Your approach to experimenting AND documenting/comparing results really sets you apart from other content creators in this kind of stuff. I continue to dig it! :D My suggestion, if you keep flying this one alongside developing your next project, would be exactly as you said: move the CG back by a good chunk. If you're worried about spins/waggle due to shortening of your verts' moment arms, just hot-glue tack a bit of Corflute on to your verts to give them more rearward area, or lay-up a more permanent (and pretty) extension solution with glass/carbon. Any extra drag associated with bigger verts will at least partly balance with from lower trim drag requirements, and losing that "lumbering" feel... I'm perhaps an unpopular minority in the hobby on this point, but I will always prefer flying a SLIGHTLY tail-heavy plane to a moderately nose-heavy one, which appears to be what we have here. All my first planes when I got into the hobby were flying wings, and I recall well the ongoing struggles with porpoising/CG/reflex/control surface moment arm, etc., etc. I started flying my old wing again a day or two ago and realized how soft I'd gotten from flying deltas all the time - deltas have flare authority from Hell itself, so even with a decent-sized plane, landings are a matter of flying to roughly where your hand is located, stopping suddenly in mid-air, and grabbing the plane with said hand before it hits the ground! :P Wings tend to land hotter. Your one's shrugged off some pretty firm landings there. Great build all round, lots of useful data for yourself and others! Keep 'em coming!
The porpoising (or short period pitch instability) as you have clarified it is not likely due to the washout (twist) of the wing, or the trim setting of the control surfaces. The fact everyone seemingly ignores about blended bodies is that the center of pressure on top of the fuselage/wing/center section shifts forward when the AOA increases. This actually creates a negative stability that gets worse, and in itself is not stable. The fact that the aircraft is stable is because of the Wing washout and the relatively forward C.G., but does not change the instability factor. it is still there.. So you end up with a longer period stability with a shorter period instability. Obviously, the long period stability is winning, as the craft is overall very stable, but both are present. The short period instability may be observable at only a limited speed range due to the harmonics of the mass distribution that it is moving. A flight controller can help to arrest the instability if in a reactive damping mode, but the underlying problem is still there. What may help, is to add VG's to the upper surface to define the location where the turbulent section of air begins. this is a band-aid, and will not fix the problem totally, but if done properly, should limit the movement of the CP substantially. All aircraft wings with non infinite wing Chord suffer from the effect of shifting CP, (all of them) but flying cars, flying wings, BWB's, and other flying plywood sheets suffer the worst. it's the reason we have the 1/3 rule of thumb for CG, incidence in horizontal stabs, etc. etc. The type of wing that suffers the least is one with a very small relative wing chord, and the Horizontal stab a long way away (long moment arm) from the wing, such as sailplanes... Not surprising really.. So this is why flying wings and BWB's have not seen wide adoption. The compromises made to the wing itself in terms of planform, twist, airfoil, reflex to that airfoil, and sweep, in to achieve stability, are significant, and outweigh the benefits of drag reduction in elimination of the tail surfaces in ALMOST all use cases. anyway, hope this makes sense.
Yes, makes sense at least to the extent I understand what you're saying :) Thanks for the detailed analysis. My next plane is on the drawing board already, a much more conventional layout this time.
Now you are a little use to the plane maybe try moving the battery back to achieve some flare in the landing, its going to help with the launching also being tail heavy But hay that may suit the plane design more, cheers Brett
@@kermets Use more than the usual caution when moving CG back on BWB or flying wing. If the CP ever moves past the CG, (Which it easily can), the long period stability will become an instability. In that case, the likelihood of entering a spin before a stall recovery can be made(because the plane will not want to recover from the stall, and may not)is very high, and a conventional spin recovery by using elevons to first stop spin rotation will not work, and you can never get to the next step which is to nose down. so it can get into a spin that it cannot recover from. Flying wings and BWB's are famous for that. It's what happened to Northrop's large flying wings, and resulted in the death of test pilots, and cancellation of his funding. it can only be solved by FBW control system with AOA sensors (among others) to provide direct input. move CG back very slightly, and at some risk. to reduce risk, test high AOA flight regime at very high altitude, and familiarize yourself with non standard spin recovery technique. by using elevons in the same direction of spin, and nose down slightly once the rate of spin increases. try to pull out of resulting dive at a low rate of pitch, so as not to enter high speed stall, as this aircraft type usually has a relatively low overall CL. If not, you risk repeating the whole process. Some flying wings cannot recover from a fully developed spin. Good news: It's just a model...
