What I saying was that simple calculations and paper experiments save a lot of physical work and time, as most of the times you can easily see if your concept will fail, where and why will fail and correct that problem even before "starting to cut foam".
Thats insane and verry cool but the real X-35 has side exaustes so it wont go from left to right out of controll so maybey u can put prop there to its an option
put some reverse props on it and see if it will hover upside down. sure a longer object balances better on your finger than a short object but something hanging is a lot more stable.
It is important to analyze what is going on. That way you can figure out a way to fix the issue. They want to share their thoughts whit everyone so that we can learn from all of this.
you know... some people (unlike you) test things so they know what to improve on. they are working on a big project that is going to be awesome when completed. also the people (like me) build airplanes just like dave.
do some research about planes but until then show some respect to knowledge, moron
i think that you have to put the motor on the uppside of the table (like in helicopters),thats like a 3D plane also has the motor uppside when hovering!
Instead of motor speed variations why not try a sliding door on one side that would be half open in neutral and as you would close or open the door it would change the pitch?
Hi, I think this project will not work some drastic changes. Firstly leave the motors and props for othe projects. The torque will make a difficult challange even harder, change to EDF's. With motors below the main weight of the model like you have on this test rig then you will have to react quicker (or your gyros will). If your power source is above the weight (battery etc..) then you will have a pendulum effect helping stability. This is my opinion anyway, good luck.
i think your problem with the sliding is that the propellers have enough power, you just need to focus that power with a duct around it. If you look at the real F-35, it has a ducted fan right behind the cockpit.
Surely the reason it's sliding, not pitching is because the C of G is above the centre of lift and it wants to turn over.
You could put the fans above the fuse you'll have much more stability and conrol.
another alternative is to add more sources of lift; total three fans would do it (four would be better), and point them all slightly in (to give stable lift like dihedral low-wings)
I don't think you can make it pivot with two positive thrust vectors underneath the body. The pivot point will always be off the body - so it's tilting is that it is trying to pivot around that axis point which is not on the body.
Think of a see-saw with two positive forces under the seats - how can it possibly pivot around a point _on_ the see-saw. I don't think it can be done. It will always pivot around a point that is away from (off of) the see-saw
dude, it would be faster on the roll with the motors further out because of something called "moments". And no thats not the sections of time your girl friends have, lol.
for your pitch you should try what helicopters with the two big blades use. by adjusting the the speed of the motors. like if the tail is tipping down. the tail motor speeds up to bring it back up and the opposite for the nose.
You goobers.....get the motors CLOSER to the rig...Your trying to balance the plane on broomsticks with this layout!! Another thing......put the blades in a tube to reduce turbulence around the blades. This also directs the thrust onto one direction.
Neat project. As others have sugested, variable pitch props should result in quick pitch control, plus 'low gear grunt'. Or, instead of angling both props for pitch control, just angel one. For nose-down pitch, angle the front prop only backward. This 'should?' cause a rearward movement like the setup in this video plus a nose down pitch because the vertical component of the thrust of the front prop is less than the rear prop's. Rear motor only tilted aft for pitch up control.
your neighbors must love you, ever thought of that? Also, you need a PLC to keep the proper pitch, you will never get this on manual. Smarter people have tried and failed.
What you've got here is basically a reverse-pendulum problem. Since it's not inherently stable, you'll either have to get it to sway so slow, that you can control it OR you'll need gyros to stabilize it (check out the quadrotor projects for some stuff you could use...)
Ah finally, i been waiting to see your testing on this.
Hey have an idea to maybe help with your pitching or sliding problem. How about going more linear in the nose and increase the EXPO in the rear. I think that will help out
How about using 2 lift fans at the front, either side of eachother, cos then u have 3 fans which is much more stable although i suppose there will have to be a resultant torque force then. Put the motors on the top for better balance and use control vanes in the thrust line, vertigo style. this should improve it
ello mate few things i wish you would try ;) either 4 or 3 motor configs turnin the rig upside down so motors pull not thrust if you want to thrustand current positioning use 5 bladed ducted fans maybe linking all speed controllers to a helicommand (please watch this vid watch?v=lVBi-1tX_uU) though i think you could mod suttin sweet without HC :D
i dont know anything about RC's but i have to say what you have so far is really nice .. i wish i could work with you and learn how to make these things =]
Try using your gyro on the speed controls. i built a V22osprey and to help with the crazy roll and and pitch i used a gyro on each speed control. it works
A simple/stupid pich controller could be made using a couple of resistors and mercury switches. Mount the mercury switches at a slight incline so that one closes at say 15 degrees down and the other 15 degrees up. Then connect a resistor in line with the speed controller so that when the nose pitches down over 15 degrees the switch closes and the resistor pulls down the speed controllers voltage thus slowing the "uphill" motor.
Its stupid but it should dampen the wildest pitching.
Obviously three props would be more stable. Rather than changing the pitch of the motors split the output of each motor via ducting with a pitching "rudder" to direct more or less air out each duct - like a Harrier.
