Custom cables - Page 1
Forum section: electronics / projects

author: Rachie5272
author_rank: Regular Contributor
timestamp: January 05, 2016, 02:28:27 am
content: I'm in need of some replacement cables for a project. Right now, four different circuit boards are all connected together using old style 4 mm header pins, long individual wires, and 30+ year oldinsulation displacing female connectors. I'm getting strange problems which can be temporarily solved by wiggling the connectors, and it's time I do something a bit more permanent.Where can I find such cables? Making my own is no longer an option. I've never had good luck with crimp connectors, and my hands simply can't take ~100 crimps.

author: station240
author_rank: Unknown
timestamp: January 05, 2016, 03:50:18 am
content: Would help if you updated your profile so people know which country you live in.

author: ajb
author_rank: Super Contributor
timestamp: January 05, 2016, 04:35:10 am
content: Are you sure the cable assemblies are the problem and not oxidation on the contact mating surfaces? Might be worth a bit of deoxit before investing in new cable assemblies. I'd expect those to go bad before the actual wire termination, as long as it's been done properly. That said, MTA connectors do seem to be a bit finicky to get installed right, although I've mostly seen problems with the 100mil versions.If you do decide that you need to replace the cable assemblies, if you're only talking about ~100 crimps you'll have a hard time farming that out economically. On the other hand, investing in proper tooling won't be cheap either, so you're in a bit of an expensive place unless you're willing to do it yourself with a cheaper generic tool and accept the consequences.And yes, knowing where you are would be a help.

author: ajb
author_rank: Super Contributor
timestamp: January 05, 2016, 04:55:11 am
content: Just to throw it out there, the hand tool for the MTA series isn't too expensive, as proper application tooling goes, at ~US$285 for the handle (TE #58074-1, $103) and applicator head (TE #58247-1, $182) at Digikey. Perversely, if you buy them as a set (TE #58580-1) it's an extra fifty bucks. If you need to do small numbers of these terminations with any frequency it may be a worthwhile investment. The actual application is really easy once you get the hang of it (and as long as you use suitable wire) and takes very little effort. The handle can be used with MTA-100, MTA-156, and several other connector series with suitable interchangeable heads, although some of the heads can get seriously expensive.

author: Rachie5272
author_rank: Regular Contributor
timestamp: January 05, 2016, 07:24:00 pm
content: I'm in the US, if it makes any difference.The problem is the connectors are falling apart. The connection force is very low, and the housing is crumbling. I'd like to replace it with something a bit more substantial.I would hardly consider $500 for a crimping tool economical. Regardless, I cannot physically perform 100 crimps. It's too painful.Might there be a ready-made cable with a 4 mm pitch available somewhere? I don't mind soldering new connectors onto the boards.

author: RobertBG
author_rank: Regular Contributor
timestamp: January 05, 2016, 07:47:21 pm
content: I recently redid something quite similar and I used these herehttp://www.amazon.com/gp/product/B00EZ3QPCU?psc=1&redirect=true&ref_=oh_aui_detailpage_o03_s00as they interlock and fit my app perfect and I conected the boards with old school 40 wire ribbon cable like this herehttp://www.protostack.com/cables/ribbon-cable-40-conductor-1.27mm-pitch-1-meterI only needed to do 2 boards with 32 wires each but for around 10$ it came out quite nice and I cant complain.I'm sure there is other options but the interlocking screw connectors with a small dab of ca glue worked well for me.Once soldered in you'd have to really look to notice that they are individual connectors all interlocked together.

author: helius
author_rank: Super Contributor
timestamp: January 05, 2016, 09:38:44 pm
content: Budget crimp tools take a lot of hand force because they are not designed very well. The better ones have greater mechanical advantage and the breakover is smoother, but they are still intended for light duty. If you did just 25 crimps a day instead of all 100 I bet your hands would thank you.For repetitive duty crimping you should be using a pneumatic tool, which sounds very funny if you think $500 is a lot of money for a tool. As a compromise, some hand crimp tools (like the Daniels HX4) can be laid flat on a bench so you only have to press down with your arm.