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Old Jul 05, 2003, 10:32 PM
Want more time to fly!
videographer's Avatar
Madison, WI
Joined Jan 2000
179 Posts
Smarten me up about brushless motors, please...

At today's MARCS (Madison, WI) E-fly, I got my first sustained exposure to the miracle of brushless motors. So much so that I am he!!-bent to install one in my X250 and another in an Aspire motorglider I am rehabbing.

Problem is...none of the manufacturers seem to do a very good job defining which of their models would adequately supplant a, say, Speed400 geared 2.33:1 in a plane that looks a lot like an X250. And which prop?

Same Q for the Aspire...I really want to fly this thing, but the motor that came in it is just screwed up all over the place.

Are the new external rotor motors that are getting such a good review on Ezone worth considering?

PS: Any upper Midwesterners that missed the Fly today really missed out. About 50 pilots, and all kinds of planes - sunny, manageable winds.

Thanks -
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Old Jul 05, 2003, 11:11 PM
Registered User
vintage1's Avatar
East Anglia, UK
Joined Sep 2002
29,705 Posts
Just my 2c worth.

No spcifics on your actual planes, but as with everything there are horses for courses and you get what you pay for.

At teh budget end, you can get ourunnres like the PJS and AXI's and some of teh highe wnd megas that run without gearboxes (or indeed teh new MPJET brushlesss that come WIH gearboxes ONLY) and these are insexpnsive ways to go BUT tend to suit particulra planes - for example teh AXI's are arguably better at faster flying models, as are teh MPjets, whereas the PJS outrrunners look better for slowfly and small 3D planes.

If you want the tops on performance, you get it from mating a very high revving performance brushless to the right gearbox, and then you get total vertical performance. BUT it costs money. Hackers etc are in there.

Other moptirs - e.g. maxcim for really big models - and astros and razors for really small ones - have their own niches.

Finally, trawl the e-zone for all teh problems - bent or broken shafts, thrown magnets, weird effects on certain loadings/cell counts and ESC combos, and also check for bad stories on after sales service.

I can't think of a single motor or manufacturer that hasn't broken in some unexpected way from my trawls here...but some are much better at fixing problems than others. Let this afect your decisions as well.

Hackers, especially when mated to theor own gearboxes and controllers, seem to be a pricey, but high performance and reliable combination. BUT they aren't US based motors, and lots of folks are being patriotic these days...so look at Aveox, Razor and Astro as 'home grown' alternatives that are also very good. And have allegedly good service records.

The bulk of the rest are from Germany and the Czech republic, which is a long way to get service from if the importer is just that...and importer. Needless to say, German design and Czech labour rates make for excellent value for money

Do your research...and make up youir own mind.
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Old Jul 06, 2003, 12:18 AM
Profiled Interfractionalist
William A's Avatar
Tacoma,WA USA
Joined Jun 2001
4,039 Posts
I've have an Aspire w/ a Mega 22/30/3, DD 9X5 Cam folder, 6 cell 1500, AUW 48.5oz.

2-3 climbs to 1000'-1200'.
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Old Jul 06, 2003, 01:48 AM
high-speed freak
opualuan's Avatar
San Jose, CA
Joined Sep 2001
3,863 Posts
your best bet is to go ooh and ah at the setups of people with similar or the same planes, then copy their setup like a maniac. or, get motocalc, a super whattmeter, an optical tachometer, and start simulating your setups. great way to start learning about the interaction of all the variables in an electric motor system.

you first need to define what performance you want. do you want more duration, more power, insane power, etc? do you want to use the same packs you already use?

if you want to copy me (go right ahead!) , and want an absolutely sick setup for the x250 that won't bankrupt you, this setup is insane:

x250
hs-81mg servos (more torque, no gear stripping)
10x1700aup nimh pack (zigzag ladder pack, if that makes sense)
mega 16/15/3
Model Motor 2:1 gearbox (lube the heck out of it, noisy bugger)
9x4.5 APC E-prop
S400 rail mount (azarr has them)

lengthen landing gear by an inch
get slightly beefier and larger wheels, dave browns are nice
put some air inlets on the side to flow some air into the plane

AUW is a bit high, 32-33oz, but duration is good and performance is incredible. any more power and I think the plane would explode midair. 2-foot rollout, instant vertical climbout, ~60mph level flight max speed, snap rolls are unbelievable. pulls 27A on the ground.

now, if you want to talk about sedate setups to give you similar power to your speed 480, but not burn out brushes and give you more duration, you're asking the wrong guy

if you want to spend a bit more, a 3s3p pack of etec 1200's should give you twice the duration, similar power, and will make the x250 weigh about 4.5oz LESS, more like 28oz... that's my next step...
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Old Jul 06, 2003, 05:26 AM
It's a Great Day to Fly
LenBFP's Avatar
Melbourne Beach, Florida
Joined Jan 2002
3,869 Posts
For the X250 I would try a Mega 16/15/7 with an APC 8 x 6E direct drive and an 8 cell pack of 1100mah HE cells or High Output cells.
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Last edited by LenBFP; Jul 06, 2003 at 05:29 AM.
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Old Jul 07, 2003, 10:51 AM
The One....
genovia's Avatar
San Jose, Ca.
Joined Jan 2002
5,813 Posts
**For the X250 I would try a Mega 16/15/7 with an APC 8 x 6E direct drive and an 8 cell pack of 1100mah HE cells or High Output cells.***

Marginal power, you can rock 8x6 using 5T, 25amps.

*****x250
hs-81mg servos (more torque, no gear stripping)
10x1700aup nimh pack (zigzag ladder pack, if that makes sense)
mega 16/15/3
Model Motor 2:1 gearbox (lube the heck out of it, noisy bugger)
9x4.5 APC E-prop
S400 rail mount (azarr has them)

***


This setup is going for duration, I question the speed

***AUW is a bit high, 32-33oz, but duration is good and performance is incredible. any more power and I think the plane would explode midair. ***

Really????? I should try this setup on my Pica Zero, my Zero rocks w/ 9Kans, 10x7APC
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Old Jul 07, 2003, 11:15 AM
Registered User
Marlborough, Massachussetts, United States
Joined May 2002
1,878 Posts
Astroflight 020 brushless is a nice replacement for a speed 400 or 480, available in direct drive and with a gearbox. Price may be higher then others, but the service is great, as is the performance. Power and duration are both better then equivalent can motors.

I'm running an old 020 sensored brushless motor with a 4.4:1 gearbox in my T-48 (48" WS high wing aileron trainer). Turns a 13x8 prop (11x8 might be better). Weighs 32 ounces with 8 cell Kan 1050 battery. Climbs fast on full throttle, loops and rolls on just over half throttle are easy. So far my runtime averages about 10 minutes, but I expect that to improve as my batteries are still fairly new.
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Old Jul 07, 2003, 11:24 AM
The One....
genovia's Avatar
San Jose, Ca.
Joined Jan 2002
5,813 Posts
*********Astroflight 020 brushless is a nice replacement for a speed 400 or 480, available in direct drive and with a gearbox. *********

I've been flying with Mega motors, mega vs. astro..... Should of went w/ Astro
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Old Jul 07, 2003, 03:01 PM
Our Daddy and Heli Junkie
Fred Bronk's Avatar
In Heli Wonderland
Joined Aug 1999
22,803 Posts
Might get more info in Power Systems, but not bad here so far!
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