Also, the CG is way higher than the props so you're fighting a balancing act that you shouldn't have to. Like balancing a stick standing on your hand. Mount the props in the body (more realistic) or even better, above the CG and the craft will instantly become more stable.
Oooor, :) if internalizing the props is out, Dave, you could try to use the "duckerons" idea turned 90 degreese (vertically) to block some of the air getting to the prop.
(Think of like an umbrella over the prop - or reverse it - make a "V" over the prop.)
This might inhibit the ability of one prop to give thrust therefore giving you a more instant thrust cut on one or the other of the engines - to get the elev. control.
If you can find a way to make one motor spin at a different speed that would give you pitch control. So, what would happen is that to pitch the nose up, make the front motor spin faster than the back, making more lift in the front. To pitch down, make the back motor spin faster. This is the same principle coaxial helis use for the yaw axis.
Yeah, he's right for sure! This was how I assumed you'd do it.
One issue though, adjusting the speeds will change the torque acting on each prop, which would give you some unwanted yaw, maybe? Variable pitch props, perhaps?
Well, Dave mentioned speed ctrl before - he said that didn't react fast enough. Also, prop pitch is probably out due to mechanical complexity.
Sooooo, I would say, Dave, you'd want to try experimenting with a variable vent. Yep, either internalize the props and have even just tiny movements on "lips" where the air exits the body. A slight closure of the "doors" would create less thrust - and therefore the pitch change you are looking for. Just a wild suggestion. - Ed (ed5k)
I don't know exactly how to do, and if anyone has posted this before.
Maybe if you adjusted separately the speeds for each motor. You could then put more power on the front or the back motor, making it pitch up or down, and maybe then leveling the flight using the same controls you are using for the pitch now.
This way it would be more stable than approaching the motors to the CG, but I don't know if it would be easy to control at all.
i'm not sure, did you take into acount the counter-ration effect on the blades?
that might be a major problem don't you think?
another advice: it's much easier to hold an aircraft from both sides (wings) than from the center (body). so what i mean with this is that you can make it more stable is you attached the motors horizontaly (left and right wings) than vertical (nose and tail). if not try it with you own hands
like sharma17 i'm not trying to be an "armchair expert" but for pitch would it be possible to get one prop spinning faster? or is that what you're doing
moving out sideways too. Anyways. I don't know ANYTHING about all this stuff, just venting my curiosity. I'm sure you'll sort it out your own way :D. Thankyou for the videos
-and if the props are spinning too close to the wings when levelled, you may be able to adjust your C.G so that your props can spin freely in the gap between the ends of the wings and in front of the elevators.
I reckon just jump the gun a bit, and try it on a near complete F35 so you can simulate the final weight of the plane. I guess I don't need to mention gyros.. I'm sure you guys thought of it already. And if you manage to get the pitch perfect, a way to fix roll is to have the motors-
Yeah looks that way. I'm not trying to be an armchair expert, and I don't think i'm any more right than a chimp, but when you're so interested in something, all you want to do is talk about it.. =)
Dave will probably be close to mastering it now on his own efforts :), but if something we suggested helped, than it can't be a bad thing right?
Hey Dave, Good attempts :D, Enjoyed watching Keith Dance, only next time you do the tests, please play some salsa on the stereo to fit the mood :)
I know everybody seems to have a suggestion for you, but here's mine anyway. I think your equip is fine, I'd like to see what would happen if you built your test peice up a bit, and had the two motors on either side of the plane, in the c.g. (try get the motors as close to the wings and the side of the fuselage as possible.
hi there, nice thing u build there :) i tryd this a few years ago with brushed motors. But i had some differences which worked nicely: my props were above the CG, they were counterrotating, which was an issue for me, because my rig was smaller. the main thing was the pitch was made by the ESC´s i only had 2 servos for roll and yaw. If your ESC is not fast enough in the response, try sth. like GM Genius 70 its fast responding! Greetz Wolf
Testing in the middle of a quiet residential area are we? I hope it wasn't too early in the morning at least. LOL
Seriously, why do think it took this long for a American fighter jet, the Lockheed F-35, to be produced? I'm actually surprised it took this long with all the historic American know-how.
I've seen old military video of all the failed attempt and test in the 60's. It makes you respect the old British Harrier a lot more. 40 years ahead of its time!
it might be a bit much but you will get 10 times better stability if you add two more motors. all four in a dimond formation and that way the thrust is equal on all four sides..front, back, and both sides. Good luck!
An idea I had was to mix the thrust on the two motors to help control pitch. Increase or decrease one to push that end up or down. It would mess with the yaw a little though so it might not work. Just an idea.
As suggested you might try changing the configuration so the planes CG is below the the props or as close a possible. it goes with the pendulum principle you describe with the stick in the Free Extra foamie video.
Could you put gyros on the hover mode and maybe have them double as flight mode gyros?
