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motor temps?

Old 03-18-2015, 07:44 PM
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Flysohigh
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Default motor temps?

I fly about 8 minutes and the motor isn't hot to the tough but after about 5-7 seconds it becomes pretty hoy. I know motors are made to operate at about 150 degrees or so but i want to know if I'm in a good range. What is a good rule of thumb to stick too?
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Old 03-18-2015, 08:36 PM
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fhhuber
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I try to have my motors not get above 140F by IR thermometer.

The magnets are potentially damaged when you go above 180F.

Stupid Turnigy used 120F melting point hot melt glue to hold the magnets in some motors... That didn't work well.
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Old 03-18-2015, 08:48 PM
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I dont have a way to check the temps on the motor can unless i buy a temp gun, trying to avoid that wondering if there is another ball park figure test i.e. if a motor is at 150 degrees is that hot to the touch?
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Old 03-18-2015, 09:31 PM
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140 for an average person you can touch it but not hold your hand on it
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Old 03-18-2015, 09:47 PM
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Ahh got it thats where mine is more or less after 5 sec i cant hold
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Old 03-19-2015, 05:03 AM
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If it gets that hot in 5 seconds, then I suspect you are pushing the limits.

Remember, at the end of a flight you generally chop the throttle and more or less glide in. That gives the motor time to cool with lots of airflow during your landing approach.
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Old 03-19-2015, 10:34 AM
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Originally Posted by Larry3215 View Post
If it gets that hot in 5 seconds, then I suspect you are pushing the limits.

Remember, at the end of a flight you generally chop the throttle and more or less glide in. That gives the motor time to cool with lots of airflow during your landing approach.
Helicopter I have not plane and I fly in IU 85% throttle
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Old 03-19-2015, 06:22 PM
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Should i raise IU to 90 or 93% across? Should higher rpm lower motor temps?
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Old 03-19-2015, 08:46 PM
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Originally Posted by Flysohigh View Post
Should i raise IU to 90 or 93% across? Should higher rpm lower motor temps?
Helis motors function the best at above 80%, preferably 100% (some may be okay at lower, but efficiency is lost). I use a curve so that I get a sort of governor, increasing throttle to 100% when the pitch is the greatest on the pitch curve, and around 80% at mid point.If you go below 80%, you are losing efficiency. Depending on the esc as well...90-93% just gets pushed to 100%. What type of heli are you flying, motor, battery, gearing? You may be geared too high, or you could, perchance, be geared to low, resulting in too low of a HS, requiring too much pitch for lift, and thus stressing the motor a lot to keep up with the hovering. You also could have too weak of a motor (it's drawing max amps to fly the heli), or the wrong motor for the voltage you are using, etc.
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Old 03-19-2015, 08:55 PM
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Its a scale trex 500e in a fuselage , 1600kv align motor, 12t pinion, 162t main, 100amp esc hobbywing, flying PC is at 50,50,50,75,100 and TC 85% across. Hiw can i get temps dowm. Mechanically set -3,0,+10
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Old 03-19-2015, 09:11 PM
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Originally Posted by Flysohigh View Post
Its a scale trex 500e in a fuselage , 1600kv align motor, 12t pinion, 162t main, 100amp esc hobbywing, flying PC is at 50,50,50,75,100 and TC 85% across. Hiw can i get temps dowm. Mechanically set -3,0,+10
I gather you are using 6s. Is 50 on your radio 0 degree pitch? Your setup should give you around 2600rpm, and the heli at stock states 13t pinion, at 2800 rpm. Your motor should be fine, the align motors work well IMO. On IU I used -100 to 100, or -12 degrees to 12 degrees pitch, constant pitch, and the pitch settings you have are more something I would use on normal mode, with a variable throttle, not a constant throttle. With all of this, I would say your motor shouldn't be getting hot really. Is your esc getting hot at all? Check all bearings in your heli, specially around the main shaft, and tail, as well as the motor yourself. Your heli, unless you upgraded to FBL recently, isn't new and there could be some wear on the bearings. This is the only thing that would likely cause overheating of the motor, as you are practically at stock setup. Your motor, depending on the age, could be dying too.
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Old 03-19-2015, 10:10 PM
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I have a 5000mah pack and the weight of the fuselage and bigger battery maybe the weight load on the motor? I can fly 2 6 minute flights and not worry about it i guess but i dont knkw if i should try a different PC and raise headspeed?
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Old 03-19-2015, 10:31 PM
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Originally Posted by Flysohigh View Post
I have a 5000mah pack and the weight of the fuselage and bigger battery maybe the weight load on the motor? I can fly 2 6 minute flights and not worry about it i guess but i dont knkw if i should try a different PC and raise headspeed?
5000mah pack?! Well that would certainly explain a lot. "When pigs fly!" That's double the weight of the pack it usually hold. The fuse will add some weight, but that pack is gonna add a lot of weight What you should do is go higher voltage, and you may benefit from a "scale" rotor, 3 or 4 blade, gives more collective pop. It seems you threw the 5000mah in to get more run time, but I doubt you are getting more at all, as you are likely hovering a fair amount above mid stick, meaning higher collective to just get it flying. Honestly, running scale, you just have to deal with a lesser flight time on the same setup. You may be able to go up to a bit bigger of a pack, but 5000 sounds a bit large to me. To get more flight time, your best bet is upping the voltage. For instance, my X3 is a fairly large 450 heli, with 360mm blades. If I ran it 3s, it would pull a lot more amps than say a 450x, due to size and weight. Flight time would also suffer, likely 3 minutes with a 3s 2200mah pack. With a 1300mah 6s pack I will get around 6 minutes.

