The fact that the airplane turns right with lower throttle and left with higher throttle tells me the airplane is flying how it was designed to. Your engine mount is angled to the right so at lower throttle it will go right, at higher throttle the torque overpowers the right angle thrust of the engine and it rolls left. Like someone in the comments said, you just need a throttle-rudder mixing and it might take a few tries to get it right. Another advice I’ll give is to angle the engine mount down 2 degrees also. This helps to offset the left yaw induced by P-factor at positive angles of attack.
I believe the wheel pants are the problem I also think they are acting like vertical fins; would it be possible to test fly without them attached. I admire your work and love your videos. Thanks for sharing
They are.... even with the just the struts the effect is noticeable ;) Same with my 1,4m version and also the big Airworld Gee Bee R3 shows the same effect (Confirmed by a friend flying the Airworld version).
So glad you've decided to repair this beautiful airplane. As a life long RC hobbyist, i am a big fan of this build!! Wish you kept the original engine...
I agree with other Comments: either you need to remove the Weelshoes or install a much bigger vertical stabilizer. This will improve the Direction-Stability. (Excuse my English).
Fit a gyro and fly it in heading hold it will make it easier to fly and counter any tendencies to deviate from level flight. I use Powerbox 3e gyros in many of my aircraft as it makes them more relaxing to fly. It won't fly it for you but it sure smoothes out the flight.
you gave it a solid effort and got a successful flight out of the beast. Maybe hang it up on the wall as it does look amazing, and scavenge the electronics and such for a future plane.
In addition of the comments about throttle and rudder mixing I would suggest to redesign the wheel pants to a thinner one that would work as a vertical stabilizer to compensate the small vertical stabilizer area
Tbh I‘m not really into gaspowered models, but I‘m just continously fascinated by your level of build quality, regardless of how it flies 😄 Your model studio tent is really a sight to behold
There will be foaming in your fuel tank because it is basically mounted to the engine and gad engines vibrate everything. There should be foam isolation around the fuel tank. Absolutely beautiful plane.
The wheel pants are absolutely a problem. Not only are they shaped like large vertical fins, they're also forward of the aerodynamic center which means they create destabilizing yawing moments with any sideslip. Since their combined side-view area seems to be much more than the integrated vertical fin/rudder of this design, they will have a large influence on the directional heading stability/control despite their short moment arm. Thankfully you must have done a very good job at aligning them with the longitudinal axis or your rudder may not have had enough authority to overcome any built-in yaw. I would expect you would be happier with the flight characteristics with the wheel pants removed.
1. The wheel pants might be making the C_n_beta more negative (tendency to continue yawing movement). It decreases the rudder efficiency to dump yaw movements since its in front of the CGy. This can get worse with high throttle since your rudder needs to overcome the airscrew and the wheel pants force with beta different then 0. 2. If you feel the yawning moment while pitching up ou down and high throttle, then might be a P-factor issue. If the flight is in high alfa (low speed, high wing load) might also be a P-factor issue. Changing the vertical angle of the engine might help. 3. The airscrew from the propeller hitting the vertical estabilizer will generate yawing moment with throttle increase. Mixing the rudder to the throttle might help if the rudder is big enough.
Like everyone has previously said, the wheel spats/ pants are the issue. I do agree with the tho/rud mix but maybe think about incorporating a rudder-style trim tab in the trailing edge of the wheel pants. It may look a bit ugly but you could get more rudder authority with each wheel pant having a trim tab to counter the planes want to veer left and right. This may clam it down and be a flyable aircraft then. If anyone can make it work, it would be you. Best of luck with this.
CG and wing loading seem to be a LOT better than before! Now it looks like 1)the engine's thrust line is pulling left, and 2)the design inherently lacks yaw stability. I agree with a test flight without the pants, and I also would increase the engine's right thrust until the plane flies straight at any rpm. Some designs need a lot of right and/or down thrust, to the point that it's easily visible and that's OK. While assessing how straight the plane flies, also assess the degree of yaw stability. If it's good without the pants, maybe reduce the side area of new pant legs and print another rudder with larger chord. Some scaled-down designs benefit from slight deviations in order to fly well as models, and it wouldn't surprise me if this is one of them.
I think the original Gee Bee design was a handful to fly too - maybe it needs more vertical stabilizer area for stability? Also could use a flight controller to fly easier… Beautiful work building it though, as always!