I think you should keep the distance and mix a little elevator with the throttle to gain proper pitch authority(although it will be a little sluggish so dont bother trying to let the gyros influence it)
I agree. I don't understand why they would place the motors so low and far from the center of gravity. I think they are going to realize it's going to very very difficult achieving their goal of a VTOL. They almost need motors out on the wingtips too in order to provide roll control.
I think it would be easier to fly if you had the lift fans as high up as possible because it goes on the same principle that an object is easier to hang than to balance above. If it were my plane i would cut holes in the plane where i wanted my props and mount them in the body. You couldn't mount the motors above the plane because you would lose all lift when the wind bounces off of the plane. This will also look much nicer.
I would also leave the fans as far apart as possible because you will lose all of your yaw athority by moving them closer together. You could then solve the pitch problem by controling it with fan speed jus like the air hogs twin thunder helicopter.
you can do elevator by diferential motor speed.The test rig is pretty primitive but I know you`ll get it done in on month or so.Please post some plans on your website when this is done,and get bigger ESC cause that can crash because of those small cheap`o esc.
What about using a gyro for your front and rear motors. I'm guessing you're running a Y cable from your ESC's to your receiver right? What about a gyro between the Y cable and the receiver?
Looks like you're using thrust vectoring for pitch. I'm not sure how well that will work with that setup. I think the best way is to keep the props spaced apart for good yaw and vary the speed of the props for pitch. I'm also wondering if once you move the props up, that the roll might not work. At the moment the thrust vectoring looks like it's causing the roll via leverage on the motor supports. At least that's my 2c as an RC heli flyer. Should be interesting to see how it all works out.
Think of the thrust like stilts, If you concentrate the stilts with a small area youll fall over, but if you spread them out they will support the weight.
having the motors on the lower side and your center of gravity up makes it lean esly on one side and unrecoverable, it'a like having a heli upside down, for testing it seems more useful to have the blades in corrispondance of the plane body or just a bit higher. with 2 motors on wings and one under the nose you can control it only wirh the rpm of the motors instead of servos.
I realy can't see it achieving a stable ascent/descent with a straight down setup.
My sugestion would be to keep the location of the hatches as they are now, but with both motors pointing outwards on opposite directions, i'd say some 30º should do the trick.
You'l get more pitch control and a far more stable hover, plus physics wise you can actualy make the hatch ports much smaller with this method.
Well, i don't think so. He could use 2 separate channels for motors and mix his radio to change motors' rpms and that would change the pitch. And for the roll and yaw he could leave thrust vectoring, as it works nice.
Read previous comments. For the "umpteenth" time, Dave has already explained in earlier comments that the throttle response, speeding up or slowing down the propeller, is too slow to compensate for changes in pitch.
I think he should try it. For me this is the only solution because I can't see where the truts vecort control should realy point at when correcting pitch. Perhaps you can do pitch by (as a example piching up) by vectoring the front strigt down and the back motor vectored backwards. So you have more lift in the front and less in the back. Also the vercor helps to "turn" the plane upwards.
is it possible to make a differential thrust on both motor just like jetset44 (steve shumate) did with his thrust vectoring yaw control on his su-37. it might help on pitch contol.
hey guys , I'd like to make a suggestion for you on this aircraft . Set the rear engine at 2 inch & the front engine at 3 inch ten try it then revers the engine settings to 2 inches in front and 3 inches in the back, then try it ,
Very nice design but your missing 2 other parts. there's small nosels on both wing close to the tip point down. those keep it stable.
Jasonjays122 1 month ago
rudderins
LUK3FAULK 1 year ago
@GPNflyman1
What I saying was that simple calculations and paper experiments save a lot of physical work and time, as most of the times you can easily see if your concept will fail, where and why will fail and correct that problem even before "starting to cut foam".
molinobeer 1 year ago
Like Tesla said "theory and calculation can save ninety percent of the labor."
So and beside I have respect for Dave, I need to say they are being amateurs in this situation.
The old man looks very cool, humble, listener and friendly.
molinobeer 1 year ago
while testing you should do it as the final project because the engines are so low from the plane the central gravity will change
MrAhmedsamir96 1 year ago
lol flying table
yaykaboom 1 year ago
In my aerodynamics class, we call it Rudderstabilators
Icarus716 1 year ago
Thats insane and verry cool but the real X-35 has side exaustes so it wont go from left to right out of controll so maybey u can put prop there to its an option
7249xxl 1 year ago
That was a very back to the future moment with the wire being unplugged.
pupeno2 2 years ago
put some reverse props on it and see if it will hover upside down. sure a longer object balances better on your finger than a short object but something hanging is a lot more stable.
RCvehicleGuy 2 years ago
It is important to analyze what is going on. That way you can figure out a way to fix the issue. They want to share their thoughts whit everyone so that we can learn from all of this.
Jermu123 2 years ago
HOMESTARRUNNER!!!!!
