My mind is boil, why so hard Blender? Would be appreciated for any advice.
You need to describe your problem better.
Anthony Forwood
Sure
1pic — twisted geometry when “U” checked
2 — the ends point are expanded (I can scale by Alt+S, but it is not a precision way)
3 — 90 degree angle problems
Not hard, just different. Adapt mindset to a change 
Modify your profile in edit mode, observe behavior on path extrusion…
eg: ExtrudeProfileOnPath.blend (pasteall.org)
preview:
IMPORTANT NOTE:
- If set to use 2D (Shape) profile needs to be reversed - mirrored over Y axis (or something alike, IIRC)
- DON’T Apply Rotation!
burnin
Thanks for blend file) but if you will turn you profile by 90 degree on Z axis, you have the same problem, you cant get rid from overlapping
I already realise that curves is not that easy, so only way is cleaning mesh by hand, just like after work with booleans
i know the limits, is why i don’t have a problem 
one has to take into account that the path is the inner boundary/frame (so of course the profile exceeding the ‘limits’ will then overlap)… offset it and it will be correct again :eyebrowlift: … basics of geometry & a pinch of human ingenuity/intelligence
You just can’t simply get rid of overlap, you have two sides, don’t forget 
you can also tweak a position of profile, but overall shape would be incorrect
got a blend?
of course you can have an infinite number of problems and only one solution… so what are you looking for?
at least show some plans, sketches or drawings…
unless you’re just learning that is, then i leave it to your judgement, intelligence & experience… systematic learning or trial and error
PyroGXPilot
of course, take it
https://yadi.sk/d/6scU0BaT3LbYDM
so what are you looking for?
man)) you funny, but read a topic title
You make me repeat my self… eh :rolleyes: i guess you are still learning.
Are you looking for a solution or a problem?
If you’re looking for a solution, provide the plan (a drawing of a final product to be).
There’s no best, correct or the right way… if you have a plan (and you must have it) there’s only one way. Otherwise there’s a different plan.
Architect: “There’s only one way to get to where the plan takes you. Otherwise we are not having a plan but only a concept, an idea.”
As well as others, if you stopped learning — you dead man
Are you looking for
I know my english bad, so I posted a lot of picture, just look at the #7,in one image you can see what I need, and what I have, and what I dislike and want to get rid of
One stops learning as soon as one knows the solution (is experienced) then moves on to other stuff as it comes & goes… it’s solving issues/problems. But if one seeks problems for the sake of solving them, then that one is not learning anymore but satisfying it’s need. All being alive or living dead, learning to find some brains to eat… zombies yeah
OK, back to topic then…
Do you have a proper, detailed plan (with dimensions) of what is to be modeled?
Makes the purpose of work defined thus easy to achieve.
Otherwise there are few things to keep in mind (dumb/inconsistent rules to follow):
- Origin of the profile is relative/connected to the path (path is inner boundary, to prevent overlapping)
- Profile plane to use (in this case) for extrusion is -X, +Y. Otherwise (ie. +X, +Y) the path becomes the outer line (boundary) and overlapping issue arises. Unless direction of path is switched.
So to fix issue on #7
Move/translate the profile back to -X+Y plane (grab and translate on X by -0.15)
Note: Relative to the origin! That is, if profile origin is elsewhere, since origin is always internally considered as the center (0,0,0) for extrusion.
Hope it’s a bit clearer now & i haven’t messed things up too much…
Crazy, ah…:spin: & welcome to the zombie land 
now that you know 