on "Drytesting Motors" Maybe something will show up?
http://www.wattflyer.com/forums/showthread.php?t=35216

groundrushesup
04-22-2009, 07:17 AM
forge,

After a mishap with the plane i mentioned earlier (the one with the scorpion motor and the E-Flite ESC) i ordered a Scorpion 45A Commander ESC as a replacement (i found out too late that the E-Flite had a capacitor with a loose trace).

Anyways, long story short - when i hooked up the new controller and programmed it to "auto" timing the start-up squeal and phase irregularity disappeared.

Theres a good chance that timing is indeed your issue.

cheers,
GRU

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ron_van_sommeren
04-22-2009, 03:27 PM
Lucien Miller (Scorpion USA (http://www.wattflyer.com/forums/www.innov8tivedesigns.com)) about squealing/jerking (http://www.rcgroups.com/forums/showthread.php?p=8731985#post8731985) motors.