I have a similar sized wing, and tried maidenening it on 100 - 100 throw and expo. It was so much movement you could do high speed stalls and end-over-end flips. I've since tuned it, and it's down to 15% throw and 30% expo. These little planks are more sensitive then you'd think.
I watched and you have a good grasp on the way to set the controls. Planks are touchy in pitch but not so much in yaw. A wing will fly nose heavy but a Tail heavy wing will fly once. Last week I made a Weasel with a small motor on the nose. The thing that made it crash constantly was I was putting in expo and the throws were high. The problem was the expo was negative expo. I never use expo but this had needed it . Once I sat and played with it on the table. I noticed there was positive Expo. Got better instead of worse. On my spectrum you can increase expo on elevator or ailerons separate but I think you may be a bit still be a bit light in the nose. Porpoising could be Dutch Roll. Not sure. Love the plane. I dont think I have ever had a plank that would fly itself. Take your eye off for a second and risk a crash. Good luck ! Im impressed with the durability of it.
Taranis Radios show a curve that you can alter from 0 - 100. Probably the same, but I know the visual helps some people to understand it, especially as it tracks the stick all the way throughout the curve.
Followed you on the build on this one, and have been enjoying coming along for the adventure. For some reason, it's always fun watching other people crash for a change!😊
Excellent work Chris. Those Li-Ion packs are great. Did some preliminary testing with my sub250 long-range FPV setup and managed a 6Km flight using less than 15% of the battery capacity. Doesn't fly nearly as quickly as yours though :-)
That was just a lipo for now, but the li-ions have arrived and I made up a 2S pack for the next outing. There is a guy on TradeMe selling 'tesla' cells for $8 each, I hope they're not crap.
For a better control, you need to move your linkage to the closest hole on your servo to the pivot point and the furthest hole on your control horn from the Elevons. This will give you more servo movement and less elevon movement. This will give you more movement of the stick and a very small, precise movement of the elevon. Flying wings always need a small amount of reflex (upward pitch) to fly correct. You are on to a good thing, keep at it.
Good job on the build. It looks like a little nose heavy now, I'd start moving back in small increments. When you have what is essentially a 5 inch long plane (roughly the wing chord?) the cg will fall in a pretty narrow range. Slow glide will improve, you may need to decrease the throws even futhur.
Having just switched to a different transmitter brand, I wondered the same thing about percentages of expo. LOL! Seems to be sort of close to my old radio? My Nano Goblin needs full throttle and a hard toss on launch too. Kind of weird for such a little light plank eh?
Now you need to adjust the mechanics, so that you can use much more of the servo travel. That will make it much nicer to fly. Usually 40-50% expo is the most to use, but get the mechanics right first.
Throw it before applying power to find the correct CG. This is what I did when doing RC flights. I have decided to save for PPL/ATP as it is actually cheaper
You seem to have it flying well by 7.30. If it is sensitive in pitch, as all planks and tail-less swept wings are, reduce the down elevator. Nice little plank!
Been thinking about modding a Mini Talon into a twin tractor VTOL plank. The relative demensions wouldn't be much different than this one except much larger, obviously.
Before you cut up the fuselage by making it shorter, try giving an up or a down relative to the wingspan, You are getting a lot of lift from the fuselage!
Re expo - on the FlySky is the equivalent of + expo on Frsky stuff, drives me about as nuts as these drive me trying to fly these little buggers too, nothing but a perfectly still day will do, the launches are sketchy as heck, high stall speed and generally acting like a toddler whose just been told he can't have chocolate at the checkout.... But fun(ish) all the same, light as nothing though, don't hurt a bit when they hit you lol... Need to keep the speed up on these little shits like an EDF so I'm told.
With a similar platform slope soarer I have I had to reduce the pitch travel to 20% to even fly it. The ailerons travel is at 80%. I don’t use much expo - about 30%
Maybe stabilize it with INAV? From what i heard about dynamic soaring planks, they have very small control surface travel. Something like 4mm total travel!
Nice aircraft. However you were progressively making the the situation worse with the control adjustments. By increasing the expo to ridiculous levels and reducing the control throw electronically that much, you have removed almost all the control resolution at the stick. Also you have run out of pitch authority at low speed, hence the inability to flare. I suggest you measure your elevon movement as it is to establish a datum. Then restore all throws to 100%. Adjust your push-rods at both ends to achieve the datum throws mechanically. You have now full resolution, which will make it much easier to fly. Set all expo to 30% as a start point. At the current CG location you need more pitch authority at low speeds ( high AoA). So you need to increase the amount of UP throw, do this electronically is you can, some radios will allow up to 120 - 130% of travel. By doing this you are increasing resolution. If this isn't enough THEN adjust mechanically to give more throw. Adjusting mechanically will give you more aileron throw as well, which you WILL have to reduce electronically, but only to a max of 70, otherwise the resolution will suffer. All this will give you a decent start point for further fine tuning, both of the CG and throw and expo. eventually you will have a really dialed in aircraft which you trust. Most modellers give no thought or effort to go through this process, which can transform the way aircraft fly. You have a really thoughtful and analytical approach that makes these videos so engaging and enjoyable to watch. Hope this helps. Cheers.
