Messages

2811

General Mach Discussion / Re: Unable to see tool path after loading new G-code file?

« on: February 03, 2014, 01:31:37 PM »

Do you have the toolpath turned off?

2812

General Mach Discussion / Re: Unable to see tool path after loading new G-code file?

« on: February 03, 2014, 12:22:09 PM »

Go to the Toolpath page, and see what the X any Min and Max values are in the upper right part of the screen.

2813

General Mach Discussion / Re: Unable to see tool path after loading new G-code file?

« on: February 03, 2014, 11:36:37 AM »

Check the program limits to see if the engraving is far away from the origin.

2814

General Mach Discussion / Re: Drag knife

« on: February 02, 2014, 04:31:20 PM »

Don't start it.
If your g-code is starting it, then edit the code or the post to remove M3 commands.

2815

General Mach Discussion / Re: Homing and Home Offset

« on: February 02, 2014, 01:01:59 PM »

If you lay a piece of stock on your table to be milled without moving anything after "Homing", you have to find the edge of the material by jogging your X axis, correct?

Not the way I work, but for some people, yes.

I have a fence located at X zero that I place my parts against, so I never have to locate the edge. Well, almost never. My table also has a grid of threaded inserts that I sometimes use to bolt parts down. I have the table drawn as a template in my CAD program. SO I can create my toolpaths, place the part anywhere I want on the table, and it's ready to go.
My normal workflow is turn on the machine, home it, and it's ready to run parts. I don't zero to the edges.
When you zero to the edge of your parts, you're setting an offset. By default, Mach3 is in the G54 offset coordinate system. I keep my G54 X and Y offsets at zero, so I'm always actually working in Machine coordinates for the X and Y offsets.

When jogging your X axis to find the edge of the material is the Home Offset used for the machine to identify how far it has until it hits the "Home"  assuming you jog 25 (45-25 = 20)?

Home Offsets set the Machine Coordinate system on your machine to a position relative to your Home Switch position. As Rich mentioned, everything is then referenced from the Machine Coordinate system. That machine coordinate system never changes. If you start at 45 and jog to 20, then  you're at Machine Coordinate 20, and if you zero the axis there, then you are at G54 X zero. Basically, you set an offset of 20 for the X axis.


You might want to watch the video on Homing, Offsets and Limits.

2816

General Mach Discussion / Re: Homing and Home Offset

« on: February 02, 2014, 09:25:10 AM »

OK, very helpful.

One last question on the subject I hope..

Since a machine is physically limited in the x,y and z planes what is the purpose of setting a "Home Offset"?

It allows you to define the Machine Coordinate system at a location other than where the home switches are physically located.

For instance, my router's X axis is 45", and my home switch is at the far right. I use a Home Offset of 45, so that X zero in machine coordinates is at the opposite end from the home switch.

For instance in my case I have them set for 2" and 1", if they physically don't set the machine's coordinates after a REF ALL then if I were to send a G code for a negative -3 or -2 in the Z axis then its going to hit the limit switches if I understand that correctly.

I think the term "physically" is a bit confusing here. The Machines coordinates are "set" to the Home Offset values.
Using the Z axis here is a bad example, as moving to Z-2 should be moving down, which should be away from the switch, as the Z home switch is typically at the top.

You need to consider where the switch is physically located as well.
If you set your X axis Home Offset to 2, and the home switch is at the positive end of travel, then you CAN move to -3. But if the switch is at the negative end of travel, then you can't go below 2, which is the switch location.

Can you tell me where the Ref All script lives?

Thanks.

Adam,

In Mach3, go to Operator >Edit Button Script, and click the Ref All button. THe script is in the button, saved in the screenset .set file.

2817

General Mach Discussion / Re: Homing and Home Offset

« on: February 02, 2014, 08:44:00 AM »

So Machine homing has to take place at each start up of the machine or in the event something goes wrong in order for it to know where it physically is, correct?

Correct.

This is exactly what it does from a visual perspective on the screen in the DRO's but the machine is not physically doing this, however the machine is not offset from the home switches 2", 2" , 2" and 1".

This is also correct. When you set a "Home Offset" of "2", your telling Mach3 the switch location is 2, rather than 0. "Home Offset" doesn't add any movment to the homing, it just changes the location of the coordinate system.
If you want the machine to move 2" off the home switches, you'll need to add those commands to the Ref All script.

2818

General Mach Discussion / Re: Homing and Home Offset

« on: February 02, 2014, 12:55:40 AM »

1) The only way to rest machine coordinates is to home the machine. Clicking Ref All is all you need to do. You can';t zero machine coordinates any other way than homing.

2)The Offsets are in machine coordinates, so if you click the Machine Coordinates button after homing, you should see 2,2, and -1 in the DRO's

2819

General Mach Discussion / Re: Iissues with my cnc router

« on: February 01, 2014, 06:54:33 PM »

G201's are not very tolerant of wiring errors.
I wouldn't think the A motor getting hot could trip an estop, as a stepper drive and motor should have nothing to do with an estop circuit.

2820

G-Code, CAD, and CAM discussions / Re: BobCAD/CAM

« on: February 01, 2014, 10:41:05 AM »

It seems like BobCAD is finally working on shedding the horrendous reputation they had gotten over the years. Unfortunately for them, that reputation is so bad that a very large number of people will never consider or recommend them.
What they really need top do is come up with a fixed pricing model for everyone. It's pretty bad when the cost of a package on their website is ~$5000, and I know people have gotten the same package for anywhere from $500-$1000. Until that happens, they won't be taken seriously by a lot of people.