Topics

1

General Mach Discussion / Backlash comp help

« on: August 30, 2010, 07:50:35 PM »

So I've read a couple different methods of testing for backlash and after trying a couple, I've come up with some numbers. I'd like some feedback on whether my test method and results appear accurate.

I set up a digital dial indicator for both the X and Y axis. For each axis I moved into (negative X) the indicator about .4in, zero'd the indicator and then used mach3 to move it .25" (positive X) and recorded the indicator reading. I repeated this five times.

So, for the X axis i have .0182, .0170, .0175, .0178, and .0170. I added those and then divided by 5 for an amount of .0175. Did the same thing for Y and got .0105.

Should these number reflect the amount of backlash on my machine or did I not perform the tests correctly?

Thanks!  

2

General Mach Discussion / Backlash or something else??

« on: August 25, 2010, 08:24:23 PM »

Hi,

I have a new CNC machine and need some assistance. I am fairly new to the CNC world - been dabbling in it for about a year now and just upgraded to a 24x36 machine. I've been running some tests, making basic geometric shapes and verifying the size. Everything had been ok for the most part except circles. Larger circles appear fine, but smallers circles have flat spots on the left and right of the circle (along the X axis). I assumed I had some backlash, but when I use a dial indicator to try an measure it, I am getting results of .003 or less on the X axis. Is that enough to throw off a small circle (.5" or so)?

Are there any other issues that may also cause this?

If it matters, I am using Vcarve Pro to crate the gcode along with Mach3.

Any help is appreciated!

Dave

3

General Mach Discussion / Help me understand....

« on: July 23, 2009, 07:44:35 AM »

Ok, I am about 95% of the way there (I think!  ). Last night I ran my first live test - tool in the router, router on, and workpiece (foam) on the table. I managed to run three small jobs and it worked! However, leading up to that, I spent about an hour in frustration, some of which I did figure out.

What I need help with is the measurement system. When I set Mach3 up, I just instinctively chose inches since it's what I am used to. I am using metric for most of the parts I am designing though. So, if I design a part in metric and then load the gcode into Mach, do I need to switch Mach to metric? If so, I assume I do this on the Settings tab and not through the config screen (heard that in the video tutorial).

Should the DRO's reflect the measurement system of the job or will they always show inches. Like I said, I did get three small jobs to run, but afterwards, I had a moment of "ok, how did I do that?". 

Thanks!

Dave

4

General Mach Discussion / Workflow with Mach

« on: July 22, 2009, 10:11:12 AM »

Hi,

As my post count shows, I am new here and just in the beginning stages of learning CNC/Mach3. I wanted to list out what I *think* my workflow should be and see if I am on track. This is a very high level view of the workflow.

I am using TurboCAD, Vectric Cut2D, and Mach3.

1. Create design in TurboCAD, save to DXF format.
2. Open DXF in Cut2D, assign tools and generate toolpaths.
3. Save toolpaths to Gcode.
4. In Mach3, open first toolpath (for objects with more than one toolpath) and run job.
5. Toolpath complete - change out tool (calibrate Z axis)
6. Open second toolpath and run job
7. Repeat steps 5 & 6 as needed for more toolpaths.

Am I missing anything? I realize that some of these steps will have quite a few sub-steps, but I am thinking "big picture" at the moment.

Also, when I assign a tool in Cut2D, should that information be passed along to Mach3 or do I still need to adjust the tool settings in Mach3? For example, if I assign a end mill with .25 diameter for toolpath 1 and a half round 30 degree cutter for toolpath 2, should the code Cut2D generates provide that information or do I need to specify it in Mach3 also.

Thanks!

Dave

5

General Mach Discussion / Toolpath display problem

« on: July 20, 2009, 09:11:38 AM »

Hi,

This my first post asking for help as I am brand new to the CNC world. I've just finished setting up my machine and configuring Mach3. Everything is working, but whenever I load Gcode, the toolpath is zoomed out extremely far. I have to zoom in more than a dozen times before I can make out the path.

I've loaded several Gcode files, with the same results on each. I loaded roadrunner file and after zooming in so that I could see, ran it and it had no problems.

I assume I have inadvertently changed a setting, but don't know what it might be.

Any help would be appreciated!

Dave