| Dr.H |
Hello all
Which method do you use to cut your PCB's. Mine are made of a material similar to fibreglass and they are therefore relatively tough.
Methods I have tried:
1. Score with a stanleyknife and then break-takes a long time to do this....
2. Use an angle-grinder (!!)-very effective/fast, but generates lots of dust (!!).
Any other easy, clean methods? |
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| mangrovejack |
A Guillotine is the easiest.
You could also use a hacksaw or a Dremel with cutting disc to cut it. ( I use the Dremel route for my boards and it works fine). Just give it a bit of sandpapering afterwards for a nice straight smooth line (provided you can cut straight with the dremel). |
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| BWRX |
| Score a straight cut line with a utlity knife then cut with a hack saw along the line and sand edge smooth. Kind of a compromise between the score and break and dremel methods. Some dust (not a lot airborne), fairly fast, and a nice straight edge. |
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| AudioWizard |
I concur, a guillotine is the best tool you can use for that.
The problem is that it's a bit expensive. You can try one of those office guillotines, but you'll need to get one that can cut through at least 2 mm of paper. The blade is going to need resharpened on a regular basis, since fiberglass is very hard on tools. I've heard some people use an office guillotine with good success. Of course, if you need a professional tool, there are expensive guillotines that can cut through metal as well. Pretty handy to make metal cases and such.
I've used a Dremel tool with a cutting disc before. It works well, but it's hard to guide it in a perfectly straight line; besides, it generates a lot of dust and it's a bit dangerous too (once, I've had the disc explode while cutting; fortunately I always cut so as not to be in the direction of the disc. The bits hit the wall pretty violently.)
Some people also use some kind of rotating saw (that's normally used to cut ceramic tiling pieces. Apparently it works well, but you'll lose more material since the cutting line is pretty wide. On the other hand, it's fast, tough and you can get one of those for pretty cheap. |
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| mzzj |
Guillotine works best, but is not cheapest possible, maybe around 50usd/eur. Tin scissors are 10 times cheaper alternative, but dont produce as nice results.
For 0.8mm glass-fiber laminate ordinary Fiskars scissors do, but dont stole your wife's precious sewing scissors :D |
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| TwoSpoons |
DON"T use a bandsaw. Fibreglass pcb will destroy a bandsaw blade in seconds.
Unless you have a cheap source of new blades, that is! :D |
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| Wombat2 |
| I've used the guillotine at work (after hours when no one is watching :D ) but the last batch of boards are very tough and I can't hold them firm enough and they "wonder" under the blade and give a rotten cut. I have cut the last couple using a hacksaw and finish off with some emery paper. |
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| K-amps |
| If I try the guillotine or Tin scissors, won't I break the PCB? |
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| AudioWizard |
| One thing to consider if your PCB isn't too large (or doesn't have any heavy component) is to use 0.032" thick boards instead of the standard 0.064". Much easier to cut (and easier on the drilling bits too). You can cut these with no problems with an office guillotine. |
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| AuroraB |
and in what is the shape of the office guillotine after cutting???
Fiber glass is an excellent abrasive,- better than most...
If you don't have any means of guillotine cutting- or similar- scribe the board deeply on both sides with a sharp knife ,- ( Stanley knife..) -break- and file edges clean. --or just use a hack saw and file clean.. and .032 boards is just too flimsy for my taste, for serious work,- in terms of mechanical stability..............
Just believe me--- i have worked with this stuff for over 30 years..... |
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| Wombat2 |
| Good quality guillotines are self sharpening ;) and I work in a Government department - nothing but the best :D |
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| Kenneth Graham |
The cleanup sucks but I've found that a ceramic tile saw produces the best results.
Kenneth |
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| Conrad Hoffman |
As Wombat2 says, guillotine cutters are self sharpening. You need the old fashioned kind with a heavy cast arm- the modern cheap ones are useless. I've used my old Premier for cutting PCBs for years, and it's none the worse for wear. I actually drilled a couple holes in it so I can mount a clamp bar. That way the material doesn't shift, and the fingers are safer.
No matter what you're cutting, try to distribute the cutting over the length of the blade. If all the cutting is done next to the guide, eventually the cutter won't cut a straight line because the lower blade wears nearest the pivot. |
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| NanoFrog |
"DON"T use a bandsaw. Fibreglass pcb will destroy a bandsaw blade in seconds."
Would scoring both sides and using a 16" scroll saw work? (As I recall, blades are inexpensive.)
David. |
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| djQUAN |
a guillotine isn't easily available so I use the dremel + cutting disc method.
lots of dust (use a mask) flying debris of exploding disc (doesn't happen to me anymore, use safety goggles) and draw a line before cutting and you get really straight, clean cuts. |
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| Nordic |
Guilotine is the last thing I would use...
I almost cried when I fetched the first batch of HRII PCBs form the fab house, as their scorer packed up, and they proceeded to guilotene the boards...
Sure it could be filed if it was a once off board, but I was not going to file over 100.. looks like a rat chewed the sides.... In fact I think I can do better with my tin shears (Big scissors made for cutting metal sheets)....
After lots of moaning I now get beatifully scored panels.
Oh and I am one up from you guys in useing dangerous methods...
My table saw for cutting DIY PCB (whe I can't find the shears). |
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| gtforme00 |
| I wonder if a ceramic tile scorer would work well for snapping boards? To be honest, I use a band saw in my prototype shop, and just deal with replacing the blades. I don't honestly notice any shorter life from them. |
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| oshifis |
| I use secateurs (hand pruners, pruning shears) with succes for smaller size PCBs. |
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| OzMikeH |
I used to use a guillotine when I was doing boards. Used to make at least a hundred at a time because we silk screened by hand and cleanup of the etch resistant paint from the screens was difficult.
cuts were nice and neat. We did take care to use the far end of the guillotine. the near end was for fine metal work.
have used tin snips for small boards, the guillotine was best though, you really do need a clamp on it. |
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| KP11520 |
Hello!
