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Old Sep 03, 2012, 10:02 AM
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United States, CA, Modesto
Joined Aug 2012
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Quote:
Originally Posted by Frank183 View Post
Errm ... could you maybe explain that more in detail ?

Ahem ...

Thanks a lot !
What slothy89 says.
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Old Sep 03, 2012, 12:23 PM
Registered User
Malaysia, Federal Territory of Kuala Lumpur, Kuala Lumpur
Joined Jul 2012
90 Posts
Hi guys;

Just wanted to share my 2 1/2 cent journal of the day, thought it might be usefull to certain extent..

well, today my f45 involves in a few hard crashes causing it to vibrate a bit. Then, I noticed that the red disc on top of the flybar is out of alignment so I tightened it but still could'nt get the right alignment. Actually, the disc is obviously inclining and I suspected that this is the reason behind the vibration.

So I removed the disc and tightened the screw and as expected, the vibration gone..
The bird flies as new again... I seriously think that we don't need a disc on top of the rotorhead only for aesthetic reason.. besides, it may introduce more friction to the flight...
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Old Sep 03, 2012, 01:12 PM
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Joined Aug 2012
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Quote:
Originally Posted by slothy89 View Post
There is a link between the swashplate dogbone, and the flybar dogbone called the "Mixer Arm". This should be oriented so that the swash connects to the shorter end, and the flybar to the longer end.

This orientation is what gives the heli its stability without dampening the movement too much. If you were to reverse both mixer arms, the heli would be extremely docile and barely have any movement authority (as I found out on my solo pro accidentally) and it also will put your trims way off.

The attached photo shows the correct orientation of these links.
Thank you so much !!!!!

However ... I checked and found my setup just like in your picture. It it anyhow possible to have something mixed up clock/counter clockwise ?

What I can see however is that this one of the 3 arms down at the swash plate that is moveable is moving down deeper than on my other F45. It also looks as if the flybar tilts up and down more. Could it be that down at the swash plate could be something wrong ?

BTW, in your picture I can't see the loops around the long dog bones. Is that intentional ?

Thanks a lot
Frank
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Old Sep 03, 2012, 01:36 PM
when is the wind stopping??
markkona's Avatar
Malta, Marsaskala
Joined Apr 2011
1,630 Posts
Quote:
Originally Posted by juang1430 View Post
Hi guys;

Just wanted to share my 2 1/2 cent journal of the day, thought it might be usefull to certain extent..

well, today my f45 involves in a few hard crashes causing it to vibrate a bit. Then, I noticed that the red disc on top of the flybar is out of alignment so I tightened it but still could'nt get the right alignment. Actually, the disc is obviously inclining and I suspected that this is the reason behind the vibration.

So I removed the disc and tightened the screw and as expected, the vibration gone..
The bird flies as new again... I seriously think that we don't need a disc on top of the rotorhead only for aesthetic reason.. besides, it may introduce more friction to the flight...

That Disc can hardly make any effect on the heli's flight but anyways if you want to know the real reason behind it and many other big heli's for that matter is so that you can stop the blades turning after landing simply by putting your finger on it without causing you any harm!! But if you like it without the disc no one is stopping you
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Old Sep 03, 2012, 03:16 PM
Brent 黑雁
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Canada, AB, Ponoka
Joined Jan 2012
1,765 Posts
Quote:
Originally Posted by markkona View Post
That Disc can hardly make any effect on the heli's flight but anyways if you want to know the real reason behind it and many other big heli's for that matter is so that you can stop the blades turning after landing simply by putting your finger on it without causing you any harm!! But if you like it without the disc no one is stopping you
It's also used when you are doing inverted flight and the blades would hit the ground, this stops complete contact. A good example is a Bert Kammer video titled how low can you go. He constantly touches the button on the pavement upside down.
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Old Sep 03, 2012, 03:31 PM
Finding Creative Ways To Crash
RCCrashTestDummy's Avatar
Joined Jun 2012
448 Posts
Quote:
Originally Posted by Whizgig View Post
And my opinion for you is to deal with Win at Aliexpress and buy the MC only F-45 and not the F-645 as the MC models are alot mor reliable that the US ver wich is the MJX-F645
Whizgig or any one else who may know; who is Win and where on Aliexpress can I find the "MC only F-45"

I ask because I just mangled-up my F45 the other day, and need a replacement/back-up. I have parts ordered, but still want a second bird so I can stay in the air.

I was suffering from a severe case of the dumb-ass, grabbed the wrong batt, (already had two flights on it) set my watch thinking I had a full charge, then watched helplessly as it plummeted to its death on the rocky ground below. It was waaaaay the hell up there when the engine just quit. All of which was caught on camera.. I'll edit the vid so you guys can enjoy the carnage...hahahahaa!

If only I had listened to you guys and bought a simple $3 low voltage buzzer/alarm my bird would still be in the air. Hell, I think S89 even gave me a link, and I still didn't heed the warning.... Needless to say, one is on it's way.

