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10x - Throttle Curve Expo?

Old 08-06-2007, 08:15 AM
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bob_nj
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Default 10x - Throttle Curve Expo?

I am trying to get a curve on my 40% gasser.
What exactly is the expo for on the curve, and what does it do?
It didn't seem to make any difference in engine performance when switched from off to on.

Also, the curve allows 5 points.
What's the best way to get more resolution within those points?
In other words, once I set points 1 and 2 on the low end of the throttle stick, I can move
3 to 4 clicks without any throttle movement because of the way it works.
Once you set the point, you can't get any more travel on the servo until you hit the next
point which is unusually far away.

Is there a way to use an 8 point mix for throttle and get more control over the curve?

Thanks
Bob
Old 08-06-2007, 08:40 AM
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dsnyder
 
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Default RE: 10x - Throttle Curve Expo?

Expo smooths the curve from point to point, so rather than the curve being jagged, going from point to point with a straight line, it will smooth over the points. With the 10X you select where you want the points to be, so you might try moving the points slightly to adjust this, it sounds like you have the curve set too flat. If you can't get it set up as desired, you might need to mechanically adjust so that you don't get as much throw with small movements, say by using a shorter servo arm.
Old 08-06-2007, 08:53 AM
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bob_nj
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Default RE: 10x - Throttle Curve Expo?

Thanks Danny.

What's the method for moving the points?
It seems to me that I am only able to set a point when the "set" icon is on the screen.

What about using an 8 point mix?
Will that workd, and does that have any benefit over the curve?
Old 08-06-2007, 05:34 PM
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krayzc-RCU
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Default RE: 10x - Throttle Curve Expo?

i use a long arm on the carb and a short on the servo and try my best to get 120 numbers on both high and low. From here i use the numbers to get the best feel for my needs example it could be like 10, 20 33, 55, 100
Old 08-06-2007, 09:20 PM
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Bobby Folsom
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Default RE: 10x - Throttle Curve Expo?

I found this technique in a book by Harry Highley. Let your engine warm up to operating temp and record the max rpm. Bring the engine to idle and record the rpm. Now take the difference between the high (Z pointt) and low (A point) rpm and divide that number by 5. This gives you 5 equal spacings between high and low. Using your tachometer, set your points such that when the throttle stick is exactly half way the rpm noted on your tack is equal to the halfway point between A and Z (i.e. half stick = half the rpm). Do this same approach for the other points. When you finish, turn on the curve smoothing option noted on the throttle curve screen). This smooths the "curve" but in reality the curve is a straight line!! And, viola - a linear throttle curve!!

It may take some getting used to when flying but once you do you'll love it!! That last 1/4 or throttle stick movement will actually change the throttle setting!!!

Try it before you pooh-pooh the technique and you'll see what I mean!!

Good luck,

Bobby
Old 08-07-2007, 08:05 AM
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bob_nj
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Default RE: 10x - Throttle Curve Expo?

Sounds like a good plan Bobby.
I'm working on the curve to get more control while in a harrier and hover with my 40%.
Smoothing out the throttle steps in the first 1/3 of stick travel has helped alot.

I worked with the curve on the bench last night and realized some things.
Those "IN' and "OUT" numbers were throwing me off.

The "OUT" doesn't change on the screen, and I thought the servo wasn't moving, but it is.
I'll work with it more to sort out the points, "IN's" and "OUT's"

Long ago Danny gave a nice explanation of exactly how this works, and what those
numbers mean.

Maybe he can do it again.
Thanks for the replies guys.
Old 08-07-2007, 08:49 AM
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dsnyder
 
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Default RE: 10x - Throttle Curve Expo?

If you need to move a point, you will have to clear it, then choose another point with the set button. IN is the input, i.e. stick position, and OUT is the output to the servo.
Old 08-07-2007, 09:08 AM
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bob_nj
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Default RE: 10x - Throttle Curve Expo?

The point I was trying to make was that the although the "OUT" number isn't changing on the screen when the stick is moving,
the servo isn't necessarily sitting still. It is moving even if the numbers aren't changing.

This became apparent while using the curve on the bench with a degree protractor and pointer.

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