This week, I had to do something I haven’t done in a long, long time: make myself a custom PCB the old-fashioned way, with laser toner and etchant. The reason? I bought a horrible K40 laser cutter, and the motion controller doesn’t seem to be able to do acceleration control, which means the machine rams full speed into and out of 90 degree corners, for instance. It sounds awful, and it dramatically limits how fast the laser cutter can run.
The plan, then, is to use a controller based on the wonderful FluidNC, but that meant making an adapter board for the flat-flex cable that connects to the X carriage, and the connector has 2 mm pin spacings instead of the usual 2.54 mm, and it just doesn’t fit into any prototyping boards that I have lying around. Besides, a custom PCB adapter board just looks neater.
I wasn’t confident that I could align and drill the dozen small holes for the flat-flex connector; they didn’t have much extra space around them for the copper pads. These holes had to be dead on, or risk ripping them up. And this is where I heard the voice of my old Jedi master.
When you have a tricky operation coming up that requires more precision than you’re immediately comfortable with, you can practice on the other parts of the project that don’t demand that much precision. Pretending that they do, and taking all the care that you can, gets you in shape to tackle the truly critical bits, and if you mess up a little on the easy stuff, it’s not a problem. I had more than a few pin-headers and other random holes to drill for practice anyway.
Now of course, you could always be giving all of your projects 100% all of the time, if time is never of the essence and effort is free. In the real world, you don’t always want to work at maximum precision. Good enough is often good enough.
But there’s also a time and a place for practicing precision, especially when you see a need for it up ahead. Drilling the big holes dead center got me back in the swing of things, and they needed to get drilled one way or the other. I find it useful to think about the job first, plan ahead where the tricky bits are going to be, and then treat the “easy” stuff along the way as practice for the more demanding operations. Hope you do too!
Ditch the flex cable. I considered what you’ve done, and it was much easier just to extend the motor and end switch cables. The fluidnc controller is an unbelievable transformation!
Good advice about practicing on the easier parts before taking on the harder part of a project. Another tip that works for me, especially when starting a project, is “swallow the frog”, meaning do the hardest part first. I find buying parts online to be really easy, and usually are the first step in a project that never gets finished. So I try to do as many steps as I can before the online shopping spree.
100% effort is a road to burnout ville. Neil Young says, if you cant write a song when you want to, go out and do something else for a while.
100% takes Zen/blackbelt focus in the best of cases.
People that casually throw 100% effort around are idiots who have never gotten to 100% at anything, not even fapping.
People that say 110% are just morons.
110%=25% Mon-Thu + 10% Friday.
You can legitimately have 110% if your standard deviation is 10%.
Yep. Along the same lines as “everything is high priority”. Which is another way of saying “I’m not going to do my job and actually make decisions about priorities.”
Thank you for this advice.
Way too much work and time, ezeda and jlcpcb (any any of them) is so much simpler and for about $25 you can have the board in 5-7 days. I haven’t made my own pcb’s in maybe 5 years.
Okay. I’ll feed the troll. Nearly every “maker” watches You Tube, and every electronics video is sponsored by PCBWay.
For Sagan’s sake, just stop! You’re not adding to the discussion and in this case you are off topic.
I had the job done in an afternoon, start to finish, and the PCB part only took maybe half an hour? I wanted to get on to the next step rather than get stuck waiting for shipping for a week.
Not saying there’s not a time for professional PCB manufacture, but this surely wasn’t it. Imagine how much same-day PCB fab would cost!
Plus doing it yourself at home is an important skill to exercise. We aren’t guaranteed that PCB fabrication will remain so accessible and affordable. home fabrication can be a very rewarding experience. Nice way to spend an afternoon.
A Sharpie and ferric chloride…
This, ugly style of simply a scribe with carbide tip. using a scribe and a ruler you can basically draw the tracks with just a few passes of the tip against the copper. It’s great for rapid RF prototyping.
Do you have a favorite brand/model of a scribe? So far I’ve been using just an utility knife, which works but dulls out really quickly.
I’ve used scribes from hardware stores and cheap ones from Amazon that come with multiple replacement tips. The tips on the higher quality ones purchased locally have remained sharp for years of homebrewing. So far, the cheaper Amazon ones have worked well and I haven’t had to replace a tip after a few months of use.
I have tried many methods of construction and the scribe is my favorite, it’s like drawing out your circuit. It tends to be easier with thinner layers of copper but only requires a bit of pressure and a few more passes with heavier copper clad. You can easily measure out approximate strip line thicknesses and just use a straight edge to get a nice clean cut for your MMIC’s etc.
Give it a try. It was a game changer for me. May your electrons flow deftly.
I use the simple Amazon Chinesium Special. Use them for all kinds of things… electronics, machining…. great for self-defense, too!
Touche
“and the connector has 2 mm pin spacings instead of the usual 2.54 mm”. I have thousands 2mm headers and ribbon cables. Some of the Chinese embedded boards used them exclusively for 15 years. I don’t know why they did not become a new standard. Maybe the RPi effect? Today with so much done serially with IIC, IIS, CSI, DSI, USB, etc. a lot of the manufactures include an RPi header or subset in the 0.1″ format if they need to break out some lines.
Also the single row headers on little uP boards like Blue Pill, ESP32, and Arduino Nano are 0.1″ to fit breadboards. That whole ecosystem could benefit from being smaller. 2mm, 0.05″, or something. I have emmc modules that plug onto 2×12 1mm pin headers. Neat but not gaudy. They are a nice compromise between the larger headers and the sort of push-click flat things used in commercial drones and cameras.
2.54 mm is the superior pin pitch because it has hidden freedom units…
That’s exactly 100 thou.
Just like metric thread pitches that come out to exactly 11.5 TPI.
YOU”LL NEVER TAKE OUR FREEDOM!
Executive Summary: Author was careful. You can be careful too.
I’m glad you succeeded.