Help with Dual Rates

[downwindleg]

Thanks fhhuber. Like xviper said it's an IX12. Was already planning on low vs high expo for rudder and nose steering. I use expo exclusively vs dual or triple rates. BTW the screen for mixes on this radio show me what's responding and not responding when I mess with rates etc. If I think I've made a breakthrough, then I take the trany out to the garage and initialize the plane to verify. Right now, since there is no cockpit installed to block the nose wheel from steering in the retracted position, I can test it a little in the up position to verify workie- no workie. These are stock retracts provided with the kit as an option. Then I sent them to Down and Locked to have them converted to electrics with a controller that is programed to handle the gear door sequence. Anyway,I'm thinking I have missed some little detail that I've overlooked....maybe on another screen.....but haven't found it yet. Currently, I have six other planes I fly with this radio with no problems, although this function is usually handled by the blue box. But this one little detail has me stumped.:Thinking:

[xviper]

He's already posted that he's got an IX12.

[fhhuber]

The exact settings are dependent on the radio. So first we need to be sure of the radio you are programming. Doing it in my DX-18 is slightly different from a friend's DX-8 and VERY different from any Futaba or my old Polks Tracker. But all can get there.

You may have to play with various settings to get the desired result.

I recommend unplugging the nose retract (and doors if they have a separate servo) while testing. You already know the retract goes up and down. Leave it down.

Mix rudder to the nose-wheel channel and assign that to the retract switch. Retracts down = mix on. Retract up = mix off. (mains moving confirms switch direction.)

You may have to use any of several tricks to make the nose-wheel steering go to center when the mix is off. This varies with the radio.

Let us know what radio and when you get to where the nose-wheel steering works with retract down but does not when retracts are up. Then we'll work on centering the nose-wheel when its up if needed.

I'll look up the manual and get it figured out if I don't already know your specific radio.

**************

I also will apply a high value expo to the nose-wheel steering when I do this mix. You need more rudder than nose-wheel steering for crosswind. You want tight turns possible for low speed taxi, but you do not want the nose-wheel to be sensitive during the take-off run.

People at the local field wonder how I get my take-off runs so straight while being able to turn very tight... Its high expo on the nose-wheel but low expo on the rudder.

[downwindleg]

Yeah, I was afraid of that. Nevertheless, there has to be something similar. Just look for something that has something to do with RX ports and Ch. input.

I certainly appreciate your efforts.

[xviper]

Thanks again xviper. Everything seems the same but the last two screens are different on the IX12. Still trying

Yeah, I was afraid of that. Nevertheless, there has to be something similar. Just look for something that has something to do with RX ports and Ch. input.

[downwindleg]

Maybe something is getting lost in translation. Here are 2 photos of my mix screen. Remember, this is on a DX8 and with my A-10. The principle should be the same.

The first picture shows "gear UP". Note the little dot under switch position "1". It's "white". If you move the rudder stick, you will NOT see any movement on the monitor for AUX2.



In this next picture, you will see "gear DOWN". Note the little dot under switch position "0". It's "blacked out". If you move the rudder stick, you WILL see movement on the monitor for AUX2.



Now, just in case there are more missing information, here's 2 more pictures. This is in "System Setup", "Channel Assign". 1 is of the "Rx port assignments. Note AUX2 (for you, it will be AUX5). Next is of the "Channel Input Config". Also, note AUX2 (AUX5 in your case).




As far as I know, ALL of these settings must be this way in order for this to work. Miss one and it won't work.

Thanks again xviper. Everything seems the same but the last two screens are different on the IX12. Still trying

[xviper]

Maybe something is getting lost in translation. Here are 2 photos of my mix screen. Remember, this is on a DX8 and with my A-10. The principle should be the same.

The first picture shows "gear UP". Note the little dot under switch position "1". It's "white". If you move the rudder stick, you will NOT see any movement on the monitor for AUX2.



In this next picture, you will see "gear DOWN". Note the little dot under switch position "0". It's "blacked out". If you move the rudder stick, you WILL see movement on the monitor for AUX2.



Now, just in case there are more missing information, here's 2 more pictures. This is in "System Setup", "Channel Assign". 1 is of the "Rx port assignments. Note AUX2 (for you, it will be AUX5). Next is of the "Channel Input Config". Also, note AUX2 (AUX5 in your case).




