[studysession]

I am learning AutoCAd and WOW there is so much to learn.

I have made some 2D drawings. I save them as DXF files. I import them into Mach2 to CNC what I drew in AutoCAD. I have to tell Mach2 how deep each line is. Is there a way I can do this in AutoCAD?

I want Z to start at 0 and have it go down to like -3 or -6. This way when I import the DXF file into Mach2 it will then know how deep each line is supposed to be.

Many thanks in advance. :cheers:

[noid]

I'm not experienced in MACH 2 but If mach 2 can interpret a 3D autocad solid (ie. see it in all three dimensions as a solid object) then it must have the capablity to read the different elevations. What I think I'm trying to say is if mach2 "see's" the Z plane in autocad then you have to draw each progressive cut on it's corosponding z plane depth. so your 0 cut will be on autocad's z plane @ 0 and the -3 cut on the autocad z plane of -3 and soon. If you need any AutoCAD help don't hesitate to ask as for mach2 sorry but you would be teaching me.(LOL)

[studysession]

Thanks!!!

I am a complete noob to AutoCAD. I am going through the AutoCAD 2005 for Dummies book this weekend. This is an intense program to learn. I am getting pretty good at the flat 2D stuff. But the 3D is where I am having trouble.

I make a hexagon shape with the polygon tool from the toolbar and choose 6 sides. When I draw the sides I am trying to make them exactly 17mm accross the hexagon that will be cut down to -6 and trying to put 3 small circles in the center. Furthest to the center will be cut -6 and the next will be down to -3.5 and then the next not 100% sure yet. But give you idea what I am doing.

The hexagon when I use the mouse to draw it does not always come out to be exactly 17mm accross and not sure how to resize it to be exact. Figured out how to move and can mess up the shape of it pretty easily. Then to figure out the depth part.

Eventually I will bring it into Mach2 for CNC. Mach2 can import the DXF files and make GCode. Just need to make the depths and accomadate for the tool size I am cutting with all in AutoCAD before I bring it into Mach2.

Hope that all makes sense.

[noid]

First when drawing a the hexagon do you want the distance across the flats to be 17mm or from corner to corner? Either way I'll attach a file for you to see later. First when drawing a hexagon of specific sizes draw a circle with the disired dimension as the diameter. Then start the hexagon command(actually its the polygon command) use the center of the circle drawn earlier as the polygon center. Then depending on which style the polygon dimensions fall under the Inscribed command inside the polygon command will result in a corner to corner to dimension equal to the diameter of the circle. When drawing the polygon use the object snap to snap to the quaderant of the circle this will ensure it is exactly the size needed. As for the other option (Circumscribed) in the polygon command will result in a "across flats" dimension equal to the circl diameter.

[studysession]

It is 17mm accross the flats.

So I make a circle and then do what to the circle to get the flats to be same as the diameter of the circle?

Thanks again!

[noid]

use the object snap setting.Which verion of AutoCAD Are you useing?

[noid]

If you look at the bottom of the screen you'll see a few buttons there. One will be labeled osnap. Right click on this and clic on the settings header. Once inside turn on the quadrant square to activate it then hit okay. Now this will automatically find the quadrant of the circle for you, a symbol of some kind (depending on your defaults) will indicate it is going to lock your selection to that point. There are many settings in the osnap area to "snap" to various selections ie the center will snap to centers of circles. endpiont to endpoints of lines and so on.

[noid]

heres the file

[studysession]

It just says AutoCAD 2005 - I am not sure which version. It is higher than the LT though.

I am still confuse though because you said make a circle and turn it into a hexagon? I know how to turn on the snap settings and stuff. But the changing the circle to hexagon with the 17mm accross the flats.

Thanks again.

[studysession]

Didn't see your second post - I need to re-read it.

[studysession]

OK have the Hexagon exact size.

Not sure what all you said to do. But re-read this thread and can get the outer edges exact size I want now.

Now just need to be sure on this depth stuff.

[studysession]

I put a value in the thickness property and it shows in AutoCAD but Mach2 still does not see the Z cut value being anything other than 0.

