Author Topic: 2D to 3D to CAM  (Read 432 times)

rjspear

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2D to 3D to CAM
« on: May 01, 2017, 05:44:24 AM »
I have been looking for a smooth transition from my design program to G-Code for CNC work. I have looked at Sketchup, Rhino, Fusion 360, and so forth for the model-to-CAM step, but for my particular requirements it is essential that I do a 2D drafting first on a custom grid. DesignCAD 2D has long been my favorite by a mile for the 2D part, and none of the integrated packages want to work that way. It's now occurring to me that at least part of the answer might have been just a click away all along.

1. How difficult would it be to put a 2D parts drawing into 3D mode and extrude it? I can upload a file if needed, and you'll see that the parts are very simple.

2. Does DC 3D allow for something like T-splines or other methods to create a curved surface (think musical instrument tops and backs)?

3. What steps would be needed to move the extruded drawing(s) into a CAM program (recommendations gratefully accepted)

If someone can give me a few buttons to click I could probably use it to leverage a deeper understanding of the program, It's about time I got this monkey off my back!

Many Thanks!

--RJ (Bob) Spear

P.S. I am using the most recent version of Max3D

bdeck

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Re: 2D to 3D to CAM
« Reply #1 on: May 01, 2017, 09:43:27 AM »
Hello Bob,

DC has good extrusion routines and can extrude along a spline. As long as you don't need parametic info such as centerlines for machined holes, the grids DC creates are reasonably servicable, with the caveat they are created for the intended purpose of visual rendering, not manufacturing.

The precision of DC grids may or may not be sufficient for your task. See discussion here: http://forum.designcadcommunity.com/index.php?topic=1958.msg10142#msg10142

Regards
bd


rjspear

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Re: 2D to 3D to CAM
« Reply #2 on: May 01, 2017, 10:07:50 AM »
Thanks, BD--

There are a couple of things that might mitigate in my favor here. First is that the grid is a custom irregular grid that I lay out on a different layer (one of the things most 3D programs don't have in quite the same way DC does), and when I make a copy to load into the 3D workspace I leave the grid behind. There's nothing in the drawing except the outline(s) to be extruded. 3D programs want to turn intersecting grid lines into surfaces, which can lead to amusing results if you like grinding your teeth.

Second, the parts to be cut are basically flat stock. I've included the 2D file so any one can have a look. Basically, all I want to do is extrude the various parts at 90 degrees to the flat plane to a height of 25 mm, which is a fat inch. This is not yet the instrument; only the form around which the body will be built. I'd also like to know how to turn the wireframes into solid-looking pieces. This might be enough to load into a CAM program for tool paths.

Regards,

--Bob

Bob P

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Re: 2D to 3D to CAM
« Reply #3 on: May 01, 2017, 11:03:58 AM »
For me, it's more intuitive to be in 3D mode for this:

In order to convert separate but connected lines into a plane, they must first all be selected and combined into a single (complex) line. (shortcut "B")

Then, you can make the outline into a plane with Edit / Selection edit / Convert / Make plane
or just "makeplane" or "mp" on the command line.

At which point, you can extrude into the z direction.

Note that Designcad's X/Y/Z directions are not the same as most other CAD programs, so it might be necessary to rotate your model 90 degrees on the X axis.

rjspear

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Re: 2D to 3D to CAM
« Reply #4 on: May 02, 2017, 06:29:38 AM »
Thanks, Bob! (Great first name, btw. Kinda like it myself . . .)

Here's what I did and what happened (and didn't happen). I put the file (same one I uploaded here yesterday) into 3D mode. I had originally used the "group" command to connect lines in just one of the shapes. This time I used the "B" shortcut. The object then registered as a single unit when I clicked on it, but it's not possible to distinguish that from the results of a grouping, so I could only assume that I was successful.

Then I made a plane out of the outline going through the Edit menu. Nothing seems to have happened. I'm used to seeing a plane surface (or face) form as I do in Sketchup or Fusion 360, but nothing visible occurred. My hope was that it wouldn't look like a wireframe after I extruded it.

The "extrude" command totally confused me. I wanted to make the extrusion a certain height (25 mm), but I couldn't see an obvious way to let the program know. Once I made an inadvertent series of clicks and the object extruded a huge distance and I was inside a gigantic wireframe!

Needless to say, I'm getting pretty good at backing out of mistakes.

