split rudder air brake programming
04-30-2024, 03:52 PM
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split rudder air brake programming
I have a single vertical stab with two independent rudder panels and servos. A Space shuttle vertical stab. I want to have available 100% left servo travel and 100% right servo travel for rudder input, not 50%. I also want to put the servos on a slider or switch for them to butter fly open for an air brake. In airbrake mode I want the rudder to still work by pulling the necessary panel in for rudder control. Any programming help would be appreciated.
05-04-2024, 11:17 PM
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I am happy to have a look but please can you confirm exactly how you want each rudder half to operate. 100% servo movement left and 100% servo movement right perhaps suggests that each rudder half will only move in one direction. Is this correct?
05-05-2024, 06:16 AM
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Yes. Each rudder half will only move in one direction. Then butterfly open as an airbrake. In Airbrake mode rudder input pulls the necessary rudder half in.
Thanks
Thanks
05-06-2024, 04:46 AM
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With no AFR (Adjustable Function Rate), and only five Program mixes on the 14SG, this setup requires a bit of “creative” programming. I think the following setup does what you are asking but, without knowing the rest of your setup, I cannot guarantee that it will not clash with something.
Go to the Function Menu. I assume that the Rudder function is already assigned to a channel with a control (J4?) and a trim (T4?). Select the channel which you intend to connect to the second part of the split rudder and assign CAMBER as its function and J4 as its control. I have chosen this because it is probably the only unused Function which can be accessed via the Dual Rate menu (required below).
If you use a rudder trim it will cause one half of the rudder to move slightly outwards leaving a gap to the other half which, of course, cannot travel towards the opposite side of the aircraft. Personally I would just take time to get the setting correct via the linkages and sub-trim and do without in-flight rudder trimming altogether. However, if you require it, I can explain how to do it.
Go to the End Point menu and change both of the 135 Limit Points to 100 on the Rudder and Camber channels. This avoids possible linkage/servo damage if both full rudder and airbrake are deployed together.
Go to the Dual Rate menu. Select RUDDER and adjust NT to +100. Now select CAMBER and again adjust NT to +100 but also change both values at the top to -100.
Go to the servo monitor which should now show the servos for both channels at one end of their travel (+100). Moving J4 in each direction should cause one servo or the other to move to its opposite limit (-100).
Go to the Program Mix menu. Select a new mix. On screen 2/2 change INH to ON but do not assign a switch. Set MASTER to LS and SLAVE to RUDDER. On screen 1/2 set both values in the top half of the screen to -100 and the Y OFFSET at the bottom to +100.
Return to the main Program Mix menu and select a second mix. Set this up exactly as above but set the SLAVE to CAMBER instead of rudder.
Return to the servo monitor and check that both channels operate together when LS is pulled down. If the airbrake is only partly deployed you will note that the rudder stick will still move the rudder further out up to its limit.
Once the air brake is fully deployed all rudder control ceases. To allow one panel to be pulled inwards to provide yaw control do the following.
At the Program Mix menu select a third mix. On screen 2/2 change INH to ON and select LS as the switch. On the same screen select ON/OFF. Move the LS slider two clicks down from the fully up position. Scroll to SET and press RTN. This will activate the mix once the air brake starts to deploy. Back on screen 2/2 of Prog Mix set MASTER to J4 and SLAVE to RUDDER. On screen 1/2 leave the top value at +0 but adjust the lower value to +100. (The line graph should go from centre to top right).
Return to the main Program Mix menu and select a fourth mix. Set screen 2/2 up exactly as above but set the SLAVE to CAMBER instead of rudder. On screen 2/1 adjust the top value at -100 but leave the lower value to +0. (The line graph should go from centre to top left).
Check with the servo monitor. This should now give you rudder control with both halves when the air brake is partly deployed and one half will pull in when fully deployed.
Depending on the linkages, it may be necessary to reverse the servos or use mirror images on some of the mixes. This is something you will have to work out for yourself with the model in front of you but hopefully my ideas will be of some help.
Go to the Function Menu. I assume that the Rudder function is already assigned to a channel with a control (J4?) and a trim (T4?). Select the channel which you intend to connect to the second part of the split rudder and assign CAMBER as its function and J4 as its control. I have chosen this because it is probably the only unused Function which can be accessed via the Dual Rate menu (required below).
If you use a rudder trim it will cause one half of the rudder to move slightly outwards leaving a gap to the other half which, of course, cannot travel towards the opposite side of the aircraft. Personally I would just take time to get the setting correct via the linkages and sub-trim and do without in-flight rudder trimming altogether. However, if you require it, I can explain how to do it.
Go to the End Point menu and change both of the 135 Limit Points to 100 on the Rudder and Camber channels. This avoids possible linkage/servo damage if both full rudder and airbrake are deployed together.
Go to the Dual Rate menu. Select RUDDER and adjust NT to +100. Now select CAMBER and again adjust NT to +100 but also change both values at the top to -100.
Go to the servo monitor which should now show the servos for both channels at one end of their travel (+100). Moving J4 in each direction should cause one servo or the other to move to its opposite limit (-100).
Go to the Program Mix menu. Select a new mix. On screen 2/2 change INH to ON but do not assign a switch. Set MASTER to LS and SLAVE to RUDDER. On screen 1/2 set both values in the top half of the screen to -100 and the Y OFFSET at the bottom to +100.
Return to the main Program Mix menu and select a second mix. Set this up exactly as above but set the SLAVE to CAMBER instead of rudder.
Return to the servo monitor and check that both channels operate together when LS is pulled down. If the airbrake is only partly deployed you will note that the rudder stick will still move the rudder further out up to its limit.
Once the air brake is fully deployed all rudder control ceases. To allow one panel to be pulled inwards to provide yaw control do the following.
At the Program Mix menu select a third mix. On screen 2/2 change INH to ON and select LS as the switch. On the same screen select ON/OFF. Move the LS slider two clicks down from the fully up position. Scroll to SET and press RTN. This will activate the mix once the air brake starts to deploy. Back on screen 2/2 of Prog Mix set MASTER to J4 and SLAVE to RUDDER. On screen 1/2 leave the top value at +0 but adjust the lower value to +100. (The line graph should go from centre to top right).
Return to the main Program Mix menu and select a fourth mix. Set screen 2/2 up exactly as above but set the SLAVE to CAMBER instead of rudder. On screen 2/1 adjust the top value at -100 but leave the lower value to +0. (The line graph should go from centre to top left).
Check with the servo monitor. This should now give you rudder control with both halves when the air brake is partly deployed and one half will pull in when fully deployed.
Depending on the linkages, it may be necessary to reverse the servos or use mirror images on some of the mixes. This is something you will have to work out for yourself with the model in front of you but hopefully my ideas will be of some help.
05-06-2024, 04:52 PM
#9
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Thanks Malcolm. The first free afternoon I have I will sit down and fumble through this. There is no clash with anything yet as this is the first thing I am trying to program. Everything else is straight forward. It is a Space Shuttle. So a delta wing with one elevon on each side and the split rudder on the vertical. That's it for aerodynamic controls. The other controls Are throttle, steering and retracts. I have no problem without rudder trim or steering trim. I can do any adjustments with the linkages, ( Old School). I'll try and take a few pictures of the project and post them here.