Yes good news its a model and it may end up hanging on the wall but while Chris is testing Id love to see the C.G move a little and maybe a old 50 cent coin glued into the wing tip that lifting.
I think you will find when you adjust your cg back a little, the porpoising will go away. The effect of nose heavy is, one has to add an amount of up elevator trim to compensate at lower speed. Then as one increases the speed , this up elevator trim makes the aircraft climb and as it climbs it slows a little and drops the nose again and so on and so forth. The best way to check for correct balance is to fly the aircraft straight and level, at around 1/2 speed, with whatever amount of elevator required to keep it in level flight. Preferably straight out in front of you running say right to left, where one can see the resultant flight path clearly. Then, without touching anything, drop the nose to around a 45 degree dive. If it climbs, it's nose heavy and visa versa. Easy peasy....cheers Jorgo. Enjoy watching the results of your work. Thanks.
To counter the pitching effects from the motor, how about mounting it on soft rubber washers _(perhaps asymmetrically: only putting them on the top screws),_ so it will flex perfectly proportional to the motor's thrust force. So the harder the motor thrusts - the more the motor will flex towards straight.
I'll share a tip for cutting tapered wings that works for me... it also allows the use of different airfoils on the root and tip. This is how I cut wings one half at a time with hot wire foam cutter. It's hard to cut the airfoil into foam evenly because you need one side to cut faster than the other so you start at the leading edge and end up at the trailing edge at the same time both on the short side, tip, and the long side, root... So I draw the outline of the wing on the table and I extend the leading and trailing edge out until they meet. Depending on the angle of the taper this can be quite a distance.... I screw a fishing swivel into the table at that point and attach one end of the wire to a line that I tie to the swivel. Now when you start cutting you only have to worry about the one end. As you guide the wire over the patterns you will enter and exit the foam on both ends at the same time.
I did that for my first scratch build, the anchored end of the wire was all the way across the room, worked quite well though: th-cam.com/video/yS2Aohz29KI/w-d-xo.html But it only works if the root and tip have the same airfoil (just at different sizes) and no twist. For this plane I have a reflex airfoil at the root and a symmetrical at the tip, and 6 degrees of twist. th-cam.com/video/15yoTLohnPQ/w-d-xo.html
Really interesting work. It'd be awesome to see the Homeslice 1.0 right next to Homeslice 2.0! Look at them from different angles and such. Maybe even fly them in the same clip. Can we get you excited about that? 🤞
Add two thin triangles to the trailing edge and cut to free control surfaces after sanding new larger trailing edge that smoothes the pitch curve as less angle is required on the surface,hope this makes sense!
Looks great. One thing I've noticed with flying wings is they behave badly when the trailing edges are perfectly perpendicular to the direction of travel. They work fine when swept forwards or backwards, but I've seen some strange stability problems with straight trailing edges. It looks cool but it's not worth the headaches.
@@iforce2d Oh, it works alright, and I have only limited experience with the design. That's just my hunch that there is a problem with the idea that gets sorted out if you angle it in either direction.
The flow fences are probably not doing a lot for stability in their current location. You might consider moving them outboard of the alerons with a degree of two of toe in.
Just a hook and a bungy. No power to get an idea, where the CG is supposed to be. Might be, the CG and/or the motor thrust line have to be adjusted. I don't have hills here, I do that with only a bit of pulling on the bungy with the plane around one meter from ground.
Thanks for the videos, always great content. The aeroelastic effect you are encountering might be because your carbon fibre reinforcement is placed too far back on the chord. With that your center of flexure moves backwards relative to the quarter chord line where the resultant lift force acts creating a moment and twisted the wing up. The carbon strip ~30% chord from LE might be better ;-)
Maybe I didn't explain it well, but there was no bending or twisting during flight. I can even pick the whole plane up and hold it horizontal, by holding just the 30cm at the end of the wing and there is maybe a couple mm of bending doing that.
