Thanks very much for this comment,carlnoki. I REALLY do appreciate it. Dr M
-My Monolog is a 110, and is powered by a PJS 6000 motor -which generates 7.5kg of Thrust on 8S LiPo ...!

Thank you for this comment, az3d. I greatly appreciate it. Dr M

Greatt annalisis, It is not how much you spend, it is how many fun miles you get for your fun tickets. At 100 feet and 60 mile an hour nobody cares what hard parts you have, it is just great to be a part of flight. </p>

Thanks so miuch for this comment, arfwrecker. I do appreciate comments like this,Very best wishes, Dr M

Yes, I agree.
Perhaps some of the most fun I have had, is with a small30g / 40g Indoor co-axial indoor helicopter like the Blade mCX / Walkera 5G6. Theseonly cost$30 or $40. But because we can fly them anytime at home, and we can also have fun flying them with family and friends, I have probably spent far more time flying this, thanany of my $2000planes or big outdoor helis ...
I have most definitely a MUCH greater "bang per buck" with this little heli, than with any other model ...

-Having said that, arfwrecker:
I do not see the point in just "wasting" money.
I do not see the point in paying $500 for four JR servos -when four really excellent Power-HD servos cost $65 ...-http://www.chd.hk/Product_List.aspx?cid=3

I do not see the point in paying $330 for a Hacker motor &amp;ESC -when other motors made in the very same factory are available, which ae completely identical; And when other ESC's also made in the very same factory are available, which have identical firmware and functions. And when these other completely identicalmotor &amp; ESC cost only $79 -less than 1/4 of the Hacker motor &amp; ESC combination.
After all, arfwrecker, what is the point ? There only seems a point if you have a psychiatric addiction to the colour purple ...

Just one more thought, arfwrecker; I remember you were kind enough to contribute the thread "Which chinese factories make various brushless motor brands?" - http://www.rcuniverse.com/forum/m_11426913/tm.htm
-This thread was "locked" for some reason that I have never understood -after all, there was never any "problem" on this thread, at all.
Perhaps we should politely ask the RCU management to re-open this thread,which seemed to be of great interest toa large number of people.

<span style="font-size: medium">SO: WHICH MOTOR MIGHT BE THE &ldquo;THE BEST ONE &ldquo; ? Turnigy SK3 3542-1000Kv or Hacker A30-12L ?</span></p>

Well, obviously these two motors are extremely close to each other. As far as performance is concerned, it is like looking at two Turnigy SK3 3542 motors, or two Hacker A30 motors, rather than one Turnigy SK3 and one Hacker motor -they are that close.
-However, there ARE some small differences between the individual examples of each motor that I tested, and it is worth pointing these out.
Now, of course one motor costs $27, and the other costs $101 (in Europe; in USA the Hacker is $66.99). But for the purpose of this comparison, let's pretend that they both cost $60 -so that price does not affect our comparison of performance and other properties.</p>

<span style="font-size: small">1. The Turnigy SK3 3542-1000Kv has better performance than the Hacker A30-12L
</span>If we compare the datasheets and graphs for the Turnigy and Hacker motors, shown in posts #5 and #6, and in #11 and #12, then we can see the following'
For the 13x6.5 prop on 3S LiPo:
Turnigy SK3 gives 1760g Thrust for 35.5A and 406W.
Hacker gives 1720g Thrust for 39.5A and 372Wg
-The Turnigy SK3 gives slightly more Thrust for a lower current.</p>

For the 14x8.5 prop on 4S LiPo:
Turnigy SK3 gives 3070g Thrust for 70.4A and 964W
Hacker gives 3060g Thrust for 77.6A and 1016W
Once again, The Turnigy SK3 gives slightly more Thrust for a lower current.</p>

For the Turnigy SK3, there was less of a fall-off in performance with the 15x8 prop, in comparison to the Hacker.
Overall then, the performance of the Turnigy SK3 is marginally better than the Hacker motor.</p>


<span style="font-size: small">2. The Turnigy SK3 3542-1000Kv is lighter than the Hacker A30-12L
</span>The Turnigy SK3 motor by itself weighs 141.1g. The hub prop adaptor weighs 10.2g. The two together weigh 151.3g.
The Hacker A30-12L motor weighs 150.3g by itself. The hub prop adaptor weighs 17.9g. The two together weigh 168.2g</p>

