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Old Nov 16, 2012, 08:42 PM
Hangin' for a strong SW
slothy89's Avatar
Australia, VIC, Sebastopol
Joined Apr 2012
769 Posts
Yea my F45 has a bit of a bob tendency, but I never bothered to try fix it nor find the source of it, as it flies just fine otherwise.

I'm just recalling what other people have experienced. Maybe not so much a balance issue, but shimming the blades too little or too much can exasperate the bobbing.
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Old Nov 16, 2012, 08:52 PM
John
Australia, QLD, Brisbane
Joined Aug 2012
542 Posts
Yep, remember the shimming comments now. Maybe 166Valerio could find an answer there to what seems (in his case) a relatively minor problem.
Like you, figured it was just part of the F45 'thing', and learned to live with it. But keen on an solution, if anyone ever finds one. Or there is one at all.
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Last edited by OldOz; Nov 16, 2012 at 09:02 PM.
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Old Nov 16, 2012, 08:59 PM
Sloooooow Flyer
S4ntai's Avatar
Australia, NSW, Glenfield
Joined Aug 2012
464 Posts
Quote:
Originally Posted by OldOz View Post
FWIW, I've always removed the horizontal fin (and the two support struts) from my F45s. Found no difference in handling whatsoever, except that shifting the CoG forward does help with wind authority. And the winds are a fair bit of a problem up here in Qld near the sea, too.
Similarly have also found about 20g of BluTack - or hot glue - right in the canopy nose helps as well. As does upgrading to BL, with a bigger battery set forward of course.
My two cents!
Thx everyone. So basically getting more weight on the front. Thx again
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Old Nov 16, 2012, 09:10 PM
John
Australia, QLD, Brisbane
Joined Aug 2012
542 Posts
S4ntai -
There's a second solution to our wind problem!
I've also found that the wind just after dawn is usually at a minimum (or nil) for the day. I agree that it's the answer of last resort, but dragging myself down to the LHS football field at around 5am gives me the daily double: a clear flying area, and flyable conditions six days out of seven.
Never thought I'd volunteer again for THAT reminder of my army days .
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Old Nov 16, 2012, 09:38 PM
Registered User
Joined Oct 2012
810 Posts
A black cloud has descended over my helis.

Crashed Wasp X3V yesterday, today F45's main motor has died after 33 flights (guess I'm the tail end of the bell curve/normal distribution).

Good news is the F45 did not crash. I lost engine power at about 70-80 feet but managed a bouncy landing . It wouldn't take off then, so I wasn't sure if it was my badly unbalanced stock battery or the motor. Charged the battery, tried to run the motor and it started briefly then died completely.

Now I need quick instructions on how to remove it. I think I will have to remove both the inner and outer side plates on one side??
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Old Nov 16, 2012, 09:48 PM
Fly Fast, Fly Hard, Fly Fun
rexless's Avatar
Canada, BC
Joined Apr 2012
1,494 Posts
I've had this problem a few times but I don't think it's happened with the EH200 + 3s Battery + HoneyBee Blades combination. It's been wintery cold and fairly windy here lately so I'm not riding any thermals to compare with. I guess I won't know until a hot summer day if I should end up in the same type of thermal.

Here's an example of the flying recently...
Winter Flying take 1 (5 min 37 sec)


And
MJX F45 Nov 15 windy wintery flight. (6 min 52 sec)
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Old Nov 16, 2012, 10:12 PM
Brent 黑雁
BThirsk's Avatar
Canada, AB, Ponoka
Joined Jan 2012
1,765 Posts
Quote:
Originally Posted by OldOz View Post
Yep, remember the shimming comments now. Maybe 166Valerio could find an answer there to what seems (in his case) a relatively minor problem.
Like you, figured it was just part of the F45 'thing', and learned to live with it. But keen on an solution, if anyone ever finds one. Or there is one at all.
That has always been my take on the bobbing, the flybar.
To see what happens, just get your Heli into a hover and then jab the ELV forward. You will see the Heli quickly react and then settle into a more stable position. Watch the flybar when this is all going on. It has a tendency to bob up and down over and under the center point that is 90 degrees in relation to the main shaft. If it would just center at this 90 degree point and stop, no bobbing would occur. If the same thing happens at altitude with thermals and the whole Heli moves, the flybar will try to move back to the center point 90degree to the main shaft but will swing over the center point causing the Heli to over correct. This process will go back and forth because the flybar has nothing to stabilize it other than centrifical force.
That is the reason I put paddles on, to stop the occelations and allow the flybar to return to the 90 degree point more slowly. This also increases the response because when the flybar returns to the 90 degree point, the pitch differential that causes cyclic movement is reduced to almost nothing and it is this differential that that creates the Heli movement.
That's the best I can explain it on short notice with out a lot of pictures and slow motion video.
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Old Nov 16, 2012, 10:53 PM
John
Australia, QLD, Brisbane
Joined Aug 2012
542 Posts
Lentar -
From memory, you'll only need to remove three screws each side to detach the top part of the F45 chassis from the bottom. There's a plastic key locator to watch out for (near the top front screw on the lower section) but if you prize the sides apart a bit, it will free automatically.