The porpoising you indicate ma be an effect called Dutch Roll . Its common with flying wings. It can be fixed . The control issues could be helped by bigger control surfaces. As for the CG you can move it back say 5-10 mm at a time till it gets to twitchy. The launch issue can be fixed with a bungy launch or a side arm launch. We launch our wings by holding it by the wing tip letting the other wing tip set on the ground hold it with the nose aimed up, Then with the arming switch off I place the throttle 3/4 to full . Then when im ready flip on the arming switch and let it fly out of my hand when its got the power aiming the nose up. You should look at the Horten Flying Wing believers on FACE BOOK lots of good bits of info on wings. The problem with flaring for landing is probably because you have just enough control surface to slow it but not stall. Try coming in low and slowing with half elev up then when its slowed down give it full up. It will either pull up or stall and set down nose up and slide. Wings with small control surfaces won't stall unless the throw gets so extreme it acts like a spoiler. Good luck I love your creation. Nothing in the design cant be fixed. What air foil did you use ?
Maybe try larger/longer ailerons? I have used monster sized ailerons to get better response; is it "touchy" in the vertical, if not, use bigger ailerons.
Not enough control surface . If you use a full span Elvon the reflex is adjustable in flight. Also Increase thrust angle so full throttle causes it to climb .
I doubt you want throttle causing it to climb when the reflex already does. If I understand it correctly these need to balance out at some point, otherwise you will not have a pretty low top speed. I already have to push the nose down as much as I can to keep it level at full throttle. Every flying wing kit I've bought has the thrust angled a little downward.
@@iforce2d I was saying that because you had said that it pitches down when you throttle up on launch. Can you put a hook on the bottom so you can use a High Start to launch. It is a bit underpowered your max Thrust according to the Manufacturer and your at 1.4 to 1.6 kilo. Motor 1380 max thrust. All of my wings have been hard to launch because of the blades. I use a side arm launch . Rig the radio with a kill switch on the motor. So I can set the throttle then I Can flip the switch and get full power at launch. I hold the right wing tip in my left hand with the left tip on the ground. Flip on the motor and let it fly up and guide it with the left hand and toss while not causing it to crash. I dont have any stabilizer . So it is an art. I would love to see you work it out.
@@iforce2d yes but the amount of down is just enough to so you can maintain a level flight at the speed you cruise at. When you hit the throttle its better to climb than to drop. and as you increase throttle the reflex will cause a different amount of climb as speed increases. When using a full length control surface you are in effect changing the reflex as you push the nose down and reducing drag so your speed is increased. Most of my wings use a full trailedge as control surface. Except about 3/4 of an inch from the prop tip . You need less travel to get the action your looking for . A surface deflection exceeding a point (not the same on all ) can actually cause a stall or a point where more travel has no effect. I love your plane ! only part I would change is bigger control surfaces. I would have used the wood trailedge as a control surface ending at the root of the wing . Just my 2cents . You are an industrious man I have seen your TH-cam channel its impressive.
Hey, I have an unrelated question, I have been looking for a while on your videos and found them very interesting. I just wanted to ask where did you get your knowledge for all these projects? I know there is a lot of self-learning from the web and just exploring by yourselves but did you study some engineering branch? perhaps electrical engineering? thank you, you have great videos.
I studied software programming, so everything you see in this particular series is learned from TH-cam or Wikipedia mostly. Any part of my videos that's not looking at boring source code on a computer would be not what I studied :)
I think the idea is that motor and wing reflex should be counteracting each other, so a steady state equilibrium can be reached. Even with the 2 degrees down I have to push the nose fully down at full throttle. If the motor was pointed up as well I don't think I'd be able to get above half throttle.
I've never seen the tips washed 'in' like that. I've seen wash "out".... The front edge of the wing should match the incidence of the leading edge of the root. The rear of the airfoil should be higher than the root. I think the tips of your wings are trying to fly lower than the center of your wing..... So they might be diving and then springing back? I'm not sure I'm using the right terminology here. When I've built wings in the past I've built them flat and then added twist by putting a block under the trailing edge while using an iron or heat gun to set the wing shape. I have never seen a leading edge lower than the root of the wings center.
The intention was as shown in the photo here at 6:53 as seen from the side: th-cam.com/video/15yoTLohnPQ/w-d-xo.html Looks like the trailing edge is a bit higher at the tip, but the leading edge is also a bit lower. It's a while ago now but I think I was going for a no-dihedral outcome.
@@iforce2d yes I'm sure I didn't explain it very well. I don't think dehidral is a problem, as a matter of fact you can have negative dehidral. The problem is I believe that the way you set it up your leading-edge is lower than your trailing Edge but it's also lower than the root Leading Edge. Meaning instead of twisting the wing so that the rear of the wing lifts up which would give you some reflex in your turns, what you've got is actually negative incident on your wingtip compared to your wing root which means that the faster you go the harder your wingtips are trying to push down and that's going to cause some fluttering and all kinds of stuff. Its probably also a testament to how strong you build your airplanes because it should be trying to rip those wings off. Well actually, it is trying to rip them off. It just hasn't been successful yet. Not that you've told us about anyway....
try launching it by grabing one of the wings from the front and throwing it a bit like a boomerang. ever since i saw this guys video th-cam.com/video/1U2LaAnzQQU/w-d-xo.html i've been doing it this way and it is so much better than the belly tickle launch, cause you can have your trottle set before the launch and dont have to worry about choping your fingers of.
The throttle pushes the nose down though, is the problem. I've never tried the sidearm launch, it looks awkward and seems like you can only get about half the force as a javelin style throw. For a small plane like the wingwing I do a frisbee throw, but this plane is too big for that.
Thanks for taking the time to document your build and flights. It is really appreciated!
Your approach to experimenting AND documenting/comparing results really sets you apart from other content creators in this kind of stuff. I continue to dig it! :D
My suggestion, if you keep flying this one alongside developing your next project, would be exactly as you said: move the CG back by a good chunk. If you're worried about spins/waggle due to shortening of your verts' moment arms, just hot-glue tack a bit of Corflute on to your verts to give them more rearward area, or lay-up a more permanent (and pretty) extension solution with glass/carbon. Any extra drag associated with bigger verts will at least partly balance with from lower trim drag requirements, and losing that "lumbering" feel... I'm perhaps an unpopular minority in the hobby on this point, but I will always prefer flying a SLIGHTLY tail-heavy plane to a moderately nose-heavy one, which appears to be what we have here.
All my first planes when I got into the hobby were flying wings, and I recall well the ongoing struggles with porpoising/CG/reflex/control surface moment arm, etc., etc. I started flying my old wing again a day or two ago and realized how soft I'd gotten from flying deltas all the time - deltas have flare authority from Hell itself, so even with a decent-sized plane, landings are a matter of flying to roughly where your hand is located, stopping suddenly in mid-air, and grabbing the plane with said hand before it hits the ground! :P Wings tend to land hotter. Your one's shrugged off some pretty firm landings there. Great build all round, lots of useful data for yourself and others! Keep 'em coming!
The porpoising (or short period pitch instability) as you have clarified it is not likely due to the washout (twist) of the wing, or the trim setting of the control surfaces. The fact everyone seemingly ignores about blended bodies is that the center of pressure on top of the fuselage/wing/center section shifts forward when the AOA increases. This actually creates a negative stability that gets worse, and in itself is not stable. The fact that the aircraft is stable is because of the Wing washout and the relatively forward C.G., but does not change the instability factor. it is still there.. So you end up with a longer period stability with a shorter period instability. Obviously, the long period stability is winning, as the craft is overall very stable, but both are present. The short period instability may be observable at only a limited speed range due to the harmonics of the mass distribution that it is moving. A flight controller can help to arrest the instability if in a reactive damping mode, but the underlying problem is still there.
What may help, is to add VG's to the upper surface to define the location where the turbulent section of air begins. this is a band-aid, and will not fix the problem totally, but if done properly, should limit the movement of the CP substantially.
All aircraft wings with non infinite wing Chord suffer from the effect of shifting CP, (all of them) but flying cars, flying wings, BWB's, and other flying plywood sheets suffer the worst. it's the reason we have the 1/3 rule of thumb for CG, incidence in horizontal stabs, etc. etc.
The type of wing that suffers the least is one with a very small relative wing chord, and the Horizontal stab a long way away (long moment arm) from the wing, such as sailplanes... Not surprising really..
So this is why flying wings and BWB's have not seen wide adoption. The compromises made to the wing itself in terms of planform, twist, airfoil, reflex to that airfoil, and sweep, in to achieve stability, are significant, and outweigh the benefits of drag reduction in elimination of the tail surfaces in ALMOST all use cases. anyway, hope this makes sense.
Yes, makes sense at least to the extent I understand what you're saying :) Thanks for the detailed analysis. My next plane is on the drawing board already, a much more conventional layout this time.
