<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<style type="text/css" style="display:none;"> P {margin-top:0;margin-bottom:0;} </style>
</head>
<body dir="ltr">
<div style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
Well you've confused Google. In the UK that shows the 2cent Euro coin :-)<br>
</div>
<div id="appendonsend"></div>
<hr style="display:inline-block;width:98%" tabindex="-1">
<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> Synth-diy <synth-diy-bounces@synth-diy.org> on behalf of cheater cheater via Synth-diy <synth-diy@synth-diy.org><br>
<b>Sent:</b> 03 February 2024 15:24<br>
<b>To:</b> Ben Stuyts <ben@stuyts.nl><br>
<b>Cc:</b> synth-diy <synth-diy@synth-diy.org><br>
<b>Subject:</b> Re: [sdiy] PCB extenders with a flexible ribbon cable - looking for suggestions on construction method</font>
<div> </div>
</div>
<div class="BodyFragment"><font size="2"><span style="font-size:11pt;">
<div class="PlainText">I guess this isn't easy to google, so here's the exact thing I mean:<br>
<br>
<a href="https://www.google.com/search?q=eurokopplung+&tbm=isch">https://www.google.com/search?q=eurokopplung+&tbm=isch</a><br>
<br>
On Sat, Feb 3, 2024 at 4:20 PM cheater cheater<br>
<cheater00social@gmail.com> wrote:<br>
><br>
> On Sat, Feb 3, 2024 at 4:16 PM Ben Stuyts <ben@stuyts.nl> wrote:<br>
> ><br>
> > You don’t mention the length of the cable, but perhaps some other possibilities are:<br>
><br>
> between 10cm and 2m, usually 15-50 cm. Thanks for asking!<br>
><br>
> > - rigid/flex pcb (but could be expensive depending on length of the tail, panelising will help here)<br>
> > - FPC cables (e.g. <a href="https://www.we-online.com/en/components/products/em/connectors/fpc_connector_and_ffc_cab/wr-ffc_flat_flexible_cable_0_50mm)">
https://www.we-online.com/en/components/products/em/connectors/fpc_connector_and_ffc_cab/wr-ffc_flat_flexible_cable_0_50mm)</a><br>
><br>
> I'm not looking for a connector! I already have one. I'm looking for a<br>
> good way of quickly and reliably soldering ribbon to a pcb, and I'm<br>
> also looking for an enclosure.<br>
><br>
> > Consider 3d-printing the case.<br>
><br>
> I did! It's mentioned in the OP. It's better to find something that<br>
> already exists. Currently I'm thinking about whether a cable mount<br>
> europlug receptacle will be good for that, it seems to have the right<br>
> dimensions, and i can just remove the mains related inner life.<br>
><br>
><br>
> > Ben<br>
> ><br>
> > On 3 Feb 2024, at 12:26, cheater cheater via Synth-diy <synth-diy@synth-diy.org> wrote:<br>
> ><br>
> > Hi all,<br>
> > I need to build a bunch of PCB extenders. Basically, they're two PCBs,<br>
> > connected with a ribbon cable. I have to build like a 100 or so. Both<br>
> > sides have gold finger PCB edge connectors, there is no slot on either<br>
> > side.<br>
> ><br>
> > I was wondering if anyone had suggestions on how to best do this to<br>
> > keep the cost, assembly time, and rejects to a minimum.<br>
> ><br>
> > The specs are:<br>
> > - The signals carried are up to 35Vpp, tiny current, sub-500kHz, balanced<br>
> > - Each pcb is 25mm wide (but can be a little wider) and can be<br>
> > anywhere between 10 and 80mm long. No logic, purely 1-1<br>
> > straight-through connection. They can have vias if needed, but<br>
> > hopefully not needed. Produced in a pcb house, not at home.<br>
> > - The card edge is on the 25mm long edge and the ribbon would be going<br>
> > out of the opposite edge<br>
> > - 32-36 pins need to be carried by ribbon. 32 is the minimum, but more<br>
> > is fine (I'd just carry ground)<br>
> > - The ribbon needs to be as flexible as possible. what is the most<br>
> > flexible ribbon you've ever seen? I'm looking to keep BOM cost down<br>
> > but if the thing is tough to bend like a stick then that doesn't help.<br>
> > Are more core strands better? Mouser lists a few stranding options:<br>
> > ones that start with 7 and ones that start with 19. The options seem<br>
> > to be: 7, 7x34, 7x36, 7x38, 19x40, solid. I assume the left number is<br>
> > the number of strands and the right number is the AWG. What's better<br>
> > here for flexibility? The cable isn't going to be moved a lot or<br>
> > strained, but up to 2 meters of it are going to hang off the<br>
> > connector. I assume higher AWG (=smaller strand diameter) is better,<br>
> > and more strands is better, but is 19x40 not going to be, in<br>
> > aggregate, thicker than 7x38, and therefore less flexible?<br>
> > - What sort of material should the insulation be made out of to be<br>
> > (and remain over a few, say 5, years) the most flexible? The options<br>
> > are: EPDM, PO, EVA, FEP, PFA, Polyester, PE, PP, PUR, PVC, TPE. Am I<br>
> > right to assume that PVC and Polyester are going to be the least<br>
> > flexible?<br>
