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Old Jul 21, 2011, 04:52 PM
Specializing in RC since 1972
Temple, GA, USA
Joined Jun 2009
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Originally Posted by dmoores View Post
Built mine last night and as soon as I throttled her up it ran about 30 seconds and the motor started smoking. I was going to replace it anyway, but the motor must be crap!
Sadly, I saw a friend destroy his CF motor in one flight by (I think) mounting the stock prop backwards. It is less slippery that way and the motor runs slower. I know the sound it should make and it was so much lower I asked him (just before it burned up) is that full throttle (yes). Any time the motor is running slower at full throttle, you are pulling more amps.

Others should note that anything that makes it run slower can burn it out. To be correct, the prop goes on "backwards" and then the little prop adapter ring goes on the outside (glued into the prop) or you have it backwards.

An improperly adapted (shaft slop) or badly out of balance prop can do it too.

Don't know if this was your problem though.

I recommend getting a 3mm collet type prop adapter to help with some of this, and make sure your prop is on correctly. There is a good chance you have it wrong unless you have already learned the hard way.
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Old Jul 21, 2011, 04:53 PM
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struggleforlife's Avatar
The Netherlands, LI, Gennep
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I flew my CF a bunch of times with the prop backwards. No problem. Just flies a little slower.
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Old Jul 21, 2011, 04:58 PM
Specializing in RC since 1972
Temple, GA, USA
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Originally Posted by struggleforlife View Post
I flew my CF a bunch of times with the prop backwards. No problem. Just flies a little slower.
At continuous WOT for several minutes? That must not be it then. His motor was definitely slower though.
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Old Jul 21, 2011, 05:54 PM
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Asheville,NC
Joined Jun 2002
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Shuttle cockpit

this is a bit off topic but have a look

........te

http://360vr.com/2011/06/22-discover...236/index.html
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Old Jul 21, 2011, 06:48 PM
RC Airplane (Recently Crashed)
mutha's Avatar
Australia, VIC, Melbourne
Joined Jan 2011
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Originally Posted by Tom Eutsler View Post
this is a bit off topic but have a look

........te

http://360vr.com/2011/06/22-discover...236/index.html
Mmmm comfy chairs ...
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Old Jul 21, 2011, 07:19 PM
Argue for your limitations
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Lincoln, CA
Joined Oct 2006
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Quote:
Originally Posted by dmoores View Post
Built mine last night and as soon as I throttled her up it ran about 30 seconds and the motor started smoking. I was going to replace it anyway, but the motor must be crap!
What prop and battery were you using?
AJ
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Old Jul 21, 2011, 07:29 PM
Argue for your limitations
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Lincoln, CA
Joined Oct 2006
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Quote:
Originally Posted by theothercliff View Post
Sadly, I saw a friend
1. destroy his CF motor in one flight by (I think) mounting the stock prop backwards. It is less slippery that way and the motor runs slower. I know the sound it should make and it was so much lower I asked him (just before it burned up) is that full throttle (yes).

2.Any time the motor is running slower at full throttle, you are pulling more amps.

Others should note that anything that makes it run slower can burn it out. To be correct, the prop goes on "backwards" and then the little prop adapter ring goes on the outside (glued into the prop) or you have it backwards.

3. An improperly adapted (shaft slop) or badly out of balance prop can do it too.

4. Don't know if this was your problem though.

I recommend getting a 3mm collet type prop adapter to help with some of this, and make sure your prop is on correctly.

5. There is a good chance you have it wrong unless you have already learned the hard way.
1. A prop put on backwards will simply not run as efficiently. Actually, the motor will draw LESS amps when put on backwards - therefore, cooler. Try it.
2. Not True. See #1.
3. It would have to be terribly out of balance to cause a heat problem. It would have to be so bad that a person would have to be nuts to fly it.
4. It probably was not the problem.
5. Unable to determine with the small amount of information provided.
More information is needed to uncover the answer. Since the latest motors are known to be crap, it could be something wrong with the motor - like loose magnets rubbing the rotor, etc.....
AJ
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Old Jul 21, 2011, 07:37 PM
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Canton, Michigan USA
Joined Jul 2007
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Originally Posted by JLT_GTI View Post
One advanced question on this plane...

-Aileron differential

Anyone has it? does it work in this kind of plane (with dihedral curved wingtips) and how should it be setup..

Im asking this at this stage after more than a year with it cause the other day i found a rather embarrasing fact.. i wasnt using aileron differential when i tought i was..

When i first setup ailerons in this plane due to my ignorance i used endpoints to set that differential..but that just sets up the limit for movement and not gives anydifferential unless using full stick (found this on my SIG Ninja while at the field after having a bit of adverse yaw with it in some conditions and wondering what it was when i found out my big embarrasing mistake)..

While doing some research on aileron differential it seems standard to asign more throw to the top aileron than the bottom one.. but also steped on some guide wich says that if the aileron is hinged at the top rather than the midle ..aileron differential should be inverted (more throw downward than upwards)... and the CF has the ailerons hinged at the top..

