Flap switch as UP elevator on Hand launch of Delta Wing

[dmarko]

I figured out the programable mixing on my Spektrum DX6 to use the flap switch "on" position to keep elevons a bit up on hand launching my delta wing. From elevons neutral position I have 50% movement up programmed into this switch. My hope is that when it is hand launched overhead while holding the skid at full power I can then just flip the FLAP switch off once its airborn.

My question is:
Is 50% too much or too little or just right ?

The worse case I see that maybe it will want to do a loop in a split second before I can instantaneously switch the FLAP switch off.

CG seems perfect..

Thanks
David

[EpoweredRc]

um. have you flown it before? you know deltas flying wings take a lil up in the elevons to even fly right!. 50% of anything seems like to much but again no clue where your EPA's are set or how touchy u have it

[mesh]

Why not hold the elevon stick with one hand, and launch the plane with the other
Launching with the wrong hand isn't that hard, if you side-launch it.
(yes, I have a cheap-ass radio without mixes

[dmarko]

Epowered - 50% goes a tad bit less than where my low rates are set for smooth operation.

Mesh - I'm bound to mess up trying that . Plus it would put full throws or (low rates throws) and I'm bound to get confused in all the excitement.

Epowered - I tried to fly with landing gear and could never get it off the ground. Weight was lower than 2 different motors I tried (Eflite 480 and then Eflite Power 10) outrunners. Now I'm back to no landing gear and redid front with an Eflite 450 motor also an outrunner swinging a 11 * 4.7 prop. Watts per pound at WOT are 112 watts per pound calculated on the AUW of 27 ounces.
CG is dead on based on running the numbers for a delta calculator at 6.5" behind motor mount.

Here is pic. This is with landing gear. Now it doesn't have them.

[RU55EL]

I like to use the three position flap switch on my DX7 in a similar way with my 33" flying wing.

In normal position, I have the wing trimmed to fly level at full throttle.

In position one, trimmed for level flight at about half speed.

In position two, trimmed for level flight a slow speed.

When I hand launch, I put the flap switch in position three and side launch with the motor at full throttle. Once the wing is starts to climb I switch the flap switch to normal.

I spent a couple hours launching and landing so that I could dial in the "flap" (elevon) positions for each speed. The percentages really depend upon the plane. If I use a battery weighing 80 grams instead of 95 grams, with the wing CG adjusted accordingly, the "flap" (elevon) positions are way off. With the smaller battery full throttle isn't too far off, but position one (mid) is almost too much up elevon for slow flight. So, it really has to be adjusted to the plane.

In short, whatever pecentage allows you to fly at the plane's slow speed without having to give any up elevator should work fine for hand launch.

[flymess]

Originally Posted by dmarko

I figured out the programable mixing on my Spektrum DX6 to use the flap switch "on" position to keep elevons a bit up on hand launching my delta wing. From elevons neutral position I have 50% movement up programmed into this switch. My hope is that when it is hand launched overhead while holding the skid at full power I can then just flip the FLAP switch off once its airborn.

My question is:
Is 50% too much or too little or just right ?

The worse case I see that maybe it will want to do a loop in a split second before I can instantaneously switch the FLAP switch off.

CG seems perfect..

Thanks
David

I know I'm a year late on this thread but I'm having the same problem with launching my Delta. I have been giving it full up trim on the elevator and then retrimming in flight but this is not really satisfactory. Thanks to your thread I got some ideas and thought I'd better get more aquainted with the functions on my DX6i. I figure the Dual rate switch must be there for some reason so I've set it so that when the switch is on zero, its set at 50%, then when it's flicked on it's 100%. I plan to launch at 100% then flick back to 50%. Not sure if it will work. Hope the rain stops by tomorrow.

[JetPlaneFlyer]

Originally Posted by RU55EL

I like to use the three position flap switch on my DX7 in a similar way with my 33" flying wing.

In normal position, I have the wing trimmed to fly level at full throttle.

In position one, trimmed for level flight at about half speed.