Not sure here.

[ger21]

If you want a Hexagon with six sides, Start the polygon command, and type E and hit enter for edge mode. Click on the screen. Make sure ortho mode is active, you can tell at the bottom of the screen. Toggle it with F8. Once its active, drag the mouse to the right, the line should be constrained horizontally. Type 17 and hit enter. You could also type @17,0 and hit enter, which wouldn't require ortho mode.

Mach2 will NOT convert any 3D objects to g-code, and I don't think it can derive any depth info from the .dxf. It will only convert lines arcs and circles I believe.

I wrote a macro that will create g-code from inside AutoCAD. It will only work with polylines, but all lines and arcs can be converted to polylines (and joined together) with the PEDIT command. If you set the elevation (use properties) to the depth you want or move it to the depth (same thing), it will create the g-code to the correct depth. I haven't tried it in AutoCAD 2005, but it should work. There is a thread on it in this forum, called G-code exporter. The version there doesn't do the depth thing, so I'll attach one that does. Make sure you read the readme.
Before running it, a folder needs to be created on your C: drive called Gcode.

I'm currently rewriting it to be much more useful, but it works good the way it is.

[studysession]

Thanks for the file - I will give it a go in a bit.

[studysession]

I have been trying your program and it installs and seem to function. I have to now play with the settings to get to understand it better. Thanks!!!

Another AutoCAD question - If I have all my settings in metric/milimeters because all my tools and everything I work with is in metric here in the UK. A friend of mine in the US emails me an AutoCAD file in inches. When I open it, I want to have it in metric and keep the correct size and shape. Right now if I try to open it, it is really tiny.

Any help on this??? Thanks!!!

[ger21]

Use the scale command, and enter 25.4 for the scale factor. When asked for a base point, make sure that if you scale from a point on the object, that the points Z-value is 0. If not, the object will scale up or down the Z-axis, as well as the X and Y. Unless you want it to scale from a certain point (sometimes its beneficial) it's easier to just click on a blank area of the screen to scale. After scaling, just do a Zoom extents.

If you want to make a toolbar button to run my macro, you won't have to load it everytime you want to use it.

First, make sure the directory it's in is in the "Working Support File Search Path". You can add the directory using Options, and files. To add a toolbar button, right click on a toolbar, and choose customize. In the dialog box that opens, under the command tab, choose user defined. Then, click on the User Defined Button and drag it to the toolbar you want. Then right click on it, and choose properties. For the macro, enter this:
^C^C_-vbarun gcode.dvb!GcodeExport.Gcode

If you loaded it and got the dialog box, it should work fine. Just make sure you create a folder C:\gcode, or it will crash when saving.

[ger21]

I am learning AutoCAd and WOW there is so much to learn.

You have no idea how true that is.

But you only need to learn a small percentage for it to be useful.

[kevpau]

The best way is to learn how to draw with auto cad in 3d. in 2d auto cad z is always 0, when you start to draw in auto cad pick draw line and enter 0,0 this starts your first line at absolute 0. To draw in 3d you have to extrude z to make a 3d drawing.
To extrude in z the line must be a closed poly line. To draw a poly line do this, type pl then enter (sample) 3,6,3 then enter C on key board, this closes the line so you can extrude.
look in tool bars for 3d, there are 2 extrudes icons but only one works with poly lines.
When you extrude enter z value enter enter. You now have 3d

[ger21]

Kevpau, for what he's doing, he doesn't need 3D, and 3D won't work. dxf to g-code converters won't read solids.

Also, your example won't work. PL is the command for polyline, which won't let you enter a 3D point. (3,6,3)

To extrude in z the line must be a closed poly line

Or planar 3D faces, polygons, circles, ellipses, closed splines, donuts, and regions.


Study, stick with 2D until you have a good handle on it. You'll be much better off.

[studysession]

Thanks - for now I will stick with the 2D -

Any more on how to do this one:
Use the scale command, and enter 25.4 for the scale factor.

Do I type "sclae" at the command line for that?