setting up a centerline in 2d that can dimension diameter

Hi everyone,

Hope someone here can understand and help me with this problem I have been struggling with for a while now. I am using Autocad 2007.

I need to draw a front view of a cylinder (half a cylinder) because at my company we only draw one side of the cylinder due to the fact it takes up so much space.

The centerline is supposed to be an axis of symmetry of this cylinder of 12" diameter. I cannot for the life of me figure out how to dimension it so that it reads 12" with the arrow pointing towards the left. If i select diameter, it tells me that i cannot diameter a line, but only an arc or circle. We are drawing impellers if anyone must know.

Attached is a rough image of the drawing.

Can anyone help me with this problem? Thank you very much in advance!

Use a linear dimension of any length, then re-select the dimension, open the property sheet and type whatever you wish into the Text Override line. Then you can stretch one end to wherever you wish and the number won't change.

Put a dimension break to the phantom side so it will be obvious what the dimension means. You can shorten up to zero length, the extension line on the side that is not attached to anything so there is just an arrowhead there.

My example uses architectural tick marks but you get the idea.

Yes, in newer releases, the property sheet goes transparent, then auto-hides when the cursor is not over it. Now that you have seen all the wizz-bang super cool stuff, like a dark drawing window, makes you wanna upgrade, right?

If you can accept a non-associative dimension then I would suggest you edit the text on your 6.0000 dimension to %%c12.0000 and then explode the dimension so you can delete the right arrowhead and extension line. It ain't cool but it looks ok.

If you're going to be doing these on a regular basis and your half-cylinder geometry is accurate, you might want to create a new dimstyle with the centerline side arrowhead changed, as Dana W says, to something like an arch tick, a filled dot, or integral symbol, put in the break jog, then change the DIMLFAC to "2" and add the prefix (%%c) or suffix (_DIA) diameter info.

Just another thought...

BKT, thanks. I changed the scale to 2.000 and suppressed dim 1 and arrow 1 in a new dimstyle

I also need to use tolerances (deviation). For example, I need it to look like 1.4082 +.001 -.001 Ø. Is there a way I can use Ø as a suffix after the tolerances but not on both deviations? I dont need it to show up 3 times per dimension. Any way to set that?

dimension in question is at the bottom

note that not all dimensions are included at the moment

Not all companies like it this way, but can you live with the diameter symbol as prefix instead of suffix? It looks like AutoCAD places the symbol three times as you've shown when suffix is used, but only once when prefix is used.

I just tested this on an older version of AutoCAD and it worked so you could try this out if your company really needs to have the diameter symbol in the suffix position. Go to the text override and enter "Ø" without the quotes. The will keep your original dimension, and the symbol should show up as a suffix. Since the "Ø" is a special character you would need to cut/paste the Ø into the override field.

Hope this works for you...

Or, you could simply type %%c. The %%c is the way AutoCad recognizes the diameter symbol.

When one uses the symbol dropdown list in the text editor, one should peruse the special character representation next to the symbols on the list. They are useful to know.

Thanks, Dana W - sometimes when you're digging down you forget to look around. In my post #4 above I mentioned using %%c in the prefix but got caught up in trying out solutions using AutoCAD, intelliCAD and BricsCAD.

VincentHT, using %%c is a cleaner way to go.

Thanks, Dana W - sometimes when you're digging down you forget to look around. In my post #4 above I mentioned using %%c in the prefix but got caught up in trying out solutions using AutoCAD, intelliCAD and BricsCAD.

 

VincentHT, using %%c is a cleaner way to go.

Dana W and BKT,

Thank you both so much!!! I love this forum already

One day I'll be proficient enough with AutoCAD to be able to give back to the community, but until then, I'll be asking questions -_-

Is there a way to give rep points or something of the like?

Dana W and BKT, Is there a way to give rep points or something of the like?

By the way, have you thought about making a stretchy dynamic block for the one sided diameter thingy? An attribute for the distance, and a stretch for the dimension line(s). Maybe there could even be a field for the length, but then it would have to be stretched to its full length.

Dana W,

I'm not sure what exactly you mean, but I suppressed dim line 1 and arrow 1. When measuring diameter, I select the center line as my origin. Does this answer your question? Ha! You are too humble

Dana W,

 

I'm not sure what exactly you mean, but I suppressed dim line 1 and arrow 1. When measuring diameter, I select the center line as my origin. Does this answer your question?

Do you use blocks? Does the 2007 release have dynamic block capability? I forgot, but I think it does. The last time I used that version was in 2008. By the way, using the center line gives you the radius, but I guess you know that. The point is getting something that looks like a dimension to work with, right. Actually to represent a "phantom" diameter the dim should start at the edge, and point toward where the other side should be, passing through the center line.

Dana W and BKT,

 

Thank you both so much!!! I love this forum already

One day I'll be proficient enough with AutoCAD to be able to give back to the community, but until then, I'll be asking questions -_-

Is there a way to give rep points or something of the like?

Thanks, Dana W - sometimes when you're digging down you forget to look around. In my post #4 above I mentioned using %%c in the prefix but got caught up in trying out solutions using AutoCAD, intelliCAD and BricsCAD.

 

VincentHT, using %%c is a cleaner way to go.

Longer message needed.*******

Ah man, when I was writing that I meant when "I'M" digging down into a problem. Hope that didn't come off as a shot -it certainly wasn't what I intended!

Sometimes I'll try using a 2007 version of intelliCAD, BricsCAD V15 and AutoCAD to see if the problem responds differently with different packages. In the case here, each package responded a little differently and going back and forth I overlooked the easiest solution (%%c).

Sorry if I was unclear...

I actually can't figure out how to get diameter measurements from centerlines. What I have set up is a dimension modifier that scales my measurements by 2.000 using linear dimensions for which I only use to measure diameters. Its kind of annoying because I need to change my dimension type for when I'm doing standard dimensions scaled at 1.000 vs diameter dimensions scaled to 2.000. Hope this makes sense.

Honestly, I started using AutoCAD a few days ago. I have no idea what a block is.

To go into a bit of detail. My centerline is basically add linetype (centerline 2x). I just draw a line, and change it to centerline with the drop down menu - selecting [Other...] and adding centerline to my other 3 lines that are there by default. (By Layer, By Block, Continuous, and Other...)

Thanks again for all your help!

Ah man, when I was writing that I meant when "I'M" digging down into a problem. Hope that didn't come off as a shot -it certainly wasn't what I intended!

 

Sometimes I'll try using a 2007 version of intelliCAD, BricsCAD V15 and AutoCAD to see if the problem responds differently with different packages. In the case here, each package responded a little differently and going back and forth I overlooked the easiest solution (%%c).

 

Sorry if I was unclear...

No, not at all. I knew your you're was you, not me. My response is a Wink. And then the forum software needed more characters in my message before I could post it.

Excellent! So we're good then?

Say, I'm looking at #18 above and it kind of sounds like what VincentHT is talking about is what you can do in a parametric modeling program like Solidworks, and maybe Inventor, NX, etc. You can use a centerline to do diameter measurements in a section view as he's trying to do with those programs. Here's a Solidworks 2012 example:

http://help.solidworks.com/2012/English/WhatsNew/t_dimensioning_centerlines.htm

I don't have access to them so I can't check in the new(er) versions of AutoCAD to see if this is possible. VincentHT, have you used a different package where you could dimension diameters using centerlines?