JETCAR223 2 years ago 3
What's under the car cover?
spectre1209 2 years ago
u talk too much
just show it fly
gadix11 2 years ago
you know... some people (unlike you) test things so they know what to improve on. they are working on a big project that is going to be awesome when completed. also the people (like me) build airplanes just like dave.
do some research about planes but until then show some respect to knowledge, moron
sterworks 2 years ago 5
differential power will give pitch, moving BOTH motors will only give movement back and forth.
set up an extra mixer between elevator and controllers, add a switch to turn it off when in flight
polaritDK 2 years ago
The F 35 has puffers either side to stablize the aircraft in VTOL.
G777GUN 2 years ago
i think that you have to put the motor on the uppside of the table (like in helicopters),thats like a 3D plane also has the motor uppside when hovering!
KedmenecMartin 2 years ago
thrust is way below the CG, balancing a table on two sticks, if the motors were moved up closer to the fuse, it would give stability.
GSXED 2 years ago
If the door was to be controlled by a gyro it might self stable-ize as the prop wash on one motor would vary the pitch on that one side.
bnrusso 2 years ago
Instead of motor speed variations why not try a sliding door on one side that would be half open in neutral and as you would close or open the door it would change the pitch?
bnrusso 2 years ago
hahahahahhahha
thomdoe 2 years ago
In a way, it's like an upside down helicopter.
Mav1843 2 years ago
Hi, I think this project will not work some drastic changes. Firstly leave the motors and props for othe projects. The torque will make a difficult challange even harder, change to EDF's. With motors below the main weight of the model like you have on this test rig then you will have to react quicker (or your gyros will). If your power source is above the weight (battery etc..) then you will have a pendulum effect helping stability. This is my opinion anyway, good luck.
awood12345 2 years ago
edf have no top end power
skittlepower95 2 years ago
2 inch extension wire = HILARIOUS lol.
DaveESPI 2 years ago
Comment removed
therock27374 2 years ago
he will use this in the future for the plane to hover
john55223 2 years ago 2
*Facepalm*
ImperialElite1 2 years ago
not ur best model, but its alright, i cant even built it so lol....
upurhoe12321 2 years ago
it there to try to hover technic (developing it over 2 years...)
utti104 2 years ago
its a test rig u mug, for the F-35
j4cko56 2 years ago
u should try 3 motars for huver 1 under each wing and 1 under cokpit maby thatly stabalize it
tdbSaints 2 years ago
i think your problem with the sliding is that the propellers have enough power, you just need to focus that power with a duct around it. If you look at the real F-35, it has a ducted fan right behind the cockpit.
drummerboy0998 2 years ago
who is your camera girl?
MrMacManPro 2 years ago
His GF/wife. I don't know which.
forrest225 2 years ago
i suggest tie a ball to the center and let it hang 5 inches off the body and it'll be stable.
pietruski 2 years ago
Surely the reason it's sliding, not pitching is because the C of G is above the centre of lift and it wants to turn over.
You could put the fans above the fuse you'll have much more stability and conrol.
another alternative is to add more sources of lift; total three fans would do it (four would be better), and point them all slightly in (to give stable lift like dihedral low-wings)
ChrisHeli1978 2 years ago
Home Star ruiner
WizardofWoz132 2 years ago
on the shirt from Stong Bad series
WizardofWoz132 2 years ago
I think you should set 2-3 cups of coffee on top... a few magazines, some scones, etc. "Dave & Keith present: The World's 1st flying coffee table"!
RCEbooks 2 years ago
I don't think you can make it pivot with two positive thrust vectors underneath the body. The pivot point will always be off the body - so it's tilting is that it is trying to pivot around that axis point which is not on the body.
Think of a see-saw with two positive forces under the seats - how can it possibly pivot around a point _on_ the see-saw. I don't think it can be done. It will always pivot around a point that is away from (off of) the see-saw
LivingDog94 2 years ago
dude, it would be faster on the roll with the motors further out because of something called "moments". And no thats not the sections of time your girl friends have, lol.
liambowers666 2 years ago
it looks really close to the real one!
burningsponge 2 years ago
ailevor :D
shayshopen 2 years ago
UFO hhhaaa
unitspace13 2 years ago
those motors sound bad...:D
MovieMorris 2 years ago
for your pitch you should try what helicopters with the two big blades use. by adjusting the the speed of the motors. like if the tail is tipping down. the tail motor speeds up to bring it back up and the opposite for the nose.
mojo323 2 years ago
the engines or what ever you call them lol..on those leg things...are too low? perhaps closer to the hull
si6dayz 2 years ago
i think it shold be a ducted fan, right in the center of gravity to keep it more stable
DKF22 2 years ago
no other wise how could it pivot?
14cyproit14 2 years ago
Bottom vents.
genesis344 2 years ago
ailaruderons
BoscoWins 3 years ago
hey dave, how heavy is that whole plane?
annihil8ted 3 years ago
A gyro is needed for this application.