Right, I have changed the linkage positions now but it was a pain in the butt to do in the middle of a flying session, especially when the much easier electronic methods were making it reasonably flyable and also showing me how much travel to set mechanically.
Oh, your videos are inspirational ! I want to build another DIY flying wing after watching your videos. Your videos have been a good resource of information.
I'm not sure stability is reasonable expectation of an aircraft engineered with no rudders, no horizontal "stabilizer" (hum, I wonder why they call it that?), no elevators, no dihedral, huge ailerons, and no weight allowance for an autopilot. Not even red paint would help very much. It is amazing, though, that it can be launched by tossing like a boomerang at about half of stall speed. Have you tried throwing it power-off to see if it would come back? Maybe it has a hypersonic pedigree working its way to the surface, and has no interest in flying around like a pregnant duck. That would explain it, and also suggest application of the universal fix for all aircraft problems: more speed! And maybe a couple red stripes down the side.
Wow, the flights at the End of the Video looking very promising👏🏻👏🏻👏🏻, do You have experimented with the Position of the Finns along the span? 🔔 is clicked👍🏻
There's not much leeway in the fin position because they would either hit the prop or the elevons. I don't think it would make a whole lot of difference.
?? MH64 has reflex, Clark Y does not. airfoiltools.com/airfoil/details?airfoil=mh64-il airfoiltools.com/airfoil/details?airfoil=clarky-il If you are guessing at the wing section how do you know it's incorrect :) But in any case, reflex is not critical as long as the elevons can cover for it.
dihedral on a plank? planks are usually set to a tiny, tiny bit negative dihedral, to keep it agile and responsive. fixing the fins, ans optimizing their size is key. especially with such small planes, it's important to keep all weight (servos, epoxy, glass) as much upfront as possible in order to give it a really short front fuselage. every bit of fuselage in front of the cg will introduce a counterforce to the tailfins.
..30% of what? Please stop talking about percent of travel and give us an idea of how many mm (for the decimal world) this is. In former days all models kits had these infos for every control. But finally even a plank flys well.
@@iforce2d .. but how much throw (mm) at the tip of the aileron/elevator? This all depends on the servo throw, servo arm length and the point to which the linkage is attached. This info is the only one which we need for all combinations. Btw, with so much expo it will be like a sport car equipped with an old american style servo steering. No control at the center.
"Looks like a fish, moves like a fish, steers like a cow". - D.Adams
What a beautiful place to fly!
Planks are a lot of fine tuning. If they survive tuning, they are fun!
I have a similar sized wing, and tried maidenening it on 100 - 100 throw and expo. It was so much movement you could do high speed stalls and end-over-end flips. I've since tuned it, and it's down to 15% throw and 30% expo. These little planks are more sensitive then you'd think.
Very thorough durability testing!
I watched and you have a good grasp on the way to set the controls. Planks are touchy in pitch but not so much in yaw. A wing will fly nose heavy but a Tail heavy wing will fly once. Last week I made a Weasel with a small motor on the nose. The thing that made it crash constantly was I was putting in expo and the throws were high. The problem was the expo was negative expo. I never use expo but this had needed it . Once I sat and played with it on the table. I noticed there was positive Expo. Got better instead of worse. On my spectrum you can increase expo on elevator or ailerons separate but I think you may be a bit still be a bit light in the nose. Porpoising could be Dutch Roll. Not sure. Love the plane. I dont think I have ever had a plank that would fly itself. Take your eye off for a second and risk a crash. Good luck ! Im impressed with the durability of it.
oh i just put a motor on my wisel, too
front seems unpractical to me, though
i've broken two props while "landing"
Taranis Radios show a curve that you can alter from 0 - 100. Probably the same, but I know the visual helps some people to understand it, especially as it tracks the stick all the way throughout the curve.
I admire your ability to make beautiful planes from foam. I always end up with a blocky plane.
Thanks. This is a very well documented video to walk people through the different response of the plane and what changes contribute to what.
Followed you on the build on this one, and have been enjoying coming along for the adventure. For some reason, it's always fun watching other people crash for a change!😊
Excellent work Chris. Those Li-Ion packs are great. Did some preliminary testing with my sub250 long-range FPV setup and managed a 6Km flight using less than 15% of the battery capacity. Doesn't fly nearly as quickly as yours though :-)
That was just a lipo for now, but the li-ions have arrived and I made up a 2S pack for the next outing. There is a guy on TradeMe selling 'tesla' cells for $8 each, I hope they're not crap.