<span style="font-size: small">So: The Turnigy SK3 motor is lighter than the Hacker, by 18g.</span></p>


<span style="font-size: small">3. The Turnigy motor has lower No-Load Current than Hacker</span>
With 3S LiPo, the Turnigy had a No-Load Current of 2.1A; With 4S LiPo it was 2.5A.
The Hacker, however, had a No-Load current of 2.7 A with 3S LiPo; and with 4S LiPo it was 3.5A</p>


<span style="font-size: small">4. The Turnigy SK3 motor mostly had similar specs to those given by HobbyKing (HK).
-Whereas the Hacker motor didNOT have the specs quoted by Hacker.</span></p>

a. HK quote a weight of 141g for the Turnigy SK3 3542-1000Kv -and it did indeed weigh 141.1g
-Hacker quote a weight of 143g for the A30-12L, and it actually weighed 150.3g.</p>

b. HK quote a Kv of 1000 for the Turnigy SK3 3542-1000Kv, and PeakEff calculated a Kv of 1008.
Hacker quote a Kv of 1000 for the A30-12L, and PeakEff calculated a Kv of 976.</p>

c. HK do not quote a No-Load current for this motor. Hacker quote a No-Load current of 1.8A for the A30-12L, where in reality it was 2.7 A with 3S LiPo; and 3.5A with 4S LiPo.</p>

d. The quoted dimensions for the Hacker motor are confusing. Hacker themselves quote a length of 42.85mm, whereas AeroModel quote a length of 46mm. None of these quoted lengths were correct. As stated in post #4 of this thread, the main motor body had a length of 39mm, and with the hub on the rear housing the total length of the motor was 49mm.</p>

HK quote a total length of 43mm for the SK3 3542-1000Kv, and this was correct -I actually measured a total length of 44mm for this motor, but what is 1mm between friends &hellip;?</p>

5. The values of Internal resistance quoted by both HK and Hacker were far below what I actually measured. HK quote an internal resistance of 31mOhn, and I measured 70mOhm. Hacker quote an internal resistance of 30mOhm, and I measured 58mOhm.</p>


<span style="font-size: medium">SO: WHICH OF THE TWO MOTORS IS BEST ?
</span><span style="font-size: medium"> Well, the Turnigy SK3 3542-1000Kv is lighter and has slightly better performance than the Hacker A30-12L.
So: If the motors were the same price, I would buy the Turnigy SK3 3542-1000Kv in preference to the Hacker A30-12L.
</span></p>

<span style="font-size: large">But the two motors are <u>NOT</u> the same price &hellip;!</span></p>

<span style="font-size: small">The Turnigy SK3 3542-1000Kv costs $27.76
Whilst the Hacker A30-12L costs $101.53 &hellip;.!</span></p>

<span style="font-size: medium">And we have reached a <span style="font-size: large">REALLY CRAZY situation </span>-when a $27 motor actually has better performance and is a lighter and better motor, than one costing $101 &hellip; !</span></p>

<span style="font-size: large">!!!!</span></p>

Oh really? Not the same price?

After reading your thread Iwould never have guessed.

You do love to repeat yourself.

Hello Ed: I make 2 points:
1. As a moderator, I am surprised you can make such a comment. RCU does say about making posts on the forum: " ... Please resist the urge to curse, flame, degrade, insult or embarrass someone in your post. ... If you have to vent, take it offline. We carefully monitor posts and will ban individuals who engage in offensive conduct within the forums ..."
The comment you have made here: "You do love to repeat yourself" -would seem to fit into the category of "embarrassing someone".
A moderator such as yourself should not be doing this, and should be setting a good example.

