PDA

View Full Version : Wire-wrap product sources



RickNel
November 23rd, 2009, 01:57 PM
Any suggestions on a good source for wire-wrap IC sockets, loose pins and wire?

The online sources I have located so far either will not ship outside US/Canada, or they demand huge minimum order sizes, or they charge 200% premium prices, or they stock a very limited range, or all of the above.

Also, has anyone come across 40-50 pin IDC headers with wire-wrap extended pins? Haven't found them in any catalogs so far.

Maybe there's a brilliant little stockist somewhere who would like one more customer?

Thanks for any ideas...

Rick

Chuck(G)
November 23rd, 2009, 02:14 PM
Digi-Key carries all of the above.

here's an example of a wire-wrap header (http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=CHA40G-ND)

Just search on the Digi-Key site for "wire wrap".

Lou - N2MIY
November 23rd, 2009, 04:37 PM
Rick,

Jameco is a good source. They are a bit more friendly for the home hobbyist. www.jameco.com . The catalog in front of me says they will indeed ship internationally.

But, they don't have the header you want. Digikey will usually have what you want.

It's a bit of a kludge, but you can take wire wrap strip sockets (cf. Jameco p/n 104054) and line up two rows of them. Then, use a normal straight double row male header (cf. Jameco p/n 103342) to be a double male adapter.

Lou

Chuck(G)
November 23rd, 2009, 06:34 PM
If you're wire-wrapping, you way want to consider using push-in socket pins. They usually can be scavenged off of old commercial prototyping boards pretty easily.

I like to use a piece of single-sided FR4 blank PCB and drill my hole pattern into it. The copper on the reverse side acts as a great ground plane and the bare copper wire connecting the pins connecting the decoupling caps carries Vcc.

Here's a shot of a board I'm just starting to stuff--you can see the pins in place for the 40-pin DIP and a 14-pin DIP inserted into installed pins. I used 0.060" FR4, but 0.090" might have been even better:

http://vintage-computer.com/vcforum/attachment.php?attachmentid=2268&stc=1&d=1259029948

RickNel
November 23rd, 2009, 09:30 PM
Thanks again for the advice, guys,

I've put in an order for sockets with Jameco - they are indeed user-friendly.

I'll follow up with those hard-to-get items from DigiKey if we can't find work-arounds - at $10 per header our kludge wire-wrap prototype board could end up more expensive than the total market value of the restored machine:rolleyes:.

Chuck, your construction looks very clean. Those push-in socket pins look great for flexibility and space-saving. Is it possible to get hold of them without starting 20 years ago? Strip sockets mentioned by Lou might offer some similar flexibility. Like pushing two 25pin wire-wrap socket strips through the board, then inserting standard (much cheaper) IDC headers into those strips.

I'm building on one of Andrew Lynch's recent s100 proto-boards with VCC circuits, 100-pin bus connectors, and then just acreage of .1" plated holes - so ground plane is limited to the bottom of the board.

What does the other side of your board look like? Did you scrape off a lot of copper, or do you just burr back around your individual holes?

Rick

Chuck(G)
November 23rd, 2009, 10:53 PM
You can apparently still get the socket pins through DigiKey, but they're gold plated and are pretty costly on an "each" basis. Used prototype boards aren't hard to come by if you can pry them out of the hands of the gold bugs. I've made both Andrew and myself two "pusher" tools to remove pins fairly easily from the boards--just a widget made from 1/4" brass rod, bored to 0.025 in the center and turned down in the lathe to form a "nose" to fit between pins about an inch long. To set the pins, I use an inexpensive (i.e. Harbor Freight special) automatic center punch. Works like a dream.

On the reverse side of the board, I use a 3/16" drill bit glued into a wooden handle. It nicely deburrs and relieves the copper around the hole. For things that aren't socket pins, I remove an "island" of copper around the hole, if required with a 3/32" diamond "core drill".

Holes for the pins are drilled with a #54 drill--for non-pin holes, I use a #57 drill--solid carbide works best, but you could probably get by with HSS.

The foil side is finished up with a tin plating, so it doesn't corrode.

I can take some detail photos if you'd like.

I used to assemble wirewrap boards as if they needed only to hang together for a week or two. But then, I noticed that I was still using boards that I'd assembled more than 20 years ago, so I decided that it was worth doing them right.

monahan_z
November 24th, 2009, 11:02 AM
FWIW, I have over the years shopped with Jameco, DigiKey & Mauser. I find that Jameco are the best. Easy to find things on the web (with pictures of items), great catalogue and at least here in SF bay area lightening fast. They just seem to cater for hobbiest better. I find DigiKey web very frustrating finding things. MTBW

Chuck(G)
November 24th, 2009, 03:47 PM
Don't know where you are, Rick, but Electronics Plus (http://www.electronicplus.com/search-return.asp?search=wire+wrap&Submit=Search) in San Rafael still has a selection of wire-wrap sockets and headers, a bit cheaper than Digi-Key.

RickNel
November 27th, 2009, 01:50 PM
Well, I'm in Australia, so any order attracts significant postage or freight.

I've checked with Electronics Plus and they will post orders economically, so I'll try them first when putting together an order. DigiKey are efficient but more expensive. Andrew Lynch was able to post me 10 prototype boards for around $20 postage, but DigiKey are costing $30 postage for 3 headers and a bag of 100 pins. It adds up pretty fast, but there are very limited local sources where I live.

I agree with John M about DigiKey on-line catalogue. It's a nightmare unless you know pretty well exactly what they happen to call the thing you are looking for. Jameco catalogue is more intuitive.

Rick

Bungo Pony
November 30th, 2009, 02:05 PM
Too bad you didn't ask about a year and a half ago. There was tons of that stuff at my old workplace that got dumped. Lots of IC sockets, wire, and even a large case to store individual lengths of wire. The only thing I walked out with was the paper tape reader that was used to control the wire-wrap machine.

RickNel
December 2nd, 2009, 09:43 PM
There should be a special thread for all those "too bad" stories, and also for the "guess what I just found in the dumpster" stories that most people in this forum would have.

My problem is the years between when something becomes obsolete rubbish and when it later becomes collectable treasure. You cant keep everything, but I'm already regretting throwing out 486 motherboards and monochrome monitors only a few months ago!

At this point, wire-wrap products are more expensive than the ICs that they connect. Not sure why this should be so, since these days they are made in China. It's a weird supply chain.

Chuck(G)
December 3rd, 2009, 09:17 AM
Over the years, I've tossed a lot of "treasure". One can't keep everything and one never knows what will become collectible. (For example, North Korea is starting up a factory to make jeans. Will those be a collectible in 30 years?) 20-20 foresight is impossible.

I suspect the driving force behind some of the wirewrap supplies cost is the market price for gold and silver.

But yeah, it's an odd supply chain. I get some of my components from Thailand. The latest package bore a Thai return address but was mailed from Hongkong.

NobodyIsHere
December 4th, 2009, 06:29 AM
Hi! Well, I've posted on the subject before but in case someone new is reading... PLEASE DON'T THROW AWAY YOUR OLD WIRE WRAP PARTS!

Wire wrap parts are invaluable for making homebrew electronics projects so if you'd like to support us making them please donate/sell your old stock!

Don't let some metal scrapper melt them down for pennies when myself and others could use them to make things the whole community can use and enjoy!

Thanks and have a nice day!

Andrew Lynch

Jim8
December 5th, 2010, 10:27 AM
You can also find cheaper headers at http://cacnelectronics.com/ The price is cheaper but the shipping is higher if you buy small quantity.