Please help me with user arrow in dimension style.

[leewh246]

I am trying to create a new Dimension Tick (Arrowhead) to replace one I created back in the early 1990s and have been using ever since. Please refer to the included image of my dimension styles below.

There are three different dimension styles with the only difference between them being the Arrowhead. The first dimension is my original one. The second dimension is my original using the Architectural Tick supplied with AutoCad. These both appear as desired. The third dimension uses a new arrowhead I created similar to the Architectural Tick supplied with AutoCad but it does not display as desired and as you can see in the image, the dimension line stops short of the extension lines.

Below each dimension is an exploded version of each with the right arrowhead moved to the side. For my original dimension style you can see that the dimension line does not extend all the way to the extension line and my arrowhead is an architectural tick with a short portion of dimension line to fill the gap. I do not remember the exact reason for this but it was required at the time, or so I thought, something about needing to fit in a square one unit by one unit. In the second dimension using the Architectural Tick supplied with AutoCad you can see that the dimension line does extend all the way to the extension line and the arrowhead is just a tick. This tick is a block named "_ArchTick" and when exploded, it is just a polyline with a thickness. The third exploded dimension uses my new custom arrowhead, a polyline with thickness, similar to "_ArchTick" supplied with AutoCad, and as you can see in the image, the dimension line does not extend all the way to the extension lines.

My question is, how do I get the dimension line to be continuous between extension lines using a custom arrowhead? In the Dimension Style Manager I have tried every combination of settings and nothing works. As a test, I also used a renamed, unmodified "_ArchTick" supplied with AutoCad and the dimension line was not continuous between extension lines. This made me think, is there something about the name of the arrowhead that makes AutoCad construct dimensions in a different way?

Thanks,

Lee

[David_W_Koch]

I suppose that for the built-in Architectural Tick arrowhead, the program "knows" it is a "tick" and runs the dimension line to the extension lines.  For User Arrows, it assumes that the custom block will have a "length".  For a tick, that means you have to draw a horizontal line (one unit long works nicely), which appears to be be what you did back in the early 1990s.  If you do not like the graphics of the _ArchTick block (when applied as the built-in Architectural Tick), then you will have to include the horizontal line as part of your amended graphics (which I assume you want to change from what you created in the early 1990s).

[leewh246]

Thank you for your reply. It appears that things are exactly as I determined. AutoCad treats _ArchTick differently than User Arrowheads or even an unmodified _ArchTick with a different name. To use a User Arrowhead (Tick), a one unit long horizontal line is required for it to display properly with the dimension line continuous between extension lines.

One problem that I have been trying to correct is that with my original User Arrowhead named DTICK1, when dimensioning small distances the "Tick" disappears. At 1:1 scale, the Tick disappears below 5/16". To get around this problem I wrote a LISP routine to automate adding the missing Tick at the current Dimscale. The added Tick is just the Tick without the one unit horizontal line. This problem does not happen with _ArchTick and you can dimension all the way down to zero and the Ticks do not disappear. To solve this problem I have recently created a new Dimstyle that uses _ArchTick. What I wanted to do however, is create a new User Arrowhead that behaves like _ArchTick but I would name it DTICK1 to match my old Dimstyle. This way when I insert an older detail into a new drawing, the dimensions would update using the new DTICK1.  This appears to not be possible. 

Another problem I am now trying to solve is that using _ArchTick and dimensioning small distances, the two "Tick" marks blend into one fat "Tick" mark. My added Ticks to replace the missing DTICK1 do not have this problem because their lineweight is not as thick as _ArchTick. The screen shot included in my post does not show the lineweight for my DTICK1 because it is controlled by color in my Plot Style Table. If I could get a new DTICK1 to behave like _ArchTick I would propably control the lineweight by using a ployline with a thickness similar to _ArchTick but not as thick as _ArchTick. I have looked at using AutoCad's _Oblique Arrowhead instead of _ArchTick but this does not give me the lineweight for the Tick that I want.

The only solution that I see that will get me close to what I want is to use a new Dimstyle that uses _ArchTick and just accept the single fat Tick for small dimensions and when I insert older details, I will need to manually update the dimensions to the new Dimstyle.

Another reason for modifying my old DTICK1 that I had not mentioned is that I am now needing to conform to standards and Plot Style Tables from other offices that I am now doing work for. For nearly 30 years I was a one man show and could do things as I liked. Now doing work for other offices, initially I was conforming to the standards and Plot Style Table for each office. This was becoming overwhelming and new drawing components or details created for one office are not useable in a project for a different office without time consuming modifications.  I have since convinced each office to let me do things, for the most part, the way I want and I am reverting back to my original standards for all offices. I have created different strategies to conform to different Plot Style Tables for each office but there are a few bugs to work out with these strategies. Dimensions are one of those bugs that I am currently trying to address. Besides needing to get a consistent lineweight for Arrowheads for each office, I am also trying to get a consistent lineweight for extension lines. The Dimstyles that I use and the Dimstyles the other offices use all have extension lines thinner than the dimension lines and are set by color in the Dimension Style Manager with the lineweight determined by different Plot Style Tables. I can assign a color that is compatible with the current offices I work for but the next new office will most likely have a completely different Plot Style Table and I will need to change the color of my extension lines again. To get around this problem I experimented with setting a lineweight for extension lines in the Dimension Style Manager but the color of the extension line took precedence over the set lineweight. I would like to have dimension text and dimension lines controlled by the color of the layer they are created on and the arrowheads and extension lines to have a consistent lineweight regardless of the layer color.

Do you have any suggestions or comments about my conclusions and desires?

Thanks,

Lee

[David_W_Koch · Accepted solution]

@leewh246 

I do not have a solution for trying to keep the old block name while getting the behavior of the _ArchTick block.  But if you want the Polyline in _ArchTick to have a smaller width, or to have its plotted width controlled by the plot style by setting the width to 0 or exploding it to a Line, you can redefine the _ArchTick block and do that.  Have your redefined block in your template file(s), and keep a WBLOCK file of the _ArchTick block handy so you can redefine in in drawings created with the out-of-the-box _ArchTick block (or some other definition of it).

[leewh246]

I was prepared to accept that I would not be able create my own Arrowhead block that would behave like the _ArchTick block. For now I will just use the _ArchTick block as it is. I knew that I could redefine the _ArchTick block to appear as I wanted but I really did not want to do that. I have never redefined anything out-of-the-box in AutoCad and have always created something new when I wanted something different or something that AutoCad did not offer. The _ArchTick block may be my first exception to that rule.

Thank you for your help. Even though we did not find the solution that I wanted, it is comforting to know that the reason I could not find a solution on my own is because it is just not possible.

[David_W_Koch · Accepted solution]

I totally understand not wanting to customize an out-of-the-box item (without changing the name).  You always have to worry that the out-of-the-box version will overwrite your customized version (or be their first, and win), and you would not see it until it was too late.