[Sterob]

Hi,
I have searched and Googled and not found answers. I even read the CopperCAM manual...lol

1. What is the purpose of the 'Margins' oprion in the Active Tools Window? Nobody seems to use it.......?

2. When 'Calculating Contours', what affect does increasing the setting have?
I've tried it and cannot see any changes.

Thanks

Attachment 491520


Attachment 491522

[RaderSidetrack]

I'm not a CopperCam user, but this document appears to offer 'margin' explanations:

https://cnctar.hobbycnc.hu/Deffent%2...M%20manual.pdf

[Sterob]

Thanks, but thats the CopperCAM manual I was referring to.
It does seem a bit scant of detail.....Maybe Its just me....lol

[blinkenlight]

I don't use this software but margins seem pretty self-explanatory to me - it adds extra space around your traces. Normally, a tool with a 0.1mm tip radius will pass 0.1mm away around your copper traces thereby cutting your trace to the exact size it's supposed to be - in theory. In practice, you might find your 0.5mm wide trace ends up being 0.2mm instead for various reasons, so I suppose you just increase margin from zero to 0.15mm and hopefully get actual 0.5mm traces. It should be the same thing as lying about your tool being larger than it actually is (har, har) in order to force the toolpath further away from the trace than it would normally be - just in a more convenient separate setting.

[Sterob]

I don't use this software but margins seem pretty self-explanatory to me - it adds extra space around your traces. Normally, a tool with a 0.1mm tip radius will pass 0.1mm away around your copper traces thereby cutting your trace to the exact size it's supposed to be - in theory. In practice, you might find your 0.5mm wide trace ends up being 0.2mm instead for various reasons, so I suppose you just increase margin from zero to 0.15mm and hopefully get actual 0.5mm traces. It should be the same thing as lying about your tool being larger than it actually is (har, har) in order to force the toolpath further away from the trace than it would normally be - just in a more convenient separate setting.

Thanks blinkenlight. That explains it pretty well.
I have heard someone say they run a test program for their tools to determine exactly the width of cut they get with each tool, so maybe I will look into that.
Its frustrating that a stated tool doesn't cut the width its supposed to, but I guess I should have anticipated that....as I'm using cheap chinese tools...lol

I am actually getting narrower tracks than I wanted and I have played with the 'margin' setting to see if I got any changes but did not see anything.
I assumed the software would compensate for the depth of cut requested to keep giving the required track width. It doesn't appear to do that.
I am also using 'Autoleveller' software to compensate for machine and PCB irregularities.

I tried reducing the DOC from 0.05mm to 0.04mm to see if the track widened but got problems with insufficient copper removal.

I'll do some testing.

Thanks again.

[joeavaerage]

Hi,
I use Fusion 360 to design the board, which is a re-work of EAGLE, and then use PCB-to-Gcode software utility to generate the Gcode. I use Autoleveller at the machine, at that cures the
'got problems with insufficient copper removal.' problem.

In PCB-Gcode you nominate the size of the tool tip, my preferred tools are 0.175mm in diameter and you specify a stepover and a target isolation. I use a stepover of 0.1mm
and a target isolation of 1mm. This means that the Gcode goes around about eight passes to get 1mm clear of copper.

I'v been using this method for eight-nine years and daily for the last three years, many hundreds of boards.

I would imagine CopperCAM must be similar.

Craig

[jiajia]

"pcb capacitance"www.ipcb.com/technical/9254.html

[jiajia]

I use Cam350 software to design PCB circuit boards. For information about Cam350,www.ipcb.com/news/4510.html, you can click on the relevant link below to view it,thankyou.

[Sterob]

Hi,
I use Fusion 360 to design the board, which is a re-work of EAGLE, and then use PCB-to-Gcode software utility to generate the Gcode. I use Autoleveller at the machine, at that cures the
'got problems with insufficient copper removal.' problem.

In PCB-Gcode you nominate the size of the tool tip, my preferred tools are 0.175mm in diameter and you specify a stepover and a target isolation. I use a stepover of 0.1mm
and a target isolation of 1mm. This means that the Gcode goes around about eight passes to get 1mm clear of copper.

