snap and grid problem

[kxt]

Beginner CAD user here.

 

I've used AutoCAD 2000 a little bit and now have AutoCAD 2009.

 

When I draw a straight line in '09 with snap and grid on the line does not fall on the grid properly. If zoomed out it looks good but as you zoom in you see the line and grid are not aligned. Snap and grid are both set to the same value. What gives?

[eldon]

Perhaps you should also be using Polar tracking or Ortho to help you draw the line.

 

If Snap and Grid are set to the same value, then your lines will always be on a grid point, if you are drawing by picking with the cursor. But that grid point might not be the desired one

[dbroada]

check that "adaptive grid" is not on. (right click the grid box and check settings). I HATE adaptive grid. It keeps changing the zoom rate to something less appropriate all the time.

[kxt]

Check the lines below. Snap and Grid are on, settings are default and adaptive grid is turned off. The lines and grid are not aligned!!!!!

 

[eldon]

How did the lower hozirontal line get into the drawing? Did you offset it from the upper line, or did you draw it?

[kxt]

No offset. Those are just drawn with the mouse w/ snap and grid on and set to the same value. This is a fresh install with no adjustments so everything is default. I just drew some random lines and zoomed in to see that they were not aligned. I've adjusted the apeture also but that didn't help.

[eldon]

It certainly does not look how it should be. Have you tried opening up the drawing on some other machine? Is the distance from one line to the other correct?

 

It may be that you never get a satisfactory explanation.

[kxt]

This is a classroom and we're just talking about the basics of autoCAD so the students can draw some basic 2d drawings. These are brand new machines with autocad '09. I've got all the students experimenting right now trying to figure out the alignment problem.

 

The distance from one line to the other is correct when measured using the distance command.

[kxt]

does any body think this could be a video card problem?

 

I am running directx 9.0c which is required

[Glen Smith]

Could the grid that is being displayed be substantially larger than the snap grid? What I'm trying to say (and not succeding I know) is check the settings on the grid display.

 

Until you figure out what is going on set the "major line every" setting to a low number - like 1 or 2. That way you know that the line should be either exactly on the dot or exactly halfway between the dots. If that is set to - say 100, I could see how the line would be near the visible grid, it's on the grid, but not on the major line that is showing.

 

Glen

[kxt]

MORE WEIRDNESS

 

I noticed that when I draw some horizontal lines with snap and grid spacing set to the same value and zoom in they do not align as shown above. BUT if I enter teh REGEN command the grid moves to align itself with the snap points.

[rkent]

Beginner CAD user here.

 

I've used AutoCAD 2000 a little bit and now have AutoCAD 2009.

 

When I draw a straight line in '09 with snap and grid on the line does not fall on the grid properly. If zoomed out it looks good but as you zoom in you see the line and grid are not aligned. Snap and grid are both set to the same value. What gives?

 

 

Maybe this is a rounding error, I am assuming you are set to architectural units, First check Units and see what your precision is set to, then set Units to Decimal, then set the snap and grid settings to the same decimal number and see if this helps.

 

If the precision is set to a larger fraction and someone enters decimal numbers those will be displayed the same but will be different.

[kxt]

The units are set to about 5 decimel places out, the drafting setting are also about 5 decimel places out. So precision is not the problem (i hope).

 

I also noticed as you zoom in and out that sometimes the grid and drawn lines are aligned at other times they are not. When zooming in very close to one grid point that grid point should be aligned to the drawn line but it is usually not. The grid point may be above or below the line -- it actually changes. If you REGEN then they align themselves but if you zoom all then back in they will be more than likely misaligned.

[eldon]

I don't think that you have a fault, rather you are observing the quirky behaviour of AutoCAD not refreshing the display when it does not want to. You will probably also observe circles changing into polygons. A Regen will reset the display. To do a regen faster, it is worth while learning the keyboard shortcut which is typing RE then a Return or space.

[kxt]

Previous versions i've used (2000 & 2005) did not have this trouble. Its more than the grid gliching or circle/polygon thing. I would have to regen after every zoom to see the grid accurately. Is there a way to set REGEN to regenerate more often?

[eldon]

Is the grid that important? After all the grid is like connecting the dots. Personally, I have never ever used the grid.

[kxt]

This is used for younger students to draw small drawings. The grid really helps them organize their drawings.

[MFish]

This is used for younger students to draw small drawings. The grid really helps them organize their drawings.

 

 

I understand the importance of a grid in some cases, so I can understand the need in learning how to use it. :wink:

 

As far as your problem goes, it was mentioned previously in this thread, but it seems to be a fairly new habit of Autocad that I have come across. Everything comes out just right, but if you don't regen the drawing then the grid will appear as your screen shot did. I had '09 electrical and had the same issue. It didn't really bother me however because I am in the habit of using regen often anyway

[ReMark]

This is used for younger students to draw small drawings. The grid really helps them organize their drawings.

 

The grid really disrupts their young minds and forces conformity upon them. Turn both off. When needed rely upon ortho mode, polar tracking and/or object snap tracking. Get them used to freeform design too. Snap/grid are to CAD what staying within the lines was to coloring, too darn restrictive.

[kxt]

For those that are using '09. Does your display act like mine?

 

Now y'all got me wondering if this is actually a problem/fault or just the way '09 acts. Seems backwards since '00 and '05 can keep up w/ lines and grid without needing a regen.