How to Make Great Looking Modular Front Panels - Part 3 Module Circuit Board Layout
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- Опубліковано 23 лип 2024
- Using a passive multiple as an example, I show how I make great looking front panels out of PCB boards and they're very inexpensive!
Part 1, Overview, ordering - • Video
Part 2, Front panel design, graphics, and layout - • Modular PCB Front Pane...
Thonkiconn jacks or equivalent:
Thonk site (UK) part # PJ398SM - www.thonk.co.uk/shop/thonkiconn/
Ebay - (US vendor) - www.ebay.com/itm/233302087475
Affiliate link:
Beginner soldering iron kit - amzn.to/3cRY4qf
Doepfer Eurorack standards - www.doepfer.de/a100_man/a100m_...
KiCad Software (PC design, board layout) - kicad.org/
Inkscape (vector graphics design) - inkscape.org/
svg2shenzhen (Inkscape plugin to convert to Kicad) - github.com/badgeek/svg2shenzhen
JLCPCB (manufacturer) - jlcpcb.com/
00:00 Intro
00:57 Creating the schematic
08:09 Modifying the jack footprint
13:10 Associate footprints with components
16:32 Setting up for PCB layout
18:06 Lay out guides for footprint placement
23:00 Import footprints
24:19 Placing the footprints
28:05 Routing the traces
33:50 Draw the board outline
36:30 Add version and date information
37:58 Outro
Commenting to watch this later!
Really great tutorial, thank you! One question, aren't you supposed ro place the text on the bottom silk screen as mirrored text, so it reads correctly when viewed from the bottom?
Thanks a ton for making these.
Workflow question: Is there any way to keep the panel edge cuts and the footprints in sync somehow? Or at least overlay both boards to make sure things line up? Otherwise I can see this getting old *very* quickly when dealing with more than a handful of components.
That's a great question and I've played around with some ideas in the past and not yet hit on something I really liked. I was playing around a bit with filtered selections in Pcbnew and it looks like you can filter out everything but the user drawings and board layout and copy that from one PC layout window to past in another. I may try to figure out a workflow to create a layout that way that can be used for both the front panel and PC board and if that works demonstrate it in my next series.
Another question: This pcb that you're designing here has a height of 113 mm (as seen at 35:50). The absolute maximum of other boards I've seen is 111,5 mm and the TipTop Happy Ending Kit offers a space of 112,5 mm. It looks like this design won't fit!? How did you get this pcb into your euro rack case?
I'm designing a module based on this tutorial and I'm trying to figure out how to make this pcb a bit less high, which means pushing the minijack sockets a bit closer together.
Great points! I had other plans for how I was going to wire things together using different jacks and not have a PC board for them at all (so literally just solder them together with wire). That is when I planned the jack spacing and now that you mention it I might not have revisited how big the dimension on the board had become. I think I ended up getting lucky that that 113mm happens to fit in my rack (but there isn't much extra clearance now that I look at it)
My rack is 100% DIY including the 3d printed end panels that secure the Synthrotek rails I have. It may be inadvertently spaced slightly wider than other racks out there at what looks to be about 114mm.
At one time, I did look for a spec on how tall the guts of a module can be and much like I've found a lot of the Eurorack standard to be, I couldn't find anything. It does sound like to be safe boards inside the module should shoot for being no wider than 110mm.
Some thoughts on what could be done to the PC board to shrink it a bit:
1) the board sticks out at least 0.5mm beyond the housing of the jacks at the ends. The pads near the ends are 0.5mm to the edge of the board. JLCPCB says that dimension can be as small as 0.2 mm. Also, the drill holes for the T pin are 1.42mm on the footprint and the S pins are 1.22mm and the pins themselves look to all be 1mm wide. So you could change the pads to shrink those T holes by 0.2mm in diameter or 0.1mm of radius. Given all this, you should be able to move the end edge cuts in by 0.4mm (so gaining 0.8mm off the total board length).
2) The center of the T pin to the S pin (the one that's external to the housing of the jack) is 11.4mm. Looking at the jacks themselves, because that pin is on the outside, it could easily be sprung to say 11mm (and the pad spacing between S and TN should still be enough for manufacturing) saving 0.4mm spacing between jacks in a group which is 6 spots - so there's another 2.4mm total.
3) The spacing of the pads between the two groups is about 1.0mm. That could be shrunk another 0.5mm and still not violate JLCPCBs stated capabilities.
