help with tool path window

[dominic gailgan]

I am new to cnc and mach3 and i have lots of questions about mach3. Most of all I want to know about homeing a 3020 machine without home switches? Do I need to do that? Also I am confused about knowing how do I know were the gcode picture is when it is in the tool path window in relation to the material on the machine table? Were will it be engraved on the material? I have been useing the road runner gcode to try and figure this out. Have watched the mach support videos and read the manual but as i don't have home switches am confused what to do. Any help will be great. Thanks Dom.

[ger21]

I answered this on another forum, but I'll reply again here as it may help someone else.

First, let me say that a post like this will rarely get any replies, as it's not a simple question to answer. What you're basically asking is for someone to teach you how to use your machine.
Very few people have the time or patience to do that on a forum like this.
You might want to post in the Australian section here to see if you can find someone local to show you the ropes. In 30 minutes of face to face "training", you can learn more than you can gather in weeks of reading. This is especially true for a beginner with zero CNC experience, who may not even know what they should be looking for.

Now, to your questions. I'm going to answer them a bit differently this time.

Most of all I want to know about homeing a 3020 machine without home switches? Do I need to do that?

Technically, no, you don't need to home your machine. But you'll be missing out on a few advantages.
1) Softlimits. You can't use them without homing the machine
2) Repeatable Position. With Home switches, everytime you turn on the machine and home it, it will be in the exact same place. This can have many advantages. If you lose power, and the machine loses position, you can easily re-home it and resume cutting without losing alignment. If you have a very complex project that needs to be spread out over several days, you can be assured that each day the machine will be in the exact same position.

Also I am confused about knowing how do I know were the gcode picture is when it is in the tool path window in relation to the material on the machine table? Were will it be engraved on the material?

The quick answer is that there is no easy way to know unless you create the g-code yourself.

When you create a g-code program in a CAM package, location (origin) and depth of cut are defined by you the user.
When you load your g-code into Mach3, you move the tool to the origin you defined in your CAM program and zero the axis at that point.

If you did not create the g-code, you don't know where the origin is. However, Using the Program Limits DRO's will tell you the extents of the g-code, so that you can hopefully set your origin (0,0) in a safe place.
I'd recommend jogging the machine to X0 Y0 before loading the g-code. Usually, most g-code will have the origin at the lower left or in the center of the part (but it can be anywhere). If you are at 0,0, the crosshairs on the toolpath window should give you a good indication of where the part will be cut in relation to X0 Y0. And the Program Limits should indicate how far the tool will move in the + and - directions from zero, so you can make sure you have sufficient room on each side.

Hope this is helpful.