How is the origin in a 2d sketch determined?

[donovandigital]

It seems no matter how much I futz around with planes, axes, and work points, ssoner or later I will make a 2d drawing and find that the origin (which is what I am assuming the intersection of the gray lines are) is not where I need it to be. How does Inventor decide where to put it? Can I change it manually from within the sketch somehow? I realize I can move the UCS but of course that will affect everything else, right?

Many thanks in advance

Joe

[JDMather]

Can you attach an example file (and indicate why you would change position)?

[Cadmanto]

Joe,

Any chance this is a imported part/assembly file we are talking about?  Check out this link.

http://inventortrenches.blogspot.com/2011/06/change-origin-of-imported-model.html

If this solved your issue please mark this posting "Accept as Solution".

Or if you like something that was said and it was helpful, Kudos are appreciated. Thanks!!!! 

     

[mcgyvr]

tools...application options..sketch tab.. check "autoproject part origin on sketch create"

Then when you create a sketch the "center point" is projected for you to use..

My first sketch is usually a rectangle or circle and I always make sure the center of my rectangle (using the newish 2 point rectangle tool) or the center of my circle is constrainted to that projected center point. 

[rmerlob]

I know what you mean, whe you select a face for a new sketch it sometimes places the origin on one of the edges and aligns axes to the edges as well, I find it annoying too, exit the sketch right click it and select ´´edit coordinate system´´ and you will get a glyph that let´s you relocate it.

RM

BTW: the ´´project part origin on sketch creation´´ is useful but won´t actually move the sketch´s coordinates to it.

[donovandigital]

Consider sketch 22. This is meant to be pushed out to an assembly, and is therefore not ultra organized. The origin in sketch 22 appears to be at bottom left. I would settle at least for the y axis to be centered, but the general idea is to put zero at the center of the cube face. I manually set ucs to the bottom center of the cube before creating the sketch.

Thanks again

Joe

[donovandigital]

Nope, sorry, I am referring to defining a new sketch.

[donovandigital]

Was already checked by default. In fact, the origin is correctly projected as a geometric pont (should be in my attachment in reply to jdmather) but the gray lines (again, I am assuming these are the 2d axes) are incorrect. 

[donovandigital]

Exactly

[JDMather]

---

@donovandigital wrote:
....(which is what I am assuming the intersection of the gray lines are) is not where I need it to be.  

---

I think I did not fully understand your problem description.  I never ever have the Tools>Application Options>Sketch tab Axes turned on (see Tip #3 http://home.pct.edu/~jmather/skillsusa%20university.pdf) so I have never ever needed them to be in a particular location.  I assume by "gray lines" you are referring to the Sketch>Axes.

I thought your question might be about a more interesting problem that a user posted here several months ago.

[donny]

Not sure if this was stated already,

What I normally do is create two lines (construction type) along the "grey lines" Inventor puts and then constrain them vertical / horizontal / ect.. So that I have something I can build my sketch from and I know it will remain the origin no matter what happens because I build the rest of the sketch around the lines I made.

[donovandigital]

Ok, but then, how is the origin of the extruded solid determined? If not from these axes?

[rmerlob]

Aren't the origins of a solid the same as the part file's origins?

[LT.Rusty]

I'm not 100% positive, but I suspect that he's asking more about how Inventor determines horizontal / vertical in a 2D sketch.  I know this is something I've wondered about as well ... I'd love it if a vertical constraint was ALWAYS up / down, and a horizonal constraint was ALWAYS left / right.  As it is, when I put a sketch on anything other than the actual XY / XZ origin planes, it's a crap shoot whether a horizontal or a vertical constraint will be the one that I need, and I'm really bad at rolling the dice.  I'd love a way to predict this as well.

[JDMather]

---

@LT.Rusty wrote:
... it's a crap shoot whether a horizontal or a vertical constraint will be the one that I need....

---

...

Well, if you do have the axes visible, the thicker one is Horizontal.
I don't worry about it, if I guess wrong I simply undo and select the other option.

[LT.Rusty]

Yeah, that's what I do too - I just wish that it was more consistent, that's all. I find myself undoing and redoing my horizontal and vertical constraints far too often, and then I wind up with sketches where it's all skewed and horizontal / vertical are not in any rational relation to the UCS at all.

If your sketch plane is not perpendicular to the Y-axis, then - in my opinion - vertical should ALWAYS be parallel to the Y-axis, and horizontal should ALWAYS be perpendicular to it. If you are perpendicular to the Y, then Z should always be vertical and X horizontal, no matter how you placed your sketch.

This is, of course, just my opinion.

[donovandigital]

That sounds really smart, I will go with that next time

[donny]

It was an idea I had when I first got into Inventor. It helps if you draw the construction lines in a sketch and close it so they reside alone. Then build your part in a new sketch. Just a nice way to get a true origin to work from and maintain design intent ect with multiple parts.

[JDMather]

---

@Donny wrote:
Just a nice way to get a true origin to work from

---

.......

There already is a true origin that can't be deleted.

[ksanger]

It would help if Inventor did not change the axis between sketches within the same part.  I put down a circle and an intersecting rectangle.  When I change the size of the circle the rectangle rotated the axis.  Now I can't align the part to the view, its no longer in my XYZ frame of "mind".  Plus the additional sketches that I want to do are all rotated from the original.  What a pain.  In the you know what.  Also a big waste of my time.  I must be using the wrong tools.

Or I don't know what I've done wrong.