There is no solution - other than to completely redesign the tail of the aircraft to include SIGNIFICANT vertical stabilizer/rudder area. But your fabrication skills are the BOMB!!
If you look at some other GeeBee R3's, the wheel pant is just the wheel, and the main and rear struts are faired individually. This would significantly reduce the rudder effect. Your design, while sexy, probably acts as mentioned below, like rudders. as for right thrust, I think I'd try a bit more. Just throw a couple more washers in and keep testing. Once you find the right amount, gin up another firewall mount. Also fly without the wheel pants.
Glad you repaired it because it’s a beautiful model, but clearly a real handful to fly. I agree with previous comments - try flying without the wheel fairings and see if that helps?
By design it’s made to fly fast and turn left. It will never be pleasant to fly appart using it for pylon racing. The build is wonderfull like always 👍👍
I've an idea. Maybe it will sound strange but, why not to try it. Just attach your R3, motor off, prop off, to a bigger airplaine, like a glider, and then, glide it and see how it flies. Then you will have a first answer. Is it due to the engine angle or not... If it doesnt flies right, then adjust the size of the wheelpants and/or the rudder size (its true that visually, it seems small) if it flies right, just adjust the mounting angle of the engine. for this type of plane, this is not rare to need a consequent angle to the right. Sometimes also an angle that makes it go up (depends on your wing profile and placement). It shouldnt go to the right at low throotle even if your engine is angled that way, as I read higher in the comments. It should fly straight no matter the amount of throotle. By the way, in the air, i see a bit of a tail heavy plane, maybe i'm wrong and your CG is probably not responsible of everything, but pushing it forward a bit would maybe make things better By the way you really are an awesome builder, this plane is an absolute beauty, congratulations, keep up the work, we love it!
"Just attach your R3, motor off, prop off, to a bigger airplaine, like a glider, and then, glide it and see how it flies" That's not a good idea. Some planes fly like a rock without engine power ;)
I am pleased to see you repaired the Bee Gee R3 It is not very relaxing to fly is it? Like many have said below I would try it without the wheel Pants, and try and get some established base line you can go forward with.
Magnífico trabajo como siempre. Si entendí bien, gira a derecha cuando le das potencia, parece un problema de ángulo del motor. Has comprobado el peso lateral del modelo?...es decir...sujetando de la cola y cono y ver hacia dónde cae? Saludos y buena suerte. Ánimo!!
As my here have already noted, the instability about the vertical axis is due to insufficient vertical stabilizer surface area. The vertical stabilizer can enlarged however that may ruin the aesthetic of the aircraft. You can try to add some fences on the bottom and top of the horizontal stabilizer to reduce the slip of the air traveling over the stabilizer during a turn. I also like the idea of a clear fin on the bottom of the aircraft. Maybe both are needed.
I think you should Rafe the plane off. €10 to €20 a ticket. I looks hard to fly, however I would love to own it and just have it as a display item. You have done a fantastic job on this model and I feel incredibly sorry for you that after all that hard work it doesn’t fly like you want it. BUT it’s incredibly beautiful 😍
Btw, I'd try to fly it without the wheel pants if possible just to see if they are affecting the flight somehow, since they can act like a vertical stabilizer, if any of them mount slightly left, that might cause the problem.
Take the wheel pants off and see if that makes a difference...... also the thrust angles.... the motor should be to the right (which you did) and down 2-3 degrees... I dont think the pants will do much but its worth a try... definitely worth investing some time in the thrust angles. Also have you done a lateral balance....... hang the plane upside down and using fishing line tie one end around the prop shaft (with the prop removed) and the other end around the tail wheel and lift it....... I bet your plane is one side heavier than the other... I had an extra that flew like that and it was out so adding a lead weight to the wing tip made it perfect to fly..... plus I get a lot of "whats that on the end of the wing" comments.... if that fixes the issue you will need to cut into the wing tip to bury the weight...... good luck and dont give up.... I bet is a combination of a few small thing which adds up.
My thoughts are that wheel strut airfoil should have very shallow lift coefficient gradient. It would help maintain a little more calm direction stability.Aany small jaw produces too much "lift-side force" on the struts ahead of CG that small vertical tail cant deal with, or probably that resulted in constant chasing of direction balance.
