Part design sketch plane correct order: XY, YZ, ZX

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Re: Part design sketch plane correct order: XY, YZ, ZX

Postby jruiz » Sat Sep 15, 2018 10:49 am

jruiz wrote:
Fri Sep 14, 2018 9:55 pm
I propose that you do a little mental exercise with the help of another person who knows about Cartesian coordinate system but with no notions about any CAD software:
0.- Please try not to influence the selections made by your assistant and ask him / her to:
1.- Choose mentally any object, for example a car.
2.- Associate names up, down, left, right, forward and backward to the portions of the selected object as deemed appropriate.
3.- Place the object inside a rectangular parallelepiped of a suitable size so that the object barely fits.
4.- Finally, place the positive semi-axes + X, + Y and + Z coinciding with the axes in
where three edges of the parallelepiped rest.
5.- Repeat the exercise with other people.

Now answer please: Did the selections made by your assistants mostly coincide with the scheme used by CAD software?
After item 4, please do not forget to remark the location of the origin respect to the selected object...

And please answer the question...
I have uploaded some FreeCAD video tutorials to
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Re: Part design sketch plane correct order: XY, YZ, ZX

Postby Jee-Bee » Sat Sep 15, 2018 12:20 pm

I don't think the hole dicussion about directions and origins don't matter.
It all a choice to follow the/ a standard or to complain about.

Just like you're list. Almost every person use positive real numbers. you start you're list with 0 however this is (except in programming) not common. It is a choice you make and you are free to do so. But you can complain about others since it is not the standard.
So it the same for engineering. they have other standards as you. You can do what you want (and add it to FreeCAD *) or except the standard...

Jee-Bee wrote:
Fri Sep 14, 2018 7:54 pm
If you want a mathematical approach. I think you have to do it you're self because the (core) developers have other priorities.
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Re: Part design sketch plane correct order: XY, YZ, ZX

Postby DeepSOIC » Sat Sep 15, 2018 12:51 pm

Now I looked up axis conventions once again, to find out they are all over the place: ... n_vehicles
The convention I chose for my paperplanes is standard for cars. And for flying stuff, the convention is X=forward, Y=Right, Z=Down. Oops :shock:
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Re: Part design sketch plane correct order: XY, YZ, ZX

Postby tom » Sat Sep 15, 2018 4:37 pm

Should we learn from physicians?