bracesport DLG

bracesport

Legendary member
@The Hangar - correct!

I will add some guides for the tail pull strings to navigate past the aileron servos - actually this is the only ship I have flown with a rudder! I have being trying to use it when pointing into the wind as I tend to over use the elevator/ailerons for what should be a gentle turn. :)
 
Last edited:

bracesport

Legendary member
On to the aileron pushrods.

The secret for doing this is to glue (epoxy) wire with L bend into one end of CF rod (for both rods) - usually this is the aileron end of the rod - let this end fully cure before you move on - make up the L bend wires for the servo end - put a small 10mm block between the fixed bit of the wing and aileron to 'jack up' the aileron by 10mm and put some masking tape or something to bind it together so blocks don't fall out and the aileron is firmly on the block - set the servos to both full up (with no trim, sub-trims, offsets etc) - use calibration mode (or a servo tester) - put slow-setting epoxy on the L bend wires and in the hole of the servo end rod and put the wires into the rod - now let epoxy cure - remove wing and rods and bind the rod ends in kevlar thread and soak with CA - re-assemble and program up radio.

I m at the stage where I am ready to glue in the servo end L bend. :)

IMG_1540.JPG
IMG_1543.JPG
IMG_1544.JPG
IMG_1549.JPG
IMG_1550.JPG
IMG_1551.JPG
 

bracesport

Legendary member
I have set up a new OTX and will fire it all up next week to finalise the aileron arm position. I have some pull strings that are a braided fishing line, but my mates tell me to use wire. I will have a look through my supplies to see if I have anything suitable. :)
 

bracesport

Legendary member
this morning I checked the centres and end points before glueing in the servo end 'L' rods - first I made a 10mm block to hold the ailerons in the most up position - then I pushed some slow cure epoxy into the CF push rods with a fine wire - then I rolled the 'L' rods in epoxy and slithered them into place - I then fired up the radio and while in calibration mode (servos travel together) I put the servos in their highest position and then disconnected the battery - now I will leave it to cure.

I also inserted two pull wires to draw through the pull strings. :)

IMG_1563.JPG
IMG_1564.JPG
IMG_1566.JPG
 

Wildthing

Legendary member
this morning I checked the centres and end points before glueing in the servo end 'L' rods - first I made a 10mm block to hold the ailerons in the most up position - then I pushed some slow cure epoxy into the CF push rods with a fine wire - then I rolled the 'L' rods in epoxy and slithered them into place - I then fired up the radio and while in calibration mode (servos travel together) I put the servos in their highest position and then disconnected the battery - now I will leave it to cure.

I also inserted two pull wires to draw through the pull strings. :)

View attachment 193201 View attachment 193202 View attachment 193203
Did you knurl or roughen up the ends of the rods so the epoxy had more to hold onto?
 

bracesport

Legendary member
so while the dust settles I am tinkering with my TX setup - running Open TX is pretty cool and there is always something to improve and endless possibilities to try - as some of you may know I have a generic setup on the radio (a default setting if you like), and by holding the ail/ele stick in various positions and hitting a switch I introduce more modes (like DLG launch, or slope soaring rates) - this is working well.

for the DLG in particular, the flaperon servos sit above centre with the TE's aligned to the root TE to have minimal up travel, and heaps of down travel for the brakes - I have to be honest and say this was a bit of a challenge and none of the standard flaperon settings/tutorials seem to explain properly how to do it - so I have worked on two ways that I will fine test/tune on the DLG.

both setups use curves to match the max/min throws in the outputs window - that will ensure the servos are never over driven - at this point with the servos centred the TE's of the flaperons will droop slightly below the root TE - both setups also use a curve for the brakes on the throttle stick to drive them from zero to max down with a bit of wiggle room for aileron control when braking - my servos are only using 80% of their travel in each direction.

setup 1 - uses 80% weight and 20% offset (the 20% offset makes the FLAPPERON TEs align with the root TE) and DIFFERENTIAL is applied via Gvars in their respective flight modes - the throttle weight is 120% to account for the 20% servo centre offset - you can see in the images that the flaperons in CRUISE are 16% up (16/80 max throw = 20% offset) - you can see in THERMAL mode they are cambered down 6% with 2% ELEVATOR compensation - can see in the final image with full right AILERON the left side is drooping less with the DIFFERENTIAL.

All these settings will be tweaked on the model, but the theory seems to be working.

Screen Shot 2021-02-28 at 6.06.18 PM.png

thumbnails
Screen Shot 2021-02-28 at 6.02.48 PM.png Screen Shot 2021-02-28 at 6.03.07 PM.png Screen Shot 2021-02-28 at 6.07.15 PM.png Screen Shot 2021-02-28 at 6.17.21 PM.png

setup 2 - uses essentially the same setup but for the AILERON and DIFFERENTIAL settings I am using curves - you can see the curve in CRUISE mode (AiC) has the centre +20 and the left aileron drooping less with full right AILERON - you can also see the in SPEED mode (AiS) there is no difference in aileron travel - in this way the curves can accurately control the position and differential.

each curve is triggered in its respective flight mode (speed, cruise, thermal) - note that the CRUISE mode is also used for the LAUNCH modes.

Screen Shot 2021-02-28 at 6.29.34 PM.png

thumbnails
Screen Shot 2021-02-28 at 6.27.16 PM.png Screen Shot 2021-02-28 at 6.35.23 PM.png Screen Shot 2021-02-28 at 6.26.43 PM.png Screen Shot 2021-02-28 at 6.35.42 PM.png

one other thing I am trying is using a stepped curve in the CALIBRATION of the FLAPERONS - the idea is that the throttle stick is the INPUT and INDEXED to -100/-50/0/50/100 which (in theory) will snap the FLAPERONS through 5 points of travel - given the THROTTLE stick is unsprung the stick position is maintained allowing you to focus on trimming the FLAPPERON servo curves - we shall see!

Screen Shot 2021-02-28 at 6.45.22 PM.png
 
Last edited:

flyboa

Elite member
I was wondering if when at full flaps the plane is just about stopped and the wing stalled. Is it possible to reverse aileron control so to turn right the right aileron would go down more instead of up. Since it is stalled anyway why not just grab more air and increase drag to get the plane to turn in that direction.

Or maybe just run 100% reverse differential and not let the wing stall.
 
Last edited:

bracesport

Legendary member
it is interesting what you say - you can do anything in Open TX programming! You can easily change to reverse Dif when the throttle stick comes into play with braking - something to try I guess!

I was wondering if when at full flaps the plane is just about stopped and the wing stalled. Is it possible to reverse aileron control so to turn right the right aileron would go down more instead of up. Since it is stalled anyway why not just grab more air and increase drag to get the plane to turn in that direction.

Or maybe just run 100% reverse differential and not let the wing stall.
 

bracesport

Legendary member
here is a video of my setup progress using curves to adjust the flaperons for the DLG - this is my setup 2 from a previous post - the upside is that it is easy to set the profile of each flight mode (including differential), but it does not enable inflight adjustment of the differential - the camber can be adjusted which is probably more useful.

in the video there is a quick overview of the universal settings I am setting up (not a how to) - the logical functions and the special functions are used to make it all possible.

Still a bit of tinkering required, but we are almost ready for flying now!

 
Last edited: