Non-Chemical Pin removal for Wirewrap boards

[macfixer01]

hi,
I mentioned this technique I use before, but I just got some more wirewrap boards recently so thought I'd post a few photos. One photo shows some of my favorite tools to use, namely three different sizes of end-cutters and two different pairs of small diagonal cutters. Basically I just break off a sliver of the board at a time, right along the row of pins. The pins fall out or are left hanging ready to pull off with your fingers. Another use for end cutters is removing components such as chips, small relays, and dip switches by just twisting them and breaking the pins off. They're also good for popping the ceramic caps off eproms or cracking open dips to check for gold content.

macfixer01

 

[junkelly]

Those boards sure are pretty. I have not come across anything like them. (Most of my scrap is from personal computers.) I was wondering what type of industry they are used in / where I might be able to find them.

Thanks,
-junkelly

 

[draftinu]

hi mf01, I was curoius how good did those boards yield? (#'s of pins per board) Thanks, draftinu

 

[macfixer01]

Those boards sure are pretty. I have not come across anything like them. (Most of my scrap is from personal computers.) I was wondering what type of industry they are used in / where I might be able to find them.

Thanks,
-junkelly

Wirewrap boards are used in just about any industry for checking and testing new electronic designs. They're typically used for prototyping before having dedicated circuit boards made. However they may be used directly for special jobs where only a few parts are needed so having custom circuit boards drafted and produced isn't economical. The best kind are those where the majority of the pins are just press-fitted into the holes and not soldered. The board you see in the photo is one of two I bought in a lot on Ebay. Wire wrap boards come up for sale on Ebay fairly often but don't always sell cheaply enough to make recovery worthwhile. One seller who consistently tries to charge too much for everything is Panik's Surplus. They will occasionally accept a lower offer though. The best bet is to find a lot of boards to get the per-board cost down and save on shipping costs.

Some custom made backplane boards also use press-fitted pins and so are more easily recovered than those with soldered connectors. See my other post regarding pulling pins. The board in those photos was a huge backplane from some piece of test equipment made by Terradyne. It looked really great but after pulling the pins off an entire board the yield was only about a pound of pins. Luckily for me in the meantime the seller got greedy, and I decided not to buy more than the 4 boards I had already purchased.

macfixer01

 

[macfixer01]

hi mf01, I was curoius how good did those boards yield? (#'s of pins per board) Thanks, draftinu

Those boards in theory yielded about 5000 pins each based on the number of rows and columns. Most were the Augat socket-type pins. That also includes some sets of straight pins near the edge that had been wired over to externally mounted connectors.

macfixer01