Mach / GCode question

[WarrenW]

I am just starting to learn to use Mach 2 before I have my cnc router complete. I have 2 questions.

1. Where in the software do I setup the leadscrews I am using? I am using 1/2-10 Acme screws.

2. One thing I want to do is cut out letters in thin wood. I used one program to save letters as DXF and then i converted them to gcode and then loaded it into Mach 2. When i run it and watch it cut, for letters like A, B, D, etc. it cuts the outside of the letters first and then the inside. Won't I need the inside cut first? Otherwise, the letters will not stay down if they are cut loose from the wood for the inside to be cut out. Any suggestions?

Thanks!

Warren

[ger21]

First, you really should learn Mach3. It has many more features than Mach2, and the settings are not transferable, so it's best to just start with Mach3. Just my opinion, though.

1) In the motor tuning, steps per unit. For example, a 200 step/rev stepper, with 1/10 microstepping and a 1/2-10 screw would be 200*10*10 = 20,000 steps per unit, units being inches.

2) The best way is to use a CAM program, like SheetCAM that will let you cut things in the order you want. I'm guessing that when Mach reads a .dxf, it cuts things in the order they are drawn. If that's the case, you can reorder the .dxf by copying and pasting. One by one, copy the inside of the letter, delete the original, and then paste a new one in its place. Do this for all the insides, then all the outsides. This may or may not work, but it's probably your best chance without using a CAM program.

Just out of curiosity, what are you using to create .dxf's?

[joecnc2006]

I always elevate my material above the table with stanoffs and cut the holes, inside cutouts and then generate a g-code for the part cutout last. then it just falls down away from the cutter.

In Mach 2/3 you set your lead screw in motor tuning and setup, you have to also use formula for motor steps in the equation as well as controler steps 1/2 1/4 1/8 etc.

Joe

Originally Posted by WarrenW I am just starting to learn to use Mach 2 before I have my cnc router complete. I have 2 questions. 1. Where in the software do I setup the leadscrews I am using? I am using 1/2-10 Acme screws. 2. One thing I want to do is cut out letters in thin wood. I used one program to save letters as DXF and then i converted them to gcode and then loaded it into Mach 2. When i run it and watch it cut, for letters like A, B, D, etc. it cuts the outside of the letters first and then the inside. Won't I need the inside cut first? Otherwise, the letters will not stay down if they are cut loose from the wood for the inside to be cut out. Any suggestions? Thanks! Warren

[WarrenW]

I used a program I downloaded called TTFtoDXF. It will convert any true type font to a DXF file. Then I used ACEconverter to generate the GCode from the file. Then I load it into the Mach software. I was wanting to find a way to generate gcode from font letters.

I'll look at Mach 3 but heck, I'm already overwhelmed with the number of features in Mach 2! I suppose I won't use alot of the features though. I just want to load my GCode and set where to start cutting at after jogging the tool into position and go from there.

Warren

[ger21]

SheetCAM will do what you want, then, but it's $150.

[WarrenW]

Is SheetCam just for creating the gcode or does it run the router also like Mach software? I don't mind $150 if it works well. The TTFtoDXF is $100 after the trial expires also. By next Tuesday all of my parts will be here and I should have it all together within 2-3 days at the most.

Warren

[ger21]

SheetCAM just creates the g-code. But it has a lot of features that you don't get with Mach's .dxf import. A free trial is available at www.sheetcam.com

[WarrenW]

I'm at their web page now and will download a demo today. Do you know if it will let me select the order of areas to cut so it will cut the inner parts of the letters first and then the outside cut?

[ger21]

You may have to put the different areas on different layers, which would require an inexpensive CAD program.

[WarrenW]

I looked at SheetCam but what I'm trying to find is one program that will let me enter the letters, select the font stule and size and then generate the gcode to use in Mach2 or 3.

Does anyone know of this kind fo software? If I need it to set the correct order for where to cut in letters (inside parts first).

I saw there is one called VFontz - anyone try this program?

Thanks

Warren

[ger21]

Although it's for engraving, DeskEngrave might work, It's free, too. http://deskam.com/deskengrave.html

[WarrenW]

I tried DeskEngrave and liked the way it worked but when it showed the path for cutting, it did it right for the A but not the E. There has got to be an easy solution to cutting letters and doing it in the right order.

So far the only one I can change is DeskCNC but I can't actually try it out without their controller and I have to buy more stuff.

Any thoughts anyone?

Thanks!