wall locations

[Anonymous]

Hi to all......this may seem like a very odd question but has anyone had the problem of over time your walls shifting infinitesimal amounts (not even registering any type of dim. in your info. box). We have only noticed this since we work mostly in hairlines and, for example, we may have a col. center-line set 1'-0" off the face of a 1'-4" wall with the walls ref. line offset being 1'-0". Our working units for fractions are set to 1/8". We'll then continue to work on the file for a length of time and when zooming in to an area the wall's ref. line has shifted off the col. line (but only by a very minute distance). We keep shifting the wall so that the wall's ref line and col. center-line line up perfectly. But it seems to happen again over time. Is this something anyone has run into? Thanks.

[Anonymous]

Even if you have the units set to 1/8", AC is still capable of moving an object less distance than that but it won't register until you have crossed the middle of the working unit and then it will calculate the distance to the next tick.

And I find moving stuff using the tracker can introduce the possibility of inaccuracy such as by clicking on a wrong hot spot and starting from there. A quick example of that is with walls I find that sometimes when I'm panned out from the wall corner and I try to use the reference line hot spot in the corner for a hot spot, sometimes AC will select the skin corner inside the wall instead of the reference line hot spot and panned out I can't tell otherwise. So I pan in now to avoid that.

However, I have found a system that really helps me stop the introduction of inaccuracy. It adds a little overhead so it's up to you if you find it useful but at least keep the concept in your head as occasionally it will be useful (which is drawing a line for an exact distance).

But I make a layer called Measuring Notes and it's hidden on all layer combos except for drafting combos. I then draw a line and type out its distance so I know that line is that exact distance, then I use the line as a measuring stick to use as a hot spot. For instance I will have a wall, a perpendicular line, then another wall and I will know that those two walls are separated by that exact distance.

Besides accuracy another big benefit for me is I can see where I've been and that those distances are on purpose and it easy to see if something has shifted because the line won't have moved. And I'll color code my lines and keep a little quick and dirty legend off to the side that tells me when I used what color on what date and for what purpose. An added bonus is when a job hasn't been touched for a couple of years and I forget the little details of what when on, things like this can really help me remember what I was doing.

[David Maudlin]

andyb:

This is why I have my Working Units set to feet & decimal inches to 3 decimal places (as opposed to Dimensions, which typically are rounded to 1/8"): small errors, wherever they come from, are readily seen in the Tracker/Coordinates palette. I don't think the application is causing these errors, it is slightly inaccurate user input. Also, as zeropointreference mentioned, use keyboard input for accurate modeling. And watch the Angle as you draw, very small Angle errors can be a source of these type of issues.

You should add a Signature to your Profile (click the Profile button near the top of this page) with your ArchiCAD version and operating system (see mine for an example) for more accurate help in this forum.

David

[Laszlo Nagy]

I, too, always set my Working Units to the highest possible accuracy. (Dimensioning Accurary is a different matter, there are standards for that.)
Here in Hungary, we usually work in meters, in that case I set all coordinate fields to 4 decimals accuracy, which is 1/10th of a millimeter.

[Anonymous]

Thank you all for your responses........and I will update my profile. Thanks!