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Old Mar 20, 2007, 11:57 PM
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Axe EZ - How to Tell if Motor is Burned Out?

I have been flying a Heli-Max Axe EZ for two months . . . with great pleasure. It flew perfectly through my last flight on Sunday afternoon. But when I tried to fly it again tonight, it just spun on its axis, because the bottom rotor blades aren't turning at all; only its top rotor blades spin now.

I then took the EZ apart (i.e., I took the body off of it), because I thought a screw may have loosened on the shaft collar assembly. Alas, I discovered the screw is tight, and instead, the problem is that the front motor shaft isn't turning, at all, not even slowly. The wires to the motor all seem to be secure. So I'm afraid the motor burned out.

My last flight on Sunday was not overly-long, and I didn't notice that the battery or the motor was hot. Is there any other explanation -- other than that the motor burned out -- that could explain why the motor suddenly isn't working any more?

If the motor has burned out, how difficult will it be to replace? It looks as though some soldering may be necessary; and I haven't owned a soldering gun since I was in junior high school (more than 40 years ago)!

Thanks for your thoughts,

-Lon
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Old Mar 21, 2007, 05:21 PM
BeeZaur 480
BowerR64's Avatar
Parkville Mo.
Joined Dec 2004
5,522 Posts
Try tapping on the motor can with the handle of a screwdriver. Sometimes a brush can stick or bind up and not make a connection.

THe only way to check it is to unsolder it from the circuit and apply some voltage to it and see if it spins. If it does spin then it could be a problem with the ESC

Have you tried to google the problem? maybe there are others with this same problem and they have found a fix.
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Old Mar 21, 2007, 11:13 PM
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BoweR64,

Thanks for your suggestion. I tried it, and it worked . . . sort of. I say "sort of" because the lower rotor blades now spin, but they don't begin spinning until the throttle stick is at about the 50% point (i.e., half-way up), while the top rotor blades begin to spin when the throttle stick is at about the 10% point. As a consequence, when I throttle up enough to get the heli to lift off the ground, it spins on its axis.

The Axe EZ has three adjustments that can be made using things that look like screw heads on its 4-in-1: a throttle adjustment; a gyro gain; and a tail rotor trim. I tried adjusting the first two: the throttle adjustment and the gyro gain. But neither adjustment got the lower rotor blades to begin spinning at the same time as the upper rotor blades.

I didn't make any adjustments to the tail rotor trim, because the EZ manual says that the tail rotor trim is to be used "If the helicopter wants to drift in one direction in a stable hover...." My heli doesn't do that. It spins because the forward motor, and thus the lower blades, don't begin spinning until the throttle is half-way forward.

Do these symptoms suggest anything to you?

Thanks for your advice,

-Lon
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Old Mar 24, 2007, 06:10 PM
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Joined Mar 2007
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Mystery Solved

It turns out my motor wasn't burned out, after all. I went to my LHS -- Hobby People, where I bought the EZ in the first place -- to buy a replacement motor, and brought my heli and transmitter with me. When I described my heli's symptoms to the sales rep, he thought the symptoms were odd. So (with rotor blades removed), he had me power up and down while he made adjustments to the screw heads on the EZ's 4-in-1. After adjusting them for more than a few minutes, he found a combination of tweeks that got both motors to power up and down simultaneously. I offered to pay for his time, but he insisted it wasn't necessary! Hat's off to Hobby People and its knowledgeable sales people!
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Old Jul 10, 2007, 05:32 PM
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Alameda, CA
Joined Dec 2005
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What I would pay for is for him to tell us what he did!! Mine is exhibiting similar behavior (top spins up before bottom)...but it sill flies ok....

Edit: Well, I decided to try making my own adjustments and the one that seemed to work the best was the tail rotor adjustment...which kinda makes sense. Anyway, now my rudder trim tab is all the way to the left...anyone have any ideas on how I can center it??
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Old Jul 14, 2007, 02:08 PM
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Alameda, CA
Joined Dec 2005
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Wow...I guess there isn't much interest in the Axe EZ? Anyway, after a bit of reading, the next thing I'm going to try to get the trim centered it is to CENTER IT ON MY RADIO BEFORE PLUGGING IN THE BATTERY!! This seems too good to be true, but kinda makes sense as well. Since an X rotor's rudder action is controlled by the speed of the motors, ie THROTTLE, it stands to reason that when arming the 4in1 (ESC), it auto-senses where you're at and centers to that setting. If you start up with your trim tab all the way to the left, it'll auto-sense and make that the center, causing you to run out of left trim when you may need it for normal trimming throughout the flight. Here's the quote from RCU:

Quote:
One of the biggest problems I had when I first got mine was the rudder trim. What I have found through trial and error is that if you turn on the Tx, center the rudder trim, then plug your battery in, but don't move the model at all until the green light stays steady, you should be ok. pull the two plugs out the the nose of the heli, place it down on it's skids, hold the two plugs, and push them together. if it takes too much force to get them to click(where the model will be jolted) then don't do that until the 4 n 1 arms. If you just let it sit there, don't touch anything, the gyro will set properly. on liftoff, note if the thing is wanting to spin circles. If it wants to stay fairly straight, then trim in the rudder on the Tx. If it is still bad, then center the trim pot on the 4 n 1. If you have the trim pot turned completely to the left(CCW) count the number of turns to the right, then back it off halfway. Do this when the thing is not plugged in. recenter your trim on the Tx, and plug it in. the adjustment to the trim pot should only be very very slight. I turned mine a 1/16 of a turn at a time. If you do all this, and it still gives you problems, then you might have a weak motor due to heat. I'd run it with the front canopy off while you are adjusting things, to make it easier to reach the battery, and the 4n1. I don't see any reason why yours should be impossible to adjust. take your time,a dn adjust ONE thing at a time. see how that affects it, and move on from there. If you make an adjustment that doesn't affect the rudder then put back that adjustment, and move on. the more things you adjust at one time without testing, the more trouble you will have.

You should be able to get this thing trimmed 100%.
Here's the link: http://www.rcuniverse.com/forum/m_40...tm.htm#4027412

I read this about a 4in1 on a Blade CX, but they all probably work similarly. I've created an "official" thread for the Axe EZ and it's a resounding failure. You can check it out here:

http://www.rcgroups.com/forums/showthread.php?t=712381

I bet if I post up pics it'll start getting some hits, tho...
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Old Dec 28, 2007, 02:30 AM
Old Noob
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Dallas, TX
Joined Dec 2007
5 Posts
Hey BigDano, I have an Axe EZ, so what you're saying with the trim tabs, long-story-short.... is to always center them on the TX before powering on and pluggin in the battery on the heli?
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