This is the best suggestion so far. What do you think about re-checking the thrust-line and/or angling the motor down a few degrees to change where the spiral 🌀 airflow is striking the vertical stab?
i owned many different type of gee bee style aircraft ,the spads will make the plane not to fly straight or it needs a lot of rudder and thats normal ,what i suggest you is ,if its possible and you are in mood to fly this one again ,remove the spads and fly without and see if thats 100% your problem ! You need to understand that all the planes of this kind dont like to fly without a good control of the rudder !
"engine angled to right, then pulls left when throttle kicks in"...Dont worry, it's the natural torque roll of many prop planes when those blades start spinning.
Great work but as you mentioned, it seems to fly strangely. It seems to want to slip into every turn which I think is likely due to the cross sectional area of the wheel pants offsetting the area of the fin and rudder. Perhaps mix in a bunch of pro turn rudder with the ailerons? Or; make a larger than scale rudder.. Amazing work though. Thx for sharing.
@markoroolaid well that should be no problem with 10 inch pitch. More side thrust should help then. I hope you have ultimate success because it's a beautiful aircraft. 😍
Nice! Do you use special resin for fiberglass? Because resin that I use and know emits heat while curing and tgat would ruin printer plastic, at leas soften it and force to lose geometry.
You have to add a THR-RUD mixer - many scale models need such a mix ! Also, I would fly such a plane only with gyros - they help big in dampening the plane and make it fly like it would be much larger than it actually is !
I second you on the THR-RUD mixer. It would also help when you have the engine on idle because with the mix you would not have the rudder to the right when on idle anymore. Don't think the wheelpants make any difference (there's some R3s if you search on youtube with different wheelpants, they all have the same issue). The small rudder surely doesn't help the plane a lot. Think the best way is the THR-RUD mixer and more angle on the firewall, and although i don't think this can be 100% solved on any R3 you can get it good enough to have joy flying it.
A geebee r3 needs ALOT of right thrust angle, atleast 2.5 degree. My hall bulldog prototype had the same acting... that is because the whole fuselage is aerodynamical, its not just a box fuselage like on a piper for example and so it behaves like a vertical fin... but the angle is actualy useless if you dont build a side offset so that the prop hub is centered with zhe fuses centerline. A prop hub not centered acts exacly the wrong way you want it, it will go even more to the left which is logical when you think about it.
Maybe if it would be possible to trim it to glide straight without engine thrust first and then add thrust angle incrementally balance could be found - the motor mounting setup looked like this could be done on the field. Actually, how stiff is the motor mount? If there's a lot of force to the mount, does it bend and allow the thrust angle to change?
I've recommended a throttle to rudder mix before, only so much advise we can give unfortunately, use it dont use it. CG is better in this video, made the model more manageable. You can reduce prop diameter, maybe even a three blade to help reduce the torque effects but at the end of the day probably best to increase the vertical size drastically which will make the plane look weird. 😊 Add a bit more right thrust. Put a throttle to rudder mix in on a switch so you can de avtivate if its all wrong, start small and tweak. You've before not taken kindly to my critique even after asking nicely to not be offended. But let's try again anyways. Please don't take offense, just commenting on my observations from the video. It really does look like you struggle with rudder control, put some time into getting better with that. You've built an aerobatic model, go fly that rudder! This Geebee is flying well, no need to bench it. You got this bud! Good job on the repair.
A throttle/rudder mix might be in order, however you first need to check your “thrust-line” which can be found on the full scale design specs. You have a counter-clockwise 🔄 swirling airflow from the prop which is knocking into the rudder, causing the yawing at higher rpm. Elliptical wings are easier to tip stall and are also more susceptible to throttle induced roll. Also the design of the wheel-pants or spats is such that they almost eliminate side slip since they behave like a fulcrum around which the centre of gravity pivots. I suspect this is why the design requires such a relatively small vertical stabiliser and control surface. Still a great maiden flight and any landing your action man can walk away from is a good one 😊 ruclips.net/user/shortsnXvR7Ct0eGE?si=eSp_XMxQ92XdOWa7 ruclips.net/video/6R3O6hc1XU4/видео.htmlsi=8OwJjb6UAC_ITxUK The cause of the unintended yaw is a combination of P-factor and rotational/spiral slipstream effect on vertical stab. The remedy may be as simple as angling the motor direction downward a few degrees as well as to the right (which you’ve already done) 👍 There are options for slimmer wheel pants/spats but I’m not convinced that they’re a problem. Of course, if you don’t have a neutral angle of attack it's possible, but I’m sure a builder of your calibre would have checked the alignment. This is a thrust line problem and for a racing aircraft design the issue is being exacerbated by the spiral 🌀 airflow striking the vertical stabiliser. I’d put money on that being the issue at this point. Short of computational fluid dynamics and tests in an air tunnel I’m almost 100% certain. Please watch the clips I sent (links provided)
So I have a thought as to why this is happening. But before I give you my thought I have a question for you, did you add right rudder trim immediately after takeoff?