@@iforce2d I'm using the LG 3000mAH 20A cells from PBTech. They seem to be working really well and when I bought them they were about $11 each.
Great to see the 200g flying!!
Thanks for sharing👍😀🎆
For a better control, you need to move your linkage to the closest hole on your servo to the pivot point and the furthest hole on your control horn from the Elevons. This will give you more servo movement and less elevon movement. This will give you more movement of the stick and a very small, precise movement of the elevon. Flying wings always need a small amount of reflex (upward pitch) to fly correct. You are on to a good thing, keep at it.
Yes, that's what I meant by "mechanical adjustment".
Good job on the build. It looks like a little nose heavy now, I'd start moving back in small increments. When you have what is essentially a 5 inch long plane (roughly the wing chord?) the cg will fall in a pretty narrow range. Slow glide will improve, you may need to decrease the throws even futhur.
Looks great. I enjoy the commentary and thoughts as you test/fly.
looks quite fast, a need for speed!
love your videos and your builds. all of them, the balloon, etc. as well.
Pretty sweet flying, dude! Really nice! 😃
Happy new year!!!
Neat Fast little plane........Wonder if Vortex Generators would help its slow speed handling ?
Brett
Great project, loved the plane and the maiden !
Good place & good plane !
Having just switched to a different transmitter brand, I wondered the same thing about percentages of expo. LOL! Seems to be sort of close to my old radio? My Nano Goblin needs full throttle and a hard toss on launch too. Kind of weird for such a little light plank eh?
С наступившим новым годом !
Now you need to adjust the mechanics, so that you can use much more of the servo travel. That will make it much nicer to fly. Usually 40-50% expo is the most to use, but get the mechanics right first.
Really cool !! Love it 👍
Throw it before applying power to find the correct CG. This is what I did when doing RC flights. I have decided to save for PPL/ATP as it is actually cheaper
You seem to have it flying well by 7.30. If it is sensitive in pitch, as all planks and tail-less swept wings are, reduce the down elevator. Nice little plank!
That flew great once you put the weight on
Very cool ! Well done , some performance slope planks only need 2-3mm elevon up or down as total throw and can be very hard to cg correctly
Could it be the fins not being secured? Maybe some wiggle in them?
Man that thing rips, makes me want to clone it!
or just buy a nano goblin :P
@@WX4CB Nothing better than flying something you made though
$75 seems a bit steep.
www.readymaderc.com/products/details/strix-nano-goblin-high-performance-fpv-plank-kit
flite test made one out of foamboard that looks a lot like it
Been thinking about modding a Mini Talon into a twin tractor VTOL plank. The relative demensions wouldn't be much different than this one except much larger, obviously.
Before you cut up the fuselage by making it shorter, try giving an up or a down relative to the wingspan, You are getting a lot of lift from the fuselage!
Re expo - on the FlySky is the equivalent of + expo on Frsky stuff, drives me about as nuts as these drive me trying to fly these little buggers too, nothing but a perfectly still day will do, the launches are sketchy as heck, high stall speed and generally acting like a toddler whose just been told he can't have chocolate at the checkout.... But fun(ish) all the same, light as nothing though, don't hurt a bit when they hit you lol... Need to keep the speed up on these little shits like an EDF so I'm told.
With a similar platform slope soarer I have I had to reduce the pitch travel to 20% to even fly it. The ailerons travel is at 80%. I don’t use much expo - about 30%
Great plane, do yo have plans for it ?
Waited for this one
Excellent
👍
Very like the Alula, it’s travel are tiny!
Would put the linkage on the inner hole on the servos and outer hole at the elevon levers ...
Yeah I did that for next time, still having to keep the travel at 50% though :)
17 min is awesome man
Maybe stabilize it with INAV?
From what i heard about dynamic soaring planks, they have very small control surface travel. Something like 4mm total travel!
Thanks Chris
Great educational video!
Nice aircraft. However you were progressively making the the situation worse with the control adjustments. By increasing the expo to ridiculous levels and reducing the control throw electronically that much, you have removed almost all the control resolution at the stick. Also you have run out of pitch authority at low speed, hence the inability to flare.
I suggest you measure your elevon movement as it is to establish a datum. Then restore all throws to 100%. Adjust your push-rods at both ends to achieve the datum throws mechanically. You have now full resolution, which will make it much easier to fly. Set all expo to 30% as a start point.
At the current CG location you need more pitch authority at low speeds ( high AoA). So you need to increase the amount of UP throw, do this electronically is you can, some radios will allow up to 120 - 130% of travel. By doing this you are increasing resolution. If this isn't enough THEN adjust mechanically to give more throw. Adjusting mechanically will give you more aileron throw as well, which you WILL have to reduce electronically, but only to a max of 70, otherwise the resolution will suffer.
