Nomad: Great results milling PCBs from Eagle


(Marc Liyanage) #21

If you check the “Generate Milling” checkbox in the output settings (see the first of my settings screenshots) then you will get an additional “.mill.nc” file per layer (“bot” or “top” for example for a two-sided board). It contains a toolpath based on the lines in layer 46 (“Milling”) of your Eagle board file.

If you use straight paths you should be able to load that directly into Carbide Motion and run it with an appropriate tool. If you use round segments, you might have to run it through something like my Python script linked above first.


(evilphox) #22

Thanks for answering so quickly! I was using layer 20 for the outline since I usually submit to oshpark to get designs done.

I have a question about how the milling works. I didn’t really see a setting for depth on the milling/routing of the PCB. I was thinking I could drill/route/mill the pcb and wasteboard to set up registration pins. Is there a setting for that or is that beyond the scope of that script?


(Marc Liyanage) #23

There is a milling depth setting, it’s right next to that “Generate Milling” checkbox, see the first settings screenshot again.

The script really only deals with the radius issue noted above, it doesn’t do any thing with registration or anything else, it simply rewrites a particular element of the G-code. In the common case where you’re cutting out a rectangle, you can just feed the .nc file from pcb-gcode directly to the Nomad.


(Robert St-Laurent) #24

Magnificent results the traces are very well defined.
I use this trick that does miracles on giving a superb final touch to a PCB after the milling process.
Before cutting out the outline of the PCB use a steel wool, preferably the ones with that come with soap, and do a strong cleanup of the board area.
It will do the difference between a ‘well it looks ok…’ board to a 'WOW! I did this myself? Superb!!!'
It is a night and day difference on the precision of the traces edges.
After doing the card outline cut redo a steel wool cleanup for the card edges, clean the card under warm water to remove the soap, wipe off the water with a paper towel and use a hairdryer to dry up the card because the drilled holes will retain water.
Be sure to spray a coat of conformal coating to prevent oxidation of the card otherwise you will have a year 1912 oxidized look on your card within a few weeks… I found an inexpensive substitute to conformal coating in a spray used for regular inkjet printers to seal the paper from the aging effect of air on it. This stuff produces toxic fumes for sure so when soldering the pads keep this in mind and have a fan to blow away the fumes and have an opened window to bring lots of new air. Do this within minutes after the outline cut and use gloves to make sure you don’t put fingerprints when handling your ‘outstanding’ quality PCB.
And… may Da Vinci be with you ;^)


(evilphox) #25

One more question actually. What determines the start position of the milling? I’m trying to use smaller pcbs and I know that once I start a mill it moves a certain distance away from the mills home position before starting. seems to start 35mm X 35mm Y or there abouts.


(Marc Liyanage) #26

I’m pretty sure that Eagle’s 0/0 origin corresponds to the x/y zero position that you set the Nomad to with Carbide Motion. I’ve never noticed any kind of offset. So you just have to make sure that your milling lines are where you want them to be relative to Eagle’s origin. Note that there are two milling files, one for bottom and one for top. You need to use the right one.


(evilphox) #27

You know what, I just now noticed the eagle coordinate system and it matches up exactly with what i’m seeing. The top left corner is at 35,35. Thanks so much.


(Trent Hamilton) #28

And this thread sold me. Looking to do small cutting and PCB … these results look great.


(clement mwenda) #29

hallo sir,
am new here
am an hobbyist in electronics world,
i normally use( pcb wizard)to dings my projects
then going the all process of exporting gebers,then using coppercam to generate g-code,to be able to mill pcb on cnc,using mach3,

but now i start working with eagle,
but when i make a pcb ,then generate g-code,;when i send to mach3,pads and width trace are very small ,
can u help or give some tips ?
thanks


(Jim Amos) #30

You might try carbide copper? I’ve had good 1-to-1 results using PCB-GCode. The preview should show your tool etch results.


#31

There are a lot of possibilities, ranging from design to machine setup. I am presuming that the overall size of the board is correct, since you didn’t mention that so it isn’t an overall scaling issue. I will also guess that you are using a 45 degree chamfer cutter (90 degree included angle point) tool with a small point, since this is the most common for PCB milling.

In order of easyness (my opinion):

Check the trace widths in Eagle. Set right? (I screw this up on a regular basis, due to the way Eagle handles trace widths, so I always recheck)

Check the trace widths on the PCB-Gcode popup after generation.

Check the PCB-Gcode settings… Tool size and type? Depth of cut specification? etc…

Be sure your machine setup is correct: Is the board flat and zero is dead on? Is your z-axis zeroes properly? Is the tool end the correct size?

IIf I was to make a guess, the MOST likely issue is the tool setting in Eagle/PCB-Gcode (the tool isn’t defined correctly and doesn’t come to a point) or the z-axis zero.

To set the z-axis zero, I tend to use a brass shim maybe 0.5mm thick (or other soft shim or feeler material so as to not damage the tool point) on top of the board, lower until the shim doesn’t slide out freely, then offset by the shim thickness. This gets within about 0.02mm. I usually start a tad high, run a test cut, and then adjust the zero based on the test cut. My test cut file usually cuts circles near the corners where mounting holes will go, as this is useful,tells me if the height is correct, and tells me if the material is out of flat.

Remember that with a 45degree cutter (90 degree included angle), every 0.01mm depth is 0.02mm of cut width, so on a 0.25mm trace, being 0.02mm low will give you a 0.21mm wide trace, 20% narrow, since you will lose 0.02mm each side. Any out-of-flat adds to this.


(Evan Benzacar) #32

I have been making single layer PCB’s on high frequency Laminates for over 10 years i have been using a much older version then the Quick Circuit QC5000 but it is about the same as the new item just an older controller. i love this machine for what i do (i build LC Microwave Filters)

i do all my drawings with CAD software and i create my cuts using IsoPro from T-Tech which is a simple yet great software.

i like the fact i can possibly do this with my nomad in the future when i need to run a large run where i can get good use of both my machines.


(Serge Sozonoff) #33

So, trying to do some PCB’s with RF componenets and need an “Area Rubout” feature to remove larger amounts of copper from certain areas. Carbide Copper supports this feature but sadly the tools library is too limited and I dont have any endmills which correspond to the fixed list.

I just played around with pcb-gcode but it does not support “Area Rubout”. Surfed the web for a while but short of complicated processes I found nothing easy. I did stumble on cirQWizard which looked really good but it does not generate gCode and requires direct connection to a CNC Router which uses their version of gCode.

I was wondering if anyone else had some other suggestions for a half way decent and reliable workflow ?

Thanks


(Evan Benzacar) #34

you can look into http://www.accuratecnc.com/PhCNCLS.php. i am not sure about the overall performance of the software becasue it has been over 5 years since i have looked at this company.

i use ISOpro and produce .plt files for my machine.


(Serge Sozonoff) #35

Thanks.

Just realized that cirQWizard is OpenSource… wonder what it would take to get it working on the Nomad…


(Serge Sozonoff) #36

So in the end I have settled on FlatCAM which seems to have everything I need.