Making your own IDC cables - yay or nay? - Page 1
Forum section: electronics / projects

author: victorhooi
author_rank: Regular Contributor
timestamp: May 14, 2025, 06:33:21 am
content: Hi,What is the general consensus on making your own IDC cables at home?Would they be nearly as reliable as factory cables? Or are there any caveats/potential issues to be aware of?The use case would be for things like:Connecting up HUB75-style LED Matrix panels (Adafruit docs,Sparkfun docs) - I believe these are 2x8 pin IDC. It would be good to get cables at the correct length - and those ribbon cables are a real pain to bundle up, or cable-manage, if there's excess cableRibbon cables needed for theProffieboard test rig/breakout board- I think this is 40-pin IDCRaspberry Pi GPIO cables (40-pin IDC).For tooling, I was thinking of using something like thePananvise 502 Panapress, along with theirPanavise 506 IDC Retrofit Kit for 502. Is that a good choice? Or are there better options?And for the cables/IDC connectors - are there recommend brands/sources for these? Does it make a big difference?I saw that 3M has bothtwisted-pair flat cable, as well asmany different types of flat cable- but I'm not sure which to pick.Thanks,Victor

author: shabaz
author_rank: Frequent Contributor
timestamp: May 14, 2025, 07:01:15 am
content: That doesn't sound like a critical use-case, nor production related, so I can't see any strong reason not to make your own IDC cables even using low-cost equipment if you wish. I make my own for prototypes and one-off personal projects, if I don't have a ready-made cable lying around. I don't use any special equipment; simply a standard workshop vise with soft jaws installed, doesn't have to be a special vise, and never had an issue. However, I also value time, so I try to use other connection methods if possible, just to reduce even prototype cabling time, e.g. flat flex is often a good, low-cost option if not buying a ready-made IDC cable. Doesn't suit all use-cases, of course. If I'm making up a cable then I use a known brand of IDC connector and cable from a distributor. The last thing I want is unreliable, perhaps oxidized connectors from Amazon/AliExpress that would waste time in troubleshooting.Incidentally, you probably can't make up your own cables for some of the popular scenarios (like Raspberry Pi related or typical 20-way cables, etc) for a lower-cost than just purchasing ready-made. The effort alone will chew up any savings even if you did manage to get the connectors and cable cheaper (which is going to be hard at typical distributor prices).

author: Gyro
author_rank: Super Contributor
timestamp: May 14, 2025, 01:09:38 pm
content: I've certainly made up plenty of IDC cables of between 10 and 40 ways using just an ordinary bench vise with a couple of bits of right angle Aluminium extrusion to protect the plastic [Edit: I quickly found them better than soft jaws as they keep the parts of the connector better aligned]. The danger with a big vise is avoiding too much pressure, just wind in until the locking tab at each end clicks home. The wide jaws are helpful for longer connectors.

author: pcprogrammer
author_rank: Super Contributor
timestamp: May 14, 2025, 02:07:22 pm
content: I concur with the other two. I have made plenty cables myself during the many years of being in electronics. A vice is an easy way to do it, but I have also done it with big tongue-and-groove pliers.https://en.wikipedia.org/wiki/Tongue-and-groove_pliersWith those you have to be careful though to not damage things, but when in need it works.

author: coromonadalix
author_rank: Super Contributor
timestamp: May 14, 2025, 02:11:10 pm
content: same here done plenty on led display / led tiles etc ... never got problems, i use a viseor you have specialized pliers to do so,or i use a wide wood block to snap the cable in ...yay

author: ZGoode
author_rank: Frequent Contributor
timestamp: May 14, 2025, 03:22:13 pm
content: IDC cables are pretty hard to mess up, even when using the cheap crappy Aliexpress connectors. I pretty much always make my own unless it's for a production scale quantity, then I outsource. The only time I don't really bother with making my own cables is if there are ready made cheap options (like why would I make my own USB cables).As others have said, it's easy enough with a vise or set of those cheap parallel jaw pliers

author: ajb
author_rank: Super Contributor
timestamp: May 14, 2025, 05:33:34 pm
content: We have the panavise press and accessories for IDC connectors and they're ok, but only worth the money if you're doing production and are willing to add some sort of jig to align the cable -- out of the box, getting the cable end positioned correctly and keeping it straight to the connector is still an entirely manual affair.For occasional use, IMO you want a good set of parallel jaw pliers. The originalKnipex Pliers Wrenchstyle are excellent, but I guess the patent expired recently as there are a ton of clones now. I particularly likethis Lenox pairfor their extra-long jaws. You still have to manually align the cable, but it's pretty easy to lightly hold the connector in the pliers while doing that, and they work equally well for 50-mil pitch and 100-mil pitch connectors.As far as connectors, it doesn't really matter for non-production use. Digikey has 10/20 conductor 25mil pitch cable (for 50mil connectors, like for ARM debug/trace) in 10ft lengths, so that's where I get that. IME, those 50mil connectors tend to wear out with repeated unplugging, so it's nice to be able to replace or reterminate them as needed. 50mil cable (for 100mil connectors) is available all over, and it's fairly easy to split and peel a larger cable apart if you don't want to have to buy a bunch of different conductor counts.

author: shabaz
author_rank: Frequent Contributor
timestamp: May 14, 2025, 11:47:51 pm
content: Quote from: Gyro on May 14, 2025, 01:09:38 pmGood point, I'd forgotten extrusion works really great. By chance I found a photo on my PC, using a cheap alu tool vise, which was quite effective, but needs a lot of force since the handle didn't have as much leverage.And just listening for the clicks as each side finally presses in as you mention.(the orange tape in the photo was just my way to keep things square, it's not necessary since it can be eyeballed, or draw a temporary line with a pen).

author: thm_w
author_rank: Super Contributor
timestamp: May 15, 2025, 12:40:32 am
content: I wouldn't bother with the panavise unless you had a specific other use for it.IDC crimper is $18 on amazon:https://www.amazon.com/Keadic-Pieces-Female-Connector-Connectors/dp/B07WHFWMYQ

author: John B
author_rank: Frequent Contributor
timestamp: May 15, 2025, 04:46:49 am
content: I purchase the connectors from LCSC and then spools of the required flat cable from Element14 (Multicomp Pro brand)That is the most economical way I've found, and worth it for much the same reasons you've listed. When mounting a RPi to a board, I think it best practice to use the shortest leads possible, and doing it with a custom IDC you can get down to 30-35mm.

author: elektryk
author_rank: Regular Contributor
timestamp: May 15, 2025, 07:24:12 am
content: That's not a problem to make those cables at home, worse are those bloody micromatch connectors...