All this will give you a decent start point for further fine tuning, both of the CG and throw and expo. eventually you will have a really dialed in aircraft which you trust.
Most modellers give no thought or effort to go through this process, which can transform the way aircraft fly.
You have a really thoughtful and analytical approach that makes these videos so engaging and enjoyable to watch. Hope this helps. Cheers.
Right, I have changed the linkage positions now but it was a pain in the butt to do in the middle of a flying session, especially when the much easier electronic methods were making it reasonably flyable and also showing me how much travel to set mechanically.
ahw yeah. seeing it fly! :D
Kinda.. i hate it when planes behave so weirdly ;p
Why do I keep trying? Last one. Haha. Yank and bank.
Would you try this again with the wings of a SpeedsterDEN Wisel?
Oh, your videos are inspirational ! I want to build another DIY flying wing after watching your videos. Your videos have been a good resource of information.
Ok well, that has been a great multiple-hour iforce2d binge
Will thut's all I huve fer today........ goo awey nauw
@@iforce2d Are we seriously subscribed to the same channels? This is uncanny
Hi Have you tried adding some reflex
Try a bit of down thrust on the motor, works for me
I'm not sure stability is reasonable expectation of an aircraft engineered with no rudders, no horizontal "stabilizer" (hum, I wonder why they call it that?), no elevators, no dihedral, huge ailerons, and no weight allowance for an autopilot. Not even red paint would help very much. It is amazing, though, that it can be launched by tossing like a boomerang at about half of stall speed. Have you tried throwing it power-off to see if it would come back? Maybe it has a hypersonic pedigree working its way to the surface, and has no interest in flying around like a pregnant duck. That would explain it, and also suggest application of the universal fix for all aircraft problems: more speed! And maybe a couple red stripes down the side.
lol some good laughs, thanks and Happy New Year :)
@@iforce2d A great new year to you too!
PS: got my CNC running. Thanks again for the videos you posted on the subject.
Wow, the flights at the End of the Video looking very promising👏🏻👏🏻👏🏻, do You have experimented with the Position of the Finns along the span?
🔔 is clicked👍🏻
There's not much leeway in the fin position because they would either hit the prop or the elevons. I don't think it would make a whole lot of difference.
planks have a very narrow range of CG. Very dificult to set sometimes.
"Bit of a knack to launching it"
The maiden flight was a short one.
New video! Hell yeah
Incorrect wing section..You need reflex and a lifting section such as a Clark Y....I'm guessing yours is more semi symmetrical..?
?? MH64 has reflex, Clark Y does not.
airfoiltools.com/airfoil/details?airfoil=mh64-il
airfoiltools.com/airfoil/details?airfoil=clarky-il
If you are guessing at the wing section how do you know it's incorrect :) But in any case, reflex is not critical as long as the elevons can cover for it.
Try tandem wing scheme
Just add some dihedral and it will become more stable
dihedral on a plank?
planks are usually set to a tiny, tiny bit negative dihedral, to keep it agile and responsive.
fixing the fins, ans optimizing their size is key.
especially with such small planes, it's important to keep all weight (servos, epoxy, glass) as much upfront as possible in order to give it a really short front fuselage.
every bit of fuselage in front of the cg will introduce a counterforce to the tailfins.
How about moving weight instead of adding weight?
The motor and servos can't go any further forward, and the batteries were already as far forward as possible.
Looks heavy for the wingspan. What's the weight to wing area like?
About 7.5oz/sqft or 23g/dm2.
@@iforce2d thats pretty good
Which wing is this. Home made?
yes, build here: ruclips.net/video/vx1PoJE8XO8/видео.html
what motor you use for this one ?
1407 3500kv
Have you set the angle of attack on the motor correct?
It seems to be flying ok if that's what you mean.
Good
TalonGoblin :-D
what was your motor and prop?
1407 3600kv, 4 inch prop
@@iforce2d Thanks!
Try adding more reflex
..30% of what? Please stop talking about percent of travel and give us an idea of how many mm (for the decimal world) this is. In former days all models kits had these infos for every control.
But finally even a plank flys well.
30% of the typical 90 degrees
@@iforce2d .. but how much throw (mm) at the tip of the aileron/elevator? This all depends on the servo throw, servo arm length and the point to which the linkage is attached. This info is the only one which we need for all combinations.
Btw, with so much expo it will be like a sport car equipped with an old american style servo steering. No control at the center.
I'd be willing to bet that given enough time, you could even make a blacksmith's anvil fly!
Take One Of Those Nose Weights Off & Go Back To 50% Expo! Then Put On Some !" Tiplets At A 45% Angle, + Possible Larger Vertical Fins... LOL
What would be the goal of doing that
@@iforce2d Soo That It Will Fly Better!