Both propellers need to be larger (for stabilitty).
Also the P-FACTOR needs to be observed so there isn't too much strain on the servos (due to the wobbling).
Rhydon1024 3 years ago
yeah I was thinking "gyros dude...gyros" lol. to control those ailarudders...haha
RogueSpear55 2 years ago
NEXT PROJECT, The super secret SR-91/Aurora spy plane.
jeffhanson1 3 years ago
RUD-ER-RONS! TM Property of Ricky Bobby Inc :)
whiskeyhotelpapa 3 years ago
What about the name Rudderons
DonLoki 3 years ago
good point that would make it tuns more stable
j55862 3 years ago
You goobers.....get the motors CLOSER to the rig...Your trying to balance the plane on broomsticks with this layout!! Another thing......put the blades in a tube to reduce turbulence around the blades. This also directs the thrust onto one direction.
killersushi99 3 years ago
Nice!! for the helys guys, the vector trust foam version /watch?v=ZjW8W31_tZs and watch?v=7pqSAnx1AXc simple iresistible!
alex681219 3 years ago
3 ducted fans?
RoboTekno 3 years ago
like they sad ducted fans takes to long to wined up
rikuwillkillu 3 years ago
Comment removed
fabiuzzugerry 3 years ago
can't you dave just take the towers off and make wholes in the acsakt plases that thee f-35 has on its fuelsaloge
jzboom 3 years ago
A good name " The hovering table" Ha Ha, anyway good job
3801Catcher 3 years ago
Neat project. As others have sugested, variable pitch props should result in quick pitch control, plus 'low gear grunt'. Or, instead of angling both props for pitch control, just angel one. For nose-down pitch, angle the front prop only backward. This 'should?' cause a rearward movement like the setup in this video plus a nose down pitch because the vertical component of the thrust of the front prop is less than the rear prop's. Rear motor only tilted aft for pitch up control.
bizzee1 3 years ago
your neighbors must love you, ever thought of that? Also, you need a PLC to keep the proper pitch, you will never get this on manual. Smarter people have tried and failed.
rotturbrain 3 years ago
i think you souhld use four smaller motors on the wingtips and on the fromnt and back.
geniusperson1 3 years ago
why don't you use different prop RPM's to controll pitch
bladeflyer7 3 years ago
Altering prop rpm's produces lag between sending the command and the actual rpm dropping. It takes time to lower and increase RPM without brakes!
PieJesuG 3 years ago
What the ? birthdefect heli lol
max4drc 3 years ago
Why the tall towers, Dave? Looks as if they make the acft very unstable.
BR5499a 3 years ago
fuck you Dave douche I commented on every video and he never answer's question's fuck you nightflyyer! fuck fagot go get fuck.
kevabolik 3 years ago
you should make a video on how you do all of your thrust vectoring.
slacker3442 3 years ago
You guys should get some test data from Lockheed lol
groeneslang 3 years ago
How about slowing down the front motor to drop.
slacky00 3 years ago
Ail-a-der *trademarked* =)
dingo7222 3 years ago
Try to add Gyros...
ASH.
ashikagaProdDesign 3 years ago
good Work!
puntalometro 3 years ago
why not buy one from a shop that works lol
EOINC8 3 years ago
What you've got here is basically a reverse-pendulum problem. Since it's not inherently stable, you'll either have to get it to sway so slow, that you can control it OR you'll need gyros to stabilize it (check out the quadrotor projects for some stuff you could use...)
bu5hm4nn 3 years ago
Ah finally, i been waiting to see your testing on this.
Hey have an idea to maybe help with your pitching or sliding problem. How about going more linear in the nose and increase the EXPO in the rear. I think that will help out
Gig540 3 years ago
You should put some gyros on the TestRigVTOL
homer6632 3 years ago
How about using 2 lift fans at the front, either side of eachother, cos then u have 3 fans which is much more stable although i suppose there will have to be a resultant torque force then. Put the motors on the top for better balance and use control vanes in the thrust line, vertigo style. this should improve it
nolsmtm 3 years ago
ello mate few things i wish you would try ;) either 4 or 3 motor configs turnin the rig upside down so motors pull not thrust if you want to thrustand current positioning use 5 bladed ducted fans maybe linking all speed controllers to a helicommand (please watch this vid watch?v=lVBi-1tX_uU) though i think you could mod suttin sweet without HC :D
0n3m1s1s0 3 years ago
noiesy little bugger isnt it =] ...
i dont know anything about RC's but i have to say what you have so far is really nice .. i wish i could work with you and learn how to make these things =]
Stuna2150 3 years ago
U should make it like a helico-plane
a helicopter blade up with servos
Allexxx96 3 years ago
Try using your gyro on the speed controls. i built a V22osprey and to help with the crazy roll and and pitch i used a gyro on each speed control. it works
3DPROSPORT 3 years ago
the dude talking is ETHAN ROM from LOST
TheInvincibleHERPO 3 years ago
haha it looks like him, but it's not him
samerce1 3 years ago
any gyros, are the props on the bottom? nice planes always!
leviterande 3 years ago
A simple/stupid pich controller could be made using a couple of resistors and mercury switches. Mount the mercury switches at a slight incline so that one closes at say 15 degrees down and the other 15 degrees up. Then connect a resistor in line with the speed controller so that when the nose pitches down over 15 degrees the switch closes and the resistor pulls down the speed controllers voltage thus slowing the "uphill" motor.
