I've really appreciated this project, because I love this plane!
I installed the plane and the panel, without facing any problem.
Before installing the panel (v4), I flew just a circuit to test flying dynamics, using default panel of B747 by FS9. The plane took off normally and the flight was good
So, very happy, I installed step_by_step the panel and I tested it following manual and checklists. All was good... but... when it came the time for lining up, ready for departure, passing Vr, the plane didn't want to lift off. The nose gear leave the ground, but main gear keep on being sticked to the runway. I tried also to make "rotation" at 200 knots, but nothing changed.
I'm posting in this section, because I think that the problem might be caused by the panel, but I'm not sure.
Peter wrote already the first point. Please check that you don't have a negative trim when take off. I personally use a trim setting of +2 to +2,5 for take off.
Anothere reason could be that you don't have any hydraullic pressure. Without any hydraullic pressure your aircraft controls (elevator, aileron, rudder and flaps) doesn't work
One thing which may help you. Please take care that NO amber or red warning light is on in the MWS when preparing a take off. Otherwise you could run into massive problems.
I didn't check trim, but this evening I'll do it! But all my aerodynamic surfaces work properly, because nose gear stay up... The plane seams to be fastened to the runway right in the middle of the fuselage, were there is main gear...
I'll do other tests this evening and I will keep you well informed on it...
I had this problem, too, when I first started using the panel, and sure enough, it was the trim. So many planes out there are created to fly so easily, that sometimes we forget the realism. Which is what I did. Even last night in the Vans 727, I forgot the TO trim, and ran right off the end of the runway. Took me 15,000 ft to take off on an 11,000 ft runway...