R/C VTOL XR-2 Ravenstar

[RisingFury]

You did account for weight, right?



One of the possible reasons is that you have to take into account that when a propeller is moving, it's thrust will be reduced. The second thing you have to take into account is that the air within the propeller starts to rotate around, effectively reducing airspeed over the propeller airfoil.

 

[NuttyPro67]

I certainly accounted for weight. What I need to find out, and what I have yet to find anywhere on the web, is a formula to calculate that exact situation. Once I get home from this business trip I'll measure thrust on the scale against wattage, then put the motor on a plane and steadily increase the weight until it won't lift it anymore. That should give me some pretty solid numbers to work off of. Thanks for your help.

 

[Brycesv1]

it prolly has to do with aerodynamics. on a scale theres nothing getting in the way of the prop while on a model, the airframe reduces the amount of air that the prop can move

 

[NuttyPro67]

So I have prototype two built. This is a technology demonstrator to test several concepts before moving onto the final design:
1. Dual motors with triple axis thrust vectoring with gyro stabilization.
2. KF step on the wings
3. Stability at speed. The initial setup, the one pictured, will only go about 40 mph. However, I have two motors that will push this thing to nearly 100mph. This, only after the 40mph tests prove to be successful and stable.
4.Maximum thrust - I need to know how much weight the motors I have will push without having to strain too much, this will prove to be valuable information when constructing and designing the final one.

If everything goes well, I can begin work on the final one. Only time and testing will tell, though.

 

[Brycesv1]

that is a very sexy plane

 

[NuttyPro67]

Alright, so I know this is a little late but I did fly the prototype. The prototype DID fly, pretty well actually, but when I started doing the VTOL/STOVL tests it wasn't nearly as good. The airplane's wings are too narrow and the motors are too close together(atleast at this scale) to offer any kind of real stabilization. I might pick up the project again in the future, but for now it's on the back burner among many other projects! Thanks!

 

[RisingFury]

You gonna make a vid of the prototype flying? Is that a 40" wingspan?