@@markoroolaid So the reason why it pulled to the right when you throttled back is because when you decreased the throttle you decreased the effect of the P-factor. The P-factor is the asymmetric torque generated by the propeller. The faster, the propeller spins the greater the torque, and therefore the more the aircraft pulls to the left. When you decreased the throttle, the P-factor was decreased, therefore the trim that you put into the rudder caused the aircraft to turn right. There’s a simple solution to fix this. Simply add more right thrust. Take a couple washers and put them between the engine and the standoffs on the left rear of the motor to give the engine more right thrust. You may have to take it up a degree at a time until you get the proper amount of thrust. Don’t be surprised if you wind up putting in 5° or more of right thrust. In addition to the right thrust is to add a flight stabilization system such as AS3X. Keep in mind a flight stabilization system will not eliminate the aircraft pulling to the left until you put in adequate right thrust. It will simply help to stabilize the aircraft in flight.
The rudder has to be much bigger in size. The wheel shoes are virtical fins in a negativ way because they are not behind the cg. Just get a bigger rudder and everything will be fine.
That plane really want to go left: 1. Maybe the wingshape isn't the same on both wings and do you have some washouts on the wing design? 2. Gee Bee look cute, but not exactly ideal aerodynamics. That oversized body maybe force air around asymmetric.
Having flown a 50cc myself I have experienced the trim issues. The plane doesn’t like to fly straight, drops the tail in turns and tracks poorly. We improved the stability of the vertical stab by adding another fin underneath the fuselage to increase the size of the vertical tail and improve stability, also known as a ventral fin. It helps to give the undersize vertical fin enough aerodynamic stability to overcome the effect of those large spats. We used clear plastic so it doesn’t change the classic look of the R3. Don’t be shy, make a big one and give it a try and then cut it down from there as the bigger it is the better it will fly. Examples here. ruclips.net/video/dqzs6kX7ZqE/видео.html
The engine sounded terrible, rough running, and I would feel better with a larger (semi scale) vertical and rudder. It is a beautiful plane. It's not the first GeeBee with handling probs. Imagine if you had to fly the real thing.
Test fly without the wheel pants they do look a little on the large size and maybe after that a bit more angle on the engine mounts I think it had a lot to do with the hard pull left, and it’s a beautiful plane 👍
The fact that the airplane turns right with lower throttle and left with higher throttle tells me the airplane is flying how it was designed to. Your engine mount is angled to the right so at lower throttle it will go right, at higher throttle the torque overpowers the right angle thrust of the engine and it rolls left. Like someone in the comments said, you just need a throttle-rudder mixing and it might take a few tries to get it right. Another advice I’ll give is to angle the engine mount down 2 degrees also. This helps to offset the left yaw induced by P-factor at positive angles of attack.
Its alive........ Good job on the rebuild.
I believe the wheel pants are the problem I also think they are acting like vertical fins; would it be possible to test fly without them attached. I admire your work and love your videos. Thanks for sharing
They are.... even with the just the struts the effect is noticeable ;) Same with my 1,4m version and also the big Airworld Gee Bee R3 shows the same effect (Confirmed by a friend flying the Airworld version).
So glad you've decided to repair this beautiful airplane. As a life long RC hobbyist, i am a big fan of this build!! Wish you kept the original engine...
I agree with other Comments: either you need to remove the Weelshoes or install a much bigger vertical stabilizer. This will improve the Direction-Stability. (Excuse my English).
Never give up!!! Thanks for the video.
