shall36

My Feedback: (23)

Danny,

A couple of questions for you...

I'm setting up a 50cc Extra with an 8103 radio.

First, a general question...the plane manufacturer has rates published for "low", "high" and "3-D". I was thinking of using the "Mix" switch to boost the throws on my elevators and ailerons to give me essentially 3 rates (actually, maybe 4 rates). Of course, I won't have enough "Mix" programs to include the rudder in this, but hey... Is this how you would do it?

Second, I found that the split elevators required some differential throw setup in the radio to compensate for differences in full-range of motion between the two servos. That is, one of the servos would quit moving before the other. The sub-trims might be 30 points apart (I tried physically rotating the arm on the spline, but the spline pattern was too coarse to solve this problem). Is the difference in sub-trims why one servo will quite moving before the other? I was eventually able to get equal throws, but it took a lot of work!

Third, what's your opinion on optimal travel throw setup and dual-rate setups? For example, the manufacturer of my airplane recommends +16* of elevator throw at low rate and 45* at 3-D rate. If I moved the control rod to the inner hole on the control horn at the elevator, I could get the 45* of travel, but I would end up with a dual-rate setup of like 20% for low rate. I've heard to setting throw limits at 150% will cause you to loose resolution on the sticks. What happens when you set the low dual-rate to low values like 20%? Do you gain resolution? What rules of thumb do you have with regard to maximum throw values, minimum throw values, equal throw values within a channel, throw value differentials between two linked channels, minimum and maximum DRs, etc.?

Seems that the 8103 isn't quite setup for large 3-D planes or am I wrong on that? Does the 9303 incorporate features to make the setup process easier? Should I add-on one of these servo control boxes?

Sorry for all the questions!

Thanks!

dsnyder

Yes, you can do that with the mixes.

Yes, very likely if you have the travel adjust set high, with the sub trim in, you will hit the end of the travel on one side of movement on that channel.

Actually increasing the travel adjust increases resolution and servo power vs changing mechanically, as you are using more of the servos movement and not decreasing mechanical advantage by adjusting mechanically. Setting low dual rates loses resolution, not gain. But they need to be set properly for the model. I generally set the travel adjust as high as possible (starting at say 125-130 or so that I can still increase it if needed) and adjust mechanically as necessary from there.

shall36

My Feedback: (23)

Thanks Danny!

So, if you're setting up some massive throws on your machine, you would start off with the travel adjust at 130 or so and get close to what you need on the throws, moving the links inward on the control horn if needed. Now, to get low rate throws, would you drop the DR setting all the way down to 25% or so if that's what it took or would you readjust the mechanical linkage (sacrificing high-end throws) to get the DR setting up to 50% or some other "magical minimum value"?

Thanks!

Steve

dsnyder

I haven't had an airplane that ever needed the DR to be set that low, but if you must have the full throw, and must set the DR that low to get the throw needed, you will have to set it up that way.