Its stupid but it should dampen the wildest pitching.
flyboy3633 3 years ago
Obviously three props would be more stable. Rather than changing the pitch of the motors split the output of each motor via ducting with a pitching "rudder" to direct more or less air out each duct - like a Harrier.
Also, the CG is way higher than the props so you're fighting a balancing act that you shouldn't have to. Like balancing a stick standing on your hand. Mount the props in the body (more realistic) or even better, above the CG and the craft will instantly become more stable.
flyboy3633 3 years ago
HOMESTAR RUNNER!!!
jstratton55 3 years ago
If you move the motors closer together, it'll be more unstable.
usageee 3 years ago
Oooor, :) if internalizing the props is out, Dave, you could try to use the "duckerons" idea turned 90 degreese (vertically) to block some of the air getting to the prop.
(Think of like an umbrella over the prop - or reverse it - make a "V" over the prop.)
This might inhibit the ability of one prop to give thrust therefore giving you a more instant thrust cut on one or the other of the engines - to get the elev. control.
Just another crazy idea,
Keep up the good work,
Ed
(ed5k)
ed5k 3 years ago
DAVE!!
I THINK I HAVE A GOOD IDEA!
If you can find a way to make one motor spin at a different speed that would give you pitch control. So, what would happen is that to pitch the nose up, make the front motor spin faster than the back, making more lift in the front. To pitch down, make the back motor spin faster. This is the same principle coaxial helis use for the yaw axis.
Let me know what you think!
thebigbrownbox 3 years ago
Yeah, he's right for sure! This was how I assumed you'd do it.
One issue though, adjusting the speeds will change the torque acting on each prop, which would give you some unwanted yaw, maybe? Variable pitch props, perhaps?
JonesRead 3 years ago
Well, Dave mentioned speed ctrl before - he said that didn't react fast enough. Also, prop pitch is probably out due to mechanical complexity.
Sooooo, I would say, Dave, you'd want to try experimenting with a variable vent. Yep, either internalize the props and have even just tiny movements on "lips" where the air exits the body. A slight closure of the "doors" would create less thrust - and therefore the pitch change you are looking for. Just a wild suggestion. - Ed (ed5k)
ed5k 3 years ago
I had an idea watching this video.
I don't know exactly how to do, and if anyone has posted this before.
Maybe if you adjusted separately the speeds for each motor. You could then put more power on the front or the back motor, making it pitch up or down, and maybe then leveling the flight using the same controls you are using for the pitch now.
This way it would be more stable than approaching the motors to the CG, but I don't know if it would be easy to control at all.
I hope this was useful!
danielseiti 3 years ago
i'm not sure, did you take into acount the counter-ration effect on the blades?
that might be a major problem don't you think?
another advice: it's much easier to hold an aircraft from both sides (wings) than from the center (body). so what i mean with this is that you can make it more stable is you attached the motors horizontaly (left and right wings) than vertical (nose and tail). if not try it with you own hands
jasanpahaf 3 years ago
like sharma17 i'm not trying to be an "armchair expert" but for pitch would it be possible to get one prop spinning faster? or is that what you're doing
desel09 3 years ago
moving out sideways too. Anyways. I don't know ANYTHING about all this stuff, just venting my curiosity. I'm sure you'll sort it out your own way :D. Thankyou for the videos
Sharma17 3 years ago
-and if the props are spinning too close to the wings when levelled, you may be able to adjust your C.G so that your props can spin freely in the gap between the ends of the wings and in front of the elevators.
I reckon just jump the gun a bit, and try it on a near complete F35 so you can simulate the final weight of the plane. I guess I don't need to mention gyros.. I'm sure you guys thought of it already. And if you manage to get the pitch perfect, a way to fix roll is to have the motors-
Sharma17 3 years ago
wow look at all the advice from people that im sure have never even tried what he is doing. there is always an armchairexbert when you need one.
StayStupider 3 years ago
Yeah looks that way. I'm not trying to be an armchair expert, and I don't think i'm any more right than a chimp, but when you're so interested in something, all you want to do is talk about it.. =)
Dave will probably be close to mastering it now on his own efforts :), but if something we suggested helped, than it can't be a bad thing right?
Sharma17 3 years ago
Hey Dave, Good attempts :D, Enjoyed watching Keith Dance, only next time you do the tests, please play some salsa on the stereo to fit the mood :)
I know everybody seems to have a suggestion for you, but here's mine anyway. I think your equip is fine, I'd like to see what would happen if you built your test peice up a bit, and had the two motors on either side of the plane, in the c.g. (try get the motors as close to the wings and the side of the fuselage as possible.