Obviously, I'm doing something wrong. Might you have the chance to open my file and extrude just one shape? If you can do it, that will assure me that the drawing I brought in from 2D is all right. Think of these shapes as if they were cut from a 1" thick sheet of plywood.

Rob S

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Re: 2D to 3D to CAM
« Reply #5 on: May 02, 2017, 07:58:22 AM »
So, the first thing to do after having done the convert-to-plane bit, is to turn on open-gl shading, and you will see which objects have successfully been converted to planes, in that they will appear shaded.

I tried to convert the entire drawing, and there were a few errors due to unconnected lines, those will have to be tracked down - could be just the grid lines.

Then, to extrude the result, you can first select the entire drawing "Ctrl+A", or any individual plane, and then

optionally - Ctrl+H to set a handle on a known corner of one of the objects to make it easier to control

From the menu choose draw, extrude and set two points the first on snap to the handle, and then using point-relative, set a point 1" from previous point in the Z direction

and there you have all of your shapes extruded into 1" thick planes - result attached

ps I also have a likeable first name!!!

User since Pro-design

Bob P

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Re: 2D to 3D to CAM
« Reply #6 on: May 02, 2017, 08:26:31 AM »
Almost posted this first...

Unless you specifically tell the program, Designcad stays in wireframe mode. You won't see any plane surfaces "filled in", nor will solids look anything more than 3D wireframes. If you double-click on the plane, the Info Box will pop up - you should see that it's labeled a plane.

You can display planes and solids with Menu: View > Display type > Active view > whichever mode you want (Most of the time, I like to keep the other views in wireframe mode.)

Once you've determined that there are actual planes and not just closed vector shapes, you can extrude the plane in the Z direction.

To extrude a plane:
1/ Select the plane. It will become highlighted.
2/ Shortcut key "x" for extrude (In this case, you don't have to select a method.)
3/ Snap (period key) to a point on the plane. That sets your first point. At this point, don't touch the mouse. You don't want to lose the current mouse position.
4/ Point relative (quote key) Mode: Last cursor position. Use the tab key to select that if that's not the current mode.
5/ Tab>Tab to DZ and enter 25. It will set a point in the +Z direction. At this time you've got two points, one on the surface and one in the Z direction.
6/ Press enter!!!!

I hope that works for you.

bdeck

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Re: 2D to 3D to CAM
« Reply #7 on: May 02, 2017, 08:38:34 AM »
Hi rjspear,

It's not clear to me why you want to draw these parts in 3D.

I create 2d dwg and dxf files in DC routinely and send them to laser shops, waterjet shops, and cnc router shops with just a material and a thickness specification. Some cnc and waterjet shops can even correct for taper on thick parts.

In 2d, a circle is a circle, and it has a center. In 3d it is a polygon with no center.

If you want relief cut into any parts, its much easier to learn to program g-code than it is to learn and use DC 3d. (hours vs ?) Or your job-shop could work from an annotated 2d dxf or dwg. (I can create g-code from a DC 2d drawing part faster than I can set up lighting to view a rendering in DC 3d. Time for a new macro.)

You can draw splines in 2d that are very smooth.

If you want a smoother spline, or a smaller file, or if your job-shop does not support splines, there are cheap programs available to convert polylines or splines into consecutive tangent arcs in your dxf or dwg files prior to conversion to g-code.

If you want to visualize the resultant part, DC 3D is the way to go.

Regards,
bd

Bob P

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Re: 2D to 3D to CAM
« Reply #8 on: May 02, 2017, 08:50:22 AM »
 :-[
BDeck's point is well taken - and I should know. That's exactly what I do with laser/punched/water-cut sheet metal parts. I never even have to combine lines, although the shop that I sub to may do that for me.

rjspear

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Re: 2D to 3D to CAM
« Reply #9 on: May 02, 2017, 02:17:53 PM »
Greetings Bobs, one and all!--

Here's the latest.

Rob S., I turned on GL shading and the drawing turned blue, but, alas, remained flat (as in a very, very thin) board). I didn't follow instructions to extrude any further since you mentioned that the drawing had already been extruded. It's obvious that I still don't have everything enabled that I need to.

Bob P., I brought up the info box and DesignCAD at least thinks it's a 3D drawing with a depth of .083 (1 inch). Just didn't display it that way. Tried all the other active views as you suggested, but the drawing was either shaded or it wasn't shaded and nothing else obvious to me. Followed the extrusion instructions as best I could, but aside from some odd shapes that popped up (and a couple of copies that appeared on other parts of the screen) I seem to have failed miserably.