So that should be a safe 3.7mm total (but definitely more fiddly in the layout requiring footprint modifications and a bit more precise jack-to-jack spacing and edge layout and that would get this board under 110mm
One more thing that could be looked at is the footprint specified for the jack itself (PJ398SM or WQP518MA) on the manufacturer's site (www.qingpu-electronics.com/en/products/wqp-pj398sm-362.html) shows the holes as slots rather than round. It looks like JLCPCB would allow this according to their capabilities (minimum width of 0.65mm which is a bit larger than the footprint in the datasheet) allowing you to shave off even a bit more at least for that external S pin. I don't think I've had a board manufactured with a slot rather than round through holes so I'm not sure if this works myself.
Oh, and also, there may be other jacks that have a smaller footprint (and are still narrow enough for a 2hp module) that could work too.
@@eurorackDIY Oh wow, what a elaborate reply. Thank you.
Yes, online documentation of this dimension is vague. On the Doepfer site (www.doepfer.de/a100_man/a100m_e.htm), which I consider the standard resource, it isn't mentioned.
I've solved it myself by modifying the jack footprint: I moved the S pin closer to the housing of the jack. After that I rearranged all parts a bit too. I have a pcb design that's now 109,5 mm high. That'll suffice. I can send the design later (when it's fully complete) if you want.
Thank you for this exchange, moving the jacks closer together makes for a neater design anyway and now I know how tall the PCBs of Eurorack modules are supposed to be! Excellent series in general! I hope there will be more!!!
And a third comment :) :
You didn't fill the back copper layer like you did for the panel design. I'm assuming, just as with the panel design, that it is easier to understand for jlcpcb if there's a filled back copper layer, right? Even if it's a fully electronically isolated layer.
Alternatively, the back copper layer could also be used as the ground connection of the circuit.
It turns out there's a bit of copper on the back of that board, where the solder pads for the pins are. The reason I filled the front panel's back side is that there aren't any through-hole pads and so there was no copper on the back at all (I think Kicad even skipped generating the file for it, which makes sense). When I submitted that panel, it got kicked back from JLCPCB when they checked it because I had ordered 2-sided but the design only had the one side. Because that adds a couple days, I figure it's always best to make sure there's less chance to get things sent back.
Speaking of JLCPCB's design checking: I've been super-impressed. My first boards I submitted I also had SMT assembly for them and it turns out I placed all the ICs upside-down! I think I might have noticed this on my order right before the boards arrived and I was really bummed that I now expected everything to be wrong because of my mistake. It turns out they had already caught the problem and flipped everything around correctly and everything worked perfectly!
@@eurorackDIY Ah, I see. That makes sense. Well, I filled in the back copper layer, keeping it isolated from those solder pads, of course. I guess both'll work. Potato potato.
Good to hear that JLCPCB really double checks stuff :)
Great set of step-by-step tutorials! Thanks so much. The added timestamps are much appreciated too.
I'm going through all 3 videos. I got stuck, though, in this one at the 22:30 mark, when importing the associated footprints from the schematic. I see this error message:
" Warning. Cannot update the PCB, because Pcbnew is opened in stand-alone mode. In order to create or update PCBs from schematics, you need to launch the KiCad project manager and create a PCB project."
As you mention, I can re-open the board.kicad_pcb file from the main Kicad project window. I've tried both that and opening the file via Eeschema, like you do in the video, multiple times, also closing and restarting all apps, but the error remains. Any other suggestions on how to solve this?
Thanks again.
You're absolutely right and I hit that surprise when running through it from my script. I edited out all the "hmm, what's going on here?" part and was hoping that my recovery description was enough. I'm sorry that it wasn't clear and the flow didn't work out right.
In addition to the .kicad_pcb and .sch files in the original project's directory there will also be a .pro (project) file for each of the Board and Panel projects. If you go back to the main Kicad window and select File->Open Project... and open Board.pro and then from there open Board.kicad_pcb (or click the mostly green PCB Layout Editor icon from the horizontal icon bar) I think that should work better.
I find Kicad's project organization and trying to work with multiple PC boards in a single project kind of frustrating. I don't know if there's a better way than what I did but if someone knows of one I'd love to give it a shot.
@@eurorackDIY Thanks, that worked! And thanks for the quick reply. I suspected the solution would be some mundane step like that.
And yeah, I agree; Kicad's project organisation seems a bit counter intuitive. But I'm new to it, so still wondering whether it's me or the tool that's confused/confusing.
the center of the top jack to the center of the bottom jack is 100mm... how did you determine this number? could you go over how you analyzed the data sheet for the thonkicons and determined their spacing and positioning? also what size gap is needed so the jacks don't overlap with the case rails? would be really helpful!
Great questions! There are mechanical drawings for the jacks on the Thonk website but I find it most reliable to get parts in hand and measure them with a micrometer or ruler myself. The same thing kind of goes for the spacing between the rails as I don't think the Eurorack standard says anything about that. I measured the distance between them in my rack and then subtracted a bit from that to provide more clearance (but maybe not enough for all cases).