Crimping trouble - Page 1
Forum section: electronics / projects

author: Rasterist
author_rank: Contributor
timestamp: November 16, 2020, 04:46:36 am
content: I need to use these crimp pins (https://www.digikey.com/en/products/detail/jst-sales-america-inc/SVH-41T-P1-1/608760) and I'm finding that my ancient but trusty crimping tool (image attached) is having trouble. The pins are supposed to be good for AWG 16 - 20 wire, but when I use it on AWG 18 wire I get a little flag of metal from one of the wings that's supposed to wrap around the insulation (see another attached image). I don't care about the cosmetic aspect, but that flag catches on the housing, making it much harder to insert the crimped pin. The recommended tool is $466, so I'm really hoping my tool isn't the problem. It works fine on other types of pins, though I haven't tried 16 or 20 gauge wire (I don't have any).So, which is it: the pin, the tool, the wire, the operator, or some combination? Thanks for any tips.

author: Shock
author_rank: Super Contributor
timestamp: November 16, 2020, 05:06:51 am
content: Looks like the crimper, try preforming them in a curve around something solid.

author: coromonadalix
author_rank: Super Contributor
timestamp: November 16, 2020, 05:15:53 am
content: Thats a wrongly put pin in the crimping tool, sometimes the pins aren't sliding well / or aren't well positioned in the crimp tool, just before closing it check if the "pin ears are well inserted"I have this tool, and sometimes if i'm doing them too fast without checking, it happensEDIT, i have a 1k$$ tool and it wil do the same problems if the pins "ears" aren't well positioned too

author: tkamiya
author_rank: Super Contributor
timestamp: November 19, 2020, 01:58:17 pm
content: I'd recommend ratcheting type crimper. There are plenty of inexpensive ones on Amazon and I've been using them successfully. If you are making satellite or surgical robot, I'd recommend factory recommended kind. But for me, it's quite sufficient. To me, it looks like your pins floated out of groove and part of it got flattened in an "in-between" space. I usually use my finger to shape it a bit before setting it in a die.

author: Gregg
author_rank: Super Contributor
timestamp: November 19, 2020, 10:07:06 pm
content: It looks to me like the tool isn’t fully compatible with the crimped part, but satisfactory crimps may be possible with the tool.The ‘ears’ of the part that crimps the insulation may be too long for the way you are using the tool. Some crimp ends are designed to have the ‘ears’ roll over the insulation with a round crimp instead of having them double roll into the insulation. I have found that starting the ‘ears’ to roll over using a larger opening and then finishing on the desired crimp often solves the problem. Other possible solutions are: lightly lubricate the tool, clip the ‘ears shorter’ or to pre bend the ‘ears’ with small pliers. If you are crimping lots of these, a proper tool may save enough time and aggravation to make it worth purchasing.

author: Benta
author_rank: Super Contributor
timestamp: November 19, 2020, 10:49:11 pm
content: I'm curious about the markings on your tool, never seen those before.I suspect that they reflect wire diameter, in which case your tool is outside of the working window of your cable/terminals.16AWG = 1.29 mm20 AWG = 0.81 mmYour smallest aperture is 1.4 mm, which will give the result you're showing.

author: cncjerry
author_rank: Unknown
timestamp: November 21, 2020, 06:40:43 pm
content: I have purchased like 5 or so tools lately trying to get the perfect crimps for not only those but others. I think your tool isn't wide enough, ha,. but there is a package on aliexpress people were purchasing that had a number of inserts and it was maybe $35USD, also came with a wire stripper in a case. It seemed to work well. In my case, for those crimps the tool was a little too wide and it made it difficult to see the wire/crimp alignment. I see no reason to spend that kind of money on a crimper with so many of them out there now. Also, I prefer a non-ratcheting type for those smaller crimps so you can set them perfectly.Jerry

author: tooki
author_rank: Super Contributor
timestamp: November 21, 2020, 11:45:32 pm
content: Quote from: Rasterist on November 16, 2020, 04:46:36 amI’m using a bunch of VH connectors in the Bluetooth speaker kit I’m designing at work, so I’ve been working with these contacts a bit.First of all, I’ll say that if you’ll be doing a lot of these crimps, the real tool will save a lot of time. (We may yet buy one, despite the cost.)The tool for the SVH-41T-P1-1 is the WC-930, which starts at about $400. But unless you need 16AWG compatibility, the tool (WC-160) for the 18-22 AWG contacts (SVH-21T-P1-1) can be had from reichelt.com for far less money, about €250 plus shipping. (To USA, about $330 shipped.)I have tested both the SVH-21T-P1-1 and SVH-41T-P1-1 contacts with 0.75mm2(sliiiigtly smaller than the 0.823mm2of 18AWG) wire, using an unofficial tool, and frankly can’t tell the difference. Perhaps I’ll have to do a more scientific test on it, as I just discovered we have the proper force gauge for that.The tool we are using is the SN-4228B tool I describe here:https://www.eevblog.com/forum/reviews/affordable-crimp-tools-for-small-connectors-(dupont-etc-)/Note that like most JST connectors, the VH have a fairly short crimp area, so most generic crimp tools (like the SN-28B that gets sold for everything under the sun) are unsuitable as the jaws are too long. The 4228B is just narrow enough to actually work with the VH. It’ll take a bit of experimentation to find the correct contact positioning in the jaws to produce good crimps, but you’ll get the hang of it. The advantage of this tool, aside from costing just $16 shipped, is that it’s fairly versatile, in that it also does a decent job on JST XH, JST SM, KF2510 (and other clones of Molex KK 254), and other small connectors.The genuine tools of course have positioners that ensure a perfect crimp every time. (The AMPMODU crimper I describe in the thread linked above is the same base tool as the JST tool, and despite me using it for different contacts than it’s intended for, it’s still afarfaster tool to work with.)