Now you are a little use to the plane maybe try moving the battery back to achieve some flare in the landing,
its going to help with the launching also being tail heavy But hay that may suit the plane design more,
cheers
Brett
@@kermets Use more than the usual caution when moving CG back on BWB or flying wing. If the CP ever moves past the CG, (Which it easily can), the long period stability will become an instability. In that case, the likelihood of entering a spin before a stall recovery can be made(because the plane will not want to recover from the stall, and may not)is very high, and a conventional spin recovery by using elevons to first stop spin rotation will not work, and you can never get to the next step which is to nose down. so it can get into a spin that it cannot recover from. Flying wings and BWB's are famous for that. It's what happened to Northrop's large flying wings, and resulted in the death of test pilots, and cancellation of his funding. it can only be solved by FBW control system with AOA sensors (among others) to provide direct input. move CG back very slightly, and at some risk. to reduce risk, test high AOA flight regime at very high altitude, and familiarize yourself with non standard spin recovery technique. by using elevons in the same direction of spin, and nose down slightly once the rate of spin increases. try to pull out of resulting dive at a low rate of pitch, so as not to enter high speed stall, as this aircraft type usually has a relatively low overall CL. If not, you risk repeating the whole process. Some flying wings cannot recover from a fully developed spin. Good news: It's just a model...
Yes good news its a model and it may end up hanging on the wall but while Chris is testing Id love to see
the C.G move a little and maybe a old 50 cent coin glued into the wing tip that lifting.
Yes I was thinking same thing about a partial weight based trim offset. Good temporary solution while gathering data
I think you will find when you adjust your cg back a little, the porpoising will go away.
The effect of nose heavy is, one has to add an amount of up elevator trim to compensate at lower speed. Then as one increases the speed , this up elevator trim makes the aircraft climb and as it climbs it slows a little and drops the nose again and so on and so forth.
The best way to check for correct balance is to fly the aircraft straight and level, at around 1/2 speed, with whatever amount of elevator required to keep it in level flight.
Preferably straight out in front of you running say right to left, where one can see the resultant flight path clearly.
Then, without touching anything, drop the nose to around a 45 degree dive. If it climbs, it's nose heavy and visa versa.
Easy peasy....cheers Jorgo.
Enjoy watching the results of your work. Thanks.
To counter the pitching effects from the motor, how about mounting it on soft rubber washers _(perhaps asymmetrically: only putting them on the top screws),_ so it will flex perfectly proportional to the motor's thrust force.
So the harder the motor thrusts - the more the motor will flex towards straight.
I'll share a tip for cutting tapered wings that works for me... it also allows the use of different airfoils on the root and tip. This is how I cut wings one half at a time with hot wire foam cutter.
It's hard to cut the airfoil into foam evenly because you need one side to cut faster than the other so you start at the leading edge and end up at the trailing edge at the same time both on the short side, tip, and the long side, root...
So I draw the outline of the wing on the table and I extend the leading and trailing edge out until they meet.
Depending on the angle of the taper this can be quite a distance....
I screw a fishing swivel into the table at that point and attach one end of the wire to a line that I tie to the swivel.
Now when you start cutting you only have to worry about the one end. As you guide the wire over the patterns you will enter and exit the foam on both ends at the same time.
I did that for my first scratch build, the anchored end of the wire was all the way across the room, worked quite well though: th-cam.com/video/yS2Aohz29KI/w-d-xo.html
But it only works if the root and tip have the same airfoil (just at different sizes) and no twist. For this plane I have a reflex airfoil at the root and a symmetrical at the tip, and 6 degrees of twist.
th-cam.com/video/15yoTLohnPQ/w-d-xo.html
Really interesting work. It'd be awesome to see the Homeslice 1.0 right next to Homeslice 2.0! Look at them from different angles and such. Maybe even fly them in the same clip. Can we get you excited about that? 🤞
I pulled the electronics off 1 to put on 2, so probably not anytime soon :)
Add two thin triangles to the trailing edge and cut to free control surfaces after sanding new larger trailing edge that smoothes the pitch curve as less angle is required on the surface,hope this makes sense!
Looks great. One thing I've noticed with flying wings is they behave badly when the trailing edges are perfectly perpendicular to the direction of travel. They work fine when swept forwards or backwards, but I've seen some strange stability problems with straight trailing edges. It looks cool but it's not worth the headaches.
