In need of advice on configuring radios

Aplam

New member
I'm building my first plane from scratch and I've run into problem that I cannot solve alone.

I purchased one of those radios programmable via USB cable, Turnigy T6A-V2. I decided to use program called Digital Radio to configure it, because it has more functions. After connecting radio to computer i've noticed that by default all maximum rates of all sticks are about 70%.

Should I reconfigure it to reach 100% on full stick forward ord is it some safety thing to protect my ESC/servos?

Thanks for replies.
 
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Merv

Site Moderator
Staff member
Should I reconfigure it to reach 100% on full stick forward ord is it some safety thing to protect my ESC/servos?
I'm not familiar with you Tx or program. On most Tx's the max value will be 100% to 120%, it depends on the brand of Tx. The propose of this is to limit may servo travel, because the servo is hitting something. If your system will permit you, I'd change your value to 100% or 120%, then see if you need to reduce it when the plane is built.
 

pressalltheknobs

Posted a thousand or more times
I'm building my first plane from scratch and I've run into problem that I cannot solve alone.

I purchased one of those radios programmable via USB cable, Turnigy T6A-V2. I decided to use program called Digital Radio to configure it, because it has more functions. After connecting radio to computer i've noticed that by default all maximum rates of all sticks are about 70%.

Should I reconfigure it to reach 100% on full stick forward ord is it some safety thing to protect my ESC/servos?

Thanks for replies.

I'm not quite clear what you mean by "by default all maximum rates of all sticks are about 70%." Do you mean that 70% is set as the default rate, default endpoint or that it is all defaulted to 100% byt you only get 70% of the servo movement you expect?

First you need to distinguish between rates and endpoints.

"Endpoints" set the maximum amount that the TX will let the channel move. At the very least the min and max should be set so that the servo does not move the control surface linkage more than the model physically allows without damage but that is not really the idea behind it. Generally you want to set these so that the servo on the channel moves the control surface between its minimum and maximum designed deflection from the model you are configuring. Most flite test planes have a template for setting the maximum deflection. This should correspond to your 100% "rate". That is moving the stick from one side to the other will move the control surface through the full designed deflection range from min endpoint to the max endpoint.

Subtrim sets the middle of the range and either the stick movement will scale on each side to the endpoint, which is good for simple planes, or the range will be offset and truncate at the endpoint which is good if you want to be more accurate and don't mind dead space in the stick travel. Different TXs may allow one or both ways to scale.

"Dual Rates" is a way of reducing the amount of servo movement from the maximum 100% rate to say 70% to make the plane calmer to fly. Generally you want a 100% rate and a reduced rate and 70% is a good place to start. This means the control surfaces will move less for the same stick movement and will not be able to move beyond +-70% of the +-100% positions you set with the endpoints.

Some TXs allow extended endpoints to say +- 125% but that is for special cases. This allows a wider range of servo movement. However the 100% rate is still 100% rate. It just means that that stick controls 100% of the servo range defined by the endpoints.

Edit: typo and clarity around subtrim scaling
 
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