Getting the dimension chains to add up with out the 1/64"

[Steve Jepson]

Ever chase your tail trying to get the tiny fractions out of your dimension chains? Fix it in one place, makes it worse in another...Of course you have. Here is a tip. After trying to move something the distance of the fraction, if that doesn't work, try moving it 1/256" at a time in stead of 1/64".

What is the smallest distance you can move an intersecting wall at a corner and not need to clean it up with the Intersect tool? 1/2,550" ? To test this, be sure to use the Intersect tool after each try or Ctrl-Z so you don't get a cumulative distance.

[Richard Morrison]

Wouldn't the best way be to move the offending entity to an exact dimension? Seems like what you are proposing is just converting inaccuracies to a smaller order of magnitude. You could also try a snap grid of, say, 1/8", or whatever tolerance you are seeking.

[Steve Jepson]

Richard wrote:
Wouldn't the best way be to move the offending entity to an exact dimension? Seems like what you are proposing is just converting inaccuracies to a smaller order of magnitude. You could also try a snap grid of, say, 1/8", or whatever tolerance you are seeking.

It doesn't always work to move something the fraction that is showing in the dimension. That is the first thing you try, but when that does not work (almost never) other measures will have to be taken in you want to flush out those dimensions so the dimension chains will add up to the overall dimension, or for what ever other purpose you may have for wanting the dimensions to display as they should.

The purpose for doing this is almost never for the sake of accuracy. It is done for all of the other reasons you need the dimensions to be precise.
For example, graphics in an elevation or something where you must model with great precision in order to get rid of some line that is showing up, or to make sure there is one where it is not showing up. The precise display of the dimensions is perhaps the least important reason to model with extreme precision.

Printing a set of plans with dimensions rounded off to the nearest 1/4" is fine. But you will not get good results unless you work in ArchiCAD to the 1/64". In actuality, that is not always close enough to achieve the necessary graphic results ( clean ups, lines in elevations, etc..)

We do have the ability to manage the inconsistencies of dimension chains to some degree rounding off how we display dimensions, however, just because we got rid of some fractions, does not mean the dimension chain still adds up. That is never an acceptable situation for me.

And these are some of the reasons why ArchiCAD users quite often have a need to flush out some of the unwanted fractions. Getting that down to 1/64" is not much of a problem. Getting rid of that 1/64" in a dimension chain or over all dimension can be challenging when it is also related to important graphics in some other view.

And then there are the problems that can come up collaborating with someone in AutoCAD who is working to the 256th of an inch for a similar set of reasons.

Getting a good set of Working Dimensions displayed in the Plans is easy, and that is not the main reason why working to higher levels of precision are necessary.

If your walls wont clean up correctly unless they are with in 1/2500th of an inch, that is the level of precision we need to work with in model space.

The problems that arise while working in ArchiCAD are due to the discrepancy of minimum cleanup tolerance (1/2,500" +/- i am not sure what it is) and the 1/64" display of dimensions.

1/64" is not close enough when the industry standard in 1/265".

Just to be clear, these dimensions are not related to the size of things, or how dimensions are displayed in a set of Working Drawings for a building.
We can get by with what we have for that just fine.

The main reason we need for more accurate display of dimensions is because there is such a big gap in the precision of the modeling we can do, (and must do with ArchiCAD for the sake of graphics) and our ability to keep keep track of that and control that with dimensions.

That...and I may have a developed a bit of an OCD about dimensions.
That is the most important thing to me in a set of working drawings, even though I know it really isn't.

Most of the time snap grid or just working carefully is all that this needed, however, some projects are full of things that come form other sources, copy and paste, things like that. So at some point, everyone is going to have a few of those 1/64" fractions they would like to get rid of and it is impossible if you just keep moving things the distance that the fractions says it is. That is what I mean by chasing your tail.