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Old Jan 25, 2013, 12:17 AM
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United States, CA, Santa Monica
Joined Feb 2006
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UM 4site low on power???

Just got a used UM 4site off ebay and it seems low on power. It can't quite maintain a hover, just stalls out. The plane is all stock and i'm using a dx6i transmitter. I'm wondering if its possibly my batteries? They are no name chinese knockoffs i've had for over a year with a buncha charges used with my p51. If not the batteries could it be the motor, do these tend to wear out?
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Old Jan 25, 2013, 12:53 AM
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Digital Don's Avatar
United States, IL, Manteno
Joined Dec 2006
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Motor and batteries are the most likely suspects. Try a battery that you know is good and you'll be able to narrow it down.

Don
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Old Jan 25, 2013, 01:54 AM
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United States, CA, Santa Monica
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Same result with all the batteries I tried. Anyone know where I can buy a 4site motor? Everywhere says backordered and it looks like eflite doesn't make the 4site micro anymore?
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Old Jan 25, 2013, 03:03 AM
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Digital Don's Avatar
United States, IL, Manteno
Joined Dec 2006
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Search for EFL9052.

I found several places that show them in stock. However, you might want to call before actually placing any order if they're becoming scarce.

Web site stock information is not always current.

Don
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Old Jan 25, 2013, 07:31 AM
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Southlake, TX
Joined Jan 2008
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To hover, its going to need good batteries like hyperions or thunderpower. Fresh (1 - 4 week old) nanotech 160's will work, but if they are older than 1 month, they may not have the power to hover, anymore.

I swapped motors in my Extra 300 4 times before realizing it was the batteries losing power.
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Old Jan 25, 2013, 09:40 AM
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Oxford, Michigan, United States
Joined Aug 1999
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From here: http://www.rcgroups.com/forums/showthread.php?t=1788535

"There are basically 2 different HH UM micro 8.4mm motors:

The translucent white belled SU-26/Champ motor which is the lower power and the Black belled Polecat/Mosquito/T-28/Mustang/4 site/XP/E300/Corsair/Spitfire motor which is the higher power.

ALL 8.4mm Airplane motors use the same 9 tooth pinion & Spur gear/1.5mm shaft (Except for the Mosquito, which has a reverse rotation shaft on one side), but there are few different gearboxes depending on how they mount in the plane.

There are 3 different 8.4mm wire lengths, so far: Polecat/Sukhoi/Champ is the shortest, Mustang/T-28 is mid range and 4 site/Extra 300 is the longest. To put an XP motor in a Mustang or 4 site, you would have to extend the wires, though the motor is basically the same."
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Old Jan 25, 2013, 11:00 AM
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Vince Herman's Avatar
United States, OH, Strongsville
Joined Nov 2000
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If you want to replace the motor, why not go to a 2s brushless setup?
Watch this video
4-Site BL upgrade by Scharlach (0 min 30 sec)

See his offer here
http://www.rcgroups.com/forums/showthread.php?t=1141842

I am not associated with Dan other than as a happy customer. I and the rest of our flying crew have upgraded many planes to the 2s brushless power Dan offers.
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Old Jan 25, 2013, 02:05 PM
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Oxford, Michigan, United States
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What's the weight gain. One of the things I like about 1S geared is the low wing loading.
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Old Jan 25, 2013, 03:26 PM
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United States, OH, Strongsville
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Hi Pete,
Oh, there is definitely some weight gain. I'll try to measure the components and see.
But the performance change in a hover was monstrous.
1s 160mAh battery, low cycle count, with a low hours stock 4-site battery resulted in mild climbout from a hover on a fresh charge, almost no climbout half way in to a flight, and no hover ability after that.
2s brushless conversion gives great climbout right up to LVC. Maybe the last bit of hovering before LVC had only mild climbout.
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Old Jan 25, 2013, 09:59 PM
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United States, CA, Santa Monica
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Vince I only got into RC again recently and have only been playing with the 1s planes. I love having a handful of cheap batteries charging 4 at a time in my eflight charger. Can you give me any info/point me in a direction on 2s charging? I know chargers with these new lipos can get pretty nuts. The 1s stuff is just so easy to deal with right now I dont know if i want to mess with fancier batteries and chargers.
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Old Jan 25, 2013, 11:12 PM
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You can always use two of the 1S batteries in a series wire harness and then charge them separately.
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Old Feb 06, 2013, 09:31 PM
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Pretty disappointed. I spent $25 on 3 hyperion 160mah batteries thinking maybe that was the cause of not enough power to hover. I held the plane in my hand and gave it full throttle and it would not climb out of my hand, only sink towards the floor. So i figured the motor was used up and i spent $15 on a new motor. Tried again, same results. Apparently the 4site is just not as powerful as I thought and can't do a vertical climb. Too bad it took me $40 to figure that out.
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Old Feb 06, 2013, 09:46 PM
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Mine will and it's over 2 years old on the original motor.
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Old Feb 06, 2013, 09:58 PM
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United States, WA, Goldendale
Joined Nov 2011
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Quote:
Originally Posted by JonnyJ View Post
Pretty disappointed. I spent $25 on 3 hyperion 160mah batteries thinking maybe that was the cause of not enough power to hover. I held the plane in my hand and gave it full throttle and it would not climb out of my hand, only sink towards the floor. So i figured the motor was used up and i spent $15 on a new motor. Tried again, same results. Apparently the 4site is just not as powerful as I thought and can't do a vertical climb. Too bad it took me $40 to figure that out.
Are you sure your props not on backwards???
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Old Feb 06, 2013, 10:09 PM
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United States, CA, Santa Monica
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Well if anyone has any other ideas i'm open to them. But between motor and batteries I have no idea what else it could be. Prop is stock and seems to spin easily so no binding.
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