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250 Class Electric Helicopters 250 Class Electric Helicopters manufactured by Align, Tarot, SYMA, Airhog, Chaos, HK and similar.


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Old 04-18-2009, 03:25 AM   #1
J.A.C
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Default GP750 & DX7 Gain Question

Hi all, nearly completed my little 250 now and have a question regarding gyro gain. It seems that most people are only setting the gain to around 25% and this is where I'm slightly confused. As I understand it the gain for HH (I'm using the gear atv's on my DX7) needs to be at least 50% for it to be in HH mode and less than 50% for rate mode, so surely if I set my gain at 25% ish the gyro would only be functioning in rate mode. Do I set the gain at 75% in HH mode therefore having a 25% gain value?

Any help and clarification on this would be greatly appreciated, thanks.
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Old 04-18-2009, 03:57 AM   #2
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Quote:
...Do I set the gain at 75% in HH mode therefore having a 25% gain value?
Yes. HH mode starts at 50% so that is effectively 0%. So 51% on the radio is 1% gain in HH....then to get to 25% gain the radio will read 75%.

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Old 04-18-2009, 04:29 AM   #3
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Yes. HH mode starts at 50% so that is effectively 0%. So 51% on the radio is 1% gain in HH....then to get to 25% gain the radio will read 75%.

Paul
Many thanks for clearing that up, your help is appreciated.
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Old 04-18-2009, 11:17 AM   #4
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This is not how I under stand it.

I aways thought 50% - 100% was HH mode and 0% - 50& rate. Understanding 50% is really gyro off.

So if we are talking 0% to 100% in HH this would equate on the radio as 50% to 100%. So my thinking is 50% is 0% and 100% is 100%. Now doing the math if you wanted 25% gain you would need to set the radio to 62.5%, that would be half of the 25% plus the 50% (or 0% gain) I think if you put 25% gain or 75% reading on the radio you would really have 50% gain.

Guys I could be wrong, this is just how I always looked at it.

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Old 04-18-2009, 11:31 AM   #5
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Hope this helps.
Attached Thumbnails
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Old 04-18-2009, 11:34 AM   #6
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Hope this helps.
So I was correct.........could be the first time this year.


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Old 04-18-2009, 11:54 AM   #7
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Hope this helps.
Where did that come from!? That's a great scale!

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Old 04-18-2009, 02:35 PM   #8
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Hope this helps.
Thanks DVS, is that chart only if you use the gyro sensitivity part of the DX7 though or does it also apply when setting the gain through the atv's?

Thanks again
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Old 04-18-2009, 03:24 PM   #9
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Craig was mostly right. Watch the Finless gyro gain 101 video. I believe the true gain will actually be X-50 times 1.4. For some reason it is not 2X.
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Old 04-18-2009, 03:39 PM   #10
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Originally Posted by J.A.C View Post
Thanks DVS, is that chart only if you use the gyro sensitivity part of the DX7 though or does it also apply when setting the gain through the atv's?

Thanks again
Sorry I don't know the answer to that.
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Old 04-18-2009, 07:49 PM   #11
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the top row of numbers is what you would use if you're using end points for gyro gain. the bottom is for the gyro sensing menu if you set your gear/aux channel to gyro. It shows corresponding numbers for both.
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