EP8 - DIY PCB - Corner Probe for CNC3018 (Contactless)
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- เผยแพร่เมื่อ 27 พ.ย. 2022
- For the first time I am making a PCB with my new method that I am really going to use.
Actually this is an optical probe module for my CNC, so effectively I am making a PCB to help me make better PCB’s.
Sadly, it was not all fun and games, but new discoveries have been made, so cup half full and all of that… feel free to join the fun and check out the video for more info ;-)
This is the eighth episode in a series where I am challenging myself to make the best possible DIY PCB’s using commonly available low cost CNC technologies. - วิทยาศาสตร์และเทคโนโลยี
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Great design buy I still just use an edge finder. Before becoming disabled starting my home biz I worked as a machinist and design eng, the last few years designing desktop cnc units and 3d printers. As my wife would agree, I have far too many hobbies. So many that they all come together to help each other.
I am greatly enjoying all your videos, I am also envious that you get to be in japan. I don't want to live there as much as I would love to see the sakura bloom in person.
Well, you're in good company, as I also have way too many hobbies.. actually I am doing some motorcycle stuff lately, but I am not doing videos for that as it doesn't fit with the channel (thus the lack of recent videos). The sensor works really well I think, it has already saved me once when I lost the origin for a board I was working on. Thanks for the comment!
Metal polish...brilliant! I had considered using Autosol, but it will attack the paint I'm using and has a wax component that would have to be removed. Just tried a kitchen product designed for cleaning stainless pans...works perfectly. Great tip!
Your welcome! Thanks for the comment.
I collect leds and have tens of thousands and I'd love to find vintage ones. You can take the small spout off the heat gun and just go at it from the top. I find the surface tension works better then.
Sometimes I take it off, sometimes Ieave it one, depends on my mood ;-)
See if you can get some 3000 grit sandpaper at the auto store and scrub across the pads, (or some 0000 steel wool or scotch brite) then try a wee bit of liquid flux before applying the solder paste, also I wonder if you can use some really thin acrylic sheet to burn out the solder stencil (or maybe capton tape?)
Very cool...the laser cutting the traces and pads are nice and the green solder mask looks very professional!
P.S. Carbon (aka burnt stuff) and even graphite from a pencil across a SMD resistor can create resistive traces
Thanks for the comment! I used to always use brasso and steel wool to clean off photo resist from PCB's, it works a treat! The problem is that the mask resin sits above the surface creating a shallow pocket which can't be reached easily. Thankfully the fine toothbrush cleaning with Pikal (Japanese Brasso) is now working great, so for now this problem is solved enough(ish). And yes, others also pointed out that the burnt resin is becoming carbon after burning.. obviously ;-) Anyway, you live and you learn!
Great videos. How about using a metal brush in the CNC, to clean the green solder mask off the copper pads?
It's an interesting idea, but it would have to be a pretty tiny brush! In a way it seems somewhat similar to using a spring bit that other people use (also shown in my earlier episode). I have also thought up some completely different methods to clear these pads, but actually the laser clear works pretty good, and is an easy process to do (I am just not doing it right!). In my final solution I am thinking to simply apply more power to pads that sink heat well, and allot less to those that don't. From what I have seen so far, this should work well. Thanks for the comment and idea!
Sorry for the repeated comments but I'm looking to buy a laser to do the same thing. You built you own mill ehh? You are a very smart man.
I am not sure you can say I built it, just customized a standard 3018 CNC.
@ForOurGood I realized that after watching more videos haha. I plan on buying one. I need a new 3d printer. I've got like 30 rolls of filament and no printer. I'm shopping for one today. Some dude on ali has an flsun 400 for super cheap compared to everyone else and I'm hesitant to pull the trigger because it may be cheaper than everyone else but it's not cheap if that makes sense. It prints super fast. I had 5 printers at one point but I dropped down to 2 and hurricane Fiona hit and took half of our roof off and I've been living in my workshop for like 5 months and needed the room so I posted them for super cheap and if I didn't get a bit I was gonna give them away but some dude gave me an isolation transformer 1kva and a tektronix tds2002c. I gave him probably 2k worth of parts along with the printers because he was so kind.