As far as I know, ALL of these settings must be this way in order for this to work. Miss one and it won't work.

[downwindleg]

It should work for you. Here are the settings I use for this configuration:

RUD>AX5
Rate: 70% 70%
Offset 0%
Trim: Inh
Switch: Switch A
and the "0" switch position is black "1" is white

Everything else is normal.

Thanks Twowingtj. I have it set up just like you said but the AUX5 is still going back and forth on the screen whether trim is inhibited or not. Everything else is working exactly as it should on the screen and on the plane. No Joy!

[Twowingtj]

It should work for you. Here are the settings I use for this configuration:

RUD>AX5
Rate: 70% 70%
Offset 0%
Trim: Inh
Switch: Switch A
and the "0" switch position is black "1" is white

Everything else is normal.

[downwindleg]

OK guys, this is what I need help with. I have a Yellow Aircraft P-38 electric that I am setting up with a 12 channel receiver. I've got all the basic control surfaces done including the flaps and retracts. I have attempted a mix with the rudder controlled by the rudder stick and the nose wheel steering linked to AUX5 for nose steering. Switch A controls the retracts. All of this works fine but I'm trying make Switch A also control the off and on for nose steering so that when the gear are retracted there is no nose steering. I started on a Pmix in the mixing screen. Used rudder>Aux5 to link the two and assigned Switch A as the control. Gear continues to steer whether up or down. I need a step by step walkthrough to find the issue with making this work right. xviper gave it a shot but no joy.:Thinking:I would appreciate any knowledgeable help. I'm guessing it's something simple that I have overlooked.:Confused:

[chipset35]

The referance in the Spektrum manual that you are mentioning, is talking about Expo. The higher your value, the less sensitive it is around center. The Rate is actually the percentage of servo travel each direction from center. So, the higher the value, the more the servo arm travels.

The reason most aircraft manuals give you a measurement for a control surface movement, is through testing they have determined that movement works best for flight. If they gave a percentage, the actual control surface travel would be radically different depending on what hole the control rod was in for both the servo arm and the horn on the surface itself. In addition, some servos have a greater range of motion than others. So 50% on one could be quite different if you swap to a different brand or model servo. By giving a travel measurement for a given surface, you have a standard value to work with.

Thank you TwoWing!

[chipset35]

Thanks Viper!

[boomer108]

Very good explanation Xviper. I use Tactic transmitters and Expo is negative (-) for more sensitivity at center so yes no one transmitter or plane are the same in this hobby.

[Twowingtj]

xviper must have been typing at the same time. He's given a good detailed explanation.

[Twowingtj]

All defaults are at 100% for dual rates, and the Spectrum manual states the higher you go in a positive value the less sensitive the control is for a selected gimball.
More sensitive with lower or negative values

The referance in the Spektrum manual that you are mentioning, is talking about Expo. The higher your value, the less sensitive it is around center. The Rate is actually the percentage of servo travel each direction from center. So, the higher the value, the more the servo arm travels.

The reason most aircraft manuals give you a measurement for a control surface movement, is through testing they have determined that movement works best for flight. If they gave a percentage, the actual control surface travel would be radically different depending on what hole the control rod was in for both the servo arm and the horn on the surface itself. In addition, some servos have a greater range of motion than others. So 50% on one could be quite different if you swap to a different brand or model servo. By giving a travel measurement for a given surface, you have a standard value to work with.

[xviper]

My issue is that FMS and E-Flite post their recommended dual rates in the aircraft manuals but they are in millimeters" and not a percentage.
So using my FMS GOSHAWK T-45 as an example they have two sets of dual rates both in mm, but my transmitter shows only a percentage.
My FMS B-25 Mitchell manual does not even mention dual rates.
All defaults are at 100% for dual rates, and the Spectrum manual states the higher you go in a positive value the less sensitive the control is for a selected gimball.
More sensitive with lower or negative values