> > - Are there tools that can strip all wires of a ribbon at once? Are<br>
> > they good? Are they expensive? Can someone suggest such a tool?<br>
> ><br>
> > Here's are some construction methods I was considering:<br>
> ><br>
> > Method 1. Take a ribbon that's been stripped and pre-tinned in a<br>
> > solder pot with 7mm bare wire sticking out. using a press, pre-bend<br>
> > the bare wires so if the ribbon is placed flat on a surface, the wires<br>
> > aren't "up in the air", and clip the leads to size (think something<br>
> > like the surface-mount leads of a QFP or something). The pcb has<br>
> > surface-soldering lands on it that will mate those 3mm bare wires.<br>
> > Take the pcb and lay the ribbon parallel with it, so the tips of the<br>
> > wires align with the pcb. However, the ribbon should go from that edge<br>
> > *towards the card edge connector side* which is "the other way" than<br>
> > you would expect. Then, you stick the whole thing in a solder pot, and<br>
> > after a few seconds, it's all soldered in place. Add a mechanical<br>
> > brace around the pcb+ribbon for retention. Finally, bend the ribbon<br>
> > 180 degrees so it's going in the right direction.<br>
> ><br>
> > Method 2. similar to above, but instead of using a pcb ribbon, use a<br>
> > hot bar soldering iron tip. Mount the soldering iron in something that<br>
> > looks like an arbor press, put the pcb and ribbon in, press down while<br>
> > feeding solder.<br>
> ><br>
> > Method 3. Everything's through hole, put the wires through the holes,<br>
> > and put the thing in a solder pot; add a mechanical brace.<br>
> ><br>
> > One thing that's kind of questionable is whether the pcb is wide<br>
> > enough to comfortably solder a 32-wire ribbon without microsoldering<br>
> > needed for bridge removal. If not, I considered putting the ribbon on<br>
> > a diagonal across the PCB.<br>
> ><br>
> > Do you think any of that would work? Which method is the best? If<br>
> > yes/no, what's necessary to make it work better? Does anyone have<br>
> > better suggestions?<br>
> ><br>
> > Finally, I'd have to find some sort of enclosure. Basically, I'm<br>
> > trying to make something that will look like the "cartridge" in this:<br>
> ><br>
> > <a href="http://devkits.handheldmuseum.com/IS-CGB-EMU/index.htm">http://devkits.handheldmuseum.com/IS-CGB-EMU/index.htm</a><br>
> ><br>
> > ...but obviously I'd need some sort of cartridge casing. I'd prefer to<br>
> > buy something that's ubiquitous and can be repurposed for what I'm<br>
> > doing. Sadly gameboy cartridges are just too wide for my use, at 60mm<br>
> > (vs 28-30mm being perfect), and I'd like to find something thicker<br>
> > because I'd like to fit the ribbon inside them for mechanical<br>
> > retention. I considered DB-15 connector back shells, but they have<br>
> > those "wings" on the side that the mounting screws go through which I<br>
> > guess I would have to cut off or something, plus idk if these cases<br>
> > would be easy to mount a pcb in. 3d printing is an option, but I'd<br>
> > really like to avoid it, given the cost + maybe they're not as<br>
> > mechanically durable (it's a connector after all). Essentially i'm<br>
> > kind of looking for something shaped like the rectangular container of<br>
> > a PEZ dispenser, so I'd welcome suggestions. It's fine if I have to<br>
> > lop off one of the sides to make an opening.<br>
> ><br>
> > Also, after assembling the extender, I guess it would be nice to have<br>
> > a test harness (pass/fail on all signals indicated by LEDs plus<br>
> > per-wire LEDs).<br>
> ><br>
> > PS does anyone know why PCIE slot connectors (like on motherboards)<br>
> > have those slanted "rasps" on one side? Always found that weird. What<br>
> > are they for? Some sort of retention mechanism? Curious.<br>
> > ________________________________________________________<br>
> > This is the Synth-diy mailing list<br>
> > Submit email to: Synth-diy@synth-diy.org<br>
> > View archive at: <a href="https://synth-diy.org/pipermail/synth-diy/">https://synth-diy.org/pipermail/synth-diy/</a><br>
> > Check your settings at: <a href="https://synth-diy.org/mailman/listinfo/synth-diy">
https://synth-diy.org/mailman/listinfo/synth-diy</a><br>
> > Selling or trading? Use marketplace@synth-diy.org<br>
> ><br>
> ><br>
<br>
________________________________________________________<br>
This is the Synth-diy mailing list<br>
Submit email to: Synth-diy@synth-diy.org<br>
View archive at: <a href="https://synth-diy.org/pipermail/synth-diy/">https://synth-diy.org/pipermail/synth-diy/</a><br>
Check your settings at: <a href="https://synth-diy.org/mailman/listinfo/synth-diy">
https://synth-diy.org/mailman/listinfo/synth-diy</a><br>
Selling or trading? Use marketplace@synth-diy.org<br>
</div>
</span></font></div>
</body>
</html>