Dimensioning in 3d space is HARD!

Okay, for the most part I know how to manipulate the UCS so that I am able to draw in 3D fairly easily. However, whenever it comes to dimensioning, it is an absolute headache for me to figure out how the X/Y/Z axis should be oriented. I can't simply click on the linear dimension command and expect the dimension line to show up where I want it to. The thing I am specifically trying to do is dimension a piping isometric drawing that I did in 3D. Is there an easier way for me to do this? Any help would greatly be appreciated.

I always use Face UCS, or 3 point UCS, do you have that option in AutoCAD 2008 Face UCS?

Yes, I use face UCS all the time when drawing in 3D. I usually just draw a cube somewhere then use its faces to re-orient my UCS. But it simply doesn't work as well when dealing with dimensioning.

I have uploaded a small video about 3D Dimensioning in AutoCAD, but I do not have permission to post links. You can go to youtube.com/madpoener Go to video: 3 point ucs.

Thank you for sharing that video with me, but I actually have no problems dimensioning 3D objects, especially simple ones like a cube. Its lines that I am trying to dimension in 3D space, which is a lot different and seems much more difficult (at least to me).

ahaaa can you mak a printscreen of it

Good that you are familiar enough with the UCS to know you need to reorient for the various planes. What you need to also know is that AutoCAD will allways place a dimension at z = 0.00 so in order to get your dimensions placed where you want them, after aligning your "work plane" set the origin to the geometry you are attempting to dimension.

I takes a a bit of practice.

You might want to give a program a try called AutoUCS which is on my website. It allows quick manipulation of the UCS for things like you are trying to do. There is a link to a YouTube video on how to use it as well.

The easiest way I have found is after orienting ucs to face, right or left I then place ucs on the snap location I'm attempting to dimension.

Hope this helps

I do a lot of 3D dimensioning and find that using the 3point ucs works fastest.

KC

Thanks for the help everyone. I never used 3-point before so I tried it out to see how it worked, and after a short while it started doing what I expected it to do for my dimensioning of lines.

Yep, 3 point has the effect of setting the z-axis origin to the first point picked. If you need to set it to a different "level" after you've got the orentation set select "Origin" to simplify it to a single pick point.