BD, in this case I am the CNC shop with a newly built CNC machine to subdue. If you send just a DXF drawing out, then your shop must be processing it in some kind of a CAM program to create tool paths. That would be fine for me, except that this is just the beginning of an assembly process. The shapes in my drawing will be cut from plywood or MDF sheets and the ribs, linings, and structural blocks will be assembled on these forms.  Next comes tops and backs, which have contours so I need to learn how to create them, extruded them, and then shape them. Would appreciate any advice as to whether this is not what DesignCAD was intended to do so I know whether to struggle on or not.

Thanks again for all your help.

--Bob

Bob P

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Re: 2D to 3D to CAM
« Reply #10 on: May 02, 2017, 02:59:23 PM »
RJ,

Could you post what you have now so that we can take a look?

Rob S

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Re: 2D to 3D to CAM
« Reply #11 on: May 02, 2017, 07:31:37 PM »
I extruded your shapes to a 1" thickness because that was what you asked for, on the size of shapes you have 1" is relatively thin.

I think the concept of creating the toolpath in 2D is the right direction to pursue, which you have basically already done.

As mentioned elsewhere, the 3D mode is more useful to envision complex objects, and not necessary to create flat shapes.

What file format does your CNC expect?
User since Pro-design

bdeck

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Re: 2D to 3D to CAM
« Reply #12 on: May 03, 2017, 04:39:32 AM »
Next comes tops and backs, which have contours so I need to learn how to create them, extruded them, and then shape them.

I presume you have a cnc router.

Dunno what software you are using, but, for 2d work, here's a decent gnu download to convert simple 2d dxf files to g-code: http://www.dakeng.com/man/ace.html It's old, and requires R12 dxf files. But its quick and free. It doesn't do splines.

For the 3d contours you mentioned, you would not use "extrude" except maybe to create a base for the contoured surface. For contoured surfaces, you draw 2d splines using the "Curve" command (I typically do this in 2d mode, then switch to 3d mode and space them apart.) Then use the "Surface Connect" command to create a grid connecting the spaced curves. Use shading and lighting to view the grid from all angles. Then erase the grid and edit the curves and reconnect until the grid looks the way you want. Or edit the grid directly. (Use vdd macro to view the 3d rendering here http://forum.designcadcommunity.com/index.php?topic=5522.msg37962#msg37962, if you don't mind the y axis being vertical and the z horizontal. Need a new version for drawings with a vertical z axis.)

At that point there are then a number of ways to proceed. You could try exporting an STL file. Find a converter to convert the STL file to G-code. (See STL notes here: http://forum.designcadcommunity.com/index.php?topic=6296.msg44996#msg44996) Same for 3d dxf, etc.

Depending on the type of output you need for your converter, you may have to "Convert Planes to Solids." Others here are much more well-versed in DC 3d and g-code than I.   

The publisher of a native DesignCad g-code generator disappeared last year, and I fear the worst.

RobS, I used point select mode to stretch your extrusion from 1 to 25 units thick. The units appear to be mm.  Then I rotated it 90 degrees in the side view, so that the infernal y axis would be vertical. Easier to view with vdd, but wont lay flat on a router table.

bd
« Last Edit: May 26, 2017, 09:07:01 AM by bdeck »

Dr PR

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Re: 2D to 3D to CAM
« Reply #13 on: May 04, 2017, 07:04:06 PM »
ContourCAM v. 16 for DesignCAD 3D MAX v. 14 - 25 is the program that converts DesignCAD drawings directly to 2D and 3D G-code.

Apparent;y it is available on Amazon.

It was available from Magic Systems. ContourCAD was a plug-in add-on that integrated directly with DesignCAD.

Unfortunately magic, one of our Hero members, hasn't posted on the Forum for a while, so we don't know what happened to him.

But if you find a copy we'll try to help you with it.

Phil
DesignCAD user since 1987

bdeck

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Re: 2D to 3D to CAM
« Reply #14 on: May 04, 2017, 09:45:04 PM »
ContourCAM v. 16 Apparently it is available on Amazon.

Hi Phil,

The only remaining trace of Magic Systems I could find is an old abandoned listing on Amazon.UK and Facebook. As I said, I fear the worst for our friend, but I hope he is OK. 

I had hoped Imsi would find a way to revive CountourCAM, but maybe the support required is too much. 

bd
« Last Edit: May 07, 2017, 03:42:46 AM by bdeck »