HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Mar 30, 2007, 01:47 PM
Registered User
Joined Aug 2004
734 Posts
Just out of curiosity why are they all delta? Is it a question of ease of production (like the multistranded wire) or something else?

Adam
latrans is offline Find More Posts by latrans
Reply With Quote
Sign up now
to remove ads between posts
Old Mar 30, 2007, 01:51 PM
Flying motor mount master
fly_boy99's Avatar
San Jose, California, United States
Joined Oct 2004
8,745 Posts
Higher current handling.

Pure and simple
B
fly_boy99 is offline Find More Posts by fly_boy99
Reply With Quote
Old Mar 30, 2007, 01:56 PM
Dance the skies...
Tom Frank's Avatar
United States, MA, Walpole
Joined Dec 2003
17,728 Posts
Quote:
Originally Posted by Skinner46
This is great stuff and I congratulate Lucien on a creating data that is rare on motor sales sites!!
I would like to point out that inexperienced people should be wary of comparing data just based on motor size, prop size, etc. You must also be aware of the winding connections (WYE or DELTA) and the effects thereof on charted data. I believe all of the scorpion motors, at present, are DELTA connections and data should be treated accordingly.
BobK
I'm not sure if mine are WYE or DELTA, but what is of main interest to me is a comparison of how similar sized motors perform under similar load in similar input power conditions, regardless of their winding configuration. Assuming the data in Lucien's charts is actual measured data for voltage, amp draw and static thrust, my conclusions after comparing that data for the Scorpion 2212-26 with data produced by Dr. Kiwi for my similar-size gold-series AXI 2212/26 (kv=920) and Hacker A20-22L (kv=924) are that the motors I have produce roughly 6+% to 8+% more static thrust, respectively, with the same prop and similar power input. But that comes at a significant price increase!

On the other hand, the silver-series AXI 2212/26, reportedly just 2% less efficient than the gold-series, and I'd anticipate it would compare favorably with the Scorpion in bench testing. It's now selling in the upper $40 price point, several dollars more, than the Scorpion motor, but it comes with none of the extra mounting and prop hardware, so Scorpion comes out on top in that comparison.

I'm just trying to cut through all the high-temp hype and see what's left. I prop my motors conservatively, and they are barely warm to the touch after a flight, if that. The ability to withstand very high temperatures is not a feature I would normally need, just like I don't need lipo packs capable of 20-30C discharge rate. For me, the high-temp ability would be more of an insurance policy if I mistakenly put on the wrong prop.
Tom Frank is offline Find More Posts by Tom Frank
Last edited by Tom Frank; Mar 30, 2007 at 05:21 PM.
Reply With Quote
Old Mar 30, 2007, 02:31 PM
Registered User
BlazerB52's Avatar
Fenton,MO USA
Joined Aug 2005
1,272 Posts
Lucien,

Will you be trying to add your Scorpion Motor data to some of the Motor calculator programs floating around?

Example: motocalc,brauntas,Drivecalc and ect.

Blazer
BlazerB52 is offline Find More Posts by BlazerB52
Reply With Quote
Old Mar 30, 2007, 04:34 PM
Registered User
Near Kingston, Ontario, Canada
Joined Dec 2004
384 Posts
User Contributed Data

Quote:
Originally Posted by BlazerB52
Lucien,

Will you be trying to add your Scorpion Motor data to some of the Motor calculator programs floating around?

Example: motocalc,brauntas,Drivecalc and ect.

Blazer
If you take a look at the user contributed data on the Motocalc site you will see that I input the data for the 22mm series motors over a month ago. You might want to give the numbers a quick check over just in case I made some typos.

Dave
376782 is offline Find More Posts by 376782
Reply With Quote
Old Mar 30, 2007, 05:10 PM
Innov8tive's Avatar
Joined Jan 2007
1,741 Posts
We have our own coming soon!

BlazerB52,

We are currently working with a programmer developing a program called Scorpion Calc. It has all of the data for each of the Scorpion motors along with a prop data base and graphing routine. You simply select a motor from the drop-down list, input the voltage and prop you are using, and the program will calculate all of the parameters for the motor using that prop.

It is in the final stages of development right now, and will be available as a FREE download from our website when it is finished. If you prefer using another calculator program, all of the motor constants for the Scorpion motor will be there, and you can jot them down and input them into your favorite program.

As soon as it is available, I will make an announcement, and post a few screenshots showing what it looks like.

Lucien
Innov8tive is offline Find More Posts by Innov8tive
Site Sponsor
Reply With Quote
Old Mar 30, 2007, 05:12 PM
Registered User
BlazerB52's Avatar
Fenton,MO USA
Joined Aug 2005
1,272 Posts
Thanks Guy's
BlazerB52 is offline Find More Posts by BlazerB52
Reply With Quote
Old Mar 30, 2007, 06:27 PM
Registered User
Dr Kiwi's Avatar
Chattanooga, Tennessee, United States
Joined May 2003
27,205 Posts
Since Tom has made some comparisons between Scorpion and Hacker and Axi, perhaps it is time I contributed some of my test data.

