Apologies in advance for a long post, I’m simply unable to write short comments.
I have been doing isolation milling for about a year. Results have been reasonable successful, both in making single and double sided PCB’s.
End mills:Depending on the pitch I need to achieve, I usually use 0.3mm or 0.2 endmills.
The reason for not always using the smallest possible bit, is simply that I can reach higher feed rates with a 0.3mm.
Sadly I tend to break the 0.2 mm endmills, this gets rather annoying, not to mention expensive.
I haven’t tried the V shape bits yet. I have no idea what angle is or tip size is needed.
I have an (probably misplaced) idea that steeper angles are better, and tip size around 0.1 mm would be correct for 0.5 pitch IC’s ?
My hope is that these bits are sturdier than the end mills?
For via drilling, I find myself using a 0.5mm endmill, connectors are drilled using 0.8-1.0mm drill bits.
I have been experimenting with a modified a 3mm drill shaped into a V type tool. This works quite well, but also tends to break from time to them. However that isn’t a problem, as I can just grind it into shape again.
Does anyone know a good place to buy 3-3.125 mm shank 0.2 endmills/vbits for pcbmilling?
Preferably somewhere within the EU as I really don’t fancy paying silly import taxes from the US or China.
Any recommendations are very welcome.
CNC Setup.I actually have two CNC mills, both of them diy types.
The first one is an Aluminum gantry on steel frame. This has a working area of 80cmx60cm.
The other one (just finished building) is much smaller, made specifically to do light work engraving.
I aim to use this smaller CNC for PCB milling. I haven’t really tested it yet, but I have high hopes.
Everything on this machine is made with the large CNC mill, this ofc includes the motor control PCB.
Both cnc machines cost around 500€ to make, and ofc a lot of time. On that note I better mention that most aluminum parts I cast myself in a backyard foundry.
Tool chain.So far I have been using Eagle along with PCB-Gcode. Machine control is handled by MACH3.
I have been looking at Coppercam, wanting to try it out at some point.
Quality.On the large CNC machine I can manage 0.65 pitch, and 0.3 traces without too many issues. However migrating to 0.5mm pitch is probably pushing it atm.
I’m hoping that my new engraver will be able to do this.
While precision isn’t too much of at issue, milling quality isn’t quite as good as I hoped.
I tend to get a lot of burring; this is only a minor annoyance, and goes away with some light sanding.
After sanding they look excatly like the picture posted by OP.
Nearly everything I do is SMD components, so far it hasen't let me down.
Timeframe from layout is done, until I have a finished board, is usually anywhere from 20 to 60 minutes. This includes light surface sanding.
Quality is ofc nowhere near manufacture grade. You obviously end up without soldermask or silkscreen, but for a hobbyist like me it’s good enough.
Feeds&Speeds.I usually run the spindle as fast as it will go, that would be around 20000 rpm.
With 0.3 endmills I seem to avoid breakage at 150 mm/min with 0.15 milling depth.
I haven’t pushed it further In regard to speed, as I’m happy with both speed and result.
Regards Ealin.