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Mulit Point Mixing For Throttle Control - 8103

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Old 01-28-2003, 06:10 PM
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John Murdoch
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Default Mulit Point Mixing For Throttle Control - 8103

Danny,
I read somewhere once how to utilize either channel 1 or channel 2 on the 8103 to use the multi point mixing to adjust the throttle throw on the radio to correspond with the rpms of the engine. For example, an engine has a rpm range of 2000-10000 with usable range being 8000 rpm. I want to be able to adjust my throttle stick on the radio to correspond to the rpm range, meaning that 1/4 throttle stick will give me 4000 rpm, 1/2 throttle stick will give me 6000 rpm 3/4 throttle stick will give me 8000 rpm and full throttle will give me the full 10000 rpm. I hope I've explained that right. Can you give me any help on how to accomplish this?
Thanks Much Again For Your Help.
John
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Old 01-28-2003, 07:19 PM
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Default Mulit Point Mixing For Throttle Control - 8103

Yes, you would set up a throttle to throttle mix in program mixes 1 or 2. Go to either mix 1 or 2, and press the + button until the first channel says THRO. If the second channel says something other than THRO, Press the CH right button and the second channel should be underlined. Press the + button until it says THRO. At the top of the screen it should say THRO>THRO. Now press select one time. This is where you will set the points. To start with, press the + button until the number beside where it says Point-L is zero. Then press the CH right key until you get to Point-H. Press the minus button until the percentage gets to 0. Now press the CH right key once, and press the + key if you want to add expo to the curve. Press the CH right key one more time and it will bring you back to Point-L. Now you should have a straight line across the display. Now to adjust your curve, press the CH right key to Point-1, Point-2, and Point-3 and adjust the percentage as desired to get the curve set the way you want. When you set the percentage to a - value it will take away or slow the response. If you set the percentage to a + value it will speed the response. So for example if moving the throttle stick below half throttle gives too much throttle, you will want to set Points 1 and maybe 2, to a negative value. If the response above half throttle is too slow, you will want to put in a + value on point 3. Adjust these percentages as needed to get the desired throttle response.
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Old 01-28-2003, 07:29 PM
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Default Mulit Point Mixing For Throttle Control - 8103

Thanks again Danny. I'll give it a try....
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Old 01-28-2003, 07:43 PM
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Default Mulit Point Mixing For Throttle Control - 8103

If you have any problems, let us know!
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Old 02-18-2003, 02:54 PM
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Default DANNY - HELP AGAIN

Hey Danny,
I tried your scenario on my plane and can't get it to do what I want. Here's the deal. I have a Moki 2.10, 8103 Radio and the 639 receiver. I have a Mejzlik 20X10 prop. Idle speed is around 2000 and top end rpm's are about 6700. My problem is when the stick is at half or maybe a little less, I am getting around 6200-6300 rpm. I was trying to get the rpm's to corrulate directly to the stick position. This is what I get with the straight line graph and no adjustments to the mixing. With the low starting in the 0 position, I attempted adjust position 2 and 3 where there would be a "sag" in the graph line. What I get is a repeated upward rpm, then the drop, then an increase. I hope you can get what I'm trying to say.

Given the existing rpm curve, what would I be looking for in the line that would slow down the bottom half of the stick adjustment and increase the top half of the stick adjustment. What kind of a line would I be looking for?

Secondly, it asks if I want expo. I turned the expo on but I don't know how to get to it to adjust the expo. Any advise here?

Thanks for your help again. I'd really like try flying this plane where the stick matches the rpm's response.
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Old 02-18-2003, 10:14 PM
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Default Mulit Point Mixing For Throttle Control - 8103

It sounds like you are putting in too high of a percentage. You want to use a low enough percentage to alter the response, and not take away more travel than what is being added by the radio as you move the throttle stick forward. You can change point L to a slight negative value, and point H to a slight positive value but keep in mind that it will increase the travel of the servo overall. Try using smaller percentages, I'm using around 16% and it is working fine on this TX.

On the expo question, you can not change the percentage of expo. It is is a fixed rate, and is either on or off.

I hope this helps. If you have any further questions please let us know.
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