Dimensions with formula

Is it possible to override a dimension with some sort of formula or function that relates to the length of the dimension?

A simple linear scaling might be possible by inventing a new unit with the appropriate conversion ratio, but that wouldn't help me here. What I need for the dimension to display a length 400 less than the actual length.

Elliott

DimStyle > Modify > Primary Units tab > Scale Factor?

Yes but that will only scale the measurement, not add or subtract a constant, which is what I need.#

I'm guessing it's not possible.

Why would you purposely show an incorrect dimension?

I suppose you could use a custom lisp routine that would add/subtract a certain value from all dimensions in a drawing.

I'm guessing you erase the default and insert a FIELD - but I'm not sure if fields were available in 2006.

Basically what I want to do is to show the overall length of something as (for example) 3270 + 'X', and have a table next to it of the possible values of 'X'. The object that represents the 'X' length is drawn at 400mm, but can be a variety of values from 250 to 525. So the measurement of the dimension might be 3670, but I want it to display 3270 + 'X'.

I think what I am going to have to do it subtract 400 from each of the values in the table, so that the dimension will read 3670 + 'X', and the values of 'X' range from -150 to 125. Not sure that some of my customers can cope with adding a negative number though (!).

Have you given any consideration to the use of a custom lisp routine?

What determines the value of 'X'?

What determines the value of 'X'?

Nothing as such. There are just 8 different model codes, with 8 different 'X' values.

OK...third and final time I'm going to ask.

Have you considered the use of a custom lisp routine that would act upon selected dimensions either adding or subtracting a user defined value from the AutoCAD generated dimension and showing it in it's place?

Have you given any consideration to the use of a custom lisp routine?

Apologies ReMark, the short answer is that I wouldn't know where to start with using lisp, and I think that re-writing my 'X' value table might be easier.

I think I was hoping it might be possible to just type something in the override space, but that appears not to be the case.

Thanks for you help.

Elliott

I wasn't suggesting that you write a custom lisp routine. I was suggesting looking for a custom lisp routine that would subtract or add a value to any existing dimension you selected. The lisp routine would do the math. Using lisp routines is relatively easy once you learn how.

Basically what I want to do is to show the overall length of something as (for example) 3270 + 'X', and have a table next to it of the possible values of 'X'. The object that represents the 'X' length is drawn at 400mm, but can be a variety of values from 250 to 525. So the measurement of the dimension might be 3670, but I want it to display 3270 + 'X'.

I think what I am going to have to do it subtract 400 from each of the values in the table, so that the dimension will read 3670 + 'X', and the values of 'X' range from -150 to 125. Not sure that some of my customers can cope with adding a negative number though (!).

That's called table dimensioning if I understand what you are saying. You draw one shape and that shape can be made at different sizes for other parts. Example a soda bottle, you draw the bottle then for the dims you use A, B,C for height, width, depth (or what ever)then in the table you have 1 liter, 2 liter, 3 liter columns and each row for A, B, C, would have the correct value for that size bottle.

Basically what I want to do is to show the overall length of something as (for example) 3270 + 'X', and have a table next to it of the possible values of 'X'. The object that represents the 'X' length is drawn at 400mm, but can be a variety of values from 250 to 525. So the measurement of the dimension might be 3670, but I want it to display 3270 + 'X'.

I think what I am going to have to do it subtract 400 from each of the values in the table, so that the dimension will read 3670 + 'X', and the values of 'X' range from -150 to 125. Not sure that some of my customers can cope with adding a negative number though (!).

To avoid having negative values can you use the shortest 'X' (250mm) on your drawing rather than the 400mm length? That way the remaining values will all be positive.

To avoid having negative values can you use the shortest 'X' (250mm) on your drawing rather than the 400mm length? That way the remaining values will all be positive.

Hi Rossko, we think along similar lines, as that is exactly what I ended up doing!

Thanks

Elliott

Maybee I don't understand what you're looking for,

but have you tried to set the Tolerance display (select a dimension in you drawing, then: Properties palette > Tolerances > Tolerance display) to Deviation and then define the lower and upper limits - plus select the position of measurement under Tolerance pos vert

?

Hope you find a solution!

The idea of a customisable field on a dimension is a great ideal. For instance I do lighting layouts. I may use a strip of LED's that are rated as 5.5W per metre. It would be useful to have a field that shows for instance, a dimension of a 10 Metre length not showing 10.0 but showing 55 Watts in the dimension slot.