BThirsk -
I was thinking it had to be something associated with the flybar. The CP helis just sit like a rock in the same situation (well, a round rock balanced delicately on a much bigger round rock!) but no oscillations at all. Can't say I altogether follow your explanation, but - I believe!

Rexless -
As always, stunning videos. I'll get there one day , but mine look subpar when compared. But very interesting that your 'bobbing' has vanished with that configuration (you can notice it in the earlier vid).
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Old Nov 17, 2012, 12:07 AM
Sloooooow Flyer
S4ntai's Avatar
Australia, NSW, Glenfield
Joined Aug 2012
464 Posts
Quote:
Originally Posted by OldOz View Post
S4ntai -
There's a second solution to our wind problem!
I've also found that the wind just after dawn is usually at a minimum (or nil) for the day. I agree that it's the answer of last resort, but dragging myself down to the LHS football field at around 5am gives me the daily double: a clear flying area, and flyable conditions six days out of seven.
Never thought I'd volunteer again for THAT reminder of my army days .
I just removed the Horizontal Stabilizer Fin, and just done a test flight here at 5PM now its cause other problem, just like 166Valerio Post, the heli now booping up and down on the strong wind, it's perfect when there's no wind, but the moment wind start blowing strong, it push the heli back. (landed on the tree 3x just now). the only way i can fly this heli is to have it "drifting" like I do on V911 when flying outdoor (forward with left or right way), not sure if that's the right term? but that doesn't always work.

I will, put the horizontal fin back, without the support rod, and probably added 50c coin on the front to give more weight on the front. plus as you suggested OldOZ, I probably need to fly in the morning, so Sat & Sun only for me then.
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Old Nov 17, 2012, 12:58 PM
V911 F45 Super CP
Joined Apr 2012
140 Posts
Quote:
Originally Posted by slothy89 View Post
Yea my F45 has a bit of a bob tendency, but I never bothered to try fix it nor find the source of it, as it flies just fine otherwise.

I'm just recalling what other people have experienced. Maybe not so much a balance issue, but shimming the blades too little or too much can exasperate the bobbing.
Is the main shaft intact? If the linkage guides are broken off, it'll bob heavily. A new main shaft (with paper clip reinforced guides) has settled it down quite a bit.
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Old Nov 17, 2012, 01:19 PM
Registered User
Joined Oct 2012
810 Posts
Removing the main motor: steps?

How do you do this? It seems that I will have to remove the side plates, the main gear and the shaft assembly, or is there a simpler way? Please help!
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Old Nov 17, 2012, 01:36 PM
Registered User
United States, CA, Modesto
Joined Aug 2012
828 Posts
Quote:
Originally Posted by Lentar View Post
How do you do this? It seems that I will have to remove the side plates, the main gear and the shaft assembly, or is there a simpler way? Please help!
Take the three screws off of each side of the bottom of the chassis and remove the bottom plate. You will then be able to get to the motor screws.
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Old Nov 17, 2012, 03:05 PM
V911 F45 Super CP
Joined Apr 2012
140 Posts
Quote:
Originally Posted by Lentar View Post
How do you do this? It seems that I will have to remove the side plates, the main gear and the shaft assembly, or is there a simpler way? Please help!
Remove the landing gear assembly from the chassis(3 screws each side along the bottom of the chassis plates). You'll then have access to the 2 screws that hold the motor in.
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Old Nov 17, 2012, 03:34 PM
Registered User
War Horse's Avatar
United States, FL, Hernando
Joined Sep 2012
1,460 Posts
Also be carefull to watch the (+) wire , that it doesnt rub under the pressure of the canopy and short out on the motor body.
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Old Nov 17, 2012, 04:00 PM
Registered User
The Netherlands, ZH, Rotterdam
Joined Aug 2012
66 Posts
Rocking solved?

Hi guys,

Lately my yellow F45 was rocking whenever I went to fast for or backward, since I'm trying to use an 808 #16 camera I needed to stop this, I almost got seasick looking at the video's I took.

I noticed quite some play in the servo's and I came up with this simple experiment.
I used an elastic band to keep the back/forward arm of the swash plate more stable.

Eureka, really rock solid, never been better, I now can move fast forward backward and stop quickly, no rocking at all anymore

This might help some other rocking bobbing issues some others have, just try it, don't use to much down pressure, the pressure I use is just enough to keep the servo arm down but doesn't interfere with the movement.
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