How can I make sure that my landing gear is lined up properly?

[CmdrNorthpaw]

I'm trying to design a new atmospheric jet for use in survey missions in my career mode save. I am at a fairly low tech level (level 1 aviation) and so I only have a small number of parts available. The jet works fairly well (read: the engines push it along) but I can't get it to fly. This is because whenever I fire the engines, the plane starts veering to the left of the runway. This is fairly easy to correct, but it just swerves back again. 

Now I've done some Googling and it looks like this is a problem with the wheel  alignment when the back wheels are higher than the front wheels, causing the wings to act as spoilers and pushing the plane into the ground. But I tried quite a few configurations of wheel positioning and nothing seems to help. Is there a way that I can see that the wheels are lined up correctly?

On a side note, I did think it might have been something to do with control surfaces, but as I used symmetery mode I don't see how that could be the case. I have also lined up the center of mass, lift and thrust, as well as made sure that the rear wheels are more or less behind the center of mass. Screenshots of the plane are available on request.

[Entropian]

I use the mod Kronal Vessel Viewer (KVV) to align my landing gear: https://spacedock.info/mod/1092/Kronal Vessel Viewer Continued

Set the picture view to head-on and use the grids to align the landing gear.  You also can offset the landing gear into the fuselage.

[Spricigo]

Well,  we can tell you to try more different configurations until one actually works. Is easy to push the parts in Aviation beyond their capacity so it may be necessary to redesign your whole plane (add angle of incidence in the wings, reduce weight and so on). 

I have an example in kerbalX of a plane, it requires a bit higher tech (aerodynamics if I'm not mistaken) but you may be able to tweak it for your needs or just use it as an example for your own design. https://kerbalx.com/Spricigo/KarlJatho  

 

If mods are an option for you, is much easier to build craft with more control over the placement of the parts: 

 

 

4 hours ago, Entropian said:

I use the mod Kronal Vessel Viewer (KVV) to align my landing gear: https://spacedock.info/mod/1092/Kronal Vessel Viewer Continued

Set the picture view to head-on and use the grids to align the landing gear.  You also can offset the landing gear into the fuselage.

o.O I wonder how! Maybe I should take a closer look to KVV.

Edited June 19, 2020 by Spricigo
Took a look at the craft, works fine.

[bewing]

There are a great many causes of runway veering. It is a common enough problem that it is listed in the FAQ on this particular forum.

As far as I'm concerned, the most common "fix" for runway veering is to change the "Friction" on the front landing gear from "Auto" to "Manual", and then reduce the setting to something below .6. The reason for that is to create passive stability, which you do by reducing drag at the front of your craft, and perhaps increasing it at the back end of your craft.

However, to answer your question specificially, the easiest way to ensure alignment is to change to "Absolute" alignment mode and Angle Snap in the SPH, and then click the wheels one click forward and then one click back. This will set them to precisely zero degrees of toe-in.

 

[Entropian]

4 minutes ago, Spricigo said:

o.O I wonder how! Maybe I should take a closer look to KVV.

It uses an orthographic view, so the landing gear are way easier to align than in KSP's default perspective mode.

[Vanamonde]

Try using the part-moving tool to adjust the height of the landing gear and insure that the nose of the plane is elevated. 

[Stone Blue]

I find Hangar Grid useful for this... as well as a ton of other stuff