RE: EDF Airliner build thread
Hello Serdar
You have asked a rather difficult question in the sense that whatever measurement I give you, you will use to determine the wheel bay positions. You are planning retracts in the model and so all your mounting distances are unknown at this stage.
Starting with the end in mind, you need to achieve
- engine cowling ground clearance (at its lowest point ) of 25 mm;
- nose wheel sitting just above nose U/C doors (scale likeness);
- wing root profile at 1 degree of incidence.
On this subject the ONLY way to measure the angle of wing incidence is at the final assembly inspection stage by placing the model on a flat surface known to be level. A spirit level is placed on the spine of the fuselage and the nose wheel adjusted to ensure the fuselage spine is level. Both wing root profiles are measured (and the wing tips looking for 3 degrees of washout). If the wing root is not 1 degree, then the nose wheel leg is adjusted in height. So you must have this flexibility in the nose wheel. A simple grub screw should do the trick. Failure to ensure the correct wing incidence angle is used can cause problems at the flying stage –you have been warned! If you do not have a wing incidence meter –purchase one. Vital piece of equipment.
To address your question (not that I like giving this sort of answer, because without preparing a drawing of your chosen retract mechanism, it is all measurements without a fixed reference line.)
Anyway, view the below photo of the rear U/C. The distance between the surface of the wing and the wheel surface touching the ground is 80 mm. The distance perpendicular in from the wing profile to the main U/C leg is 47 mm. The distance of the leg from the trailing edge is 116mm. Important. You can not adjust the this distance of 116mm to far. The models C of G (wrt one consideration) is set relative to the U/C position and altering this can cause problems at rotation. Consider the 80 mm as a minimum value (add say 7 mm for trimming later if you have the ability –just to be on safe side). The nose wheel leg length is adjusted just to clear the nose U/C doors and is best determined once the main rear mains are in position and the fuselage spine set at zero degrees on a flat surface.
With this basic information, you should be able to plan and design ahead.
The Frontier fuselage sides are complete now with improved decals.
Ian.