In position two, trimmed for level flight a slow speed.

Sounds very much like you need to add some downthrust, and or tweak the CG back a bit.. You really shouldn't have to mess about with different flap settings for different power levels, a well trimmed plane should fly reasonably level across a wide range of throttle settings.

[UncleBob]

Originally Posted by RU55EL

I like to use the three position flap switch on my DX7 in a similar way with my 33" flying wing.

In normal position, I have the wing trimmed to fly level at full throttle.

In position one, trimmed for level flight at about half speed.

In position two, trimmed for level flight a slow speed.

When I hand launch, I put the flap switch in position three and side launch with the motor at full throttle. Once the wing is starts to climb I switch the flap switch to normal.

I spent a couple hours launching and landing so that I could dial in the "flap" (elevon) positions for each speed. The percentages really depend upon the plane. If I use a battery weighing 80 grams instead of 95 grams, with the wing CG adjusted accordingly, the "flap" (elevon) positions are way off. With the smaller battery full throttle isn't too far off, but position one (mid) is almost too much up elevon for slow flight. So, it really has to be adjusted to the plane.

In short, whatever pecentage allows you to fly at the plane's slow speed without having to give any up elevator should work fine for hand launch.

This is precisely how I have it set up as well, works fine.

[UncleBob]

Originally Posted by JetPlaneFlyer

Sounds very much like you need to add some downthrust, and or tweak the CG back a bit.. You really shouldn't have to mess about with different flap settings for different power levels, a well trimmed plane should fly reasonably level across a wide range of throttle settings.

I CG to the back of the battery hatch on a WW, and it has such a wide range of flight speeds I use the 3pos switch same as he does.

[flymess]

Originally Posted by RU55EL

I like to use the three position flap switch on my DX7 in a similar way with my 33" flying wing.

In short, whatever pecentage allows you to fly at the plane's slow speed without having to give any up elevator should work fine for hand launch.

My DX6i has only two positions on the flap switch but I can't get it to work at all. There must be more steps involved than just selecting "flaps" and typing in a percentage. Can someone please enlighten me on how it's done? The manual is basic. thanks in advance

[JetPlaneFlyer]

Originally Posted by UncleBob

This is precisely how I have it set up as well, works fine.

If you are happy fiddling with flap settings every time you move the throttle then that's fine.. I guess you might get used to it eventually (though i know i wouldn't).
Lets just say the 'traditional' way of trimming a plane so it doesn't pitch up or down when you change power levels is by using thrust offset (downthrust).

It might be worth trying? 2-3 deg down is usually in the right ballpark for most planes but you need to experiment to find the optimal setting.

Steve

[Davethebluessinger]

I have a problem with the CG on my swift II. Its exactly where the manufacturer states it should be but even with major downthrust and lead on the nose it wants to climb.
Can anyone tell me how to set up the flap switch for launch/flight on the DX 6i please?
Thanks
Dave

[UncleBob]

Originally Posted by JetPlaneFlyer

Lets just say the 'traditional' way of trimming a plane so it doesn't pitch up or down when you change power levels is by using thrust offset (downthrust).

I don't use it for power levels, I use it for two things; to (pre)set the trimmed airspeed and to apply a little up elevator while my right hand is busy hand launching.

[Davethebluessinger]

Hi UncleBob,
Thats exactly what I meant. I need to preset someup elevon for launch then knock it off once airborne into a level flying trim. Just wondered how you did it using the Flaps feature on the DX6i?

Dave

[flymess]

Originally Posted by Davethebluessinger

Hi UncleBob,
Thats exactly what I meant. I need to preset someup elevon for launch then knock it off once airborne into a level flying trim. Just wondered how you did it using the Flaps feature on the DX6i?

Dave

Me too Dave, I asked this question in April but got no help. I've moved on from that delta because of that problem but would love to fly it again if I can get a friendlier launch.

[Octavius]

I'd say just forget the programming and work more on your launch technique. i.e. 45 deg angle and then by the time you get your hand back on the Tx it shouldn't be below level flight.