Fit a gyro and fly it in heading hold it will make it easier to fly and counter any tendencies to deviate from level flight. I use Powerbox 3e gyros in many of my aircraft as it makes them more relaxing to fly. It won't fly it for you but it sure smoothes out the flight.
you gave it a solid effort and got a successful flight out of the beast. Maybe hang it up on the wall as it does look amazing, and scavenge the electronics and such for a future plane.
In addition of the comments about throttle and rudder mixing I would suggest to redesign the wheel pants to a thinner one that would work as a vertical stabilizer to compensate the small vertical stabilizer area
Tbh I‘m not really into gaspowered models, but I‘m just continously fascinated by your level of build quality, regardless of how it flies 😄 Your model studio tent is really a sight to behold
Хорошая работа,отличная модель!!! 😊
There will be foaming in your fuel tank because it is basically mounted to the engine and gad engines vibrate everything. There should be foam isolation around the fuel tank. Absolutely beautiful plane.
Ok, thank you
The wheel pants are absolutely a problem. Not only are they shaped like large vertical fins, they're also forward of the aerodynamic center which means they create destabilizing yawing moments with any sideslip. Since their combined side-view area seems to be much more than the integrated vertical fin/rudder of this design, they will have a large influence on the directional heading stability/control despite their short moment arm. Thankfully you must have done a very good job at aligning them with the longitudinal axis or your rudder may not have had enough authority to overcome any built-in yaw. I would expect you would be happier with the flight characteristics with the wheel pants removed.
1. The wheel pants might be making the C_n_beta more negative (tendency to continue yawing movement). It decreases the rudder efficiency to dump yaw movements since its in front of the CGy. This can get worse with high throttle since your rudder needs to overcome the airscrew and the wheel pants force with beta different then 0.
2. If you feel the yawning moment while pitching up ou down and high throttle, then might be a P-factor issue. If the flight is in high alfa (low speed, high wing load) might also be a P-factor issue. Changing the vertical angle of the engine might help.
3. The airscrew from the propeller hitting the vertical estabilizer will generate yawing moment with throttle increase. Mixing the rudder to the throttle might help if the rudder is big enough.
Like everyone has previously said, the wheel spats/ pants are the issue. I do agree with the tho/rud mix but maybe think about incorporating a rudder-style trim tab in the trailing edge of the wheel pants. It may look a bit ugly but you could get more rudder authority with each wheel pant having a trim tab to counter the planes want to veer left and right. This may clam it down and be a flyable aircraft then. If anyone can make it work, it would be you. Best of luck with this.
CG and wing loading seem to be a LOT better than before! Now it looks like 1)the engine's thrust line is pulling left, and 2)the design inherently lacks yaw stability.
I agree with a test flight without the pants, and I also would increase the engine's right thrust until the plane flies straight at any rpm. Some designs need a lot of right and/or down thrust, to the point that it's easily visible and that's OK.
While assessing how straight the plane flies, also assess the degree of yaw stability. If it's good without the pants, maybe reduce the side area of new pant legs and print another rudder with larger chord.
Some scaled-down designs benefit from slight deviations in order to fly well as models, and it wouldn't surprise me if this is one of them.
A throttle-rudder mix will probably do the job. I even had a Piper Cub fly like this.
I think the original Gee Bee design was a handful to fly too - maybe it needs more vertical stabilizer area for stability? Also could use a flight controller to fly easier… Beautiful work building it though, as always!
There is no solution - other than to completely redesign the tail of the aircraft to include SIGNIFICANT vertical stabilizer/rudder area. But your fabrication skills are the BOMB!!
Bloody good effort Sir ! Looks like a handful.A super model.Just wish I had your workshop an kit.
If you look at some other GeeBee R3's, the wheel pant is just the wheel, and the main and rear struts are faired individually. This would significantly reduce the rudder effect. Your design, while sexy, probably acts as mentioned below, like rudders.
as for right thrust, I think I'd try a bit more. Just throw a couple more washers in and keep testing. Once you find the right amount, gin up another firewall mount. Also fly without the wheel pants.
Glad you repaired it because it’s a beautiful model, but clearly a real handful to fly. I agree with previous comments - try flying without the wheel fairings and see if that helps?
By design it’s made to fly fast and turn left.
It will never be pleasant to fly appart using it for pylon racing.
The build is wonderfull like always 👍👍
I've an idea. Maybe it will sound strange but, why not to try it.