Here are some figures for the 2208/34, 2212/26 and 2215/22 which Lucien and Georges sent for me to play with. You'll see that I often tried to use 10.5v and 14.0v to match up with Lucien's posted data.

Tom, I haven't made exhaustive analysis but, for some reason [pusher stand?], though Lucien seems to get slightly higher rpm at similar amp draws, his thrust numbers are a fraction lower than I would get at that same rpm. So the Scorpions may be a bit closer to your Hackers and Axis than you thought.

I am still concerned about heating, especially when the motors are loaded with large props. Put smaller props on 'em and, even at higher voltages and higher total watts, they do well.

Some earlier prototypes got rather hotter, rather faster - but all the data presented here are for factory packaged motors, presumably plucked straight from Lucien's shelves - what you see is what you get.

It is not easy to find exact matches (weight and Kv) for these Scorpions, but I've made some comparison with somewhat similar motors.

I found that the Scorpion ESC's set on default, seemed to limit current draw quite a bit. Apparently 15 degrees advance gets you a little more power, but I have not tried that yet. I found that my trusty Phoenix 25, set on default, did a good job, so all these tests were done with that ESC.

One somewhat mystifying result was that all of the motors I used for comparison, though lower in Kv than the Scorpion I matched them with, drew similar or somewhat higher currents (with a proportionate increase in power output). The 1100Kv 2208/34 Axi was very close to the 1206Kv Scorpion 2208/34, but really should, I would have thought, have drawn significantly less. The Komodo 2208-8 (1150Kv) also drew a bit more than the Scorpion 2208/34 and generated a little more rpm and thrust. The Torque 22T/930 drew a lot more than the 994Kv Scorpion 2212/26 - in fact I dared not try the Torque on 4s voltage (as I did the Scorpion) because it would have been way over its limit. And the Axi 2212/26 (920Kv) should have drawn less than the 987Kv Scorpion 2215/22 - but in fact it drew almost exactly the same current at the same voltages.

In general, these beautifully packaged, loaded with all the accessories, modestly-priced Scorpions perform well - the watts/rpm graphs I generated indicate how similar they are to others brands of motor of roughly the same Kv and weight.

The numbers are here for you all to peruse, compare, and comment upon.

Cheers, Phil
Dr Kiwi is offline Find More Posts by Dr Kiwi
Last edited by Dr Kiwi; Mar 30, 2007 at 06:42 PM.
Reply With Quote
Old Mar 31, 2007, 12:47 AM
Dance the skies...
Tom Frank's Avatar
United States, MA, Walpole
Joined Dec 2003
17,728 Posts
Quote:
Originally Posted by Dr Kiwi
Since Tom has made some comparisons between Scorpion and Hacker and Axi, perhaps it is time I contributed some of my test data.
...
Tom, I haven't made exhaustive analysis but, for some reason [pusher stand?], though Lucien seems to get slightly higher rpm at similar amp draws, his thrust numbers are a fraction lower than I would get at that same rpm. So the Scorpions may be a bit closer to your Hackers and Axis than you thought.
...
I found that my trusty Phoenix 25, set on default, did a good job, so all these tests were done with that ESC.

...And the Axi 2212/26 (920Kv) should have drawn less than the 987Kv Scorpion 2215/22 - but in fact it drew almost exactly the same current at the same voltages.

...The numbers are here for you all to peruse, compare, and comment upon.

Cheers, Phil
Phil, thanks for taking the time to add this additional data... it helps to have comparative info from a common source. And you are right... test variables were a factor between Lucien's charts and yours. I was having to interpolate your data to compare with Lucien's charts, and the ESC used is likely a big factor. The Scorpion 2212-26 performs within a percent or two of the AXI 2212/26 based on your data. And since I tend to prop conservatively, the temperature issue is pretty much identical to the AXI for this particular motor size up to the 10x6HD prop size I use.

Quote:
Originally Posted by Dr Kiwi
...In general, these beautifully packaged, loaded with all the accessories, modestly-priced Scorpions perform well - the watts/rpm graphs I generated indicate how similar they are to others brands of motor of roughly the same Kv and weight.
I have to agree after seeing your data... I'm in need of another motor of this size class, so will have to try one, I guess
Tom Frank is offline Find More Posts by Tom Frank
Reply With Quote
Old Mar 31, 2007, 09:28 AM
Registered User
sneu's Avatar
United States, CA, San Diego
Joined Dec 1999
7,353 Posts
Quote:
Originally Posted by fly_boy99
Higher current handling.

Pure and simple
B
Just why is that? Delta connected motors are nothing special when it comes to power handeling.

