Mini-CNC

[Demon]

I bought a Vevor mini-CNC last year . Had a few boo-boos, but Vevor made it right at no cost to me.

https://www.vevor.ca/wood-engraving-...p_010386974707


I never thought I could make a PCB with 0.5mm traces using el-cheapo bits on a $200CAD machine.



(this is the bottom side, double-sided circuit is flipped vertically)




I made 2 mistakes; error in the footprint for a slide potentiometer, and forgot a command for 2 oval holes when I editted the files from FlatCAM (I have to separate the drill and mill sizes - I don't have an automated tool changer).

But still, I'm impressed that we can now make at home such a delicate trace.

[Demon]

Mapping the height of the PCB surface.

[Demon]

Drilling an oval hole has never been easier.

I think this was a 1mm mill bit. I mill only 0.1mm deep at a time to save the bit.

[Ioannis]

As I do not have a CNC machine, nor I like chemicals anymore, I prefer JLC for my pcbs, mainly because they offer DDP or Europacket shipping. This helps pass customs wiht no worries.

I just received my 5 test boards and found a tragic and embarrasing mistake in the power supply connection of the 12F675 chip. Reversed them. Cannot believe that stupid mistake I did...

Rule number 1: Never work late at night!

Rule number 2: Double check next day of the design, before sending to production!

Other than the terrible mistake, they look great. Better than the image here.


Ioannis

[Demon]

- Did you have a lot made?
- Is cutting the trace and adding a jumper an option?
- are these for resale or personal use?




This board was to test custom drill footprints, different solder temps, and various solder paste and flux products.

I only share here a fragment of the boo-boos I've made. I don't mind serving as an example of "don't do this".

[Ioannis]

Yes, I' ll do that. Cut two traces and wire jump one, short the other.

Fortunatelly, only 5 pcs were made as they are the prototypes. Corrected for the production now.

But I wonder how such a stupid mistake was done... I have an explanation. It was very late when finished and sent over to production.

Ioannis

[Demon]

Drilling and milling PCBs is awesome. It takes a bit of time to draw the test circuit on Kicad, import into FlatCam and generate g-code, import separate files into Candle, change the bits, align the Z axis.

But this is waaaay more precise than a hand-held dremel, or even mounted on a vertical press. The only thing with the dremel is that it's much quicker setup, and you can tape a sheet of paper over the PCB with all the holes.

It's a great way to test custom footprints before sending them out. Some specs ask for a huge hole. My components will be hand installed; I don't need such a huge margin.





I didn't even bother passing a steel wool to remove the burrs on the holes.

[Ioannis]

Oh man! That's awesome!!!

Ioannis