i recently build my front wheel with new spokes (old ones were failing), but without any tools like tension meter or dishing tool to check for equal dishing (not sure if this is also a use of it on front), i only borrowed a truing stand of lower quality as it seemed. Anyway i followed the ruler on it and i completed the truing but the wheel on thr fork seems to be 3 to 5 milimeters off the brake axle but completely true, i checked the quick release many times and it sits fine on the fork. Then i just changed sides on tne whole wheel together with qr and now it sits almost perfect (barely one mm.)

Is the fork out of true, the wheel or both? im confused. dont know of it matters now but just to learn

thanks

Not sure what you mean by a "brake axle"?

IF the wheel is dished properly, you can install it either way and it will remain centered.
If NOT, it'll be offset to one side or the other by the same amount.
If the fork is off, the wheel will stay to the same side. (if dished correctly)
It sounds like you have a little of both problems.

If your truing stand only has one "indicator", you have to flip the wheel in the stand and make sure you have the same distance from the indicator in either orientation. (You can't assume the indicator is correct until proven)

by brake axle, sorry my bad english, i mean the bolt that tightens the brake on the fork, anyway the problem is visibke on sides of the fork also.

I havent flipped the wheel on the stand, but i dont want to borrow the stand again.

a potential solution that just now came to my mind is to attach the wheel to another older fork i have which i remember it was balanced and check it there.
if it is off a little, i loosen a little one side and tighten the other? (By a quarter)
Current fork is carbon old is steel

If the wheel sits off center, and mirrors when flipped it's the wheel. If it doesn't move when flipped, it's the fork. If it moves, but doesn't mirror, it's both.

However, there are other variables, like possibly a bent axle, or worn area where it sits in the fork. So paint a reference dot on the locknut, and repeat the test with the dot on top to ensure the axle is in the same place (except for flipping). Then with variables controles, the 3 conditions I listed hold true.

i just tested the wheel to the old fork, but before that last answer for marking the axle, and it sits perfect on one side and little off on the other,as i believe that fork is straight , it has to be the axle then, i will further investigate it tomorrow with marking it(here is late night)
Thank for the replies