-Pat
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Old Sep 03, 2012, 03:42 PM
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United States, CA, Modesto
Joined Aug 2012
828 Posts
Juang1430 is correct. Everything on that shaft needs to be in as close to perfect balance as possible or you will get a vibration. To test, simply loosen the screw holding the red disk and cock it to one side. When you spool up the heli it will start to dance on the ground. I too know this from first hand. True it does not effect flight too much, but you can see the vibration in the tail in the air.
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Old Sep 03, 2012, 05:06 PM
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Malaysia, Federal Territory of Kuala Lumpur, Kuala Lumpur
Joined Jul 2012
90 Posts
Quote:
Originally Posted by arrowshooter View Post
Juang1430 is correct. Everything on that shaft needs to be in as close to perfect balance as possible or you will get a vibration. To test, simply loosen the screw holding the red disk and cock it to one side. When you spool up the heli it will start to dance on the ground. I too know this from first hand. True it does not effect flight too much, but you can see the vibration in the tail in the air.
Thanks for the enlightment arrow... Well, you can't stop a wild dog from stealing a lion's catch, can you? lol...
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Old Sep 03, 2012, 05:39 PM
John
Australia, QLD, Brisbane
Joined Aug 2012
542 Posts
RCCrashtest -
This link (which purports to be from MJX itself) offers F45's - Chinese box! - through Ali Express.
http://www.aliexpress.com/product-fm...olesalers.html
Catch is you've got to buy 2. But free EMS, camera included, and if you had a mate wanting to buy 'the best' 450gram AUW FP?
Sorry to hear about the disaster.

PS: just now received another f645 direct from Banggood (got an unresolved dispute with aliEx atm, been running a while). Well packed, reasonably fast delivery, and hovers fine out of the box: but I share Slothy's reservations about anything other than '1 of X' from BG.
But BG does do PayPal.
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Last edited by OldOz; Sep 03, 2012 at 06:13 PM.
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Old Sep 03, 2012, 08:27 PM
Eugene
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Australia, VIC, Delacombe
Joined Oct 2006
918 Posts
Quote:
Originally Posted by RCCrashTestDummy View Post
Whizgig or any one else who may know; who is Win and where on Aliexpress can I find the "MC only F-45"

I ask because I just mangled-up my F45 the other day, and need a replacement/back-up. I have parts ordered, but still want a second bird so I can stay in the air.

I was suffering from a severe case of the dumb-ass, grabbed the wrong batt, (already had two flights on it) set my watch thinking I had a full charge, then watched helplessly as it plummeted to its death on the rocky ground below. It was waaaaay the hell up there when the engine just quit. All of which was caught on camera.. I'll edit the vid so you guys can enjoy the carnage...hahahahaa!

If only I had listened to you guys and bought a simple $3 low voltage buzzer/alarm my bird would still be in the air. Hell, I think S89 even gave me a link, and I still didn't heed the warning.... Needless to say, one is on it's way.

-Pat
Here ya go Wayne's shop F45
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Old Sep 03, 2012, 09:50 PM
Hangin' for a strong SW
slothy89's Avatar
Australia, VIC, Sebastopol
Joined Apr 2012
770 Posts
Quote:
Originally Posted by Frank183 View Post
What I can see however is that this one of the 3 arms down at the swash plate that is moveable is moving down deeper than on my other F45. It also looks as if the flybar tilts up and down more. Could it be that down at the swash plate could be something wrong ?
Not quite sure what you are talking about? Perhaps a picture may help?

Quote:
Originally Posted by Frank183 View Post
BTW, in your picture I can't see the loops around the long dog bones. Is that intentional ?
That would just be the poor quality of the photo

I have highlighted the loop below:
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Old Sep 04, 2012, 12:21 AM
Fly Fast, Fly Hard, Fly Fun
rexless's Avatar
Canada, BC
Joined Apr 2012
1,498 Posts
So today I take the F45 out for a flight and about 2 minutes in she starts acting kids sluggish. I bring her back, land and suddenly there is not enough power to lift off again.

I've since replaced the motor with my spare. I took apart the dead motor and one brush is toasted. If I were to guess I'd say I've had 40-50 flights. I guess that's pretty reasonable considering the hot summer weather we've had.

:-)
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Old Sep 04, 2012, 12:53 AM
Hangin' for a strong SW
slothy89's Avatar
Australia, VIC, Sebastopol
Joined Apr 2012
770 Posts
Quote:
Originally Posted by rexless View Post
So today I take the F45 out for a flight and about 2 minutes in she starts acting kids sluggish. I bring her back, land and suddenly there is not enough power to lift off again.

I've since replaced the motor with my spare. I took apart the dead motor and one brush is toasted. If I were to guess I'd say I've had 40-50 flights. I guess that's pretty reasonable considering the hot summer weather we've had.

:-)
Someone a couple pages back did a stress test on a stock motor, and determined it was around 8 hours running time before a failure. I just calculated that at 12min/flight, 50 flights is about 10hrs running time. So really that's about to be expected. Brushed motors just can't last all that long, especially for what we pay for them.

I mean, you can see Brushless motors on sale anywhere between $15 and $200, and they're all around the same size/kV rating. I'm sure there'd be some $50 Brushed motor out there that would last 5x longer, but it's not really worth it.
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Old Sep 04, 2012, 04:56 AM
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Quote:
Originally Posted by slothy89 View Post
Not quite sure what you are talking about? Perhaps a picture may help?

That would just be the poor quality of the photo
Umm ... it's rather the poor quality of my eyes ....

I don't have it here, so I'm misusing your picture. There are 3 arms on the swash, one is moveable. Not sure if I put the blue box around the correct one.
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Old Sep 04, 2012, 05:17 AM
Hangin' for a strong SW
slothy89's Avatar
Australia, VIC, Sebastopol
Joined Apr 2012
770 Posts
Quote:
Originally Posted by Frank183 View Post
Umm ... it's rather the poor quality of my eyes ....

I don't have it here, so I'm misusing your picture. There are 3 arms on the swash, one is moveable. Not sure if I put the blue box around the correct one.
Ah yes I get a what you're saying a little better now. The part you highlighted is the Swash Anti-Rotation Pin. This stops the bottom half of the swash from wanting to spin around the main shaft with the rest of the head.

If you think one heli's swash has more movement, try swapping the swashes over? see if the restricted movement moves with the swash, or if it stays with the same Heli. That will confirm if the swash has a problem, or maybe your servos do.
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