Efficiency of High End vs. Low End Motors - RC Groups
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Jan 06, 2013, 10:10 AM
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Efficiency of High End vs. Low End Motors

I have always liked the dependability of higher end motors such as Axi, Hacker, Motrofly, E-flite.......

However, many people believe the cloned versions of these motors that sell at ~1/2 the price are a much better bargain. Other than material quality/bearings being questionable quality, do the cheap motors exhibit decreased efficiency?
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Jan 06, 2013, 10:38 AM
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Dr Kiwi's Avatar
This is by no means a detailed analysis! High quality motors tend to have slightly higher peak efficiency - say 80%-85%, versus the 70%-75% for cheaper motors. The main difference I see in looking at www.drivecalc.de graphs is that high quality motors have flatter efficiency curves (maintaining good efficiency all the way up to max. amp draw)... in lower quality motors there is a far more pronounced drop off in efficiency as max. amps is approached.
Last edited by Dr Kiwi; Jan 06, 2013 at 10:48 AM.
Jan 08, 2013, 01:03 PM
rebell's Avatar
I will not place E-Flite and Motrofly on the same level as Axi and Hacker.

High efficiency is not an exclusive feature of high class motors. I tested a lot of motors on a dynamometer and found some cheap motors with efficiency just as high of even higher than the expensive motors. One of those I always recommend is Suppo, also marketed under different other names.

Efficiency and power are not always synonym. Some of the manufacturers such as scorpion claim highest power and highest efficiency, but it is not. Suppo does not do such claims, but when I dyno tested it together with a lot other similar sized motors including some more expensive motors like Hyperion and Axi, the power output of the Suppo was not far behind, however, it was the most efficient of them all.
Jan 08, 2013, 02:49 PM
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Dr Kiwi's Avatar
I've tested a lot of Suppo too... and have always been impressed. When I was hunting for an efficiency curve for a low end motor (like this E-max... and there are plenty worse, but no use for this comparison, since they were not in the same size class or Kv as the Axi I happened to use as the high-quality baseline) I had to exclude Suppo from my search since they looked too good for my purpose!!
Jan 08, 2013, 03:31 PM
rebell's Avatar
Interesting you mention E-Max. I tested the E-Max 2826 as well and it came 3rd on the efficiency list. 1st was Suppo, then Axi and then E-Max with other motors to follow. I don't think the E-Max data in the Drive Calc database is accurate. Hyperion 3025, the old one before Scorpion made it, was the most powerful but the least efficient.
Jan 08, 2013, 07:35 PM
Suspended Account
I have an Emax BL 2210/30 machine wound motor that dose perform as advertised (barely) Although inspecting the winding shows lots of empty space. I don't think a machine can pack wire like a skilled winder but the end product will be consistent. I marvel at the incredibly inconsistent turn counts on budget based motors and that they work as well as they do.That's the problem with testing motors unless I wound it or unwind it I don't know precisely what is being tested. So machine wound motors are likely to be on the light side of wire (lower eff. even when better magnets are used to try to recover some performance)) at least if the motors replaced the new one should be the same as the old one. I like low cost motors because the bang for the buck is there with good copper fill and a great improvement is realized. That doesn't really happen with the top shelf motors in fact performance can be lost deviating from their original design.

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