Flap question

[Tmcfarland]

I am building a 3 meter REF glider. First time setting up flaps. X14 transmitter and a GR6 receiver. Flaps are on channels 5 and 6 and activated by the AB switch. I have it set for a slow down (1.5 sec) and fast up (0 sec). Works fine going down but when I retract flaps they come up at a slightly different speed. Just enough that I worry it might induce a roll. I am wondering if it could be a servo issue. I am using Emax servos. Any ideas would be appreciated.
Tom.

 

[Red]

Hi Tom,

I can't be of much help with your programming on the X14, but assuming that is good I would look hard at your linkage geometry. I have seen this very thing happen due to small differences side to side.

Start with the servo, assuming they are both centered with minimal differences in sub-trim. Are the arms in the same spot? Even 1 spline off can cause a mis-match. Are the pushrods the same distance from the center of the servo? Are the pushrods the same height on the control horn? Are they attached in the same spot, fore/aft on the horn relative to the hinge line?

A couple of pics might help.

Cheers
Red

 

[gnichola]

To the speed difference, I would first go to the Outputs page and flip your flaps switch to see that both flap channels do in fact return to "up" immediately.
Second, and I am most certainly not the expert here, but I have to ask why your flaps would be on a switch? In my (limited) experience, flaps are put on a stick, either the throttle or one of the side sliders.
I would seriously consider using Mike Shellim's F3F template from here: https://rc-soar.com/ethos/templates/f3f/

 

[Tmcfarland]

Hi Tom,

I can't be of much help with your programming on the X14, but assuming that is good I would look hard at your linkage geometry. I have seen this very thing happen due to small differences side to side.

Start with the servo, assuming they are both centered with minimal differences in sub-trim. Are the arms in the same spot? Even 1 spline off can cause a mis-match. Are the pushrods the same distance from the center of the servo? Are the pushrods the same height on the control horn? Are they attached in the same spot, fore/aft on the horn relative to the hinge line?

A couple of pics might help.

Cheers
Red

I believe it is all in order. But I will double check. Thanks for the help.

 

[Tmcfarland]

To the speed difference, I would first go to the Outputs page and flip your flaps switch to see that both flap channels do in fact return to "up" immediately.
Second, and I am most certainly not the expert here, but I have to ask why your flaps would be on a switch? In my (limited) experience, flaps are put on a stick, either the throttle or one of the side sliders.
I would seriously consider using Mike Shellim's F3F template from here: https://rc-soar.com/ethos/templates/f3f/

 

[Tmcfarland]

Thank you. I will check that.

 

[Wayne]

First off - Do not know why people love to put their flaps down with the speed setting. DONT.

Totally agree with not using a switch for flaps. You may want to use a switch for camber, but not for flaps. That is an old school hold over when radios were dumb and forced us to use a switch as the companies were cheap and a switch cost less than a pot, and they had not worked out the ergonomics of using another pot.

 

[Tmcfarland]

First off - Do not know why people love to put their flaps down with the speed setting. DONT.

Totally agree with not using a switch for flaps. You may want to use a switch for camber, but not for flaps. That is an old school hold over when radios were dumb and forced us to use a switch as the companies were cheap and a switch cost less than a pot, and they had not worked out the ergonomics of using another pot.

I saw a YouTube by Frsky Steve and he suggested a Slow down of 2 seconds on flapsso the glider won’t ballon up. Made sense but this is all new to me. How should I control flaps. Not sure what a pot is. On my x14 I see switches, sliders, knobs and buttons.

 

[gnichola]

Again, Mike Shellim's template allows for elevator compensation trim using a 5 point curve. Doing that will avoid the ballooning problem

 

[gnichola]

re: switch vs. stick. Again, not an expert here, and I don't know your experience with gliders, but when I land, I am constantly playing with the flap control (throttle in my case) to adjust speed and descent. There is no way I would try to fly with them being on a switch.

 

[Hill Hobbit]

Tim, your glider is not a warbird, it’s a lightly loaded thermal ship. As such, you need to control the flaps using the throttle stick. You don’t have the brakes on your car operated by a switch in an on/off fashion do you? No, the amount of braking is regulated by how hard you press the pedal.
In terms of our gliders, whether on the slope or a flat field, having the ability to slow down or speed up the model for landing using a proportional control (the throttle stick) gives the pilot the ultimate in control. It’s a revelation as you learn how to use them properly for the first few times, believe me!
Please Tim, if your model doesn’t have a motor, install Mike Shellim’s F3f template and make life for yourself really easy. For REF control, plug your rudder servo into the aileron output, then just follow the flap set up steps in the manual, not forgetting the elevator compensation set up as well. The correct down elevator compensation curve is very important.

Mike’s template also offers you the very useful thermal/climb mode, which will give you much better height gain in low lift then “wow” in a good thermal, even though you’re only using flaps. Again, this is already set up for you, you just have to input how much maximum camber you may want, then it is adjusted in flight by a knob or a slider of your choice if you want to do so.

If you choose to not take this advice, I’ll leave it up to others to try and help out
All the best!

 

[Tmcfarland]

re: switch vs. stick. Again, not an expert here, and I don't know your experience with gliders, but when I land, I am constantly playing with the flap control (throttle in my case) to adjust speed and descent. There is no way I would try to fly with them being on a switch.

Thank you. I moved them to a slider and they work great. Using templates is beyond my capability for now. But I am learning.