Sharma17 3 years ago
I would recommend trying mixing the motorspeeds for pitch control. A deltamixer would work nice for this.
dadde87 3 years ago
hi there, nice thing u build there :) i tryd this a few years ago with brushed motors. But i had some differences which worked nicely: my props were above the CG, they were counterrotating, which was an issue for me, because my rig was smaller. the main thing was the pitch was made by the ESC´s i only had 2 servos for roll and yaw. If your ESC is not fast enough in the response, try sth. like GM Genius 70 its fast responding! Greetz Wolf
rcwolfman 3 years ago
Constantly inventing new terms when I don't know the real ones is amusing but probably not helping me any.
Sadly that thing flies as well as my mini copter... or maybe it's just me.
Craydon 3 years ago
Testing in the middle of a quiet residential area are we? I hope it wasn't too early in the morning at least. LOL
Seriously, why do think it took this long for a American fighter jet, the Lockheed F-35, to be produced? I'm actually surprised it took this long with all the historic American know-how.
I've seen old military video of all the failed attempt and test in the 60's. It makes you respect the old British Harrier a lot more. 40 years ahead of its time!
jeffhanson1 3 years ago
it might be a bit much but you will get 10 times better stability if you add two more motors. all four in a dimond formation and that way the thrust is equal on all four sides..front, back, and both sides. Good luck!
nascarfan383 3 years ago
i agree, it would be more stable and you would have more pitch/roll control if you are changing the thrust from each engine
ghostofrazgriz1 3 years ago
testing that close to the ground will put it in ground effect whcih will make it a challenge to hold in one place
idigrc2 3 years ago
An idea I had was to mix the thrust on the two motors to help control pitch. Increase or decrease one to push that end up or down. It would mess with the yaw a little though so it might not work. Just an idea.
metalmikexx 3 years ago
it's all trial and error bro
BrutalWaffle 3 years ago
Thank you!
RCSuperPowers 3 years ago
amazing! i really hope you get it to work!
amazing¨ that's all i have to say
mpkappert 3 years ago
cool stuff Dave!
As suggested you might try changing the configuration so the planes CG is below the the props or as close a possible. it goes with the pendulum principle you describe with the stick in the Free Extra foamie video.
Could you put gyros on the hover mode and maybe have them double as flight mode gyros?
morgandhunter 3 years ago
Maybe his thinking behind setting the motors so far from the center of gravity is like when you are balancing a broom on your hand, ya know?
taofledermaus 3 years ago
Why not control the pitch with the engine speed?
havrekli 3 years ago
Or is the speed control to slow for compensating sudden pitch change?
havrekli 3 years ago
I've been waiting for this :D
bf2fsxcod4412 3 years ago
I think you should keep the distance and mix a little elevator with the throttle to gain proper pitch authority(although it will be a little sluggish so dont bother trying to let the gyros influence it)
Ragath87 3 years ago
It looks too top heavy. maybe you should move the motors closer to the body of the jet. it might make it more stable.
mozart237 3 years ago 3
I agree. I don't understand why they would place the motors so low and far from the center of gravity. I think they are going to realize it's going to very very difficult achieving their goal of a VTOL. They almost need motors out on the wingtips too in order to provide roll control.
taofledermaus 3 years ago
must have four or three motors
kameldenuit 3 years ago
The flying bedstead!
frankstrudel 3 years ago
i am making an f-35 simalar to this and i have very stable by having four motors all pointing outwards but the control is slightly lagish
HPIRCFAN1990 3 years ago
wtc r any ov u talking about
munee4fud 3 years ago
I think it would be easier to fly if you had the lift fans as high up as possible because it goes on the same principle that an object is easier to hang than to balance above. If it were my plane i would cut holes in the plane where i wanted my props and mount them in the body. You couldn't mount the motors above the plane because you would lose all lift when the wind bounces off of the plane. This will also look much nicer.
luciferq7 3 years ago
I would also leave the fans as far apart as possible because you will lose all of your yaw athority by moving them closer together. You could then solve the pitch problem by controling it with fan speed jus like the air hogs twin thunder helicopter.
luciferq7 3 years ago
your stupid thats not an f-35!!
jaden1592 3 years ago
dude it is a mok-up for the vertical take off it wasnt made to look like the actual plane
HPIRCFAN1990 3 years ago
you can do elevator by diferential motor speed.The test rig is pretty primitive but I know you`ll get it done in on month or so.Please post some plans on your website when this is done,and get bigger ESC cause that can crash because of those small cheap`o esc.
mouselg 3 years ago
What about using a gyro for your front and rear motors. I'm guessing you're running a Y cable from your ESC's to your receiver right? What about a gyro between the Y cable and the receiver?
