Cutting FR4 boards

[Monkeh]

I may be a bit late on this thread but reading though it, I can't believe all the flaming hoops people are going through to cut FR4.  Here's how I do it.  Take a straight edge and secure it along the cut line.  Then take your garden variety chisel and run one of the corners along the straight edge.  First pass go lightly to just get a bit of a groove dug in for the tool to follow so it wont jump out on subsequent passes.  Next pass or two press HARD, and dig in for a deep groove.  Now just snap the board material off.  If you want a really finished look on the edge make a pass or two along it with a fine file to knock the fuzz off.  This whole process takes less than a minute, creates virtually no mess, and uses hand tools that most people have laying around the house.

I feel sorry for your chisels.

People, don't do this with chisels worth using on wood.

[ampdoctor]

Oh hell no!  A few passes and you'll need to sharpen the chisel if you're going to use it on wood.  But the point is that an el cheapo chisel or even an old rusty junker you never use that's laying around in the garage is more than adequate for the job.

[Monkeh]

Oh hell no!  A few passes and you'll need to sharpen the chisel if you're going to use it on wood.  But the point is that an el cheapo chisel or even an old rusty junker you never use that's laying around in the garage is more than adequate for the job.

I'm sensible. I have a set of shitty, awful, nasty chisels so crap I had to glue the handles back on, which I use for bad things. Like prying mouldings off. Then I have a set of nice chisels I check the edge on before and after using them.

[GK]

A bit hard not to damage/scratch the photo resist if you're using presensitised board. I bought one of these:

http://www.machineryhouse.com.au/S650

[poptones]

Seems like one of these would work for the size boards he mentioned, and far cheaper.

http://www.ebay.com/itm/Antique-Milton-Bradley-Dandy-Wooden-Guillotine-Paper-Cutter-9-x-9-/330781703942?pt=LH_DefaultDomain_0&hash=item4d04203f06#ht_568wt_1141

What about just having a line of drill holes, and snapping?

[amspire]

A good hand nibbler is great.  I have one of these exact nibbler models and they are brilliant - over 40 years old and still works great:

http://www.ebay.com/itm/SET-OF-TWO-Adel-Tool-Co-Soft-Material-Nibbler-18-GA-047-steel-/120957823482?pt=LH_DefaultDomain_0&hash=item1c29a5e9fa

The drill mounted nibblers are not bad, but a bit more cumbersome to use. Here is an example:

http://www.ebay.com/itm/FIRSTINFO-Power-Drill-Nibbler-Metal-Sheet-Cutter-for-brass-Aluminum-Stainless-/280945835213?pt=Drills&hash=item4169ad3ccd

Richard.

[cellularmitosis]

I've been using this $10 set of shears to cut up copper clad recently (for doing manhattan-style prototyping).

http://www.harborfreight.com/12-inch-power-snips-98091.html

The blades are removable, but unfortunately harbor freight doesn't sell a set of replacement blades.

[nanofrog]

I've been using this $10 set of shears to cut up copper clad recently (for doing manhattan-style prototyping).

http://www.harborfreight.com/12-inch-power-snips-98091.html

The blades are removable, but unfortunately harbor freight doesn't sell a set of replacement blades.

I have a similar pair, but haven't ever tried them for cutting PCB. Will have to give it a try sometime. Thanks for the idea. 

[Rory]

I've had a Kepro 12" PCB shear for years. Still sharp and accurate. It was a very good investment.
Not my pic.


If you were in the USA, I'd recommend looking at these:

Grizzly has a suitable one:
http://www.grizzly.com/products/12-Bench-Shear/T10051

Harbor Freight has one that is mentioned on Adafruit.
http://www.harborfreight.com/8-inch-bench-top-shear-brake-90757.html

[robrenz]

I have the Grizzly shear.  I bought it thinking it would be the typical Chinese quality. Meaning as long as you consider it as a kit that will need a lot of work you will be ok.  It is pretty sad as purchased but it will probably do an ok job on circuit board as purchased.  I spent a whole day in my machine shop adding stiffening bracing material and re machining just about every piece of it along with replacing all the sub par metric fasteners. it works great now.

[notsob]

I have something similar to this, it cuts and bends and rolls. Got it years ago and cannot remember where I got it from.

http://www.machineryhouse.com.au/S648

[Monkeh]

along with replacing all the sub par metric fasteners.

You may want to reword that, as I can't see what them being sane has to do with anything.

[robrenz]

along with replacing all the sub par metric fasteners.

You may want to reword that, as I can't see what them being sane has to do with anything.

I was using "sub par" as a general term for very poor quality.  From the free dictionary "Not measuring up to traditional standards of performance, value, or production."

