Thanks for the advice!
@quorneng makes a good point, your main gear may be too far forward of your CG.
Thanks for the advice!
Im not sure but that look likely a control line plane to me.Stirring the pot.
Just a question! I have a pic of a flying model that will take off from the ground so is the undercarriage location shown better or acceptable?
Stirring the pot.
Have fun!
Nice try but you would not require that level of dihedral for a control line! It is RC with functional rudder and elevator!Im not sure but that look likely a control line plane to me.
Again nice try! Yes it does take off quite rapidly but the rudder is more than enough to keep it straight for a long run take off and a taxi back to the pits if required.I would say a high wing plane like that, with apparent positive wing incidence, would tend to leap into the air. It's not going to roll up on the mains and run along the ground.
I think that there are other things going on too, though it's not easy to say which is most significant. In order to make a driving force, there has to be a reaction force, which manifests itself as a twisting force through the motor mounting. that twisting force causes there to be more weight on the left wheel than the right, so more drag. Also, there are strange gyroscopic forces that twist the plane due to slightly different thrust between when the propeller blade is up and down due to the boundary layer effect, and finally, there's a transient torque from the acceleration of the motor while the propeller spins up to full rpm from zero.As the motor thrust is applied in front of the axles then something else is causing the issue. The only remaining things to consider are the spiral of air from the propeller turning and a lack of rudder authority! A steerable tail wheel may be of assistance at very low speed but the real solution is to use proper control inputs, (including throttle usage).
I would like to point you to the analogy of a single axle trailer. As long as the hitch is in front of the axles the trailer will always want to track straight behind the tow hitch.
The weight distribution argument is off as the original video showed the problem whilst the tail was still in contact with the ground and hence fully stable. If and when the tail raises the plane is balanced around the undercarriage so the issue of weight is actually less relevant than many seem to think.I must disagree with your statement, in a trailer, the weight distribution is critical. If the CG is to far aft of the trailer axels, it will cause uncontrollable fish tailing. As shown in this video and many others. This plane has too little toe in. Possibly wheals that are too far forward of the CG and a high angle of attack while rolling. The high angle of attack pushes the wheals forward, they may be in the correct spot when the plane pivots to rolling level. But it never gets that far before it spins out of control. Adding a tail wheal will lift the tail, reducing the angle of attack. That alone will move the main wheals aft. The tail wheal will also hold the plane straight until it has enough air speed for the rudder to become effective.
@openatheclose you might try some adding camber to your main wheals. When the plane is level, make sure the bottoms of the wheals are closer together that the tops. Your plane needs quite a lot of rotation to go from sitting, tail on the ground, to a level roll. A lot of rotation means, what is camber when the plane is level becomes toe in when the tail is on the ground. You may need both camber & toe in.
Any update?I can't seem to get my custom plane off the ground.