[jazz352060]

Hi All,

I have a home built CNC Router which I bought a couple of years ago. I do not use it very often. It is not the best or the fastest in the world, but it worked, or at least it used to.

It started to cut random arcs where no arcs are coded. That is, if I am cutting a shape, perhaps with 6 or 7 runs to complete the full shape, it will cut some runs as coded, but other cuts will produce a small arc somewhere, even though the code for the arc has not been in the original drawing. I have checked for extra layers in the drawings.

Mostly, these arcs will even appear on the display screen while they are cutting. When it starts to cut one of these mystery arcs, then it will follow the same track when it cuts that arc again, within the same cutting run.

Occasionally, the arcs will appear, but as full circles, after the code is loaded and before the cutting starts. This happens only on the XP, not the Windows 7 computer.

The drawings are coded via CamBam, using a Windows 7 computer. The NC Files are always run through Mach3 on the Win 7 computer, then taken to the Windows XP computer attached to the Router when they have been run successfully.

I purchased a refurbished XP computer, (no Mach3), then installed Mach3 on it, but the arcs still appear when a file is cut.

I can't try the Windows 7 computer on the Router due to no Printer port.

Thinking it might be the Router electronics, I have disconnected the Router from the XP, then run the various NC files, but the problem remains.

I am at my wits end with this. I have not been able to make a complete accurate cut for quite a while, so I am just wasting material.

If anyone has any idea what could be causing this problem, I would very much appreciate hearing about it and trying it. It will help to save the sanity of another Oldie who loves the idea of CNC Routing.

Thanks in advance,

Albert

[ger21]

Try changing your IJ mode to get rid of the arcs and circles.

[jazz352060]

Hi Gerry,

Thanks for the info, but now I have to ask, what is the IJ? Mach 3 was set up by the previous owner and I don't play with it because I don't want to break it.

Albert

[jazz352060]

Hi again, Gerry,

I found the IJ in the Win 7 computer and it is set to Incremental. It is Version R3.043.022. However, the XP is running Version R1.083.xxx and it doesn't seem to have the General Config section. I don't really want to upgrade until this problem is sorted out.

[MasterSpoon]

Hi Albert

Not sure if this will solve your problem or not but I had a similar issue

In cambam click on the Machining then go to Code option -> Arc Centre Mode
set it to Absolute and see if that solves the issue.

You can also setup a new default profile thing in Cambam to make it default to Absolute.

Cheers
Wayne

[jazz352060]

Hi Wayne,

I tried your suggestion. Setting CamBam to Absolute as you suggested, then loading the resulting code into Mach3, starts cutting an enormous circle as soon as the cutter reaches the first cutting co-ordinates in the file.

Mach3 does the same if I change from Incremental to Absolute.

I am still puzzled as to why Mach3 under Windows 7 does not have the problem while XT does. Same file, different computer, different Operating system. Pitty7 I can't cut with the Win 7 computer.

Albert

[ger21]

Hi again, Gerry,

I found the IJ in the Win 7 computer and it is set to Incremental. It is Version R3.043.022. However, the XP is running Version R1.083.xxx and it doesn't seem to have the General Config section. I don't really want to upgrade until this problem is sorted out.

Try Config > State

[MasterSpoon]

Hi Albert

Sounds like your problem was different to the one I had them.

Just checking have you set the output / Gcode type in Cambam to Mach 3 ?
they talk about it in the cambam FAQ's
CamBam CNC Software - FAQ

Also you mentioned that the machining (XP) system is running an older version of Mach 3, why not upgrade this as it may fix the issue.

Cheers