2ND POINT:
I must admit that I carry on being quite amazed and very shocked, that Hacker have the audacity and chutzpah and the cynicism to sell a motor for $101, whilst HK sell exactly the same identical motor for $27 ...
-I just cannot think how we have all allowed such a totally ridiculous situation to develop ....

quote] ORIGINAL: aeajr After reading <span style="font-size: medium">your</span> thread [/quote]
Ed: It is not<span style="font-size: medium"> "MY"</span> thread ... It is a thread on a public forum
-The thread actually belong to everybody ... -to all the members of RCU ...
And everyone CAN contribute .. <u><span style="font-size: medium">I very much hope that they do ...</span></u>

<span style="font-size: medium">HYPERION Z3019-12T, "900Kv"
</span>
I have JUST made 1 or 2 of the first test runs on the HYPERION Z3019-12Tmotor. Hyperion quote a Kv of900 for this motor -whereas all the other 12T motors with 3020stator have a Kv near 1000.

Well -guess what ? For the first runs, PeakEff gives a Kv of 1008, and DriveCalc givs a Kv of 1014 ....!
It is <span style="font-size: small"><u>NOT</u></span> a 900Kv motor -it is 1000Kv, like all the others .....!

More on thismotor test , in next few days ...

No flame, just fact. If we go back throughthe thread you say the same things over and over again. If you don't want it pointed out, don't do it.


I always consider the first poster, sometimes called the orignial poster or OP as the owner of the thread. Just a personal prospective. On some forums the OPhas moderator power within that thread.


But we digress from your discussion about motors. Please, continue.

For DR Motor

Trying to PM you sir, it appears that RCU has taken this option away from you. You may quote any part of my first response to you. Interested in your private opinion of several name brand motor sizes and the best bang for the buck IE> PRICE!!!!!!.

Bob

Hello Bob, Great to hear from you again. Yes, we cannot communicate via PM.
You can email me at: [email protected].
-I look forward very much to hearing from you. Best wishes, Dr M

Bob, if we look back at the thread: "Which chinese factories make various brushless motor brands?" - http://www.rcuniverse.com/forum/m_11426913/tm.htm; posts #20 to #25, I compared the prices for several motor brands.
I found that:

a. Turnigy SK3 motors are generally about 30% of the price of the matching and equivalent (and identical) same-size Hacker USA motor price.

b.Hyperion-Z motors purchasedfrom Aircraft World in Japan, arebetween one third and one half of the Hacker USA motor price.

c.OK Hobby Infinite motors are ~35% to 40% of Hacker USA price
Gens Ace motors are ~40% to 50% of Hacker USA price
LiPolice motors are ~50 to 60% of Hacker USA price
Pelikan Foxy motors are ~75% of Hacker USA price
Pilotage Nova-Line motors (mostly in Russia &amp; Ukraine) are ~same price as Hacker USA.

d. Extreme Flight Torque motors are about same price as Hacker USA, occasionally slightly more.

- http://www.rcuniverse.com/forum/fb.asp?m=11432142

On 4 May 2013, bufordbob sent this message, in connection with the thread "Which chinese factories make various brushless motor brands?" - http://www.rcuniverse.com/forum/m_11426913/tm.htm

I have worked for years with the University of Windsor SAE Aerodesign students who compete each year in international competition. If the equipment you use for testing is as pictured it not in the slightest professional in any way. A simple lever on a postal scale, give me a break. Cripe the students do a much more thorough job testing than you could ever accomplish with that hay rube cobbled together junk. No bearings or counterweight to eliminate or reduce friction for crying out loud anyone can see the wiring the way it is unsecured to the apparatus is one more variable. All you have done is basic static testing through a lousy fulcrum hardly a controlled environment or testing to destruction and no dynamic testing through out the range. Even the students do this before selecting props, motors or battery packs. Hardly the work one would expect from someone who claims a clinical and professional background.

Dennis

About Test bench in pictures.
I think it can not get absolute value testing, sure.
BUT,
with the some test machinery , in the some place and in the some situation, changing only motor.
You'll sure have one relative safe and precise comparative value.

So,
you can seed this is motor is better that that motor
( on that test motor stand, on that place , on on that temperature situation ).
That's not so bud![8D]

"2. The Turnigy SK3 3542-1000Kv is lighter than the Hacker A30-12L
The Turnigy SK3 motor by itself weighs 141.1g. The hub prop adaptor weighs 10.2g. The two together weigh 151.3g.
The Hacker A30-12L motor weighs 150.3g by itself. The hub prop adaptor weighs 17.9g. The two together weigh 168.2g

So: The Turnigy SK3 motor is lighter than the Hacker, by 18g."


