LFS: Cheap wire wrap tool and sockets (UK)

[BytesGuy]

Hi everyone,

I am interested in moving a large, but on going design, from a breadboard onto something a bit more permanent so I thought I would give wire wrapping a go.

Problem is I can't find the wire wrap tools for any decent price. Thirty quid for a basic hand one (looks like a screwdriver) seems a bit steep unless I am mistaken. The wire goes pretty cheaply, but again the sockets seem pretty expensive.

If anyone knows of a cheapish source of these that would be great.

Cheers 

[Psi]

Why wirewrap when you can just solder/unsolder?

Have a look on aliexpress/ebay for connectors, im sure you will find something really cheap that should work fine. $5 for 10 etc.

[BytesGuy]

Why wirewrap when you can just solder/unsolder?

Have a look on aliexpress/ebay for connectors, im sure you will find something really cheap that should work fine. $5 for 10 etc.

Partly to try something new and partly because I couldn't get on with doing it on perfboard. I did give it a go, but it just got annoying having to keep desoldering parts especially as I'm not too good at soldering

[tggzzz]

Wirewrap is largely an obsolete technique nowadays. It was fine for LSTTL 30 years ago with 20MHz clocks and 10ns risetime.

It has never been good for analogue: too many long wires/antannae that cross each other randomly => random capacitance => random oscillation.

It isn't much good for modern digital logic, due to their ~1ns edge rates (N.B. bit rate or clock rate is irrelevant). Problems: poor ground planes due to inductance of the GND/VCC wires, ground bounce, socket pins being an electricially significant length => signal integrity problems.

[dom0]

You'd probably more after verowire / road runner like wiring technique.

[MarkL]

You'd probably more after verowire / road runner like wiring technique.

If you do use Verowire be aware that the polyurethane insulation creates toxic fumes when melting through it with solder.  It has to be used in a well ventilated area.

Wire wrapping, although antiquated, is at least safer.

[mtdoc]

I recently learned about wire wrapping from by Tom Igoe at NYU IT physical computing. It seems there still are some good uses for this technique.

I was surprised to find out how expensive the tools were. I  found nothing  worthwhile on eBay. The best I could find was this radio shack tool on Amazon for $20.  I'm not sure if available and for what price in the UK though?

[PaulAm]

I occasionally wirewrap a project if it's suitable.  There's lots of places you wouldn't want to use it, but once in a while it's useful.

For the connection to be dependable, the wire needs to be wrapped around the post with sufficient force for the edge to bite into the wire.   That's why wirewrap posts are square with sharp corners.  Done right, this forms a gas tight joint that is very reliable.  Done wrong, the wire oxidizes and you end up with an unreliable mess with problems that are impossible to track down.  To get good wirewrap joints, you really must use a powered wirewrap gun.  I like the pneumatic guns because they are very small and lightweight.  I think I  paid $5 US for the last one I picked up at a hamfest.  There are also electric guns, both line powered and battery operated.  Avoid the cheap hobby tools; there are enough surplus industrial tools floating around that there's no excuse not to get something that works.

If you use a hand wrap tool, you'll probably get carpal wrist syndrome, the connections will be unreliable and you'll probably join the legions of people who think wirewrap is a bad way to build things.

There was a tool that allowed you to  hand wrap and daisy chain connections using a clever trick to remove the wire insulation as you wrapped.  I would avoid that also (see above for reasons).  Invest in a really good pair of wire strippers and stick with silver plated kynar insulated wire.  Most of it is 30 ga, but I like 26 or 28 better, although it's harder to find.  Get different colors; it helps to keep track of what you're doing.

Before gold went crazy, you could find gold plated wirewrap sockets and posts for reasonable money.  If you end up with tin, beware of tarnish and oxidation.  You can still find good sockets for reasonable money on the surplus market.  Avoid anything from China.

If you wirewrap directly to component leads, solder the joints.  You will not get a reliable connection on a wrap to a round wire.  You used to be able to get 14 and 16 pin headers that plugged into a socket; you could solder the components onto the header and wrap the socket.  You also used to be able to get IC sockets with integrated bypass caps which helped a lot..

[BytesGuy]

Thanks for all the replies guys.

I did look are verowire, but as MarkL points out the fumes are toxic. Although I have a fume extractor, I would rather not use that stuff.

I have found some hand wrap tools for about £15 ($23 ish), but as pointed out by PaulAm a proper tool would make it more reliable.

