Can Zack stop smashing his bits long enough to make a circuit board?
Get your own Snapmaker CNC + Printer + Laser: shop.snapmaker.com/?rfsn=6333...
I called this the A350, but it's actually the AT model! Either way, it's also available on Amazon now! www.amazon.com/dp/B09G36C1Y2?...
3D printing is fast. Fabricating circuit boards is not. If we can rapidly prototype circuit boards right here in the Lab, I might be able to escape the bottomless 3D-printing pit of my own creation. The only problem: Milling circuit boards turns out to be way harder than I expected...
PSA: Using FR-4 was a bad choice. I should have used FR-1 (phenolic or bakelite) boards instead - they're safer for long-term exposure.
My free printable models from this episode:
🧩 Slopboard drilling jig: bit.ly/3u90OH8
💨 Snapmaker Vacuum Port + Clips: bit.ly/3thsbza
🔧 CNC Bit Tray UwU: bit.ly/3thsbza
Supplies and tools:
🔩 Tiny end mills: amzn.to/3MGiKRA
📍 Alignment pins: amzn.to/3I64TAy
🤏 0.8mm drills: amzn.to/3t1INep
🔪 Sketchy SainSmart 0.1mm V-bits: amzn.to/3ML7h3w
🏹 Decent Huhao Dual-Flute V-bits: amzn.to/3I2XHoP
🗜 Collets for tiny mills: amzn.to/3J3UxCJ
💎 Diamond pattern mills + more: amzn.to/3sZqJl5
💨 Hose for chip extractor: amzn.to/3t3Em2Q
🛹 Double-sided copper-clad FR4: amzn.to/3MGj8j0
📼 Carpet tape (very sticky): amzn.to/36cYoil
🔩 Tiny rivets: www.ebay.com/itm/273600722201
How to Mill Circuit Boards with the Snapmaker:
0) If possible, print a dust extractor and hook it up to a powerful vacuum with a true HEPA filter. Open windows.
1) Print a slopboard jig. Use it to mark holes on a one-foot square of 3/4" MDF.
2) Drill 13/64" holes on the marks and countersink.
3) Remove your Snapmaker's slopboard and install the new one.
4) Use a 1/8" flat end mill to hog a big ol' square into it. 0.5mm depth, 200mm/min feed, one pass should be enough.
5) Slap some carpet tape on you copper clad and stick it to the bed.
6) Export Gerbers with 14 mil trace and space, 0.8mm minimum drill.
7) Import top copper, bottom copper, and drills into FlatCam. Note that you may need to scale the drills down to 0.1.
8) Use FlatCam's double-sided tool to mirror the bottom copper and generate alignment holes. Position the holes at least 5/8" from the board edge.
9) Create a drilling or milling job from the alignment holes, to fit your alignment pins. Make the holes as tight as you can fit the dowels into.
10) Generate a CNC job from the alignment drill/mill job. Make sure to put G21 in the End G-Code. I recommend 0.5" depth, 0.1" stepdown, 10in/min feed. Save the resulting G-code file with a .cnc extension.
11) Open the G-code in a text editor and change the line F10 to G1 F10.
12) Install your selected drill or end mill, zero, and execute the job. DO NOT change the home position or remove the board.
13) Create drill and mill jobs from the Excellon file. I recommend drilling all holes 0.04" and smaller with your 0.8mm bit, and milling the rest with a 1mm diamond-pattern mill. Depth is the thiccness of your board plus 0.05", stepdown all the way for drills and 0.1" for mills, 5in/min feed.
14) Generate CNC jobs for the drills and mills, generate G-code, change the F[number] line to G1 F[number], mount and home the appropriate drills or mills, and run the jobs.
15) Install a V-bit or micro end mill and home Z very, very carefully. DO NOT change the X or Y origins. Check the Z in multiple places with a slip of paper to make sure the board is flat. Your Z origin should be at the lowest point on the board.
16) Generate isolation routing for the top layer. A 20-degree 0.1mm bit effectively has an 0.012" diameter. I found that one width pass was OK. Look for shorts that the tool can't cut!
17) Generate a CNC job from the isolation routing. I got the best results with an 0.002" depth, 5"/min feed, one pass. Travel Z and spindle speed are irrelevant.
18) Output G-code, change F to G1 F, import into Luban.
19) Apply a thin layer of cutting fluid or light machine oil to the copper clad. Be careful not to let it soak into the slopboard.
20) Run the top copper job.
21) Remove the copper clad from the slopboard, peel off the tape, degrease thoroughly, apply fresh tape to the newly-cut side, and use dowels to pin copper clad to slopboard upside-down. Remove the pins and zero the tool again!
22) Grease up the board, generate the bottom isolation G-code, and run it.
23) Swap in an end mill. Generate cutout G-code FROM THE BOTTOM COPPER, NOT THE TOP COPPER! Use the same settings as the alignment holes, and run the job.
24) Remove board, carefully cut out with moistened tools, clean board, and populate!
25) Use damp rags to thoroughly clean all fiberglass dust.
Interference SFX by Partners in Rhyme
Other SFX from www.zapsplat.com