WHY do you think we have teeth?
I don't need no tools.
Tools are for Marys! LOL
All kidding aside, I measure 1 or 2 mm larger than I need. I score the copper several passes with a utility knife (new blade) with a straight edge as a guide. If you have a way to clamp the straight edge, even better. Then I cut it with the finest tooth hacksaw blade I can find (I told you I use my teeth) just over the waste side of the line.
Then I turn on my belt sander with a very fine sanding belt and lock the trigger on, I turn it upside down on the bench (mine sits flat) and hold the PCB to the belt on the flat surface at varying pressure until it looks like a professional cut.
Nico, this is what you needed to do with those 100 boards. It goes fast. Just wear a mask as the dust is very fine and can make its way to where it shouldn't be.
The belt sander is one of the best small adjustment tools ever designed!
BTW, I guess I am a Mary but I love my tools!
Regards//Keith |
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| richie00boy |
I used to use a belt sander, but unless you have only a little material to trim away it quickly becomes hard to see where you are meant to stop. Also I could never get it dead square or dead flat.
Now I use a mini circular saw meant for cutting ceramic tiles. I can use a set square to get everything square once I have one good edge. Also make a lot less dust than the belt sander and the edge is perfect no finishing required. |
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| seventenths |
I use a dremel and then clean up the edges with a long machinist file...
7/10 |
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| KP11520 |
At one point in my life I had a custom home remodeling business with my cousin. Between the two of us, there wasn't much we couldn't do and do it well.
We did a lot of Ceramic tile (and I have the knees and back to prove it) and many other specialties. Maybe I should use my wet saw to cut larger PCBs.
Another thought, when we did siding work, there was a siding product called Nailite. It was a fiberglass/plastic siding that emulates hand split shakes. Snips were out of the question. Circular saws with panel blades worked marginally in warm weather and forget it in the cold...shatter!
Then we reversed the blade and it cut slowly like refrigerated butter! No shattering, chipping, losing control of the material or saw, etc. We were even able to use larger toothed carbide blades when on backwards.
Maybe this is applicable to PCBs as well? Maybe this is the answer to the bandsaw too!
Regards//Keith |
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| gmikol |
No need to mount a saw blade backwards...I would imagine that any blade with a 0 or negative hook angle will probably work. Like the ones for cutting Corian or similar materials, I would guess.
--Greg |
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| gtforme00 |
I just gave the reversed band saw blade a shot. Comparing a couple of cuts with the blade normal and backwards, here are the results. The blade has a low hook angle and 14TPI.
Normal
Cut quickly, leaving many shreds of copper on the exit side of material.
Difficult to control a straight line.
Backwards
Cut much more slowly, accompanied by increased smell due to increased heat.
Fewer shreds of copper on exit side, but still too many to consider a finished cut.
Easier to control a straight line.
Conclusion
I will not bother to change the blade around when I cut PCB material.
I always finish my cuts with a belt or disc sander, mounted right next to the band saw. |
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| KP11520 |
Well thank you GTF.
Looks like I am sticking with the knife/hacksaw/beltsander routine.
But tell the truth, the burning fiberglass smelled good, didn't it? Kinda like the smell of napalm in the morning! LOL
This makes sense, the "Nailite" was nowhere near as dense and had no copper. We also hid the cut edge with a self trimming edging called J-Channel. This kind of precision wasn't required.
Regards//Keith |
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| pinkmouse |
| This all sounds like far too much agro. I just score both sides, put the board in the bench vice to the line, and snap the spare off. A little sandpaper, and Robert is your mother's brother. |
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| gtforme00 |
| quote: | Originally posted by pinkmouse
and Robert is your mother's brother. |
now that is creepy, how did you know that?
Burning fiberglass gives me a headache and bad memories of wrecked race cars. |
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| pinkmouse |
| quote: | Originally posted by gtforme00
now that is creepy, how did you know that? |
I'm a moderator, we know everything... :D |
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| Nordic |
Something to keep in mind is the orientation of boards... the side that gets cut first should be the top, and the break away side should be the copper... side. this keeps the board from threading away... so imagine you were using a table saw, you would push the board through coper side to the bottom...
Also with my metal shears there is a diffirence in the boards depending on which side faced up while cutting.... |
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| MikeHunt79 |
| I normally hacksaw it outside - the dust isn't really a problem then. :) |
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| gmikol |
| quote: | Originally posted by gtforme00
I just gave the reversed band saw blade a shot. Comparing a couple of cuts with the blade normal and backwards, here are the results. The blade has a low hook angle and 14TPI.
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Yeesh....I would never run a bandsaw blade backwards. I think KP11520 was talking about reversing a circular saw blade.
No wonder you had so much heat...
--Greg |
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| gmikol |
I've been thinking about this:
http://www.harborfreight.com/cpi/ct...temnumber=93211
It comes with a continuous rim diamond blade, which might not be a bad choice. I understand there are carbide tooth blades out there too for this size.
I just haven't been willing to spend the money to try it out.
--Greg |
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| AuroraB |
Jeez, folks....
Most rotary blades will have a cutting speed thats too high - the laminate can get burnt.
A guillotine is the preferred method, without specialized eqpt.
Otherwise - use Pinkmouse's method - clean up with a file or a sanding block. |
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