Meh, just fix it in the software

[vigilante397]

A couple years ago my dear sweet wife got sick of seeing ferric chloride stains EVERYWHERE and said I was no longer allowed to etch my own boards, so she let me pull the trigger on a small (7"x7") desktop CNC mill. It runs off an Arduino UNO so the software interface it came with was a little clunky, but it got the job done and with some patience I was able to etch boards and enclosures with a way tighter tolerance than I could do with chemicals (though I know others here have perfected the art and could probably beat out my machine).

There were two problems I had though: first, no matter how many times I took it apart and adjusted it I could never get the bed level with the axis so on medium to large boards I had one side that was perfect and the other side was either too shallow and everything shorted or too deep and the traces were destroyed. The second problem was that there wasn't a really good way built-in to flip the board over so while the machine could theoretically do two-layered boards I had never succeeded in doing so.

Fast-forward to this weekend, and I found new CAM software, which converts my Gerber files into GCODE for the machine to read it. This one is open-source freeware, but is a million times better than the $80 one I was using before. The main point being it had a very good interface built in for convenient board-flipping that took the guess-work out so double-sided boards were now a possibility. I also found a new GCODE sender that takes the GCODE and tells the Arduino what to do with it. This solved the calibration problem as it has a beautiful auto-leveller: I attach a ground wire to the copper clad and a probe from the Arduino to the drill, then it probes the surface of the copper reading where it hits ground and adjusts the GCODE depth to compensate for it. On smaller boards or boards with thick traces I can choose to speed it up and only probe a handful of points, or on bigger boards I can probe several hundred points for more accuracy. To top it off, the new sender works on Linux, so instead of leaving my $1000 laptop in my garage I can run everything on my $35 Raspberry Pi

In summary, I've increased the time I take to make boards by about 10 minutes and I can now make boards significantly nicer than before. I couldn't remember where I put my double-sided copper clad, so I just tested on a single-layer design and did a "silkscreen," though if I'm going to do silkscreens I should probably change the way I do it so you can actually read them





Getting to the point of this post, I've been contemplating recently how much of my electrical engineering knowledge came from my formal education and how much of it came from you fabulous people. So I've been trying to give back by answering questions and such, but I'm also thinking about offering quick prototyping services to those that don't have the means (or the motivation ) to make their own. I would charge a buck or two for the cost of copper clad and a stamp, but I would basically be donating my time. It wouldn't be as high-quality as professionally fabbed boards, but the turnaround would be a lot faster. It takes about an hour to mill a basic double-layer board, then I could throw it in the mail and someone in the US could have it in a few days.

Thoughts? I wanted to see if anyone would be interested before stocking up on copper clad

[Kipper4]

Great work Nathan.

I like that you battled through and found a solution. A testament to you're ingenuity sir.
Empowering future generations of stompboxers.
If I was to take maker class ,I'd want a teacher like you.

I love the idea of a proto service.

Good luck in the future.

Ps . You dear sweet wife did you a massive favour.

[Rob Strand]

Great stuff.

I've seen the CNC method many times over the years.  Some people outlaying a *lot* of money to kick it off.
Finally it's becoming more reachable at home.  Not to mention all the cool software out there these days.

In a similar vein, one company I worked for set-up a plastic 3D printer.   Like all these things it take a few tweaks and a change of software to get a working recipe.

[aron]

How much does one of these cost? Those are the 2 things I would be really interested in - 3D printing and CNC. Solves so many problems.

[vigilante397]

How much does one of these cost?

There's a huge "it depends." There are tons of machines on eBay and the like that are ~$500, not sure how they are though. Mine cost me $700 as a kit (no complaints here, fun assembly), but the company doesn't offer my exact machine anymore. The same size with an upgraded spindle is about $900: https://www.zencnc.com/product/zen-toolworks-7x7-cnc-machine/

So it's a bit of a leap to make for a hobby, but I was selling pedals at the time and it allowed me to make higher quality pedals and faster, so with the bump in productivity it paid for itself in about 6 months. I had been looking enviously at other models, and I think I'll get a bigger one eventually, but with these software upgrades this one still has some good use left in it.

[Rob Strand]

How much does one of these cost?

I honestly can't remember how much the one we finally got cost.   There were some in the $1000 to $2000 zone but you can also get them down around the $500 mark (and less!).   

The type I'm talking about use the "plastic wire" that feeds through a head.  The part is placed on a heated x/y table.  It's quite critical to set-up and things like drafts from air conditioner outlets can upset the result.  It builds up in layers with the new hot plastic creating a bond by melting into the previous one.  If it doesn't bond properly the part is weak as the layers can separate.  You obviously need to stock certain color plastic if that's important.

The boss/CEO actually built one from junk scrounged from printers and a few specific parts, together with a video monitor so he didn't to keep going out to the garage.  One of the few companies where the CEO was smarter than all of us.

[antonis]

Should you got the nerve to call your pedals "DIY" anymore, Nathan..?? 

[vigilante397]

Should you got the nerve to call your pedals "DIY" anymore, Nathan..?? 

It's a fair point, but "DIWSMIYG" (Do It With Some Machine In Your Garage) isn't quite as catchy, and doesn't have a dedicated forum yet