I've just converted my ShopNotes Router Machine over to a 3-axis XZA CNC and have set it up under Mach3.  Y-axis has been designated as the A axis, and set as a rotary.

Now, I'm just learning ViaCAD and DraftSight to create my Shaker centerpost and furniture leg CAD drawings.  I've just completed my first centerpost drawing, but now I need some assistance in converting that drawing over to G-code.  I've attached my basic drawing of the centerpost and the DXF file (in mm) I created in ViaCAD.

Could someone who has experience with 4th axis turning between centers give me a hand in converting this over to G-code so that I can use it as a learning tool on how to operate my new XZA CNC correctly?

Also, can you advise me on creating new CAD drawings - should I be only drawing 1/2 of the leg/centerpost instead of the whole piece since the final Gcode will be used on a lathe?

Plus, can you advise me on the process to converting my CAD drawings over to Gcode perhaps via a CAM program?  I need to learn one of those as well, I guess.

Thanks in advance,

JD

Um, sorry, the system wouldn't let me attach the DXF.

Here it is.

Thanks.

And, here is the basic drawing of the centerpost. 

Can't understand why this system won't let me post both DXF and PDF at once. 

JD

Unfortunately, I don't think it'll be as simple as you may think.

First, will your A axis be continuously spinning, like a lathe? If so, then you'd probably only draw half of the outline. The problem, is that you'd need CAM software to properly calculate the offset of the tool as it travels along the profile. You also need to calculate roughing passes, as you won't be cutting this in one pass.
Now, I'm not aware of any CAM software out there that's designed to do this.

If the A axis will be moving by gcode, then the method I mentioned the other day would be a much easier option. Create a 3D model, and use a 4 axis CAM program like DeskProto to create the g-code.

Gerry,

I have set up the A axis as a rotary axis in Mach3, so I plan to move it via gcode.  And, I believe that I can create a 3D model in one of the CAD program trials I've downloaded.  Plus, I'll take another look at DeskPronto. 

But, I'm wondering if I could get CNC Wrapper to work using the first method of drawing only half the outline, creating gcode from the DXF, and converting it via CNC Wrapper.  I wonder if anyone has tried this before.

JD

Using the A as a spindle with Gcode is not going to work very well for obvious reasons.

Unless you have a lot of hair you want to get rid of I would suggest doing it either in 3d with a 4th and live tooling OR Lathe style with singlepoint tooling or live tooling.

Those are the 2 options that you will find CAM support for.

(;-) TP

No, CNC Wrapper will not work like that.

Gerry,

Okay, so I guess I continue following your other suggestions.

 did find a YouTube video that uses GMAX for modeling and CNC ToolKit to create a 4th axis toolpath.  I have to create a 3D model first, then follow their instructions on Yahoo Groups.  I'll give that a try

I'll also download a CNC Lathe Simulator to try some of the code that I'm running into regarding 4th axis turning to get a better idea of the issues involved.

Thanks for all your help.

JD