Originally shared by Shane Gough
I put 7 of the most important things I learned while developing a PCB milling process into a post - hopefully this will help others who are trying to do the same thing.
http://thegaragelab.com/seven-pcb-milling-tips/
Hi, what do you use for generating G-code from a PCB-layout (e.g. gerber files for top and bottom and excellon for drills)?
At work with an LPKF PCB mill we use CircuitCAM but this is a very old version, commercial/closed-source, with a lot of bugs and a working open-source solution would be interesting.
The take away lesson is getting boards made is cheaper than you think http://www.pcbway.com/?ngaw=32&gclid=Cj0KEQjwsIWvBRCnzevvor2g4L8BEiQAAN234TR8YMvt0KzXFhO1y1QL07hjPkHfHffP-6k7ccXcdU8aAs988P8HAQ
@Anders_Wallin have a look at ChiliPeppr. It’s an open source g code sender with (among many other things) Eagle import capability.
@Anders_Wallin I use LineGrinder - http://www.ofitselfso.com/LineGrinder/LineGrinder.php - which has worked well for me so far.
@Paul_Frederick It depends on the purpose of the board, I can design, mill and solder a PCB in an afternoon - having it fabricated generally requires a 2 to 3 week delay for delivery. Repeat as needed as you make changes to the prototype.
Milling isn’t a complete replacement for having boards made externally but it certainly speeds up the prototyping process and is very handy for one-off boards.
There is a bit of a religious argument around milling vs etching (of any form). There are pros and cons both ways but for one off relatively simple layouts I really like milling.
@Paul_Frederick
You don’t understand the advantages of cnc’ing pcbs. And it seems like you have a strong opinion but no experience to go along with it.
A big advantage of cnc’ing pcbs:
*you can route the board and drill it without much additional effort. You like drilling? How about drill 30 holes * 10 boards? You won’t like it after a while.
These advantages are especially awesome in a work place setting where time is truly money. For example, I made about 20 PCBs, each had about 5 SMT components and 2 thru-hole parts (5 vias each), in half a day. The boards were milled/routed/drilled all on the same machine.
Another example: our engineering group received about 10 PCBAs with missing routed features because of a design flaw. I made a small fixture and mounted these boards to my machine and routed the missing cutouts. It took a few hours. Sending the boards back to the fab house would’ve been days.
Shane,
I went through the trial and error milling pcbs and can make a good quality board with 10mil traces without issue. There were virtually no burrs.
Here are a few things to try:
i strongly recommend double-sided tape under the pcb. i used MDF as my base. works quite well.
your spindle RPM probably needs increased. looks like you’re rubbing as opposed to cutting. calculate your chip load (aka chip thickness). it should be around 0.1mm. if it’s something like 10x less, you’re rubbing copper, not cutting it.
use a bit with 45degree angle. looks like you’re using 20-30 degree bits. this means the tip surface speed is pretty low (hence one reason for increasing rpm). the shallow angle bits tend to pull the copper upwards. try a 45 deg bit, it tends to push copper to the side more and cut it. i can consistently make traces without any burrs.