Be interested to hear how they can be exactly the same motor yet you posted the above quote

Turnigy 141.1g yet the Hacker is 150.3? Over a 1/4 oz difference yet they are exactly the same motor?
You yourself proved right there that there MUST be some differences between the two.
If they are exactly the same motor just branded differently then by rights they should weigh EXACTLY THE SAME AMOUNT, shouldn't they?
How do you explain the mystery 1/4 oz? That is a lot of weight when you're dealing with something this size.
Oh well can't argue with this kind of logic, I'm not that kind of crazy!

Dr Motor, I have a few comments for you. I apologize for not having yet read through the whole thread as I am at work, but a few things caught my attention:

1) I appreciate that you have a thread on this topic. I understand your passion toward the subject and appreciate the scientific method. It does have a place in the RCU forums, just not sprinkled into threads of other topics (so thanks for doing this here).

2) It appears to me that the magnets look a little different - can you measure the width and thickness of the magnets of each brand? I believe I see the same differences on the inner and outer magnets. I don't know how the metal cans compare in weight otherwise it would be interesting to see if one set of outer magnets is heavier than the other. But it appears that the Hacker motor has less spacing between the magnets.

3) It also appears to me that the copper windings look a little different, as if there was more copper in the Hacker motor.

4) Can you report on what markings are stamped on each brand's bearings?

5) I would like to re-iterate my point that despite all of this 'reasearch' - there is still too much information missing to claim that the motors are identical. We don't know what kind of glue is hodling the magnets on. We don't know the strength of the magnets. We do not know much about the windings, either, other than the Hacker appears to have more.

With a higher quality glue and more magnet/copper metal to handle power and dissipate heat, it is very plausible that the Hacker will withstand punishment more than the Turnigy. Unfortunately longevity is not something that can be tested on a stand in a matter of a few hours or even days.

One reason that many of us choose to pay a lot more money for what looks awfully similar to something that costs a lot less, is a matter of trust. I am not going to drive hundreds of miles and many hours to a contest field to have a motor fail on me, because I opted to go with a less expensive look-alike. I am not saying that the Turnigy motor will definitely fail first, just saying that there is not yet any longevity behind the SK motors, and there is a longevity of products with the same name brand or sold by the same retailers to not last very long.

I would take a slightly heavier motor, with slightly less thrust, if I knew it would outlast the competition (putting aside the fact that one brand gives great customer service).

Before this thread gets going I would like to pass on a warning I recieved via pm for consideration. I have removed the links sent with personal links and left only links to RC related items.

Dennis,

You might want to put DrMotor on your Ignore/blocked list before he starts spamming your inbox with more of his nonsense. Dr Motor's (real name is Dr Allan Levi) issues are much more serious than a shoddy test rig. He's bipolar, diagnosed in 1999, and since the demise of his AllFlight webstore, he's been obsessed with undermining certain reputable brands of RC products. The guys on RG Groups did a lot of research on Allan Levi when he did the same thing over there under about a dozen aliases. Also, he doesn't live in NZ, but rather Bristol, England. Here are some links with good info in the doctor.

Rob


http://www.rcgroups.com/forums/showthread.php?t=1377748

http://www.rcgroups.com/forums/showthread.php?t=1611380

http://www.rcheliaddict.co.uk/main-d...ght-co-uk.html

Propworn, Let me start with the bearing issue you mention. <span style="font-size: small">Would it not have been reasonable,for you to have first askedwhether bearings might be used in the Test Stand I have designed ? -<span style="font-size: x-small"> rather than just assuming that they are not ...?
</span>
</span>As you see from below,<span style="font-size: medium"> BEARINGS <u>ARE</u> USED ...</span>-They are 1/2in inner diam, 1-1/8in outer diam; Japanese high quality KLNJ</p>

I actually thought very carefully indeed about this Motor Test Stand design,and designed and built it over severalmonths -Also with the advice and input of Dr Kiwi, who has been testing brushless motors since 2004, and who has published probably well over 100 brushless motor tests -see: http://www.geocities.ws/dr.kiwitn/</p>

<span style="font-size: medium">So Propworn, we have tackled the first thing you mentioned-bearings. And we have shown they are of course used in the MotorTestStand...


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