[UncleBob]

Originally Posted by Davethebluessinger

Hi UncleBob,
Thats exactly what I meant. I need to preset someup elevon for launch then knock it off once airborne into a level flying trim. Just wondered how you did it using the Flaps feature on the DX6i?

Dave

Originally Posted by flymess

Me too Dave, I asked this question in April but got no help. I've moved on from that delta because of that problem but would love to fly it again if I can get a friendlier launch.

Sorry, I wasn't ignoring you, I don't have an answer for you since I use the DX7. I am just hoping you get help from a fellow DX6i user.

[cbatters]

Assuming you have the right amount of reflex dialed into your delta for normal flight, I would just launch at full power on low rates at a 20-30 degree angle. (took me a while to realize that delta wings need up elevon for normal flight which I believe is called reflex. I tuned this by hand launching without power while adding up elevator until I got a good glide.)


Ps - Flying a Great Planes Miglet jet as my first delta EDF. A blast.

[flymess]

Originally Posted by UncleBob

Sorry, I wasn't ignoring you, I don't have an answer for you since I use the DX7. I am just hoping you get help from a fellow DX6i user.

Hi UncleBob, it was an open question, I wasn't expecting help from anyone in particular. On the DX6i the flap function just doesn't seem to work or I'm not doing it right (probably the latter, there's still a lot for me to learn about this little gadget)

[Freehands]

Need Advice, I have a DX6i radio and I'm trying to program the elevon function.
I want the right stick to raise and lower both elevons for pitch control and right and left for roll. I activated "Elevon" control in "Wing Tail Mix" but when I use the right stick the functions are reverse. Up and down gives me right and left aileron roll and right and left gives me up and down pitch control. What am I doing wrong. Any advice will be appreciated, it's probably something simple... I hope.

[JetPlaneFlyer]

Originally Posted by Freehands

Need Advice, I have a DX6i radio and I'm trying to program the elevon function.
I want the right stick to raise and lower both elevons for pitch control and right and left for roll. I activated "Elevon" control in "Wing Tail Mix" but when I use the right stick the functions are reverse. Up and down gives me right and left aileron roll and right and left gives me up and down pitch control. What am I doing wrong. Any advice will be appreciated, it's probably something simple... I hope.

You need to reverse one of the servos(the one that goes the wrong way) which is easily done in the programming.

[flymess]

Originally Posted by Freehands

Need Advice, I have a DX6i radio and I'm trying to program the elevon function.
I want the right stick to raise and lower both elevons for pitch control and right and left for roll. I activated "Elevon" control in "Wing Tail Mix" but when I use the right stick the functions are reverse. Up and down gives me right and left aileron roll and right and left gives me up and down pitch control. What am I doing wrong. Any advice will be appreciated, it's probably something simple... I hope.

Hi Freehands. I've been where your at. It's a case of trial and error. In my set-up it's right side (looking from aft) goes to aileron on rx, left to elevator. Then you just try reversing one or the other using the reverse function. There's only so many options. If it doesn't work then switch your servos on the rx and try again. Hope this helps.

[Freehands]

Thanks Guys, the hobby is getting complicated. I started flying electric when they were still using the RC car batteries, like putting a brick in your plane. I'll try the reversing servos using the radio, I've tried unplugging on the rx and reversing but that didn't work.
I'll keep you posted. Need a fancy picture for my profile... 20 years in the Air Force, I should be able to come up with something.

[Davethebluessinger]

Yep, go to the menu "Adjust List" scroll to the very bottom to "Setup List", Scroll to and select the "reverse" option then reverse the aileron channel. I just changed out some 9g generic servos for some 12g towerpros in my MS Composit Mini Swift and everything was back to front!
I had to reverse both Elevator and Aileron channels to get things working correctly.
The 9g servos only required the aileron to be reversed.

[JetPlaneFlyer]

You may have to reverse the auxiliary channel rather than the aileron one.. It depends which is moving the wrong way.