AurelionZX10R 3 years ago
Looks like you're using thrust vectoring for pitch. I'm not sure how well that will work with that setup. I think the best way is to keep the props spaced apart for good yaw and vary the speed of the props for pitch. I'm also wondering if once you move the props up, that the roll might not work. At the moment the thrust vectoring looks like it's causing the roll via leverage on the motor supports. At least that's my 2c as an RC heli flyer. Should be interesting to see how it all works out.
soupisgoodfood42 3 years ago
macts makes sense, good call
Without puffer ducts of control veins its gonna be hard
mickard001 3 years ago
Think of the thrust like stilts, If you concentrate the stilts with a small area youll fall over, but if you spread them out they will support the weight.
just a thgought
mickard001 3 years ago
having the motors on the lower side and your center of gravity up makes it lean esly on one side and unrecoverable, it'a like having a heli upside down, for testing it seems more useful to have the blades in corrispondance of the plane body or just a bit higher. with 2 motors on wings and one under the nose you can control it only wirh the rpm of the motors instead of servos.
(imho)
mactsk 3 years ago
lern to aluminum
AgentGhost 3 years ago
dang... i dont think this one is so easy... lol
good job though!
ownufools 3 years ago
Oh my, that is going to be a tough one.
I realy can't see it achieving a stable ascent/descent with a straight down setup.
My sugestion would be to keep the location of the hatches as they are now, but with both motors pointing outwards on opposite directions, i'd say some 30º should do the trick.
You'l get more pitch control and a far more stable hover, plus physics wise you can actualy make the hatch ports much smaller with this method.
The concept is sound, think about it, Dave.
00Resev 3 years ago
I like the outward cant idea, but I don't think he would need 30 degrees. 10-15 maybe.
dogsbd 3 years ago
the only way your going to get the hover machine going really good is with VARIABLE PITCH PROPELLERS.
LetsWangChung 3 years ago
Well, i don't think so. He could use 2 separate channels for motors and mix his radio to change motors' rpms and that would change the pitch. And for the roll and yaw he could leave thrust vectoring, as it works nice.
YeahYeahYeahs8 3 years ago
finally ur starting to do helis!
bratonabike 3 years ago
Hahaha Nice nice!!! i was laughing at all ur new names :-)
btw is that a Mustang under the covers???
DriftStallion 3 years ago
you should try positioning them up top instead, because it would prolly be more stable
walikai 3 years ago
for pitch you should make the motors at different speeds rather than moving them
Barrok122 3 years ago
Read previous comments. For the "umpteenth" time, Dave has already explained in earlier comments that the throttle response, speeding up or slowing down the propeller, is too slow to compensate for changes in pitch.
dogsbd 3 years ago
I think he should try it. For me this is the only solution because I can't see where the truts vecort control should realy point at when correcting pitch. Perhaps you can do pitch by (as a example piching up) by vectoring the front strigt down and the back motor vectored backwards. So you have more lift in the front and less in the back. Also the vercor helps to "turn" the plane upwards.
CamFlyerCH 3 years ago
how will this motor desghin work on the f-35? will it always have 2 motors hanging off the bottom?
uselessmidget 3 years ago
Homestarrunner!
MadMub 3 years ago
come on dave when u going ti listen to me??? u are doing it all wrong man, all wrong
djrevolution99 3 years ago
Rudder-vons
taofledermaus 3 years ago
Haven't we all needed a 2" extension once or twice in our lives?
taofledermaus 3 years ago
is it possible to make a differential thrust on both motor just like jetset44 (steve shumate) did with his thrust vectoring yaw control on his su-37. it might help on pitch contol.
kapitanC 3 years ago
this guy is really inteligent he knows exactly what hestalking about!
frankenstein04 3 years ago
hey guys , I'd like to make a suggestion for you on this aircraft . Set the rear engine at 2 inch & the front engine at 3 inch ten try it then revers the engine settings to 2 inches in front and 3 inches in the back, then try it ,
watchdog3 3 years ago
HEY he's wearing A HOMESTARRUNNER T-SHIRT!!!!!!!!
flyinportopotty 3 years ago
no their ruddivons
mike1010100 3 years ago
lol ail-a-va-rudder.
kbtwinkietwins 3 years ago
Man those motors rock. Man to they ever crank . I love the sound of them. DO NOT insert finger here.LOL Pretty cool setup
flyguy4fun 3 years ago
SWEEETTTTTTTTT This was so helpless!! TYVM Guys You've inspired me!
Skurgefaust 3 years ago
you shuld be able to control the motors separatly if you want to control the pitch
trombonista92 3 years ago
I think you need gyros on the motors lol
peisen 3 years ago
what about adding gyros dave?
sigair 3 years ago
wow u guys own u so cool
OXXBOXXO 3 years ago
ruddervons! hehe ;)
zythepsarian 3 years ago
The killer must run from the killer barker. Not nalts doing the stunts!
Chick6517 3 years ago
chopped nutz
wmacorlando 3 years ago