This is normal for the way control surface deflection is stated. That's where a ruler comes into play. Every servo and every set up for servo horn hole and control arm hole placement will produce a different throw, even from one model to another of the exact same kind. That's why they give it in mm. % would tell you absolutely nothing, since 80% many give you 15mm throw while in another plane 80% may give you 20mm throw. Transmitters give it to you in % because it's a relative term that relates to a portion of max throw (which is 100%). Some plane manuals will even give it to you in degrees. You gotta use a little common sense in this hobby and this is one area where some deductive reasoning comes in handy.
Dual rates and expo are things which individualize to achieve the desired outcome for control surface deflection and the amount of desensitization of the sticks "NEAR CENTER". Because of this, some manuals will reference it while others don't. This is another area which you must do a little research, reading and trial and error because you don't quite have this concept clear. Expo in Spektrum radios is positive (+) to achieve more "numbness" near center. If you have +20% expo, this means that the first 20% of the stick's travel is less sensitive. After that the stick reverts back to direct output. If you have +50% expo, the first 50% of the stick's travel is less sensitive and the after that, it reverts to direct output. If you go +100% expo (not generally recommended), ALL of the stick's travel will be less sensitive. If you go negative (-) expo, the sticks become much more sensitive for that portion of the travel. Some planes that are flown 3D are set up this way if the pilot wants immediately and quick response when he moves the sticks. Having said this, you may find a different brand or age of transmitter where the positive and negative expo is the opposite. Some pilots don't like expo and don't care if it's even stated. Some pilots like more or less max throws and they set it up the way they want it and don't even look at the manual. When a manual does state this kind of stuff, it all for reference only, just like CG.

[chipset35]

My issue is that FMS and E-Flite post their recommended dual rates in the aircraft manuals but they are in millimeters" and not a percentage.
So using my FMS GOSHAWK T-45 as an example they have two sets of dual rates both in mm, but my transmitter shows only a percentage.
My FMS B-25 Mitchell manual does not even mention dual rates.
All defaults are at 100% for dual rates, and the Spectrum manual states the higher you go in a positive value the less sensitive the control is for a selected gimball.
More sensitive with lower or negative values

[xviper]

Thanks, I never even thought about getting an advanced transmitter.
Any recommendations?

Everyone has their own favorites. My recommendation would be a DX8 G2 - good bang for the buck and very versatile. If money were no object, then take a look at the new IX12. Keep in mind that the more channels you use, the more expensive the receiver becomes. Nothing says you can't stay with a simple 6-ch Rx and use it on a 12-ch TX. It's just a waste of money at this point. DX6 G2 can be found at good prices now but that limits you to future growth if you plan to keep moving along in this hobby. If you plan to stay simple, the DX6 G2 should suffice nicely for a few years. These are Spektrum products. There's also Futaba and FrSky - also major players but remember, as time goes by, all your planes will have the Rx's that work with your radio. If you change to another brand of system, the Rx's may or may not work with a different brand of radio. Of course, most of the BNF planes from Horizon Hobby are Spektrum.

[chipset35]

Those two numbers are for either UP/DOWN on the elevator or ailerons OR left/right on the rudder. With more advanced Tx's, you can make the control surface go a different distance in one direction compared to the other if that's what you want. Did you try highlighting another line in the menu? Or did you flip the switch to see if it goes to the other set of numbers. Plane manuals give throws in mm because that's what you measure when you set rates. Tx give it to you in % because each transmitter may give a different throw at any given %. That's why they're different.
From the looks of some of your other threads, it would appear that you are progressing quite quickly in this hobby in terms of the kinds of planes you are acquiring. It might be time to get yourself a more advanced transmitter. That DX6e is very basic and limiting to what you can do.

Thanks, I never even thought about getting an advanced transmitter.
Any recommendations?

[Tom]

This is one of those items where there are many ways to tackle it. You can't really set the travel mechanically. You can only set the neutral position mechanically. I'd set the neutral position mechanically first then use subtrim to perfect the neutral position. Once that is complete, set travel while at 100% rates. At that point you can set your lower of the dual rates using a percentage. Personally, I'm really never worried about travel or exact measurements anywhere but flaps and elevator (assuming elevator is using multiple servos). Even then, I'm only concerned they are the same. I'm not worried about exact travel. Only that the control surfaces move in tandem and the endpoint is the same. I simply set a 100% rate, 80% rate, and 60% rate and go fly. I tweak rates on subsequent flights and never worry about total amount of travel. I do frequently separate elevator servos into two different channels so I can subtrim an exact neutral and sent endpoints identical both up and down. That makes it a very precise model. Again, I just make sure they move relative to each other. Rates, expo, and travel are a very personal thing and I like to feel out the model and develop my own settings. The manual is only meant as a baseline starting point.