After adding up all those costs and on reflection, it may be easier to break up my design into several pcbs. Certain parts I know won't change, so I could have those all together neatly on a board (maybe a proper pcb if I find a cheap place) and bring the buses I need out onto a header which could like it to a breadboard or perfboard. Hell, I may even have a look at etching my own boards, there's a first for everything right 

Thanks everyone

[chickenHeadKnob]

I recently learned about wire wrapping from by Tom Igoe at NYU IT physical computing. It seems there still are some good uses for this technique.

I was surprised to find out how expensive the tools were. I  found nothing  worthwhile on eBay. The best I could find was this radio shack tool on Amazon for $20.  I'm not sure if available and for what price in the UK though?

 STAY AWAY from that radio shack crap tool! I used to do wire-wrapping in my job professionally 35+ years ago. Even back then those radio shack tools were very inconsistent in the dimensioning of the internal working surfaces - the active part that contacts the wire. You could get one that produced passable hobby grade wraps  or one which didn't work at all, and if you are a noob you think the fault lay in your-self or wire wrapping in general.

The tool you want is OK industries WSU 30M, this:http://ca.mouser.com/ProductDetail/OK-Industries/WSU-30M/?qs=ZAOMJWF7Iq%2FJ6X%252by%2Fzsyzg%3D%3D

They used to be made in USA to high quality consistency and cost around $9.95 retail! I don't know about today. With those and some practice and skill I could get wraps comparable to best wraps with guns. Various guns were a whole other can of worms, we investigated a few and some are much better than others but you could spend a lifetime figuring that out, don't bother going there. And yes, I tested hand wraps and gun wraps to destruction to check quality. On a production board the only way I know that wrap was good was through muscle memory and external appearance. But to develop that knowledge you need to destroy some practice wraps and see which ones yield with maximum gas-tight force and check the deformations on the post and wire under magnification after you unwrapped it.

The real killer is the price of good sockets and pins and the fact that you need to develop more skill than the magnet wire + solder technique.

[tggzzz]

After adding up all those costs and on reflection, it may be easier to break up my design into several pcbs. Certain parts I know won't change, so I could have those all together neatly on a board (maybe a proper pcb if I find a cheap place) and bring the buses I need out onto a header which could like it to a breadboard or perfboard. Hell, I may even have a look at etching my own boards, there's a first for everything right 

I have been creating circuits for mumble years, using wirewrap, IDC and standard PCB technology with plate-thru hole (PTH) components. I’ve recently been "forced" to use surface mount devices (SMD), and was concerned that it would be too difficult for an amateur using only equipment available at home.

I was wrong; it was easy.

Double-sided PTH boards are remarkably cheap nowadays, starting at £10 for 10 2cm*2cm including delivery. Four layer boards are not much more expensive, but be careful about the stackup if you need impedance-controlled lines. Using those will also enable you to use SMD components, which is surprisingly easy. The laser-toner method is also possible for double-sded boards, and is useful in an "emergency".

For more details of what I used and my experiences, see https://entertaininghacks.wordpress.com/2015/03/25/creating-pcbs-with-surface-mount-components/

[Howardlong]

Having a wire wrapping tool and wire wrap wire is pretty useful in the lab even if you don't do wire wrapping: if you want to probe fine pitch parts, particularly QFN, it allows you to temporarily break out the pins of interest.

I also use wire wrap wire for one-off prototype interconnects, or for augmenting wiring on one-off home made single sided PCB prototypes that should have been double sided, but there were so few tracks on the reverse side it wasn't worth fabbing the reverse side. But I don't wire wrap the ends, I solder them.

Wiring to prototyping pin headers is also useful, for debugger connections for example.

Wire wrapping itself has never really floated my boat. 30 years or so ago it was quite popular, even for limited run production stuff, particularly back plane wiring. The reason I never used it to any great extent was that the wire wrap IC sockets and connectors were really expensive, and you had to use them. When soldering parts you didn't need to buy sockets.

My preferred method was verowire. We didn't know much about the noxious fumes 35 plus years ago. I still have some I occasionally use, but usually use wire wrap wire (soldered rather than wrapped) for point to point wiring nowadays.

Those wire wrap tools are not cheap, but they'll last you a long time. I still use the same one I had from twenty years ago, it works fine, but a decent once isn't cheap. The one from Mouser cited above is also available from Farnell for £34+VAT. Even if you don't use it for wire wrapping, it's the best tool for stripping. I don't use it for cutting the wire as shown in the video, I use normal mini side cutters for that.