Excellent video same issues I had and you confirmed with the x y play of my cnc. Thank you for sharing.. Look forward to more videos.
Happy New Year!! and thanks for he nice comment & subscription. Actually, I have just bought around $100USD of parts to upgrade the CNC and see if I can improve the main problem areas. Should be a new video about that early 2023, so it will be definitely should be interesting to see how that all turns out!
I don't know if anyone else has mentioned this. When you clear the pads have you tried first running the laser right to left and then run it again forwards and backwards? I have just started do my own research into using a laser to create pcbs, so, I am not really familiar with any cnc software yet. Overall, your procedure is very well done and quite interesting. Do you discuss what resin you use in your earlier videos? Thank you.
Thanks for the comment. Episode 6 shows the resin I use, and the way I apply it, so check it out. You can also find a lot of specific details of the process in the description of episode 7 (it's a little bit out of date, but still likely useful). The software I use to make the g-code was designed for milling PCB's, so sadly the options don't include control over the direction of clearing operation. I have given thought to writing my own converter, but for now I am still trying to avoid that. Anyway, good luck with your PCB making endeavours!
Pretty amazing series. I was hoping you got amazing results with the cnc routing but you went for etching. Thank you for sharing.
Sorry to disappoint on the CNC milled PCB, actually I was disappointed myself. I did try at first with that intent, but it became quickly obvious that milling with the cheap CNC was not going to work the way I had hoped. But I am glad I tried, because it left me down the path of a much better solution using the cheap CNC. More videos in this series to come, hopefully I will be able to further refine the process as well as start making some more interesting and useful devices. Thanks for the comment!
@@ForOurGood I am still on that path. The results are a little bit inconsistent. I try not to go to much in the boards base material. only milling about 35-40 micrometres deep. But a board of 50*70mm is a slow process. Easily taking 2h to mill without drilling. printing a few transparent sheets and using UV exposure is definitely the quicker way.
@@joerideman I have made many boards with transparencies for real world use. It's ok, but without a doubt, I like this CNC laser methods much much more.
If I was going to make more than 5 copies of a board, then I would just go to PCB Way or something once the prototyping was completed.
This inconsistencies with the milling is really what turned me off, there are just too many factors at play. Anyway, wish you the best of luck, possibly you are more persistent than me, and will ultimately get there in the end!
I'm enjoying your PCB series. I'm currently doing some experiments with the 3020 CNC and some soldermask. Using a laser is an interesting idea, but I've avoided it so far due to the fumes created when burning. I hope you have good ventilation. Keep up the good work 👍🏾
Hey thanks for the nice comment! FYI: I show my ventilation setup in one of these videos, but its basically a flexible pipe connected to a ventilation fan, then I cover my whole CNC with a cardboard box to capture the fumes and direct it too the fan (also reduces laser risk to the eyes!). I do all this in the garage, so I just stick the pipe out under the garage door. I think it is a pretty cheap & simple setup to replicate, and you could just stick the pipe out a window somewhere. The great thing about using the laser for nearly all of the process is that it is very quiet and does not produce any fiber glass dust (possibly worse that burnt resin fumes).
@@ForOurGood Nice! I have the same setup. A duct fan and a hose connected to a window. I'm milling in mineral oil to contain the dust, but I have to admit the elegance of the laser is appealing. I'll post my setup and we can compare and contrast.
I hope your channel blows up because you deserve a lot more views 🙏🏾
Maybe I think too simple but can't you increase the overlap in flatcam to clear the pads?