I'v been using this method for eight-nine years and daily for the last three years, many hundreds of boards.

I would imagine CopperCAM must be similar.

Craig

Thanks Craig,
That seems like very careful engraving to get excellent results.
The tools I got are 30 deg, 0.3mm tip.I am also clearing all of the copper off the PCB( for THIS job anyway ), so thats why I Use CopperCAM.

I understand the 'tip dia' and 'stepover' concepts. I just couldn't find any info on what 'margins' or 'contours' were for. I don't understand the need for a margin setting, if you specify the track width you want and the tool you are using.
Maybe its only to compensate for manufacturing errors in the tool taper and tip dia.....

Steve

[joeavaerage]

Hi,
I personally found that the 30 degree tools just too tender. The smallest error and the tip would break with a worsened cut quality and more importantly a changed
tool length often resulting in insufficient cut depth. I now use 60 degree tools an the last until I throw them out for poor cut quality after several hours use.

I use a minimum of 0.2mm between traces, which in turn demands that the tool be a shade under 0.2mm diameter that the tool may pass between the traces.

The tool taper is really only important if you lose control of the depth of cut. I typically have the Gcode composed to cut a nominal 60um (0.06mm) and with Autoleveller
I expect that the actual cut depth to vary no more than +-10um. Any variation in trace width as a result of the height variance is hardly noticeable, although I guess
it must vary....The important point about Autoleveller is that I can make board after board after board without either cutting too deeply and yet always get 100% isolation.
Without Autoleveller isolation routing of PCBs id just not practical.

Craig

[Sterob]

Hi,
I personally found that the 30 degree tools just too tender. The smallest error and the tip would break with a worsened cut quality and more importantly a changed
tool length often resulting in insufficient cut depth. I now use 60 degree tools an the last until I throw them out for poor cut quality after several hours use.

I use a minimum of 0.2mm between traces, which in turn demands that the tool be a shade under 0.2mm diameter that the tool may pass between the traces.

The tool taper is really only important if you lose control of the depth of cut. I typically have the Gcode composed to cut a nominal 60um (0.06mm) and with Autoleveller
I expect that the actual cut depth to vary no more than +-10um. Any variation in trace width as a result of the height variance is hardly noticeable, although I guess
it must vary....The important point about Autoleveller is that I can make board after board after board without either cutting too deeply and yet always get 100% isolation.
Without Autoleveller isolation routing of PCBs id just not practical.

Craig

Yes, Autoleveller is definitely a game changer....a great tool.

Someone has suggested that each tool should be tested to find its exact characteristics so the settings can be set for that particular tool.
I'll look into that.
Thanks again.

[joeavaerage]

Hi,

Someone has suggested that each tool should be tested to find its exact characteristics so the settings can be set for that particular tool.

I tend to agree. Whom can measure a tool tip diameter any way? They all look like a sharp point to me. The offset of the tool from the trace
is the radius of the tool. But lets say you have a 0.2mm tip tool but you put in a diameter of 0.15mm into the software. The Gcode offset would be 0.75mm and therefore
the resulting trace would be slightly under nominal size. If however you put in 0.25mm into the software then the Gcode offset would be 0.125mm and the trace would be a little
wider than nominal.

Provided you enter a number that is a fair representation of the actual tool diameter then it will work. In my case I want to be able to make pads and traces
with as little as 0.2mm spacing. I must therefore use a tool 0.2mm or smaller, or perhaps, and this is what I have actually done, a 0.2mm tool (per manufacturers spec)
but tell the software a wee porky. (pork pie-lie)..that its 0.175mm in diameter the the software will happily plot a path for the tool to pass between two features 0.2mm apart.

It took a little while for me to realise that what I tell the software about the tool and the exact tool dimensions can be slightly different and can be used to advantage.

Craig

[Sterob]

I tried lying to the software, but I didn't execute the cut as I was looking for evidence in the simulation. Maybe I was expecting too much. I didn't want to risk my pcb, but I think I should have.....lol