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Old Sep 27, 2012, 09:36 AM
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USA, MI, Portage
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I need some help. My 57 wants to turn left excessively when using high power. It happens in all phases of flight. Wondering if it is a thrust angle issue and a couple of washers will fix this, or if it could be something else.

Never had this with any other 3dhs planes.
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Old Sep 27, 2012, 09:55 AM
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Charlotte, NC
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Originally Posted by chq28 View Post
I need some help. My 57 wants to turn left excessively when using high power. It happens in all phases of flight. Wondering if it is a thrust angle issue and a couple of washers will fix this, or if it could be something else.

Never had this with any other 3dhs planes.
Have you tried correcting it with rudder trim? Unless your motorbox has been erroneously repaired (or is currently damaged) then the stock thrust angle is correct.

Does it yaw or roll left?
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Old Sep 27, 2012, 10:01 AM
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Have you tried correcting it with rudder trim? Unless your motorbox has been erroneously repaired (or is currently damaged) then the stock thrust angle is correct.

Does it yaw or roll left?
No crashes yet, so there aren't any repairs to it. I have tried the trim idea, but it took a lot of trim and ended not flying good especially in harrier. All the control surfaces look good, so I'm at a loss.
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Old Sep 27, 2012, 10:15 AM
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No crashes yet, so there aren't any repairs to it. I have tried the trim idea, but it took a lot of trim and ended not flying good especially in harrier. All the control surfaces look good, so I'm at a loss.
Have you picked the plane up by the tail and eyeballed the elevator/h stab line up evenly (on both sides) with the ailerons/wings?
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Old Sep 27, 2012, 10:19 AM
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Have you picked the plane up by the tail and eyeballed the elevator/h stab line up evenly (on both sides) with the ailerons/wings?
I will check that out. It looked good when I built it.
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Old Sep 27, 2012, 10:28 AM
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Originally Posted by chq28 View Post
No crashes yet, so there aren't any repairs to it. I have tried the trim idea, but it took a lot of trim and ended not flying good especially in harrier. All the control surfaces look good, so I'm at a loss.
This plane will definitely pull a little to the left in harrier but that's a normal trait that you just have to manage with your rudder. I think it's due to P Factor or something like that.

I'd trim it to fly straight and true both upright and inverted at about 60% throttle. If it does that then you're good. I'm greatly simplifying but if you've trimmed it to fly straight with no rudder in harrier then that's likely you're issue.
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Old Sep 27, 2012, 10:54 AM
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Originally Posted by turnerm View Post
This plane will definitely pull a little to the left in harrier but that's a normal trait that you just have to manage with your rudder. I think it's due to P Factor or something like that.

I'd trim it to fly straight and true both upright and inverted at about 60% throttle. If it does that then you're good. I'm greatly simplifying but if you've trimmed it to fly straight with no rudder in harrier then that's likely you're issue.
The problem is it takes to much trim in my opinion. It isn't a few clicks, once I'm in harrier it just feels funky with all that trim.

When I do straight up lines they aren't straight, It pulls pretty hard. Harriers, I can do a left circle without touching the rudder. (That's with no trim)

I guess that's why I'm wondering if could be a thrust angle issue. Again I've never played with thrust angle issues, never had to.
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Old Sep 27, 2012, 10:58 AM
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That's an odd one for sure!! What motor are you using and how did you mount it?
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Old Sep 27, 2012, 11:49 AM
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USA, MI, Portage
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Motrolfly 3620-750 w/15x7 xoar. I need to go and check if I used spacers, can't remember. That could be one more variable.
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Old Sep 27, 2012, 12:20 PM
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Motrolfly 3620-750 w/15x7 xoar. I need to go and check if I used spacers, can't remember. That could be one more variable.
Yep. That's where I was going with my question.
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Old Sep 27, 2012, 02:52 PM
I fly, therefore, I crash!!!
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Roll the plane inverted and see if it still goes in the same direction....if it an aileron problem, the plane will go in the same direction...I.E. to the left upright will still be to the left inverted. If it is a rudder problem and it is pulling left upright, then it will pull to the right will inverted...

SteveT
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Old Sep 27, 2012, 03:02 PM
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Originally Posted by SteveT. View Post
Roll the plane inverted and see if it still goes in the same direction....if it an aileron problem, the plane will go in the same direction...I.E. to the left upright will still be to the left inverted. If it is a rudder problem and it is pulling left upright, then it will pull to the right will inverted...

SteveT
I'm going to sound smart at the field when I steal this from you.

Good tip
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Old Sep 27, 2012, 03:33 PM
I fly, therefore, I crash!!!
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I'm going to sound smart at the field when I steal this from you.

Good tip
Well...it helped to make me sound smart.....and I stole it from somebody else....so, fairs, fair...

SteveT
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Old Sep 27, 2012, 07:12 PM
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Originally Posted by SteveT. View Post
Roll the plane inverted and see if it still goes in the same direction....if it an aileron problem, the plane will go in the same direction...I.E. to the left upright will still be to the left inverted. If it is a rudder problem and it is pulling left upright, then it will pull to the right will inverted...

SteveT
It pulls left upright and pulls to the right inverted. If that's the case I'm not sure what to do, take the rudder out and start over?

I do have my motor mounted using spacers, I'm going to make sure that they are the same length first and go from there.

Hopefully it turns out to be an easy fix.
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Old Sep 27, 2012, 07:28 PM
I fly, therefore, I crash!!!
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Originally Posted by chq28 View Post
It pulls left upright and pulls to the right inverted. If that's the case I'm not sure what to do, take the rudder out and start over?

I do have my motor mounted using spacers, I'm going to make sure that they are the same length first and go from there.

Hopefully it turns out to be an easy fix.
Then it is rudder induced...

As noted, if it was aileron induced, it would go the same direction....roll would be the same inverted or right side up.

SteveT
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