Help! When I run dual ESC should I run 2 batteries or 1

[tuckerlm]

Thank you I will try to change the mounting for my edfs such that they have less ducting and move them to be positioned outside the fuselage. Thank you for all the help!

 

[L Edge]

Having built and flown a YC-14 with a T tail, I would like to make you aware of some problems.

1) You have quite a large fuse that can block flow to you elevator when you are in a high attack angle of attack plus probably the exit flow of the 2 exhaust nozzles which can cause fluttering at low speeds. So your tail needs strengthening(are you moving the whole t-tail or only part for enough control?) for stability. I ended up moving the whole surface.
2) In your design of exhaust tubes, if the tube flow comes out slanted, it could cause a pitch up problem if not addressed.(did flying experiments to demonstrate effects for my NYGAD design)
3) Are you sure the weight is going to be around 6 lbs? You are going to have high G loadings, so the fuse and wings and tail need good strength which means more weight.

What EDF planes have you tried?

 

[Piotrsko]

Since this is a first attempt using ducted fans, might I suggest a profile design with everything hanging out in the wind, so to speak? Much easier to tweak stuff until it works as desired 5 times easier to replace crash damage. When it's flying well and comes home with only a new layer of dust, then go all out on whatever fairing, fuselage feature makes you happy.

If you ain't crashing, you're in the center of the flight envelope

 

[tuckerlm]

Having built and flown a YC-14 with a T tail, I would like to make you aware of some problems.

1) You have quite a large fuse that can block flow to you elevator when you are in a high attack angle of attack plus probably the exit flow of the 2 exhaust nozzles which can cause fluttering at low speeds. So your tail needs strengthening(are you moving the whole t-tail or only part for enough control?) for stability. I ended up moving the whole surface.
2) In your design of exhaust tubes, if the tube flow comes out slanted, it could cause a pitch up problem if not addressed.(did flying experiments to demonstrate effects for my NYGAD design)
3) Are you sure the weight is going to be around 6 lbs? You are going to have high G loadings, so the fuse and wings and tail need good strength which means more weight.

What EDF planes have you tried?

I haven't done any EDFs before. and I plan on 3d printing the plane with a internal support structure and added spars to handle the g load. The 6lbs is a very rough estimate and not all inclusive so it will probably weigh more than that when completed. adjust the T tail to use the entire surface for control

 

[tuckerlm]

This is my most recent model.

 

[quorneng]

tuckerlm
Are sure you can counter the weight of two 70mm EDFs right at the back like that. The EDFs alone could weigh nearly 1 ib.
The normal rule for airframe design is to keep the rear end light with as much of the weight as possible concentrated around the Centre of Gravity.
I know they are many full size designs with turbo jets at the rear but for the power produced a jet engine is much lighter than an equivalent power electric motor.
If you set the wing at the top of a bulky fuselage there could be enough room to mount the EDF nacelles under each wing.
Quite a popular full size layout for transport aircraft.
RC aircraft design is a complex process so there is no "perfect" solution. Ultimately it comes down to "try it and see".
Keep going!

 

[tuckerlm]

Makes sense. Thank you so much for the help and feedback. I will work on mounting the edfs under the wing near the fuselage and then run a test with a small-scale glider model and see how it flies then i'll revise it until I think it can handle the edfs.