The Home Machinist!

As I said in my first post about my little CNC mill I am currently using the trial version of Mach3 to control the machine. Included along with Mach3 is a trial version of LazyCam which will (supposedly) convert DXF files into G-code after you input the tool info, offsets etc.

There are no instructions with Lcam but there are tutorial videos. I actually purchased a disk with all of the videos and current programs so I could watch them when not connected to the internet. I have watched everything 2 or 3 times and felt fairly comfortable, I thought.

My first real project came up. I drew the items up in Autocad 2002, sent everything to a single layer and saved it as an Acad R12 DXF. (Come to find out later that a 3rd party freeware file is actually needed to convert the acad dwg file into DXF or Lcam wont load it... another story)

So I load the dxf into Lcam, arrainge my tool paths and offsets and everything looks pretty good. I click on the "post g-code" button, the text at the bottom says it did but I get nothing. Even with it set to automatically load G-code into mach3, nothing. What am I missing?

Finally after several hours I gave up and wrote the g-code manually by typing it into notepad.

I guess I can't really complain because it is a free trial version, but what good is a CAM program that won't post? -Mike

I hear this all the time......and we see it with DXF files provided to us by customers when they "won't machine" because the code is bogus..so OUR software is bad...when in reality....

You might want to check the concurrency of your DXF elements in the DXF file....

If the endpoints of the lines / arcs don't actually 'meet' some of these CAM products won't create a path.

This means digging into the DXF file and line by line checking the actual coordinates of the end points that are SUPPOSED to meet.

Looking at them on the screen isn't accurate enough. Remember, you machine tool works to 0.001" or 0.0001" while a plotter / printer only cares about what it LOOKS LIKE..and if the end points don't exactly match, doesn't care a hoot.

Remember, having them all on the same layer doesn't actually mean that they meet. Some CAM systems barf if the elements are on different Z coordinates...

Bill is probably on the right track - the endpoints of your line segments may not be concurrent, which means no machinable region is being defined to create g-code for.

You can verify this theory with a simple test. Make a new drawing that contains a single circle that is larger in dia than the endmill you will use to cut the part with. Build your dxf and g-code from this single circle drawing and see if it cuts. You should be able to cut it as a perimeter cut or a pocket cut, depending on how you set your software. Since there (theoretically) aren't any endpoints to be open in a simple circle this will test if your CAM SW is actually getting the g-code or if the problem is that there is no code generated because the open line segments don't define a machinable region.

Robert

CIRCLES in DXF format have no endpoints to work to..only a radius and center, so your idea is good, but the test may not be valid.

an arc won't work either since they are defined by center, start and end angles...

I am 100% sure that the Acad drawing features are connected. It was one of my pet peaves when I would get a dwg from engineering which was hacked and then have to make a CMM program out of it.

But just in case, I made a special dwg file, converted it to dxf and loaded it into Lcam. Same results, no gcode.

I tried to attach the DXF to a post a little bit ago and it won't let me use a DXF file. Any ideas? -Mike

Rather than a circle, why not just draw a polygon to test it!

Use the Polygon command, guaranteed connected end points.

or polyline and explode....or any connected, closed boundary...

I tried the polygon feature, 8 sides. Tried a couple of other contours. Still nothing. Ran a search on my C drive to see if it was posting a file anywhere, found nothing.

I searched through the forums for Lcam and saw where people had this problem occasionally, re-opened and it would post. I am not so lucky.

I searched for and downloaded a freeware CAM program, can't remember the name right now (I'm at work). It is very dark and clumsy with more hidden rules and archaic graphics.

I was planning on upgrading the Lcam trial to Lcam pro ($75) when I pay for the full version of Mach3 ($159). But right now I don't know if Lcam pro would work any better and don't have money to waste. The code this trial should be posting is limited to 50 lines. The objects I have been trying should've been much less than that. -Mike

Did you ask the guys at Artsoft at http://groups.yahoo.com/group/mach1mach2cnc

They're hard to beat when it comes to this kind of help

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A Legend in His Own Mind

I tried their free LazyCam, seems that I had some problems also.
Seems that if I didn't save it in AC12 DXF it didn't work.
Check and see what DFX you are saving it in.
Try 12 or older.
Jim
PS I also could be thinking of another CAM program too.

Jim,

You are correct about the R12 DXF save, I tried it and it still didn't work. That's when I found out that a DWG to DXF converter was needed. I used one suggested in the artsoft -Lcam forum and the DXFs went into Lcam straight away. The problem is code-out of Lcam is non-existant.

I have been busy completing the 4th axis (different post) and kind of let the Lcam problem dangle for awhile. -Mike

I have Mach 3 in use on a Torch/Plasma table I use ACAD V 14 when converting to dxf files for use in sheetcam. I have never tried to use the "Lazycam" that is included with Mach software.

I ran into something similar when running Mach & sheetcam in demo versions. There is limitations on how many lines of code the Demo version(s) will kick out.

Might get some help here: http://www.cnczone.com/forums/forumdisplay.php?f=357

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If it works Don't fix it....