I also was NOT implying that metric fasteners as a class of fasteners are "sub par"

[Monkeh]

along with replacing all the sub par metric fasteners.

You may want to reword that, as I can't see what them being sane has to do with anything.

I was using "sub par" as a general term for very poor quality.  From the free dictionary "Not measuring up to traditional standards of performance, value, or production."

I also was NOT implying that metric fasteners as a class of fasteners are "sub par"

I figured, it's just the way it's worded.

[Rory]

along with replacing all the sub par metric fasteners.

You may want to reword that, as I can't see what them being sane has to do with anything.

I was using "sub par" as a general term for very poor quality.  From the free dictionary "Not measuring up to traditional standards of performance, value, or production."

I also was NOT implying that metric fasteners as a class of fasteners are "sub par"

I figured, it's just the way it's worded.

It's the way us Yanks talk our gibberish... I read it as he meant, he replaced the poor quality metric hardware. "Sub par" in UK means crazy, nuts, coo-coo?

[Monkeh]

It's the way us Yanks talk our gibberish... I read it as he meant, he replaced the poor quality metric hardware. "Sub par" in UK means crazy, nuts, coo-coo?

No, it means exactly the same thing. Wording it that way, however, implies that being metric has some part of it. One must remember there is no body language, tone, or inflection in text..

[Rory]

It's the way us Yanks talk our gibberish... I read it as he meant, he replaced the poor quality metric hardware. "Sub par" in UK means crazy, nuts, coo-coo?

No, it means exactly the same thing. Wording it that way, however, implies that being metric has some part of it. One must remember there is no body language, tone, or inflection in text..

OK I understand now. Perhaps it has to do with context also, the quality of Harbor Freight and Grizzly equipment is well known. They are very popular here in the USA being readily available and cheap compared to the equipment they are copied from. Grizzly has a fairly decent reputation when it comes to table saws and wood lathes, the company claims to rework the main line products in their own facilities in USA but not all of their equipment goes through the QC process like the high end power tools.

Harbor Freight, on the other hand, well, you get what you pay for, and buyers know this is reflected in the price.

And if you've been following anything Rob has been putting out, you'd know he is too good a machinist to disparage hardware simply because it is metric.

[Monkeh]

And if you've been following anything Rob has been putting out, you'd know he is too good a machinist to disparage hardware simply because it is metric.

I'm aware of this. Others may not be, which is why I simply suggested changing the ambiguous wording.

[pickle9000]

I have one of these,

http://www.harborfreight.com/8-inch-bench-top-shear-brake-90757.html

Mine is about 10 years old and cost 60 bucks new, Busy Bee Tools (in Canada) doesn't carry them any more. It's a great tool to have and not just for cutting pcbs. It is a brake as well.

[robrenz]

I would say Monkeh made a good call considering the volatility of threads that debate the "imperial vs metric" topics

[peter.mitchell]

I just get a block of timber, put my boards on it, put some nails in the mounting holes and tap them in. Put the stack in the circular saw and cut. Just gotta make sure there is enough space between boards on the  "panel" to account for the kerf. The saw is a pretty decent one, can use many types of blades, has adjustable speed (for tiles/masonry, wood, abrasive steel and cold cut steel), it also came with a mount for a couple of dispensing tubes, for water, air or oil. I use an abrasive wheel with the water dispenser.

[Dave Turner]

Have a look at W2AEW's suggestions.



Incidentally if your board is double sided note that you have to score both sides.

[nanofrog]

Have a look at W2AEW's suggestions.

I like the scroll saw method (he called it a jig saw), as it's quick and easy.  Also already had it, which was a nice plus. 

[Dave Turner]

If not in the possession of a guillotine for straight cuts I'd prefer the craft knife, straight edge and clamp method. With practice it's less wastage, gives a cleaner break and no dust.

[Arp]

I've cut up literally 1000's of PCBs using a band-saw. The cut is about 40thou using a thin metal blade,
which will last 100M of cut or so.

This probably depends a lot on the material of the blade.
I have one of these Proxxon bench saws, and tried to use it for cutting a piece of prototyping FR4.
The stock blade was completely blunted after ~3cm of cutting 

http://www.proxxon.com/eng/html/27006.php

I use the Proxxon KS115.

Modified these cheap discs with a 10 mm diamond drill bit:

http://www.ebay.com/itm/10-pcs-50mm-2-inch-Diamond-coated-rotary-cutting-cut-off-blade-wheels-disc-/121127997238?pt=LH_DefaultDomain_0&hash=item1c33ca8f36

They are pretty thin so it doesn't need much work. Have yet to wear one out, and maybe done a 1-2 meters of total cutting.