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Old 08-07-2008, 01:40 AM
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Re: Trim Chart based on Article by Peter Goldsmith

That is really helpful. Thanks for putting it together!
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Old 08-07-2008, 02:56 AM
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Re: Trim Chart based on Article by Peter Goldsmith

Good stuff Gareth! One more addition..

Up/down thrust: hands off, WOT windward, chop throttle. If model baloons, add upthrust (you're flying with up trim).

This is the one I always forget because it's counter intuitive.

I also second Tony on the 45 CG test - I'm pretty sure that's a QQ thing, might be in his manuals. Reza, got any info on this?

Nice work brother. Smack your name on that too. ;-)
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Old 08-07-2008, 10:16 AM
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Re: Trim Chart based on Article by Peter Goldsmith

Thanks everyone!

Max, that's a good test and one I hadn't come across before. I put that in as step 4, right after setting the right thrust. I made the change to do it crosswind. You should see the effect no matter what by there will be less question if its crosswind.

There is no mention of a "down line mix" that you hear about when flying IMAC. Fly a down line with the wings edge on to the wing and you so you can see if the airplane pitches up. You want to add like 2% down elevator to the last 2 clicks of the throttle to cure that. I added that as the last step.

Where it is critical that the maneuver be flown in a particular direction relative to the wind it is the first thing noted. You might be wondering what the difference is between an "Upwind Downline" and a "Crosswind Downline". Upwind would be with the planform of the airplane facing the wind. Crosswind would be with a wing tip facing the wind.
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Old 08-07-2008, 02:57 PM
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Re: Trim Chart based on Article by Peter Goldsmith

Nice trim sheet.

However... and I really hate to nitpick, but:

"YOU'RE" using the wrong YOUR on "YOUR" trim chart.


Tom
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Old 08-07-2008, 03:12 PM
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Re: Trim Chart based on Article by Peter Goldsmith

You're welcome

I was wrong, thanks for pointing that out.
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Old 08-07-2008, 06:29 PM
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Re: Trim Chart based on Article by Peter Goldsmith

printed and read
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Old 08-08-2008, 04:05 PM
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Re: Trim Chart based on Article by Peter Goldsmith

Max,

Just saw this thread.
Anyways, WOT if you chop and model baloons up you need up thrust. Reason for that is when it is under power it is pulling the model down, when you let go of throttle now you are not forcing the model to go down and most likely you have some uptrim that needed for model to fly straight in full power that now it kicks in.

On 45 degree. Best CG for precision is (per QQ) roll inverted, hands off, model continues for about 2 seconds and starts dropping, leveling off. If model continues the line or climbs is tail heavy. If it drops quickly nose heavy.

I personally like all of my planes for 3D to have a CG as per QQ's precision. I feel I have more control over the model.


Great job Gareth. I printed multiple copies to hand out to people at the field when they ask. It saves me lots of explaining LOL


Quote:
Originally Posted by madmax View Post
Good stuff Gareth! One more addition..

Up/down thrust: hands off, WOT windward, chop throttle. If model baloons, add upthrust (you're flying with up trim).

This is the one I always forget because it's counter intuitive.

I also second Tony on the 45 CG test - I'm pretty sure that's a QQ thing, might be in his manuals. Reza, got any info on this?

Nice work brother. Smack your name on that too. ;-)
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Old 04-13-2009, 04:27 PM
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Re: Trim Chart based on Article by Peter Goldsmith

Gareth,

Had to bump this thread since our NW season opener IMAC is this weekend. Great job bro!!
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Old 07-05-2009, 05:30 AM
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Re: Trim Chart based on Article by Peter Goldsmith

Does anyone know how to find Peter Goldsmith?
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Old 07-05-2009, 06:22 AM
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Re: Trim Chart based on Article by Peter Goldsmith

I just set my plane up perfect before my first flight.......That way all my trims are set at 0.
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Old 07-05-2009, 10:25 AM
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Re: Trim Chart based on Article by Peter Goldsmith

Nice chart, I've read the article before but the chart makes a handy field guide.

JP
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Old 07-08-2009, 08:34 AM
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Re: Trim Chart based on Article by Peter Goldsmith

Gareth - Thanks for a great chart.

Pete
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Old 07-08-2009, 08:51 AM
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Re: Trim Chart based on Article by Peter Goldsmith

Quote:
Originally Posted by Mike Busutil View Post
I just set my plane up perfect before my first flight.......That way all my trims are set at 0.

Your trims may be at zero, but that dosen't mean your plane is "trimmed"

To have a properly trimmed airplane, you need to fly the plane for many flights figuring out the way the plane rolls, how it pitches during throttle, how it pitches on downlines... many mnay things. (see the P.G. chart)

I suck at trimming a plane. I can get them flying pretty straight, but I'm always amazed at what a guy who can really trim a plane can do.

When you see guys flying completely fluid lines and even throwing down the mean 3D, and they don't seem to be working too hard, their plane is probably properly trimmed.

I mean KE with 1 finger, it's amazing.

Read Pete's Article.
Use Gareth's chart!
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Old 07-08-2009, 08:13 PM
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Re: Trim Chart based on Article by Peter Goldsmith

Sleepy,
I'm sure you noticed I was being a smart ass with my last commit.......
I wanted to start flying IMAC again this year with my Yak, but 7 months later I am still trimming Since the begining of the year I have 47 trim flights at 15 mins per flight. After all this, I can say My Yak is now trimmed.
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Old 07-08-2009, 08:41 PM
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Re: Trim Chart based on Article by Peter Goldsmith

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