Just attach your R3, motor off, prop off, to a bigger airplaine, like a glider, and then, glide it and see how it flies. Then you will have a first answer. Is it due to the engine angle or not...
If it doesnt flies right, then adjust the size of the wheelpants and/or the rudder size (its true that visually, it seems small)
if it flies right, just adjust the mounting angle of the engine. for this type of plane, this is not rare to need a consequent angle to the right. Sometimes also an angle that makes it go up (depends on your wing profile and placement).
It shouldnt go to the right at low throotle even if your engine is angled that way, as I read higher in the comments. It should fly straight no matter the amount of throotle.
By the way, in the air, i see a bit of a tail heavy plane, maybe i'm wrong and your CG is probably not responsible of everything, but pushing it forward a bit would maybe make things better
By the way you really are an awesome builder, this plane is an absolute beauty, congratulations, keep up the work, we love it!
"Just attach your R3, motor off, prop off, to a bigger airplaine, like a glider, and then, glide it and see how it flies" That's not a good idea. Some planes fly like a rock without engine power ;)
I am pleased to see you repaired the Bee Gee R3 It is not very relaxing to fly is it? Like many have said below I would try it without the wheel Pants, and try and get some established base line you can go forward with.
Magnífico trabajo como siempre. Si entendí bien, gira a derecha cuando le das potencia, parece un problema de ángulo del motor. Has comprobado el peso lateral del modelo?...es decir...sujetando de la cola y cono y ver hacia dónde cae? Saludos y buena suerte. Ánimo!!
So glad to see this thing back again:) beautiful plane
You change the engine right? It had a twin before...🤔
Wowwwwww.So great.👍
It might be a mistake to chase down the aerodynamic issues, it's gorgeous though, it will be the queen of the hanger.
As my here have already noted, the instability about the vertical axis is due to insufficient vertical stabilizer surface area. The vertical stabilizer can enlarged however that may ruin the aesthetic of the aircraft. You can try to add some fences on the bottom and top of the horizontal stabilizer to reduce the slip of the air traveling over the stabilizer during a turn. I also like the idea of a clear fin on the bottom of the aircraft. Maybe both are needed.
I think you should Rafe the plane off. €10 to €20 a ticket.
I looks hard to fly, however I would love to own it and just have it as a display item.
You have done a fantastic job on this model and I feel incredibly sorry for you that after all that hard work it doesn’t fly like you want it. BUT it’s incredibly beautiful 😍
Btw, I'd try to fly it without the wheel pants if possible just to see if they are affecting the flight somehow, since they can act like a vertical stabilizer, if any of them mount slightly left, that might cause the problem.
Take the wheel pants off and see if that makes a difference...... also the thrust angles.... the motor should be to the right (which you did) and down 2-3 degrees... I dont think the pants will do much but its worth a try... definitely worth investing some time in the thrust angles. Also have you done a lateral balance....... hang the plane upside down and using fishing line tie one end around the prop shaft (with the prop removed) and the other end around the tail wheel and lift it....... I bet your plane is one side heavier than the other... I had an extra that flew like that and it was out so adding a lead weight to the wing tip made it perfect to fly..... plus I get a lot of "whats that on the end of the wing" comments.... if that fixes the issue you will need to cut into the wing tip to bury the weight...... good luck and dont give up.... I bet is a combination of a few small thing which adds up.
Did the Roto survive? Why did you change the engine?
My thoughts are that wheel strut airfoil should have very shallow lift coefficient gradient. It would help maintain a little more calm direction stability.Aany small jaw produces too much "lift-side force" on the struts ahead of CG that small vertical tail cant deal with, or probably that resulted in constant chasing of direction balance.
Great work Marko. Take a break from the Gee Bee. Maybe it is the wheel pants. Could you fly it without them?
I’ve always understood that one needed to insure washout with elliptical wings.
Nice job and maiden.
Increase 2.5 to 5 * ( easy change for big effect ?).
Thanks Maestro
This is the best suggestion so far. What do you think about re-checking the thrust-line and/or angling the motor down a few degrees to change where the spiral 🌀 airflow is striking the vertical stab?
i owned many different type of gee bee style aircraft ,the spads will make the plane not to fly straight or it needs a lot of rudder and thats normal ,what i suggest you is ,if its possible and you are in mood to fly this one again ,remove the spads and fly without and see if thats 100% your problem ! You need to understand that all the planes of this kind dont like to fly without a good control of the rudder !
