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Sequoia 2m - Build log
- Thread starter thenated0g
- Start date
chadbastian
New User
chadbastian
New User
Doc James Hammond
Very Strong User
Guys does this mean that both flaps move as one - like a control line model? Or are they individually adjustable?
Hard to see from the pics.
Doc.
chadbastian
New User
Right, good advice. I'll go do that, thanks!
chadbastian
New User
They are individual and can be used any way you program them. I set them up under Camber on my Spectrum transmitter, but my good friend can throw a switch and marry them to the ailerons for more fun! Way beyond my skill level at this time.
This particular model does not offer a lot of upward travel on the flaps - maybe 8mm, just FYI. I suppose that could be enhanced with a little work.
Konrad
Very Strong User
I find that you don't need as much up flap as aileron. In fact too much aileron flap mix actually slows things down. I have done this mix with an old DX9. With the Spektrum pull down menus it can be a bit difficult to get the action you want but it was doable. All my flight mode use aileron flap mix other than landing (crow). Do make sure the mix allows for more up flap than down flap when using the flaps as ailerons. Otherwise the adverse yaw will kill any directional control.
chadbastian
New User
Thanks, Konrad. Much of this is still way over my head, bit I am learning. I toned my ailerons down as they were pretty excited. I put the DR at 40% for high rate and 20% low with expo at 50%. There's a lot of throw with these! Maybe later I will increase this.
Konrad
Very Strong User
Have you flown this bird? WOW, why so low a servo resolution? If you need such a low high rate value you might want to look into moving the push rod a lot closer to the servo output shaft. I try to set up my servos to need 100% to 120% servo motion. This might give you some ideas as to how I got a 4.4mm long servo arm by threading the push rod into the servo arm. .This gains me a lot of resolution and power at the cost of some speed. What is real nice about the IDS is that the smallest arm is really good for this.
I'm not tell you what is good or bad. But having an expo of more than 20% often makes it difficult to make smooth maneuvers.
I'm not tell you what is good or bad. But having an expo of more than 20% often makes it difficult to make smooth maneuvers.
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Motowncali
Active User
Chad, 40% and 20% are very low numbers. What is the movement of the aileron at the trailing edge? Completely agree that D/R set this low is not a good idea. Pulling out the servos and going to a shorter arm is the solution. Best guess, low rate should be about 1/4-3/8” travel, but you are likely going to want a high rate 1/2-5/8” so that when you slow the plane down to land, you still have some control. You want the center stick to feel about the same for both rates, so low rate expo around 20-25% and high rate 30-40%.
chadbastian
New User
Ok, first flight went great! I walked up about 50 feet from our field and threw the javelin (that's what it feels like!). Took a second to stabilize, as I need to learn how to launch this girl. High rate was pretty nice, I will probably move both low and high up higher. I was just nervous about such a fast ship with all that throw. I will check the aileron deflection amount later when I assemble her again and report back.
I soared around the lower slope for about half an hour, walking slowly backwards until I was about 80 feet above the field. This Sequoia is so efficient that it could use every bit of lift it encountered. Any other sailplane I fly would have been on the ground in a matter of minutes, as the lift/wind was very light.
I finally got to playing with the flaps, and found that the plane pitches dramatically up when I add full flaps (landing setting). I'll need to mix something in to balance this, as it really upsets her. After a pitch up, she noses down and made me glad I tried it at altitude. Any suggestions here would be welcome.
I soared around the lower slope for about half an hour, walking slowly backwards until I was about 80 feet above the field. This Sequoia is so efficient that it could use every bit of lift it encountered. Any other sailplane I fly would have been on the ground in a matter of minutes, as the lift/wind was very light.
I finally got to playing with the flaps, and found that the plane pitches dramatically up when I add full flaps (landing setting). I'll need to mix something in to balance this, as it really upsets her. After a pitch up, she noses down and made me glad I tried it at altitude. Any suggestions here would be welcome.
Konrad
Very Strong User
Yes. flaps are horrible for this! This is why we use crow. The upward going aileron cancels (to some extent) the pitching moment of the added chamber from the added flaps. As you are flying a Spektrum I can say that the manual (my DX9) is a bit light on how to do this, but it is there. Also you can find some videos by Speedster that have helped my with the Spektrum radio.
So in crow I like to start with about 18% down mix, with just flaps the need for 30%+ is not uncommon! I find that this mix is best done with an asymptotic shaped curve. That is the mix needs to coming fast early in the deployment and then slowly level out.
So in crow I like to start with about 18% down mix, with just flaps the need for 30%+ is not uncommon! I find that this mix is best done with an asymptotic shaped curve. That is the mix needs to coming fast early in the deployment and then slowly level out.
chadbastian
New User
Thanks, I will have to source out how to do this. It's my first plane with real flaps, I've used camber on ailerons before but this is different. So in short, I mix some up aileron into the down flap landing setting? Am I getting the gist? Do I add any v-tail input? Thanks in advance...
chadbastian
New User
Ok, so here are the measurements of aileron throw:
Low rate is 12mm and high rate is 20mm both up and down. Looks like a lot to me, but maybe it's good since this is a larger sailplane than I am used to.
On the ailerons I increased the D/R to 30/50% and reduced the Expo to 20% for both.
My v-tail seems to have less travel so I increased these as well:
Elevator: D/R is now 60/100%, Expo is 20% for both.
Rudder: D/R is now 70/100%, Expo is 20% for both.
For the Flap setting, I brought the travel down slightly from 100% to 90% as they were making some noice at 100% (maybe not quite squared up?). I then changed the Camber preset to up 30% to offset the ballooning effect the flaps were having.
I am off to studying the Speedster videos and looking for calmer days, the wind has been in a frenzy...
Low rate is 12mm and high rate is 20mm both up and down. Looks like a lot to me, but maybe it's good since this is a larger sailplane than I am used to.
On the ailerons I increased the D/R to 30/50% and reduced the Expo to 20% for both.
My v-tail seems to have less travel so I increased these as well:
Elevator: D/R is now 60/100%, Expo is 20% for both.
Rudder: D/R is now 70/100%, Expo is 20% for both.
For the Flap setting, I brought the travel down slightly from 100% to 90% as they were making some noice at 100% (maybe not quite squared up?). I then changed the Camber preset to up 30% to offset the ballooning effect the flaps were having.
I am off to studying the Speedster videos and looking for calmer days, the wind has been in a frenzy...
Great to hear about the low wind performance. I'm not super surprised though, she is pretty light for how much wing she has. Should be a VERY well rounded slope ship.
With my Frsky radio I can adjust the flap to elevator compensation while in the air. Sure makes dialing in that mix easy. (I use throttle trim to adjust the mix.)
With my Frsky radio I can adjust the flap to elevator compensation while in the air. Sure makes dialing in that mix easy. (I use throttle trim to adjust the mix.)
chadbastian
New User
Oh wow, I didn't know you could do that. That would be nice...
Mike Shellim has some good stuff over on his blog as well as templates for FrSky that are pretty involved. Worth checking out over here https://rc-soar.com/opentx/
