[7ofclubs]

Hey guys,

My CNC machine is built, I have setup my Y axis as a permanent rotary.
I have Rhino V4

I am planning milling waxes to cast into gold and silver rings. From the outset it seems like Meshcam will handle this.

Any advice?

-=wEsLeY=-

[ger21]

Download the demo and try it out. If you need more time, email Robert, he might be able to extend the trial period for you.

[7ofclubs]

I already got it Gerry. I will try to carve a ring out this evening....here goes everything.

-=wEsLeY=-

[7ofclubs]

OK,

Got meshcam 2.0 and Rhino V4. I create the ring in Rhino save as an .STL file. I import it into Meshcam and the dimensions are off. In one case Mesh told me the ring was 26 inches across. I the oversize problem solved. The ring I am making is 1/4 inch wide and a diameter of 3/4 inches and 1/16 of an inch thick. According to Meshcam the minimum size stock I need is 2 inches? I try to reset the stock size but Mesh won't let me. Do I need to rescale everything I import into Meshcam?

-=7ofclubs=-

[ger21]

Sounds like Rhino is outputting the file in mm. Can you post the .stl?

[7ofclubs]

Here is an .stl file from Rhino that I am trying to convert.
Thanx for your help on this.

-=7ofclubs=-

[ger21]

It loads into MeshCAM fine for me. 1.7" diameter and .35" wide.

[robgrz]

Make sure you're using the latest version from http://www.grzsoftware.com/v2dl.php . Some earlier versions had small bugs that kept a small number of STL files from loading.

-Robert

[7ofclubs]

I download the latest and try again tomorrow.

7ofclubs

[7ofclubs]

For the past several days I have been trying to get Meshcam to generate a workable g-code, but I can't. Here is the lowdown-

I have Rhino V4.0. And I have created an extremely simple ring with it and saved it as an .STL (.STL and Meshcam generated g-code are attached). I load up Meshcam and generate the g-code. The g-code generates fine and I also use Cutviewer to verify it. Everything at this point looks good....except

When I view the g-code I find several lines that contain code that cuts way below the ring...if I were to run the code it would cut through my axis all the way to the bottom of the ring.

If I was going to cut a simple ring out of a tube of wax I would expect something like this:

G01 X.800 Y.900 Z-.01 F5.0
G00 X.000 Y.890 Z-.01
G00 X.800 Y.880 Z-.01
G00 X.000 Y.870 Z-.01

This code makes complete sense to me because it is moving the y axis in small amounts and then dragging the tool over my stock as the x axis moves back and forth, this isn't what I'm getting in Meshcam.

Here is an actually snippet from a Meshcam generated .NC file:

G01 X0.150 Y-0.500 Z0.193
G01 X0.100 Y-0.500 Z0.114
G01 X0.050 Y-0.500 Z-0.438
G01 X0.050 Y-0.450 Z-0.438

The first two lines kind of make sense because they are dragging the cutter across my wax stock while the x and y axis move around. But why the heck does Meshcam insist on burying the Z axis into my stock? Lines 3 and 4 require the Z axis to go .438 inches BELOW the center of my stock. I have played with Meshcam for the last three days for about 8 hours a day and I can't figure this one out.

Here's another thing. I drew the attached model and then grabbed a calculator and generated my own g-code for the model, put it in TurboCNC and it worked great! But when I try to generate the same code with Meshcam I get tons of lines requiring the Z axis to extend way below the model. I have changed the settings in Meshcam, altered the stock size, changed the retract, you name it, nothing.

Love Meshcam, its easy to use, graphical, and I want it, but I just can't figure this one out!

-=7ofclubs=-

[ger21]

Under the CAM menu, use the "Set program Zero" and "Set Max Depth" options. also be aware of whether you're in machine coordinates or world coordinates when in the set max depth screen.

If I set the zero to the center, and set the depth of cut to 0.000, with a 1/8" tool I get something like this.

[ger21]

Should mention that I'm assuming you're running it through MeshCAM as a straight 3 axis part, not 2 sided or 4 axis. Correct?

[7ofclubs]

Hi Gerry,

No I am using a 4 axis part. When I try to set the zero Meshcam says that it can't for a part like this.

[ger21]

I'll check it out tonight.

[ger21]

Sorry, forgot about ya.

I loaded the ring into MeshCAM, and rotated it 90° around the Z-axis. Then set the stock to the default size, go to "Set Max Depth" and click middle in the stock section. You're right, I get the same "can't set zero" error when using 4 axis mode. That's because the Z=0 must be the center of rotation. You might also want to check the box that says "machine geometry only" in the toolpath screen.

But, once I set Max Depth to center, I didn't have any problems. I set up Mach3 for 4 axis and it appeared worked perfectly. (don't have a machine to actualy try it.)

I also found what appears to be a bug and will submit it to Robert. MeshCAM doesn't write a G1 A0 line of code at the start. I'll also request a rotation feedrate and the ability to use rapid rotations.