"engine angled to right, then pulls left when throttle kicks in"...Dont worry, it's the natural torque roll of many prop planes when those blades start spinning.
Great work but as you mentioned, it seems to fly strangely. It seems to want to slip into every turn which I think is likely due to the cross sectional area of the wheel pants offsetting the area of the fin and rudder. Perhaps mix in a bunch of pro turn rudder with the ailerons? Or; make a larger than scale rudder..
Amazing work though. Thx for sharing.
Be G wizz good too see her flying.
How about towing in the wheel pants or stall strips on the outside?
I don't know what propeller you are using but you could try a finer pitch to reduce the P effect.
hi, 23x10 Biela 2-blade carbon propeller
@markoroolaid well that should be no problem with 10 inch pitch. More side thrust should help then. I hope you have ultimate success because it's a beautiful aircraft. 😍
On another point. The spats are huge and could ha a detrimental effect. Alignment is crucial and maybe a bit of toe in could be good.
Nice! Do you use special resin for fiberglass? Because resin that I use and know emits heat while curing and tgat would ruin printer plastic, at leas soften it and force to lose geometry.
hi, I use epoxy resin larit 285
You have to add a THR-RUD mixer - many scale models need such a mix !
Also, I would fly such a plane only with gyros - they help big in dampening the plane and make it fly like it would be much larger than it actually is !
I second you on the THR-RUD mixer. It would also help when you have the engine on idle because with the mix you would not have the rudder to the right when on idle anymore.
Don't think the wheelpants make any difference (there's some R3s if you search on youtube with different wheelpants, they all have the same issue). The small rudder surely doesn't help the plane a lot.
Think the best way is the THR-RUD mixer and more angle on the firewall, and although i don't think this can be 100% solved on any R3 you can get it good enough to have joy flying it.
A geebee r3 needs ALOT of right thrust angle, atleast 2.5 degree.
My hall bulldog prototype had the same acting... that is because the whole fuselage is aerodynamical, its not just a box fuselage like on a piper for example and so it behaves like a vertical fin...
but the angle is actualy useless if you dont build a side offset so that the prop hub is centered with zhe fuses centerline. A prop hub not centered acts exacly the wrong way you want it, it will go even more to the left which is logical when you think about it.
Pitty you didn’t try again with that nice earlier engine
Very nice model. I have a plane like your but the Engine has set with 4 degrees to the right.
Maybe if it would be possible to trim it to glide straight without engine thrust first and then add thrust angle incrementally balance could be found - the motor mounting setup looked like this could be done on the field.
Actually, how stiff is the motor mount? If there's a lot of force to the mount, does it bend and allow the thrust angle to change?
What's the wall thickness of the 3D printed fuselage parts?
With fiberglass 1.1-1.2mm
@@markoroolaid and without fiberglass?
Turbine ready, L39 jet.. now i would pay for that!!!!
I've recommended a throttle to rudder mix before, only so much advise we can give unfortunately, use it dont use it. CG is better in this video, made the model more manageable. You can reduce prop diameter, maybe even a three blade to help reduce the torque effects but at the end of the day probably best to increase the vertical size drastically which will make the plane look weird. 😊 Add a bit more right thrust. Put a throttle to rudder mix in on a switch so you can de avtivate if its all wrong, start small and tweak.
You've before not taken kindly to my critique even after asking nicely to not be offended. But let's try again anyways. Please don't take offense, just commenting on my observations from the video. It really does look like you struggle with rudder control, put some time into getting better with that. You've built an aerobatic model, go fly that rudder! This Geebee is flying well, no need to bench it. You got this bud! Good job on the repair.
You hear the community. One more flight. This time pants down.
A throttle/rudder mix might be in order, however you first need to check your “thrust-line” which can be found on the full scale design specs. You have a counter-clockwise 🔄 swirling airflow from the prop which is knocking into the rudder, causing the yawing at higher rpm. Elliptical wings are easier to tip stall and are also more susceptible to throttle induced roll. Also the design of the wheel-pants or spats is such that they almost eliminate side slip since they behave like a fulcrum around which the centre of gravity pivots. I suspect this is why the design requires such a relatively small vertical stabiliser and control surface.
