Milled PCB for pixel array

My first attempt at milling a PCB. The V bit I used was way too big (90degree) but it worked out OK as it is basically just a power bus with a few data relocation paths for the pixel data line.

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Quick youtube clip showing it in action. As usual the camera can’t even come close to capturing the vividness of these LEDs.
https://youtu.be/ftQY-u8Ch-Y

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That’s great! I used to really want to make PCBs, but I haven’t had a need in a while. I need to find an excuse…

WOW, I am impressed.

Very nice, looks professional.

Can you elaborate how you printed the letters on the PCB ?

 

They’re RGB led strips soldered to the board.

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That’s very impressive. I’ve tried to mill PCBs a few times and can’t get good results. I’ve always ended up wiring my project up on breadboards.

I think my problem is the spoil-board isn’t 100% level. I bought a 1" end mill to face the board and haven’t done it yet.

Barry is correct, they are just stock adhesive pixel strips that you cut to size. All I did was stick them to the buss board in the first picture and then bridge solder the VCC, GND and DATA end points to the big PCB. I used one of the 144pixels/m strip versions to try and get the highest density of pixels I could without actually having to directly solder each pixel separately. (This is all in an effort to build my own version of the Eleksmaker “glow tube” clock that is listed under the Random section of the forum.)

@David: I would have had better results if I’d used a proper bit. The 90° V bit is very sensitive to any vertical inaccuracy. An incredibly small vertical change will cause the cut to vary greatly in width. (But it was all I had on hand so I gave it a shot.) I need to either get a 30° V and/or some very small end mills.

I did face my spoilboard as well, I think that probably makes the most difference for PCBs. I used a 1/4" endmill for facing (again, all I had on hand at the time) but used a high feed rate (~4500mm/m) with like a 90% stepover so it only took about 10 minutes to do my 18"x24" work area. That was only taking off about 0.25-0.5mm though at the deep end. If I had to cut deeper or had been swinging a larger diameter bit I wouldn’t be going anywhere near that fast.

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Not nearly as impressive as the versatility of the MPCNC! Every time I use it for something new, I can’t believe how well it does it and how little it cost to build.

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I was cutting the PCBs on a raised platform just slightly larger than the PCB. I’d only face the smaller board. It shouldn’t take long.

I bought a stack of the really low degree mills from Amazon. I think they go from 10º to 30º in 5º increments. They’re very hard to tell which is which and aren’t well marked.

I’ll have to give this another try.

I need to build a shop to hold all the MPCNCs I want to build.

There’s the actual CNC, the vinyl cutter, the laser cutter, an MP3DP, and now a little CNC just for PCBs. Most likely I will just stick to the one and change out the tools occasionally. Sure seems easier to have several machines. :wink:

Has anyone scaled the parts and used thinner conduit and made like a 1/2 size machine? Would that even be strong enough if it was just like a 12" x 12" working area?

You can’t really scale it that way. The hardware and bearings wouldn’t fit correctly.

And a 12"x12" work area is idea for the MPCNC you would rip through material at that size.