Maybe there's more to your experience than just the trailing edge shape, mine seems to be going ok.
@@iforce2d Oh, it works alright, and I have only limited experience with the design. That's just my hunch that there is a problem with the idea that gets sorted out if you angle it in either direction.
The flow fences are probably not doing a lot for stability in their current location. You might consider moving them outboard of the alerons with a degree of two of toe in.
Fascinating Chris. Looks weird but flies smooth. Need to build a bungy launcher?
That's just what I was about to suggest Andrew
Or a catapult
Just a hook and a bungy. No power to get an idea, where the CG is supposed to be. Might be, the CG and/or the motor thrust line have to be adjusted. I don't have hills here, I do that with only a bit of pulling on the bungy with the plane around one meter from ground.
Maybe next build look at setting a carbon tube into the fuselage and mounting the motor to that and use a folding prop for belly landings.
Thanks for the videos, always great content. The aeroelastic effect you are encountering might be because your carbon fibre reinforcement is placed too far back on the chord. With that your center of flexure moves backwards relative to the quarter chord line where the resultant lift force acts creating a moment and twisted the wing up. The carbon strip ~30% chord from LE might be better ;-)
Maybe I didn't explain it well, but there was no bending or twisting during flight. I can even pick the whole plane up and hold it horizontal, by holding just the 30cm at the end of the wing and there is maybe a couple mm of bending doing that.
That plane looks very stable.
Great flying site , and really appreciate the content ..................
The porpoising you indicate ma be an effect called Dutch Roll . Its common with flying wings. It can be fixed . The control issues could be helped by bigger control surfaces. As for the CG you can move it back say 5-10 mm at a time till it gets to twitchy. The launch issue can be fixed with a bungy launch or a side arm launch. We launch our wings by holding it by the wing tip letting the other wing tip set on the ground hold it with the nose aimed up, Then with the arming switch off I place the throttle 3/4 to full . Then when im ready flip on the arming switch and let it fly out of my hand when its got the power aiming the nose up. You should look at the Horten Flying Wing believers on FACE BOOK lots of good bits of info on wings. The problem with flaring for landing is probably because you have just enough control surface to slow it but not stall. Try coming in low and slowing with half elev up then when its slowed down give it full up. It will either pull up or stall and set down nose up and slide. Wings with small control surfaces won't stall unless the throw gets so extreme it acts like a spoiler. Good luck I love your creation. Nothing in the design cant be fixed. What air foil did you use ?
Maybe try larger/longer ailerons?
I have used monster sized ailerons to get better response; is it "touchy" in the vertical, if not, use bigger ailerons.
looks good, flies verry well and stable
I wonder if setting a bit of up elevator on a switch would help with launches.
I had that on for every launch after I added the flight controller. 50% up elevator on a switch.
@@iforce2d ah.
Much awaited and appreciated video
oh hi.... sorry I forgot about the files. Will do it soon :)
Love love love these videos
Where are you in NZ? , its great to have such a fine playground !
Not enough control surface . If you use a full span Elvon the reflex is adjustable in flight. Also Increase thrust angle so full throttle causes it to climb .
I doubt you want throttle causing it to climb when the reflex already does. If I understand it correctly these need to balance out at some point, otherwise you will not have a pretty low top speed. I already have to push the nose down as much as I can to keep it level at full throttle. Every flying wing kit I've bought has the thrust angled a little downward.
@@iforce2d I was saying that because you had said that it pitches down when you throttle up on launch. Can you put a hook on the bottom so you can use a High Start to launch. It is a bit underpowered your max Thrust according to the Manufacturer and your at 1.4 to 1.6 kilo. Motor 1380 max thrust. All of my wings have been hard to launch because of the blades. I use a side arm launch . Rig the radio with a kill switch on the motor. So I can set the throttle then I Can flip the switch and get full power at launch. I hold the right wing tip in my left hand with the left tip on the ground. Flip on the motor and let it fly up and guide it with the left hand and toss while not causing it to crash. I dont have any stabilizer . So it is an art. I would love to see you work it out.
@@iforce2d yes but the amount of down is just enough to so you can maintain a level flight at the speed you cruise at. When you hit the throttle its better to climb than to drop. and as you increase throttle the reflex will cause a different amount of climb as speed increases. When using a full length control surface you are in effect changing the reflex as you push the nose down and reducing drag so your speed is increased.