The problem is heat, and the fact that some pads actually need more heat to clear, while some pads need less heat to survive.. but these exist in he same board. Increasing the overlap just increases the heat, and so you lower the power which in turn reduces the overlap (as the beam gets smaller), and you end up just chasing your tail... Actually if the beam was properly circular, I would have already nailed this.. But there is also another spanner in the works, and this is that Flatcam "lines mode" clears vertical for some pads and horizontally for others (probably decides by dimensional proportions). As I said in the video, it seems that making the range of heat tolerance smaller (by ensuring smaller pads have at least some heat sinking capability), seems like maybe the sensible way to approach the problem for now, and I know it works. Anyway I need to do some dedication testing for this to characterise it better, same goes for exposing the text overlay.
@@ForOurGood Yes, most lasers are indeed not round. Unfortunately, they are often rectangular. Maybe you would have some sort of break in the gcode to give the pads room to cool down. or you could find a way to cool the pcb while lasering. But all in all, nice video again and nice to see how you are developing a good way to make pcb's. compliments!
@@matheokoning4456 Thanks for the comments and support. Right now I am just trying a few different things to get a solid understanding of the dynamics, but eventually I will settle on something! Still very early days ;-)
Burning the resin is turning it into carbon .
I wonder if the difference between the laser and mill spindle was caused by them having different weight ? When you have something hanging off the x axis at a distance from the guide rails any difference in weight will cause it to deflect more or less .Same goes for the elongated holes , it could just be an acceleration or jerk setting that needs tweaking to stop or lessen something similar to ringing on a 3D printer . Is the elongation consistently aligned with an axis or random ?
That is a nifty setting tool you have made !
Actually I am sure deflection is happening on the mill, the Z-Axis is basically floating for the first half a millimeter of contact. All of the holes in the older boards drilled pretty cleanly with this bit, but I suspect this time the endmill is a bit duller, causing it to wander on the surface until the slack is taken up on the a-axis and pushes it in (result is elongated holes). When I was making boards 30-years ago, I always etched out the hole of the center of the pad to make manual drilling easier, so on the top layer I am thinking to etch open the pad holes to make it less sensitive to dull endmills. This is the first time I have seen the elongation, so I can’t speak to consistency, but it was pretty much as you saw in the video this time around. The runout of the spindle is also likely a factor to the randomness seen, you can even see the runout in action as I probe the mill, the detection light flashes like crazy. My idea of spinning the mill when probing to always try to catch the same extremes of the runout when probing, but even so I am sure there is a little variation each time. Of course runout of the mill is still going to affect its accuracy in operation too, so the best solution will be to upgrade the spindle and eradicate the runout once and for all. And you’re probably right, carbon sounds about right, that makes a good resistor. Thanks for the comment!
Cant the board be cut using the laser? That way the alignment issue goes away. My CO2 laser can't cut metal, so I suppose the holes/cut tracks need to be etched first.
Thanks for the question. Actually no, even with the holes for the pads etched, this laser cannot make the through holes. I have seen a video from "techydiy" where he used a super powerful fiber laser to cut the holes in the PCB, as well as clear all the copper. It is very impressive to see. However this laser is very very expensive, and well beyond the price scope of what I am trying to demonstrate, it also looks like maintaining dimensional accuracy and positioning could be problematic, and I am not sure if you would get 0.1mm tracks with that method. With that all said, I have some relatively low cost upgrades in the pipeline for my CNC3018, hopefully after that the milling and drilling accuracy will improve by a decent margin.
really good! have you documented the process/methods of what you have done?
Glad you liked it! There is a bunch of documentation in the description of episode 7 of this series. But there are some problems with the process as documented there. After I do another round of experiments I will likely provide an update to this process in a new episode. Anyway, this is an ongoing work in progress, so changes are still likely for a little while. Thanks for taking the time to comment!
Is there any way you could make these PCBs available?
I have not been thinking about making anything for distribution, so I don't really have a way to do that. Right now, this is all just a hobby for me, with my experiences being shared in these videos. But I do appreciate the question, so thanks!