Some folks here wondered about the ability of the turnigy motors of handling more voltage than their max rating. Well I'm happy to report that after a month of running my 63-74 motor at 44.4v that its still going strong. I'm sure the gearing of the SA 3speed is helping too. My only concern now is that the CC BEC PRO is the weak link because its rated at only 10s for non airplane Alps. So with good gearing and cooling, you should be okay!
Overvolting Turnigy motors
- Thread starter MrBoots
- Start date
AussieJester
1 TW
Couple of suggestion s if your worried about your battery eliminating circuit not being upto the job, Edward Lyen sells a dc-dc converter fpr twenty five bucks thats goodd for 12-72v alternatively, google HVBEC should turn up the website fpr the only company I have found that does a high voltage BEC work on/upto 60v IIRC Lastly, you could do away with alll the Bec amd servo tester setup, and buy from ebikes.ca a rc cycle analyst, best option by far using this now after trying the rest'
Best of luck....
KiM
P.s imo the motor whil be fine on 44v
Best of luck....
KiM
P.s imo the motor whil be fine on 44v
Kurt
10 kW
It would depending on what model turnigy motor it is as to how much rpm it can handle.
I have found that any more than 9000rpm on the big turnigy 80-100 starts to sound a little unhappy. I think the 130kv (mines actually closer to 145kv) 80 - 100 is rated for 12s 48v max . I started running mine at 15s 60v and that's 8500 rpm and its feels about as high as I would want to go. Any more would start to wast energy from friction/wind and create a bit of heat in the skirt bearings. I really don't think these cheap turnigy motors outer can-magnets-glue and so on is balanced real well for high rpm.
Kurt
I have found that any more than 9000rpm on the big turnigy 80-100 starts to sound a little unhappy. I think the 130kv (mines actually closer to 145kv) 80 - 100 is rated for 12s 48v max . I started running mine at 15s 60v and that's 8500 rpm and its feels about as high as I would want to go. Any more would start to wast energy from friction/wind and create a bit of heat in the skirt bearings. I really don't think these cheap turnigy motors outer can-magnets-glue and so on is balanced real well for high rpm.
Kurt
Mr Boots,
Just made an ES seach for "Turnigy 63-74" and found very little. This thread would be so much richer if you included lots of data. Your weight, bike weight, wheel size, reduction ratios, top speed, ect. . .
Thanks for mentioning you are running the little Turnigy. I've often wonder what the smallesh RC motors can do.
Will
Just made an ES seach for "Turnigy 63-74" and found very little. This thread would be so much richer if you included lots of data. Your weight, bike weight, wheel size, reduction ratios, top speed, ect. . .
Thanks for mentioning you are running the little Turnigy. I've often wonder what the smallesh RC motors can do.
Will
liveforphysics
100 TW
I run the 130kv motors on 24s. But I have custom 4340 alloy hardened steel shafts, class 7 bearings, and I balanced them.
gwhy!1
100 kW
SoSauty said:
I have been running one for about the last year on 50v'ish and upto 5kw and it still is running well.
AussieJester
1 TW
Im not sure if "running them" for a total of 3 miles reeeealy counts does it Luke?...oh, haha, video or it never happend pal...liveforphysics said:
dare you to prove me wrong Luke..KiM
Kurt
10 kW
liveforphysics said:
WOW 24s lipo! i measured my 80-100 130kv and it was actually 144kv so on 24s it would be spinning at 14,000rpm.
I would be interested in how you went about balancing the magnet and can assembly as i realy think they all could benefit from it ? At that kind of rpm it would almost be worth dynamically balancing the primary reduction sprocket assembly.
I know mine starts sounding kinda sick
at 10k. Kinda funny hey I could rev my old Frankenstein honda motor I I built to 10k no probs. All with factory ew2 bottom end. And things have to change direction at that speed not just spin round and round. :wink: I guess it was just built back in 1984 by some crazy perfection obsessed Japanese honda factory worker. Who would have taken his life at the end of his shift if his parts didn't fall with + - 00000000000002 :wink: Got to love there dedication.
Sadly our Turnigy motors are built by some Chinese guy who isn't sure what he is making but it looks shiny.
Kurt
liveforphysics
100 TW
Yep. A motor doesn't ever 'feel' voltage, it only 'feels' current.
The voltage only has RPM effects and the risk of over-reving and mechanically flying apart if things spun up too high.
The voltage only has RPM effects and the risk of over-reving and mechanically flying apart if things spun up too high.
liveforphysics said:
OK, I'm getting into those subjective adjectives again where formulas would serve better. Everything else held the same and assuming no current limiting, wouldn't raising the voltage supplied cause increased current during acceleration conditions?
Kurt
10 kW
gogo said:
Well I have noticed one thing after going from 36v to 60v with a 45A current limited controller. On 36v I was seeing peaks of around 39 amps when accelerating from a dead stop. Usually after a ride I would see a peek of around 44-45amps recorded on the CA but it was always hard to pic where this happens.
Now on 60v I see the full 45amps on acceleration and usually see a peek reading on the CA or 55 58amps. Once again you never see the 55-58amp real time.
So I would have to say yes.
liveforphysics
100 TW
For two motors at the same RPM, being fed the same amount of power, the motor feels the exact same current regardless of pack voltage.
So, if its 1000w from 10amps at 100v from the battery, or 1000w from 10v 100a at the battery, the motor knows zero difference, and they perform identically up to the point the lower voltage packs motor reaches an RPM high enough that the BEMF prevents it from being able to pull 1000w.