Cheapest route, fly with a 2500mah pack or so, see the flight time, performance and hot how the motor gets. It likely won't get hot, and you should hover right around mid stick. You have to expect a loss of flight time with a scale fuse, and a bit of heat increase with it as well, for airflow is likely lost. Next cheapest is going with a different motor perhaps, but this will also suck more amps, and you will drain the pack faster. Going to a different motor and higher voltage will help performance and flight time, as you get end up with a lighter overall weight and less amps pulled.
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Old 03-19-2015, 10:51 PM
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Well i had another 500 pro dfc same fuselage and battery as this one and after 8 minutes it would not be this hot. Im not using a 5000mah pack for more flight time i need it to balance it correctly. Any smaller pack i would have to add nose weight which i would rather run a bigger pack and get more time (even two 6 minute flights). My other heli did have the 500mx motor that comes with the pro amd does pull double the amps. Will that help with efficiency trying that motor . Im assuming since i once had it it should be the same. As far as headspeed should i increase the rpm to maybe 93-95% see what happens?
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Old 03-19-2015, 10:57 PM
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So this particular heli is not sporting a 500MX? For that size and weight you will likely need at least a 500MX. It seems as though you motor is just too small for what you are trying to do, and with the constant higher collective to lift the excess weight of the fuse and huge battery, you are making the motor stress out throughout most of the flight.
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Old 03-19-2015, 11:09 PM
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Being that the mx motor compared to the 500L puts out more watts will have an impact on running cooler? I thought due to more power it should heat more? But again im sure my assumption was wrong. Enlighten me here
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Old 03-19-2015, 11:14 PM
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A motor will only pull what it needs, just like a gasoline engine...well I suppose some vehicles get 1mpg no matter what If you hook up that 500mx and it literally pulls twice the amps as the motor in there now, then you know that your motor was too weak. It may pull the same amos too...but the difference is, the amps it will pull will be okay, vs the maxing out the other motor. The other option is, of course, higher voltage, thus less amps.
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Old 03-19-2015, 11:46 PM
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When you say higher voltage i dont believe i can do higher voltage since im at 6s?
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Old 03-20-2015, 12:00 AM
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Well you would likely need a lower kv, 8s could be possible with enough change in gearing. The 500mx would help a lot. Just because its higher watts and amps doesn't mean it will pull more amps, it simply can pull more if it needs to. Your motor now is pulling max amps, and airflow must be keeping it cooler until you land. The 500mx will likely give you better performance as less energy will be wasted off to heat. It wouldn't hurt to go to
higher throttle. There is a point when high hs wastes performance, but you have lower hs than stock and 10% more isn't a lot really. Are you flybar on this heli?
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Old 03-20-2015, 01:56 AM
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Originally Posted by thepiper92 View Post
Well you would likely need a lower kv, 8s could be possible with enough change in gearing. The 500mx would help a lot. Just because its higher watts and amps doesn't mean it will pull more amps, it simply can pull more if it needs to. Your motor now is pulling max amps, and airflow must be keeping it cooler until you land. The 500mx will likely give you better performance as less energy will be wasted off to heat. It wouldn't hurt to go to
higher throttle. There is a point when high hs wastes performance, but you have lower hs than stock and 10% more isn't a lot really. Are you flybar on this heli?
well i cannot go 8s because the battery will be to big to fit, not only that i will have to change esc and motor. I just came back after test flying it and to make matters worse the guy that set up my heli used electrical tape to balance the blades and while in flight one blades balance tape stripped odd and the heli went into a massive vibration i quickly landed it. BUMMER now i need to find real balancing tape that is hopefully clear so it doesn't look so nasty as that electrical tape did. I went up to 90% throttle across and it seemed to be ok but i didnt get a chance to fly it much.
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Old 03-20-2015, 05:31 AM
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You must have had a terribly balanced set of blades for it to shake like that. Go for trim tape used on planes. Packing tape can work too if you don't want to see it. As for 8s not fitting, you would go to a smaller mah. For example my x3 takes a 2200 3s, or a 1300 6s
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Old 03-22-2015, 01:22 AM
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I balanced my blades and problem solved , but i need to drop
Motor temps . Heres my settings now i was thinking on lowering adv timing to 12deg its on 16 now and PWM is on 16htz as well
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Old 03-22-2015, 01:40 AM
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I would leave timing at stock settings. Timing causes a loss of efficiency and more heat from what I understand
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Old 03-22-2015, 05:51 AM
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Originally Posted by Flysohigh View Post
well i cannot go 8s because the battery will be to big to fit, not only that i will have to change esc and motor. I just came back after test flying it and to make matters worse the guy that set up my heli used electrical tape to balance the blades and while in flight one blades balance tape stripped odd and the heli went into a massive vibration i quickly landed it. BUMMER now i need to find real balancing tape that is hopefully clear so it doesn't look so nasty as that electrical tape did. I went up to 90% throttle across and it seemed to be ok but i didnt get a chance to fly it much.
If you are serious about getting the most efficient flight from that Trex, do not waste your time with balancing tape.......if moving up from wood or plastic blades to CF, tape should not be used since most quality CF blades balance (out of the bag) 99.9% true....but always test balance any prop on a quality (made for heli) balance device...!