Finally wire wrap wire tends to be silver plated so it tins really easily, facilitating easy solder connections.

A reasonably well-equipped electronics lab should have access to a WW tool and wire in my book, even if you don't use it for wire wrapping.

[dom0]

About the fumes of verowire: Continuous exposure is to be avoided. Using a fume extractor or an open window nearby eliminates issues altogether (I am assuming proper breathing technique here. You take in air before melting solder / doing the solder connection and breathe out on the solder fumes.


Notice: The fumes from soldering wire wrap wires are toxic, too (ETFE isolation, usually). They just don't write it on the packaging because the wires are not intended for soldering.

[MarkL]

If you're planning a project of any complexity, by your tenth or twentieth connection you're going to be wondering why you're using all manual tools and techniques.  It can get very laborious measuring, stripping, wrapping... repeat ad nauseum.

I realize the topic here is "cheap", but to make it a more pleasant and fun experience, I'd recommend spending a little more than rock-bottom.  Here's some suggestions (with some specifics):

- Battery powered wrapping gun with backforce and #30 modified-wrap bit. (OK BW-928-BF, bit/sleeve SB30MSH-B/P3032).

- Dedicated unwrapping tool (OK UWD-93-93-R).

- Precision stripper (Claus No-Nik 0.012").

- Selection of pre-cut, pre-stripped #30 wire, colored by length.

- Spool of #30 wire for longer runs.

The tools are available used or NOS on ebay.

Jameco.com has a limited selection of WW sockets.  They're still somewhat expensive, but not the pricing you'll see at the major distributors.  And it's generally not recommended to re-use WW sockets too many times (or not all, according to some people).  Once wrapped, the posts lose their sharp corner edges and subsequent wraps don't bite into the wire as much.

For power and ground, consider using Vector push-in WW pins (T44, T46, T68):

  http://www.vectorelect.com/Catpdf/New%20Page%2073.pdf

with wire laid on top, or with their bus strips (T107):

  http://www.vectorelect.com/Catpdf/New%20Page%2076.pdf

It provides a much lower impedance supply than daisy-chaining #30 from socket to socket.  Example below.

[TopLoser]

Pretty sure I've got a few of these somewhere, boxed and unused.

http://uk.farnell.com/weller/14yb3-a-230/wire-wrap-gun-30-18awg-30w-230v/dp/830008

£50 shipped to you in the UK?

[artag]

That's a great bargain if it has a tip. The cut-strip-wrap tips are high precision devices and don't last a huge while - they don't strip reliably once they have a little wear . I think the OK one is around £150 and I've never seen them surplus (wouldn't trust them used unless super cheap). Note that the wire you use can be crucial for good results too.

Even if you get that, I'd recommend the wsu-30m chickenHeadknob suggests : the automatic won't remove wires so easily (unless the weller has a reverse ?) so you'll also want a hand unwrapper. Nowadays I use them just for the stripper when green-wiring a mod. They do a 'modified wrap' - that's a couple of turns of insulated wire before the contacting turns, which helps with strain relief.

I've found these on ebay recently and bought one. It looks like the real deal but I haven't tried wrapping yet.

http://www.ebay.co.uk/itm/191090954301

[BytesGuy]

Thanks for all the replies, really appreciate the discussion about the topic 

I think the idea of wire wrap will have to wait for me as my wallet has had a hole burnt through it recently! It does still seem like a viable choice if you can get the equipment though, definitely something I will consider in the future. For now I am just going to re-construct the system on a huge breadboard as I have made some tweaks that need testing while neatening up the schematic the other day. I might go back and retry doing it on perfboard, but I'll try and find some better quality stuff which is more akin to proper pcbs. The stuff I have now is dirt cheap and often the copper pads just fling off if reworked too much 

Pretty sure I've got a few of these somewhere, boxed and unused.

http://uk.farnell.com/weller/14yb3-a-230/wire-wrap-gun-30-18awg-30w-230v/dp/830008

£50 shipped to you in the UK?

Thank you for the kind offer, but as explained above I can't afford it right now unfortunately. Next time I get some money in I may well take you up on the offer 

[woodchips]

The wiring method to look for is the Vero Speedwire system. This uses insulation displacement sockets on a ground plane PCB and works well to 25MHz 68020s. I have piles of it but it is the wiring tools that are hard to get now.

If you want to wire wrap then have a look at Quarndon in Derby, they have thousands in stock from decades ago, they will take very low offers on their old stock.