This is because a given power level for a given motor RPM always results in the same phase current, and this is all that creates flux (no amount of voltage creates any flux or anything the motor can feel).
So, if its 1000w from 10amps at 100v from the battery, or 1000w from 10v 100a at the battery, the motor knows zero difference, and they perform identically up to the point the lower voltage packs motor reaches an RPM high enough that the BEMF prevents it from being able to pull 1000w.
This is because a given power level for a given motor RPM always results in the same phase current, and this is all that creates flux (no amount of voltage creates any flux or anything the motor can feel).
So, now that we're close to the topic;
What does heat result from
1 power, or 2 amps, or 3 flux, or 4 resistance/impedance, or 5 ??somethin' else
Man, gotta keep pluggin' till motor theory comes together. (yea, yea, I've read all the theory links plus others)
What does heat result from
1 power, or 2 amps, or 3 flux, or 4 resistance/impedance, or 5 ??somethin' elseMan, gotta keep pluggin' till motor theory comes together. (yea, yea, I've read all the theory links plus others)
SS,SoSauty said:
Have you read the first chapter of this book?
http://books.google.co.uk/books?id=gbIDM60AvGAC&printsec=frontcover&dq=electric+motors+and+drives&hl=en&ei=U7hpTqHKF4-p8QOUroAy&sa=X&oi=book_result&ct=result&resnum=1&ved=0CDMQ6AEwAA#v=onepage&q&f=false
Anyway, I guess the short answer is:
Heat is generated by resistance to current flow, in proportion to the square of the current.
Yes! That's probably the best of the best. I lost the link after a 1st reading and may have forgotten some parts. Thanks Miles. Plan to review chap1 again and glance over later chapters for relevant info.
So R, such as Astro PDF tables resistance column, or in this case Turnigy info on HK site, is a major factor of heat. Seems a power level, possibly amps sq. and not volts would be multiplied by R. A 180Kv Turnigy @0.017mh would put off less heat than their 130Kv @0.032mh albeit the 180Kv may stress an ESC more. If hub motors have an even higher R, this makes sense.
So R, such as Astro PDF tables resistance column, or in this case Turnigy info on HK site, is a major factor of heat. Seems a power level, possibly amps sq. and not volts would be multiplied by R. A 180Kv Turnigy @0.017mh would put off less heat than their 130Kv @0.032mh albeit the 180Kv may stress an ESC more. If hub motors have an even higher R, this makes sense.
Varying the number of turns in the winding (assuming equal copper fill), will still give you the same efficiency for a given amount of torque. The maximum continuous torque available will be the same. Torque is the most important thing. You can get more continuous power by running the motor faster, until the parasitic losses dominate (eddy current losses go up as the square of rpm) or it disintegrates...SoSauty said:
Miles U r the MAN
Torque is Current
You keep repeating Urself for a reason
See lcd soundsystem over and over again lyrics
It is a tube of force not lines
See field tubes
Also http://books.google.com/books?id=n1EwAAAAIAAJ&pg=PA345&dq=%22Thoughts+on+Ray+Vibrations%22&hl=en&ei=PJjzTIPxLpC0sAPyndywCw&sa=X&oi=book_result&ct=result&resnum=1&ved=0CCoQ6AEwAA#v=onepage&q=%22Thoughts%20on%20Ray%20Vibrations%22&f=false
Thoughts on ray-vibrations
Good nite
Remember the sun doesnt rise the earth turns rounds
See u all at sunsight
Torque is Current
You keep repeating Urself for a reason
See lcd soundsystem over and over again lyrics
It is a tube of force not lines
See field tubes
Also http://books.google.com/books?id=n1EwAAAAIAAJ&pg=PA345&dq=%22Thoughts+on+Ray+Vibrations%22&hl=en&ei=PJjzTIPxLpC0sAPyndywCw&sa=X&oi=book_result&ct=result&resnum=1&ved=0CCoQ6AEwAA#v=onepage&q=%22Thoughts%20on%20Ray%20Vibrations%22&f=false
Thoughts on ray-vibrations
Good nite
Remember the sun doesnt rise the earth turns rounds
See u all at sunsight
liveforphysics said:
ive done a fair bit of testing on these (turnigy 80-100) motors and under ideal conditions when fed maximum volts they consume around 700w at 12000 rpm.
mostly this is due to eddy losses from this rpm that overheat the motor within a few minuets.
before the windings even blacken the magnets hiss when you touch them (over 100deg c, and i they appear to get eddy heating also?) and this is before it has been loaded at all, or produced power.
so i going to go right out on a limb here, and say the motor can "feel" something. :wink:
-14000 rpm is not cool with these motors, and it isn't the bearings or explosions that are the problem, its just inefficiency and heat..
Kurt
10 kW
I would have to agree with this.
Its amazing how hot the motors can get unloaded but spinning at high rpm. Short burst of high rpm is ok though. I wouldn't want to gear-volt up a bike say 18 or 20s lipo so your cruising speed had the motor spinning at 8,000 or 10,000rpm. I don't think you would get a long way at WOT even on flat ground before over heating the motor. Not from load but just the rpm. 5 or 6k is were they are way more happy for sustained use.
Kurt
Its amazing how hot the motors can get unloaded but spinning at high rpm. Short burst of high rpm is ok though. I wouldn't want to gear-volt up a bike say 18 or 20s lipo so your cruising speed had the motor spinning at 8,000 or 10,000rpm. I don't think you would get a long way at WOT even on flat ground before over heating the motor. Not from load but just the rpm. 5 or 6k is were they are way more happy for sustained use.
Kurt