 

[Tmcfarland]

Tim, your glider is not a warbird, it’s a lightly loaded thermal ship. As such, you need to control the flaps using the throttle stick. You don’t have the brakes on your car operated by a switch in an on/off fashion do you? No, the amount of braking is regulated by how hard you press the pedal.
In terms of our gliders, whether on the slope or a flat field, having the ability to slow down or speed up the model for landing using a proportional control (the throttle stick) gives the pilot the ultimate in control. It’s a revelation as you learn how to use them properly for the first few times, believe me!
Please Tim, if your model doesn’t have a motor, install Mike Shellim’s F3f template and make life for yourself really easy. For REF control, plug your rudder servo into the aileron output, then just follow the flap set up steps in the manual, not forgetting the elevator compensation set up as well. The correct down elevator compensation curve is very important.

Mike’s template also offers you the very useful thermal/climb mode, which will give you much better height gain in low lift then “wow” in a good thermal, even though you’re only using flaps. Again, this is already set up for you, you just have to input how much maximum camber you may want, then it is adjusted in flight by a knob or a slider of your choice if you want to do so.

If you choose to not take this advice, I’ll leave it up to others to try and help out
All the best!

Thank you. Moved to a slider. Works great now.

 

[Hill Hobbit]

The template mentioned by myself and Guy is the easy, simple to set up way to do what you want properly. No ‘capability’ required at all. You’ve got the wrong end the of the stick about this, believe me.

7 years ago, a friend of mine who had flown only power models using a Spektrum DX9, decided to join me and the crew on the slopes. He tried to set up his radio for a full house glider but found it very hard, so I suggested he get a Frsky Taranis x9d + and use Mike’s template. At 75 and a computer phobe, he set up his plane on his own using the manual very nicely.
The only thing that needed adjusting was the down elevator compensation curve, which is always unique to any model using flaps. Another mate the same age (even more of a computer phobe if that was possible) got the same radio soon after, purely in order to use the template. He hasn’t looked back.

Flaps on a slider? Nope… Throttle stick yes

Down elevator compensation on a curve the way you’ve got them ‘working’? It’s 100% essential for a model with flaps.

 

[Wayne]

I saw a YouTube by Frsky Steve and he suggested a Slow down of 2 seconds on flapsso the glider won’t ballon up.

Ahh yes.. That guy is not a very good source of information.

Properly set your plane will not change in pitch when flaps are deployed. And the "slow" command would only delay the ballon anyhow.

 

[JustinMader]

Recently learned all this the hard way . I put flaps on a switch for the FC to do the work per documentation (Ardupilot). As I never use flaps for landings, I never considered how much I'd like them adjustable as the approach gets closer. Just yesterday, having them static biffed a landing, so moving control to a knob/slider sounds like wonderful advice.

 

[gnichola]

I fly with a guy that "single hands" it (no rudder) and his "extra" hand is underneath the transmitter, so he uses the right hand slider. I have sat there "hovering" over the landing spot using the throttle stick and I can't imagine getting fine enough resolution from the slider.
@Tmcfarland I urge you to go read the setup guide here: https://rc-soar.com/ethos/templates/f3f/f3f-ethos-11_setupguide_EN.pdf

 

[Wayne]

Getting the most out of your flaps is a fun skill to master. I strongly suggest you play with different settings and try different configurations.. Fly with different approaches, etc. I can GUARANTEE this will be time very well spent.

Some ideas to test out:
Different ways to trigger the flaps (sliders, throttle stick, tied to low throttle when switch is flipped, etc.)
CROW/Butterfly - can be VERY effective even on things like a Cessna
90 degree down travel (if model can handle it)
Camber - Even on a Cessna a small amount of camber can help catch those big thermals blowing through

Flaps can really open up the capabilities of most any model. The exception tends to be very rare, but some planes should not use flaps. (We had a foam FW-190 that you could not use the flaps for landing, they made such a mess with the air that the elevator lost authority and the plane could not flare for landing.)

 

[Tmcfarland]

I fly with a guy that "single hands" it (no rudder) and his "extra" hand is underneath the transmitter, so he uses the right hand slider. I have sat there "hovering" over the landing spot using the throttle stick and I can't imagine getting fine enough resolution from the slider.
@Tmcfarland I urge you to go read the setup guide here: https://rc-soar.com/ethos/templates/f3f/f3f-ethos-11_setupguide_EN.pdf

Thank you. I will study the guide.

 

[Tmcfarland]

Getting the most out of your flaps is a fun skill to master. I strongly suggest you play with different settings and try different configurations.. Fly with different approaches, etc. I can GUARANTEE this will be time very well spent.

Some ideas to test out:
Different ways to trigger the flaps (sliders, throttle stick, tied to low throttle when switch is flipped, etc.)
CROW/Butterfly - can be VERY effective even on things like a Cessna
90 degree down travel (if model can handle it)
Camber - Even on a Cessna a small amount of camber can help catch those big thermals blowing through

Flaps can really open up the capabilities of most any model. The exception tends to be very rare, but some planes should not use flaps. (We had a foam FW-190 that you could not use the flaps for landing, they made such a mess with the air that the elevator lost authority and the plane could not flare for landing.)

Thank you Wayne. I plan to start slow and expand carefully. I am familiar with flaps in real sailplanes. I have over 500 hours in gliders of all types and used to own a Schweitzer 1-35 that had flaps only for glide path control. They dropped to 90 degrees. I used to love coming in high on final. With any headwind and full flaps it was like pointing it straight down and flairing at the last minute.