EMRFD Message Archive 9922
Message Date From Subject 9922 2014-04-18 13:15:27 w5jhjerry Scoring PCBs to be broken apart Back a while ago there was a discussion on here about cutting PCBs. Bob Kopski mentioned he scored the boards and then "snapped" them apart. Maybe some of you have tried this method? I would like to know what kind of tool was used to do the scoring. Bob if you are reading this, maybe you could join in here.Jerry W5JH"building something without experimenting is just solder practice" 9923 2014-04-18 13:54:24 kerrypwr Re: Scoring PCBs to be broken apart G'day Jerry.
I use either a tile scriber like this;
or an engineer's scriber like this;
A steel rule or square guides the tool on a straight path.
I have a set of bending/filing bars; just two lengths of about 2" x 2" x 1/4" steel angle held in the vise; this allows fast "snapping" and accurate squaring-off.
9924 2014-04-18 16:14:28 John Kolb Re: Scoring PCBs to be broken apart Building engineering prototypes on vectorboard, I always scored the
PCB with an exacto knife, both sides, 4 or 5 passes of the blade
each side. I then usually put the board on a block with a sharp
corner along the cut, and hit the part of the board hanging in the
air with a karate chop. Don't think I'd try that with a 0.062" thick
solid board :)
At 01:15 PM 4/18/2014, Jerry W5JH wrote:
Back a while ago there was a discussion on here about cutting PCBs. Bob Kopski mentioned he scored the boards and then "snapped" them apart. Maybe some of you have tried this method? I would like to know what kind of tool was used to do the scoring. Bob if you are reading this, maybe you could join in here.
9925 2014-04-18 16:24:24 bobtbobbo Re: Scoring PCBs to be broken apart I use a $30 tile saw. I use it the same way one would cut a piece of plywood on a table saw. 9926 2014-04-18 17:55:03 Jerry Haigwood Re: Scoring PCBs to be broken apart
I couldn’t find the orange handle tile scorer but I did find a carbide bit in a pen. I’ll give it a try and see how well it works. I also found some other tile scoring tools that might work. I will need to practice a lot to keep from ruining PCBs. ;-)
"building something without experimenting is just solder practice"
9927 2014-04-18 22:46:45 ashhar_farhan Re: Scoring PCBs to be broken apart I just use a hobby knife. The kind that has sliding blades. What I do is .. Line up a steel scale on the line I want to score, run the blade long the drawn line lightly, keeping the blade pressed against the scale. Then with almost all my body weight, score it along the ridge. If the blade breaks, just slide up the next one. About three 'strong passes cut through enough of the copper and the epoxy fibre to hold it between two wooden blocks and gently pry it back forth to break it off.
- fSent from BlackBerry® on Airtel
9928 2014-04-19 01:21:01 Sandeep Lohia Re: Scoring PCBs to be broken apart On 19/04/2014, firstname.lastname@example.org <email@example.com> wrote:
> I just use a hobby knife.costly hobby knife sets ( BAA-BZZ ) available in VU-Land, is a bakwas
thing, catches rust, not even sharp to cut papers though, even
grinding wth carborundum wheel won't make them sharp enough...
btw nowadays, here I use disposable surgical knife, works great & long
life, guys give it a try once...
(pictures attached) & I get them for free. Hi!
Please encourage recycling, reuse or repairing of E-waste.
░7░3░ ░d░e░ ░V░U░3░S░X░T░
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9929 2014-04-19 05:44:33 bkopski Re: Scoring PCBs to be broken apart
The Sept. 2003 issue of QST contained my article entitled "An Easier Way To Build PC Board Enclosures". This article was later reproduced in the ARRL publication "More QRP Power". The QST article shows the photos in color.
In this article I describe the methods I use to cut PCB board pieces including discussion and photos of some simple fixturing and cutting tools. The techniques shown result in "quality" PCB pieces of uniform size with square corners that make assembly of small enclosures relatively easy to achieve. As an incidental, my other hobby is aeromodeling and I use the same techniques (and fixtures) to cut small wood parts for this application as well!
9930 2014-04-19 09:41:25 Ancel Re: Scoring PCBs to be broken apart Hardware store item called a plexi cutter....basically a carbide tip
scorer. Been using the same one over 10 years now.
9931 2014-04-19 17:01:54 Brooke Clarke Re: Scoring PCBs to be broken apart Hi Jerry:
I spent a few years trying various things that were not practical if you want to do more than a few breaks.
Stuff that didn't work: pen type scribe, small shear break, tin snips, any saw leave a lot of dust and uses up valuable
The thing that really works well is the 12" Bench Top Metal Shear:
> Scoring PCBs to be broken apart
9932 2014-04-19 17:16:53 Mike Collins Re: Scoring PCBs to be broken apart Hi Guys,
I'm with Brooke.....I've scribed and broke a lot of PCB's but finally got smart and found a used Shear on Ebay. If you ever see a KEPRO MS-6 Multi-6 Shear; get it. They were pretty expensive when new, but I got mine pretty cheap (<$100). It can cut circuit boards up to .093 and metals up to .040. I use it all the time now. Really great for cutting strips of .040 aluminum for loop yagi's :))
One of the best tools I have ever bought.
73, Mike Collins KF4BQ
9933 2014-04-19 21:26:50 Sandeep Lohia Re: Scoring PCBs to be broken apart Brooke & Mike,
Today, I too tried with Pressure- Shear
btw, cutting is not uniform as presized wth Surgical Scalpels, might I
need to sharpen? Blade & skills...
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9943 2014-04-23 19:40:25 firstname.lastname@example.org... Re: Scoring PCBs to be broken apart Sandeep jee,
you could even use a simple decolam cutter sold at laminate seller shops for just 25 bucks.
I do use that
9945 2014-04-23 22:42:55 kerrypwr Re: Scoring PCBs to be broken apart For many years I've used a very "old-fashioned" way to make rectangular pieces of PCB.
I used to make printed circuits by a few methods (including direct-plotting to the copper) but, for a long time, I've used "ugly" or, occasionally, "Manhattan" construction; these are fast & simple and components or circuits can be changed easily.
I no longer make PCBs; in fact, only this morning I gave my etch tank etc to a keen young amateur.
I make PCB enclosures sometimes but they don't look as nice as a painted die-cast box.
I sometimes put a PCB box inside a die-cast or plastic case for appearance; this PCB "box" inside a nice plastic instrument case (for an N2PK VNA) is probably the most elaborate that i've made;
For this and other work I use bending/filing bars;
Two lengths of angle aligned by, at each end, a 6mm bolt through the front one and tapped into the rear one.
The fixture is useful to first score & snap; then drop the workpiece in and align one edge with the bars and projecting a little; tighten the vise, give a few strokes with a file until you touch metal and it's the reference edge.
(A bastard-cut file removes a lot of PCB material very quickly).
Rotate 90 degrees and align the reference edge with the engineer's square; leave a small amount protruding and file again.
If the size is unimportant, rotate & file twice more until you have a perfect rectangle; if size is critical, use Jenny or odd-leg calipers to scribe the last two sides, align the scribe-marks with the fixture top, check with the square and file.
This is an ancient technique that I don't think is seen much today.
I have made perfect rectangles in my milling machine but this method is quicker; I think I could make a piece to a nominated size in less time than it took to type this.