Most of my wings use a full trailedge as control surface. Except about 3/4 of an inch from the prop tip . You need less travel to get the action your looking for . A surface deflection exceeding a point (not the same on all ) can actually cause a stall or a point where more travel has no effect. I love your plane ! only part I would change is bigger control surfaces. I would have used the wood trailedge as a control surface ending at the root of the wing . Just my 2cents . You are an industrious man I have seen your TH-cam channel its impressive.
Down wind is hard on every thing that flies . Even Helicopters .
Again, great work Chris
👍👍👍
nice... i'm surprised that you didnt put a bungee hook under it for launch
Hey, I have an unrelated question, I have been looking for a while on your videos and found them very interesting. I just wanted to ask where did you get your knowledge for all these projects? I know there is a lot of self-learning from the web and just exploring by yourselves but did you study some engineering branch? perhaps electrical engineering? thank you, you have great videos.
I studied software programming, so everything you see in this particular series is learned from TH-cam or Wikipedia mostly. Any part of my videos that's not looking at boring source code on a computer would be not what I studied :)
Try pointing the motor level or even up 2 degrees rather than down, should reduce the pitch power couple slightly. 👍🏻
I think the idea is that motor and wing reflex should be counteracting each other, so a steady state equilibrium can be reached. Even with the 2 degrees down I have to push the nose fully down at full throttle. If the motor was pointed up as well I don't think I'd be able to get above half throttle.
if you put that into production they would sell
Flying chunks of golf course are called divots. Until they land at least !
Washout should only be in the trailing edge, not an actual twist in the section.
It's a tank! You built it well! Can you bungee it?
I was thinking a bungee, or some other kind of assisted launch device
Should of made wing area larger. Not enough area imo.
enough for what?
iforce2d lift. But seems fine. You achieved enough lift just with mid section I’m guessing
You are a genius !
sir can i know the total weight of the aircraft with the battery plz.
??? look at the bottom left of the screen from 5:06
@@iforce2d thank you so much
I've never seen the tips washed 'in' like that. I've seen wash "out"....
The front edge of the wing should match the incidence of the leading edge of the root. The rear of the airfoil should be higher than the root.
I think the tips of your wings are trying to fly lower than the center of your wing.....
So they might be diving and then springing back?
I'm not sure I'm using the right terminology here.
When I've built wings in the past I've built them flat and then added twist by putting a block under the trailing edge while using an iron or heat gun to set the wing shape.
I have never seen a leading edge lower than the root of the wings center.
The intention was as shown in the photo here at 6:53 as seen from the side: th-cam.com/video/15yoTLohnPQ/w-d-xo.html
Looks like the trailing edge is a bit higher at the tip, but the leading edge is also a bit lower. It's a while ago now but I think I was going for a no-dihedral outcome.
@@iforce2d yes I'm sure I didn't explain it very well. I don't think dehidral is a problem, as a matter of fact you can have negative dehidral. The problem is I believe that the way you set it up your leading-edge is lower than your trailing Edge but it's also lower than the root Leading Edge. Meaning instead of twisting the wing so that the rear of the wing lifts up which would give you some reflex in your turns, what you've got is actually negative incident on your wingtip compared to your wing root which means that the faster you go the harder your wingtips are trying to push down and that's going to cause some fluttering and all kinds of stuff. Its probably also a testament to how strong you build your airplanes because it should be trying to rip those wings off.
Well actually, it is trying to rip them off. It just hasn't been successful yet. Not that you've told us about anyway....
Flies good though
Nicely!! Good
Just a few seconds too late
Why you didn’t make the wing Swift
huh?
Wing are looks very small
but fuselage looks quite wide right :)
Wow, beautiful webvideo. Thnx ...
try launching it by grabing one of the wings from the front and throwing it a bit like a boomerang. ever since i saw this guys video th-cam.com/video/1U2LaAnzQQU/w-d-xo.html i've been doing it this way and it is so much better than the belly tickle launch, cause you can have your trottle set before the launch and dont have to worry about choping your fingers of.
The throttle pushes the nose down though, is the problem. I've never tried the sidearm launch, it looks awkward and seems like you can only get about half the force as a javelin style throw. For a small plane like the wingwing I do a frisbee throw, but this plane is too big for that.