Working with wire-wrap on 29 April 2009

A couple of images from the discussion and work with wire-wrap at UCC.

Vero Pin

http://harrymc.ucc.asn.au/vero_pin_small.jpg

This image is of the Vero pin which is handy for installing axial leaded components e.g. resistors and radial leaded components e.g. monolithic decoupling capacitors. The blue prototype matrix board material is soft enough to push the shoulder on the pin right into the board (it deforms the copper pad sometimes) to mechanically retain the pin prior to soldering the pin to the copper pad on the board. Component leads can then be fitted into the retaining notch at the top of the pin and soldered in place. The part can then be wire-wrapped and also desoldered and replaced if necessary without disturbing the wraps. Larger image here:

Jiffy Box Hack

http://harrymc.ucc.asn.au/jiffy_hack_small.jpg

This is an idea that I wanted to test. The jiffy boxes are a handy way to mount a prototype board to protect the wire wrap pins but still allow access to signals above for debugging. In the past I had just discarded the jiffy box lid, installed the lid retaining self-tapping screws into corner holes on the board and left the top circuit exposed for test and measurement of the circuit. The image above shows the re-use of the jiffy box cover to protect the prototype further while still retaining side access for cables, connectors, and limited test access. The jiffy box is purchased with the self tapping screws in a bag inside the box. The screws were not installed. Instead, the screw holes were resized with a 2.5mm twist drill shown in a hand mandrel in the foreground. This is the drilling size for an M3 tapered tap (also shown) and the tap and mandrel were used to tap the holes to accept the threaded standoffs like the example in the left foreground. The final prototype pictured has the board now retained with four threaded standoffs and the jiffy cover is retained on those with four M3 by 6mm phillips head metal thread screws.Larger image here:

Materials and Suppliers

Some project prototyping resources (mainly wire wrap)

Soanar Plus mail orders use the Jaycar stock numbers but their mail order prices are cheaper

Jiffy Boxes

http://members.iinet.net.au/~worcom/browse_catalog.php?sort_by_cat=Boxes\Enclosures

Only one size from Jaycar

http://www.jaycar.com.au/productView.asp?ID=HB6004&CATID=5&form=CAT&SUBCATID=343

or Soanar Plus

https://www.soanarplus.com/catalogue_active.jsp?xcid=45&pointerToCurrentItem.category=P6&pointerToCurrentItem.subCategory=BC02&pointerToCurrentItem.subSubCategory=28I

Prototyping Boards

http://au.farnell.com/jsp/search/browse.jsp?N=500001+1000344&Ntk=gensearch_001&Ntt=ROADRUNNER&Ntx=

About the lowest cost for board area

http://au.farnell.com/roadrunner/rrb-006/pcb-oktopad-sngle-sided-233-4x160/dp/8498709

Wire-Wrap Sockets

http://members.iinet.net.au/~worcom/browse_catalog.php?sort_by_cat=IC+Sockets

Nice picture for price comparison

http://au.farnell.com/jsp/search/browse.jsp?N=500001+1001030&Ntk=gensearch_001&Ntt=wire+wrap+socket&Ntx=

Wire-Wrap Wire

http://au.farnell.com/jsp/search/browse.jsp?N=500001+1000112&Ntk=gensearch_001&Ntt=wire+wrap+wire&Ntx=

50 metre rolls are cheaper at RSComponents

http://australia.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=2094805

Purchase by the metre (see P/N WWBL)

http://members.iinet.net.au/~worcom/browse_catalog.php?sort_by_cat=Cables+Misc

Or from Soanar Plus (enter "wire wrap" at Search Products)

https://www.soanarplus.com/

Wire-Wrap Tool from OK International

http://australia.rs-online.com/web/search/searchBrowseAction.html?method=searchProducts&searchTerm=wire+wrap+tool&x=0&y=0

http://au.farnell.com/ok-industries/wsu-2224/tools-pencil-wire-wrap/dp/1046720?in_merch=New Products&MER=i-e1a0-00001002

Vero Wire-Wrap Pins

For leaded resistors, decoupling capacitors etc

http://au.farnell.com/vero/18-0226/terminal-pin-ww-pcb-pk500/dp/1209344

Threaded Spacers

http://members.iinet.net.au/~worcom/browse_catalog.php?sort_by_cat=Spacers+Threaded

Pan Head Screw 3mm X 6mm Philips (M3X06PAN)

[http://members.iinet.net.au/~worcom/browse_catalog.php?sort_by_cat=Small+Screws/Nuts http://members.iinet.net.au/~worcom/browse_catalog.php?sort_by_cat=Small+Screws%2FNuts]

Single-In-Line Machine-Pin Header (D01-9923201)

http://members.iinet.net.au/~worcom/browse_catalog.php?sort_by_cat=Connectors

Nice picture for price comparison

http://au.farnell.com/harwin/d01-9923246/header-1row-32way/dp/1022218

Prototyping SMD Daughter Boards

from Bellin Dynamic Systems Inc.

http://www.beldynsys.com/

available in Australia from Electus

http://www.electusdistribution.com.au/productResults.asp?form=KEYWORD&keywords=Bellin

RS Components has quite a range but generally higher cost

http://australia.rs-online.com/web/search/searchBrowseAction.html?method=retrieveTfg&Ne=4294960157&N=4294959144