Ucs

[vikidaya]

Hi,

I am new to autocad, i familiarized with 2D, now i started with 3D. I am learning each and every option slowly. I think so far i am good.

 

But i cant follow how the views and UCS are connected?

If i want to draw a diagonal hole in a hollow cylinder, i do not know which axis, view to use to draw. As i lag in understanding the UCS, view i feel tough to do it.

I see many people draw what they want in exact position by changing the position and axis. Is there any way to understand the axis system.

Please help me:(

[David Bethel]

In Autocad, we use the Right Hand Rule ( see attached ). Not all CAD programs use this.

 

In the 2D world, the world coordinate system ( WCS ) is a given. X to the horizontal right, Y to the vertical top. Add 3D values and the Z axis is pointing at you, the operator.

 

In user coordinate systems ( UCS ) , you can translate the system to meet your needs. But it always Right Hand Rule. It can confusing at 1st, but the more you practice the better you get understand it.

 

So lets say you set the view to the right side. ( 1 0 0 ) You can use the UCS command and set it to View. Now the X axis still points to the right. But translated to the WCS system, it is actually traversing the Y axis. But it does allow you to pick points accurately so that can make circle that will intersect say a cylinder.

 

Hope the helps as a starting point. -David

[vikidaya]

Thanks for your reply.

1. I have tried the way you said, but i cant pick any point, it only gets selected to the center point of circle. But i want to draw a hole diagonally as in attached drwing.

 

As you said i think this might be hard till i understand it.

 

2. When using the right hand rule, using which axis the ucs rotates normaly when we change the UCS and view.?

[kencaz]

In your case I would probably just draw a circle on the face of your cylinder and then rotate it the desired angle, array and extrude if needed. No rotating of UCS needed.

 

 

 

KC

[vikidaya]

Hey,

that was really informative for me. Thanks for the explaning me with the drawing, that lead to my easy understanding.

 

I actually wanted to learn how UCS and view option works, so only i was drawing. I really struggle when it comes to 3D axis. so please help me with that.

[Patrick Hughes]

I actually wanted to learn how UCS and view option works, so only i was drawing. I really struggle when it comes to 3D axis. so please help me with that.

 

This may help. Also the right hand rule is applied to rotation - a postive rotation value will rotate around the axis in the direction of the curled fingers of the right hand. The plam of the hand placed closest to the axis origin.

 

I found the image by googling "right hand rule" then clicking on "Images"

[czc]

What I do is is move the ucs to the point I need and then type "ucs" and the axis I want to rotate about, and then the degrees.

 

EDIT: Also I find using construction lines helps. Draw a line in the direction and rotation you want and then just extrude along it.