Still a great maiden flight and any landing your action man can walk away from is a good one 😊
ruclips.net/user/shortsnXvR7Ct0eGE?si=eSp_XMxQ92XdOWa7
ruclips.net/video/6R3O6hc1XU4/видео.htmlsi=8OwJjb6UAC_ITxUK
The cause of the unintended yaw is a combination of P-factor and rotational/spiral slipstream effect on vertical stab. The remedy may be as simple as angling the motor direction downward a few degrees as well as to the right (which you’ve already done) 👍
There are options for slimmer wheel pants/spats but I’m not convinced that they’re a problem. Of course, if you don’t have a neutral angle of attack it's possible, but I’m sure a builder of your calibre would have checked the alignment. This is a thrust line problem and for a racing aircraft design the issue is being exacerbated by the spiral 🌀 airflow striking the vertical stabiliser. I’d put money on that being the issue at this point. Short of computational fluid dynamics and tests in an air tunnel I’m almost 100% certain.
Please watch the clips I sent (links provided)
So I have a thought as to why this is happening. But before I give you my thought I have a question for you, did you add right rudder trim immediately after takeoff?
Yes, once I took off and saw the plane turn left, I started moving the trim to the right
@@markoroolaid So the reason why it pulled to the right when you throttled back is because when you decreased the throttle you decreased the effect of the P-factor. The P-factor is the asymmetric torque generated by the propeller. The faster, the propeller spins the greater the torque, and therefore the more the aircraft pulls to the left. When you decreased the throttle, the P-factor was decreased, therefore the trim that you put into the rudder caused the aircraft to turn right. There’s a simple solution to fix this. Simply add more right thrust. Take a couple washers and put them between the engine and the standoffs on the left rear of the motor to give the engine more right thrust. You may have to take it up a degree at a time until you get the proper amount of thrust. Don’t be surprised if you wind up putting in 5° or more of right thrust. In addition to the right thrust is to add a flight stabilization system such as AS3X. Keep in mind a flight stabilization system will not eliminate the aircraft pulling to the left until you put in adequate right thrust. It will simply help to stabilize the aircraft in flight.
The rudder has to be much bigger in size. The wheel shoes are virtical fins in a negativ way because they are not behind the cg. Just get a bigger rudder and everything will be fine.
ok
Several scale aircraft had to have oversized tail surfaces to make them perform properly. This may be the issue with this model.
You are not messing around. Is this a hobby or a job?
I think the cowl is part of the problem… but what do I know?
hi, thank you very much, every opinion matters
Great stuff 🎉 prima finish on the glossy parts
Unglaublich, du hast sie wieder hergerichtet.
Was war eigentlich der Grund vom Absturz?
what is the wingspan?
hi, 2200mm
That plane really want to go left:
1. Maybe the wingshape isn't the same on both wings and do you have some washouts on the wing design?
2. Gee Bee look cute, but not exactly ideal aerodynamics. That oversized body maybe force air around asymmetric.
Having flown a 50cc myself I have experienced the trim issues. The plane doesn’t like to fly straight, drops the tail in turns and tracks poorly. We improved the stability of the vertical stab by adding another fin underneath the fuselage to increase the size of the vertical tail and improve stability, also known as a ventral fin. It helps to give the undersize vertical fin enough aerodynamic stability to overcome the effect of those large spats. We used clear plastic so it doesn’t change the classic look of the R3. Don’t be shy, make a big one and give it a try and then cut it down from there as the bigger it is the better it will fly.
Examples here. ruclips.net/video/dqzs6kX7ZqE/видео.html
It's funny people who couldn't find their way out of a wet paper bag are all the sudden internet experts in the comment section of BotTube.
The engine sounded terrible, rough running, and I would feel better with a larger (semi scale) vertical and rudder. It is a beautiful plane. It's not the first GeeBee with handling probs. Imagine if you had to fly the real thing.
I'm sure you fly less then 50% throttle .. the engjne is toooo big
bigger ruder
why post a vid were you can't see the plane WTF
Hi, I don't understand your comment, please clarify
Test fly without the wheel pants they do look a little on the large size and maybe after that a bit more angle on the engine mounts I think it had a lot to do with the hard pull left, and it’s a beautiful plane 👍
Sounds terrible, bring back the 4 stroke
its a gee bee.. they notoriuosly fly like crap so the fact it came home is a win!!
Shelf queen for now, but you are on the ground, yaaaaa.