A common problem with increased head speed is that it will start showing the tell-tell signs of thrust bearing, feather shaft and damper issues....even the washout linkage will show signs of radical vibrations that seemed non-existent until you start pushing the envelope once you move up to more efficient and higher KV motors.

Even the smallest change to blade mount thickness will have an impact on how the rotor blade holder rotation responds in cyclic rotation.......... it's all relevent....each part is related to the cause and effect of the weakest link.

As far as "timing" goes.......you have the right idea, lower Hz will help with surge and constant power cycles, and may keep the ESC/motor cooler with some noticeable launch lag......but the "timing' on todays quality brushless motors is set (intended) to respond as a function of the ESC....either low, mid or high settings pre-determined by the ESC manufacture......when switching to another outrunner, it's best to set the ESC at the motors manufacture recommendations........unless you posssess knowledge of some serious mecahanical and electronic wiring skills.

It is a very common issue with inexperienced heli flyer's to disregard "standard" technical procedures relating to pitch and throttle curves..........especially now that the TX's have so many options to control that factor. Many (if not most) believe that advanced pitch and rotation speed settings will solve the mechanical issues that have not been "properly" adjusted as a baseline control point..........it dosen't matter how informed one may be or how well they understand pitch and throttle curve displacement, If the mehanical aspects or the equipment is not dialed into its optimum performance level, no adjustments to TX curve settings will allow the craft to perform efficiently or without issues down the road.

As far as pitch and throttle range goes......the best "rule of thumb" anyone would advise when it comes to CCP........if the blade pitch is set to high, it will result in shorter flight times, (I'd suggest your stated 6min flight times are about 6min less than the average "scale" flyer gets out of a Blade 500E), and one will experience poor motor performance.
Setting the throttle curve higher in order to provide a higher (head) speed is preferable to increasing the pitch curve to accomodate flight stability....!.....the motor and ESC will perform more efficiently and last alot longer without major heat issues.....

Note:

Consider digesting the post I previously made here......:

http://www.wattflyer.com/forums/showthread.php?t=75537

It could help if one intends to keep the Trex 500E in the air for the " long run".

Last edited by pizzano; 03-22-2015 at 06:58 AM.
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Old 03-24-2015, 01:24 PM
  #25  
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I can fly 10 min with no issues and when i check temps they are about 140f , didnot last weekend but since the feel is almost hot to the touch i try ro cut the flights in half, although its not exceeding 150f but i dont want to risk anything. Im either going to buy a align 500mx or the scorpion 1360kv motor , both are double the watts and amperage that i have now. The 500mx align motor is half the price of the scorpion at 70.00, scorpion is 129.99 but i wouldnt mind paying more if the scorpion will benefit in the longrun
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