So bilded here... anyone can throw some light (we can allways do experimenting on the subjetc)
I run 50% aileron differential on my Skysurfer and will do it on this plane when it arrives later this month. I did it mechanically by simply moving the center point of the servo arms forward. It helps wil aileron rolls without using rudder.

Bill
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Old Jul 21, 2011, 07:54 PM
RC Airplane (Recently Crashed)
mutha's Avatar
Australia, VIC, Melbourne
Joined Jan 2011
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Quote:
Originally Posted by ajbaker View Post
Since the latest motors are known to be crap,
AJ
I didn't know that AJ - I must have missed this in the thread.

Are all of our new AXN purchasers experiencing issues with the motor?? feedback appreciated because I have been recommending them to many ...

(I have 2 spares sitting in the drawer - purchased some 4-6 months back )
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Old Jul 21, 2011, 10:51 PM
Argue for your limitations
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Lincoln, CA
Joined Oct 2006
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Originally Posted by mutha View Post
I didn't know that AJ - I must have missed this in the thread.

Are all of our new AXN purchasers experiencing issues with the motor?? feedback appreciated because I have been recommending them to many ...

(I have 2 spares sitting in the drawer - purchased some 4-6 months back )
Mainly, it is still the issue with the magnets coming loose. Although, the very latest ARF's have been very quiet about servos.
AJ
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Old Jul 21, 2011, 10:52 PM
Argue for your limitations
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Lincoln, CA
Joined Oct 2006
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Quote:
Originally Posted by Prof100 View Post
I run 50% aileron differential on my Skysurfer and will do it on this plane when it arrives later this month. I did it mechanically by simply moving the center point of the servo arms forward. It helps wil aileron rolls without using rudder.

Bill
When you use full flaps, do you mix in some down elevator with the flaps? I did - 25% and it makes the descent much more manageable for me.
AJ
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Old Jul 21, 2011, 11:06 PM
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Canton, Michigan USA
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Originally Posted by ajbaker View Post
When you use full flaps, do you mix in some down elevator with the flaps? I did - 25% and it makes the descent much more manageable for me.
AJ
Yes, I added down elevator with the flaps. I got tired of the ballooning.
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Old Jul 22, 2011, 03:55 AM
Specializing in RC since 1972
Temple, GA, USA
Joined Jun 2009
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Quote:
Originally Posted by ajbaker View Post
Quote:
Originally Posted by theothercliff View Post
1. destroy his CF motor in one flight by (I think) mounting the stock prop backwards. It is less slippery that way and the motor runs slower. I know the sound it should make and it was so much lower I asked him (just before it burned up) is that full throttle (yes).

2.Any time the motor is running slower at full throttle, you are pulling more amps.

Others should note that anything that makes it run slower can burn it out. To be correct, the prop goes on "backwards" and then the little prop adapter ring goes on the outside (glued into the prop) or you have it backwards.

3. An improperly adapted (shaft slop) or badly out of balance prop can do it too.
1. A prop put on backwards will simply not run as efficiently. Actually, the motor will draw LESS amps when put on backwards - therefore, cooler. Try it.
2. Not True. See #1.
3. It would have to be terribly out of balance to cause a heat problem. It would have to be so bad that a person would have to be nuts to fly it.
You're wrong. My original statement is correct. For a given throttle setting, if the motor is running slower it is pulling more amps. The simple case is when you have a larger prop. Another case is when you have any prop that simply has more drag. Do you think that a motor can tell the difference between the drag of a large slippery prop and a small draggy prop other than a slight flywheel effect? If so then you are saying that the difference in flywheel effect is the cause. Certainly you admit that a larger prop draws more amps? Why not a smaller one that has more drag?

I believe that a prop running backwards is not as slippery as one running forwards and makes the motor run slower, but admit that there may be an effect as strange as "windmilling prop causes more drag than stopped prop". Do you have a tachometer? I know you have a watt meter to measure amps.

I did say "badly out of balance", so why are you picking at this statement? Yes, a badly out of balance prop can reduce and in worst cases drastically reduce the RPM and thus increase the amps. I have seen the prop spacer come off in flight and the prop become badly out of balance. I have seen people use a prop spacer that was loose enough for noticeable shaft slop although that would not be enough to reduce the RPM by much.

Please test this (change in RPM of a forwards vs. backwards prop, with both at full throttle and change in amps with any propping that causes lower RPM at full throttle) and be prepared to post a video as I will be if you still think I am wrong and you are right.

Cliff
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Old Jul 22, 2011, 05:12 AM
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The Netherlands, LI, Gennep
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lookie lookie
http://www.hobbyking.com/hobbyking/s...dProduct=18198
(I ordered one just in case).
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Old Jul 22, 2011, 06:25 AM
RC Airplane (Recently Crashed)
mutha's Avatar
Australia, VIC, Melbourne
Joined Jan 2011
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Originally Posted by struggleforlife View Post
lookie lookie
http://www.hobbyking.com/hobbyking/s...dProduct=18198
(I ordered one just in case).
or ....

http://www.lowpricerc.com/product_in...oducts_id=1052


But HK is cheaper than LPRC for a change!! LPRC have had them for ages though.
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