Although less popular these days, wire-wrap is still a very relevant, easily reversible solder-free way to assemble (prototype) systems using wire-wrap wire and a wire-wrap tool. This latter tool can be either a hand or powered tool, but all it has to do is retain the stripped wire, fit around the wire-wrapping post and create a snug, oxidation-proof metal-metal contact fit. For the very common 30 AWG (0.25 mm) wire-wrap wire, the Jonard Tools (OK Industries) WSU-30M wire-strip-unwrap tool is pretty much the popular standard. It allows you to strip off insulation, wrap and unwrap connections all with one tool, but the question is whether you can just 3D print a wrap-unwrap tool that’s about as good?
First a note about cost, as although the genuine WSU-30M has risen in cost over the years, it can still be obtained for around $50 from retails like Mouser, while clones of varying quality can be obtained for around $15 from your favorite e-tailer website. From experience, these clones have quite sloppy tolerance, and provide a baseline of where a wrapping tool becomes unusable, as they require some modding to be reliable.
This leads us to three examples of a 3D printed wire-wrap tool with such a wire channel: by [KidSwidden] (based on a Radio Shack unit, apparently), another by [DieKatzchen] and an interesting variation by [4sStylZ]. Naturally, the problem with such fine features is that tolerance matter a lot, with an 0.2 mm nozzle (for FDM printers) recommended, and the use of an SLA printer probably a good idea. It’s also hard to say what kind of wire-wrap connection you are going to get, as there are actually two variants: regular and modified.
The starting guide to wire-wrapping by Sparkfun uses the WSU-30M, which as the name suggests uses modified wire-wrap, which means that part of the wire insulation is wrapped around the bottom of the post, for extra mechanical stability, effectively like strain-relief. A lot of such essential details are covered in this [Nuts and Volts] article which provides an invaluable starting guide to wire-wrapping, including detecting bad wraps.
Naturally, the 3D printed tools will not include a stripper for the wire insulation, so you will have to provide this yourself (PSA: using your teeth is not recommended), and none of these 3D models include an unwrap tool, which may or may not be an issue for you, as careful unwrapping allows you to reuse the wire, which can be useful while debugging or reworking a board.
Top image: completed wire-wrap on a post. (Credit: Sparkfun)
you can braise two thin metal tubes together and print a handle with a hub for a wire spool.
I probably own one of the RadioShack ones. I never did come across a bottom feeder price on a professional wire wrap gun.
I would be surprised if a plastic wire wrap tool lasts more than a few uses.
I broke one, the other that lasted wasn’t too good. I had better luck with plastic pen tube used for ink normally and putting a hole where the wire comes through on side of tube. Simple and somewhat effective but better than 3d printed one but less effective than real one.
Been several decades since I regularly used a wire wrap gun. But I do remember that hand wrap tools do NOT make qualified hermetic gas tight wraps. Qualified wraps last 30 years or more. Only you know how reliable you need the connection to be. I never use hand wrap. Wrap gun only. The hand tool I use is for unwrapping.
Have you looked on Amazon lately? Even the simplest made-in-China manual wire-wrap/unwrap tool will cost you twenty bucks before tax and shipping. I remember before Amazon existed I could buy the same Chinese wrap-tool at the local mom & pop electronic parts store in a blister pack for like six bucks. Today Amazon put the local electronic parts store out of business, then the same Chinese wrap-tool price skyrocketed to twenty bucks plus tax and shipping.
Oh well it could be worse – have you looked at the price of insulin these days?[1]
[One] Price of medicinal insulin in the U.S.
https://en.wikipedia.org/wiki/Insulin_(medication)#Society_and_culture
most of the drug resale outfits got busted for price fixing insulin.
Otoh, a proper.wire wrap will resist some pull because the wire has brazed itself to the pin perhaps 20 or more times and leave evidence dents on the wire when you get it off
the mom and pop stores were done and gone by the time amazon got big enough to make a dent so if your thinking like 20 something years ago then the price today isnt that much more than yesteryear
Fun fact: walmart will sell you Humulin, without a prescription, for $25 a bottle.
Bonus fact: you can get a box of Lantus, with (5) 3ml pens, for $35 a month with a freely avaliable discount card. Yes, even without insurance.
A tube with a slot in it has always worked for me… but I rarely resort to using wire-wrapping. The last time I used it was for making custom coils for vaping with nichrome wire.
The biggest problem with wire wrapping is not with the tools, it is with the socket. The corners of the header pins shown in the picture above are not sharp enough to cause the “cold welding” action that wire wrapping relies upon for reliable connections. And sockets that are suitable for wire wrapping have always been quite expensive, and you need new ones for every project. That was the main reason I never bought a wire wrapping gun.
I made my from big nail. Drill 1-1.5 mm hole, cut slot on side with very thin metal saw blade, wrap bottom with copper wire ~0.3mm, solder copper wire to create ferule, file little bit to reduce diameter, chamfer 1mm hole with bigger drill bit (without chamfer it will not wrap). It worked nicely for price ~1 euro.
i made one out of an old precision screwdriver who’s bit had detatched. i just cut a diagaonal slot to form a hook. it sort of worked, was able to wire wrap magnet wire to header pins and it seemed to break the insulation on its own to make a connection. though idk how long it will last. i dont do much wire wrap and wanted to try it out of curiosity about old technology. i suppose it could be useful if you wanted to make core memory.
Nope.
3d printing is for:
– art.
– prototyping.
– toys.
– temporary fixes, for time sensitive repairs, that will be fixed properly at the FIRST available opportunity.
Anything else is outright abuse and waste.
You can’t say “nope” and then give several examples of why 3D printing a wire wrap tool is valid. Why shouldn’t this be a prototype? Why shouldn’t this be a toy? Why shouldn’t this be a temporary fix [yadda yadda]?
You’ve imagined a scenario where this shouldn’t be used and you’re only disagreeing with that.
Did I get too close?
Here’s what I wrote about a while back regarding what that I learned from this article, that never got through “awaiting moderation”… (Did I get too close to the truth?)
There are so many folk out there using wire-wrapping, still, that there’s numerous folk making 3D models of wirewrapping tools, all choosing the same platform to upload to…?!
Was it Fermi who rather accurately estimated the number of professional piano tuners in Chicago by breaking it down into a bunch of related estimates…? I recall the takeaway being that even if one is off by an order of magnitude in one estimate, its error would be cancelled out by two others’ and ultimately be extremely accurate… (Or maybe he was just a great guesser?)
So… say there are three 3D models of wirewrap tools on Thingieverse… That means, say, that 20 people thought to make and upload wirewrap tools there, (but of course, some saw that it’d already been done, or didn’t have the skill, etc)… Then that means that 1000 people think “hey, I wonder if there’s a wirewrap tool on Thingieverse!” But there are, say, 5 sites like thingieverse, so now we’re talking tens of thousands of folk who, unprompted, think a plastic wirewrap tool might be handy…?
And, then, that must mean there are several million folk who actually still do wirewrapping somewhat regularly?
Nevermind, several more million who, upon finding out they can print their own wirewrapping tool, suddenly find interest in wirewrapping…?
So, now… we’re talking something like one person out of every, say, 10,000, all around the world, is into wirewrapping in 2024?! That doesn’t seem absolutely insane?
AND if that doesn’t… then where are all the videos and project-pages for all these projects?! What cool things are being made that no one posts????
You can use an empty pen ink tube after poking a hole through the side