Steve Neu
sneu is offline Find More Posts by sneu
Reply With Quote
Old Mar 31, 2007, 01:34 PM
leh
Zoom - Crash - Repeat...
leh's Avatar
Decatur, IL
Joined Nov 2004
51 Posts
Nice looking motors. Might need to add one of these to the want list. On the delta vs wye, isn't power handling a function of wire guage used?
leh is offline Find More Posts by leh
Last edited by leh; Mar 31, 2007 at 02:43 PM. Reason: Thinking backwards on delta vs wye.
Reply With Quote
Old Mar 31, 2007, 05:59 PM
hot air rises...
jfinch's Avatar
Pleasant Grove, UT
Joined Jul 2005
7,715 Posts
The choice between delta and Y is made mostly based on what wire you want (or have) to wind the motor. And it can be used to fine tune a wind to a desired Kv. Say for instance you want a motor with a Kv somewhere between a 3 turn Y and 4 turn Y, you could go with a 2 turn delta and the Kv would be equivalent to a 3.46 turn Y (2 x squareroot of 3). As for power handling, as long as you fill up the stator slots you'll have max power handling. Two motors wound to the same Kv and same total mass of copper used with one terminated Y and the other delta will both have the same power handling capability and will perform similarly (for all intents and purposes, a 7 turn Y will be the same motor as a 4 turn delta).
jfinch is offline Find More Posts by jfinch
Reply With Quote
Old Apr 01, 2007, 02:25 AM
Flying motor mount master
fly_boy99's Avatar
San Jose, California, United States
Joined Oct 2004
8,745 Posts
[outrunners]
Funny all my delta terminated motors are able to dissapate more heat then any of my simliarly terminated wye motors.

I guess I can do an experiment.

-Wind one motor with 4T of 21G and terminate wye. (I'll even go down to 18G for good measure if you like)

-Wind another motor with 7T of 21G and terminate delta.

Run both motors WOT static until one burns out.

I believe the reason being is that Delta carries current on two wires(2/3 vs 1/3) at at time whereas wye only carries current on one at a time. I think I'll go consult my motor leprechauns again as I am tired.

Now compare this to inrunners. I believe this still holds true but you realize that the windings on inrunners are cooled by the outside surface of the can. So I don't know how much you can compare the two. Probably at the extremes of a motor you can find a difference.
fly_boy99 is offline Find More Posts by fly_boy99
Reply With Quote
Old Apr 01, 2007, 09:47 AM
Registered User
sneu's Avatar
United States, CA, San Diego
Joined Dec 1999
7,353 Posts
Quote:
Originally Posted by fly_boy99
[outrunners]
Funny all my delta terminated motors are able to dissapate more heat then any of my simliarly terminated wye motors.

I guess I can do an experiment.

-Wind one motor with 4T of 21G and terminate wye. (I'll even go down to 18G for good measure if you like)

-Wind another motor with 7T of 21G and terminate delta.

Run both motors WOT static until one burns out.

I believe the reason being is that Delta carries current on two wires(2/3 vs 1/3) at at time whereas wye only carries current on one at a time. I think I'll go consult my motor leprechauns again as I am tired.

Now compare this to inrunners. I believe this still holds true but you realize that the windings on inrunners are cooled by the outside surface of the can. So I don't know how much you can compare the two. Probably at the extremes of a motor you can find a difference.
You have to take into account that you need to have both motors wound for similar Kvs--when you do they will have similar power handling. Y motors have a small advantage in efficiency due to circulation current that is present in the non powered phase in the Delta connected motor( in a perfect motor the phases would be balanced and no current would flow--but the cheap hobby motors all have some)

Many cheaper motors are Delta only because they are easier to make--no Y connection to make. Our company makes both--depending on the desired Kv.

Steve
sneu is offline Find More Posts by sneu
Reply With Quote
Old Apr 01, 2007, 10:44 AM
hot air rises...
jfinch's Avatar
Pleasant Grove, UT
Joined Jul 2005
7,715 Posts
Flyboy, just be sure to wind to the same Kv and fill the stator slots with wire.

I have found though (this is totally antadotal) that on very high Kv outrunners the Y terminated motors are more stable then the deltas but I wonder if it has more to do with the ESC then the motor. But for modest Kv (900 - 1800) I've not noticed any real difference between Y and delta and will wind based on the wire I have available.
jfinch is offline Find More Posts by jfinch
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
zagi advice, questions, answers easy2fly Foamies (Kits) 61 Dec 11, 2009 04:38 AM
Question HB UG's - LiPo, Motors - Questions iparaglide Micro Helis 5 Nov 24, 2003 07:39 PM
Tiny-X Building - Tips, Questions, Answers, and Pictures Manchild Parkflyers 264 Dec 09, 2002 08:25 PM
Tiny-X Building - Tips, Questions, Answers, and Pictures Manchild Batteries and Chargers 2 Oct 31, 2002 11:28 AM
Didel Questions and Answers Gordon Johnson Scratchbuilt Indoor and Micro Models 2 Sep 03, 2002 01:31 PM