PCB Cutting

[Jim Douglas]

How do you guy's do this, I have bare PCB that is 6x6" and I am building a
board of 2x3", what do you use to cut the boards. Before this I used the
paper cutter at the office but got caught and don't want to get yelled at by
the admin again! I am thinking a trip to Home Depot or ??


Thanks!



--



Jim Douglas
www.genesis-software.com
Carrollton, TX USA 75006
Latitude 32.9616
Longitude 96.8916

 

[Bob Eldred]

How do you guy's do this, I have bare PCB that is 6x6" and I am building a
board of 2x3", what do you use to cut the boards. Before this I used the
paper cutter at the office but got caught and don't want to get yelled at by
the admin again! I am thinking a trip to Home Depot or ??

Thanks!
Jim Douglas

For small quantities at home with hand tools, use a hack saw then file the
edges straight and smooth with a file. I use a sheet metal shear but you
probably don't have that available. A band saw also works, use a metal
cutting blade.
Bob

 

[Michael]

Hi,

I score the board on the copper side with an exacto blade and then break
it over a table edge. You need to first make a 2 inch cut making a 2 x 6
and then cut that in half to make a 2 x 3.

I've done that too. Works fine for phenolic boards. Glass boards can require
DEEP scoring, otherwise the bending force required can be high enough to warp
the board. Occasionally I use score-bend on smaller glass boards. Clamping
board in a vise along the score while bending the waste results in less warpage.

I used paper cutter many years ago and had the warp problem described above. A
metal shear works beautifully ..... but don't let the machinists catch you
cutting glass boards on one; I'm told that glass dulls a shear beyond all reason
and that re-sharpening is very expensive.

Not having a shear, a paper cutter, nor a bandsaw, I use a nibbling tool to cut
boards and a file to clean edges afterward. Yes, it's slow and it wastes mucho
board, but it's simple ... and cheap.

 

[Luhan Monat]

How do you guy's do this, I have bare PCB that is 6x6" and I am building a
board of 2x3", what do you use to cut the boards. Before this I used the
paper cutter at the office but got caught and don't want to get yelled at by
the admin again! I am thinking a trip to Home Depot or ??


Thanks!

Hi,

I score the board on the copper side with an exacto blade and then break
it over a table edge. You need to first make a 2 inch cut making a 2 x 6
and then cut that in half to make a 2 x 3.

 

[Rich Webb]

Not having a shear, a paper cutter, nor a bandsaw, I use a nibbling tool to cut
boards and a file to clean edges afterward. Yes, it's slow and it wastes mucho
board, but it's simple ... and cheap.

Try a scroll saw. They're relatively inexpensive and much smaller than
even the smallest bandsaw. A bit hard to make a perfectly straight cut
unless you clamp an edge guide to its table. OTOH, it's useful to make
oddly shaped board and cutouts.

 

[John Popelish]

How do you guy's do this, I have bare PCB that is 6x6" and I am building a
board of 2x3", what do you use to cut the boards. Before this I used the
paper cutter at the office but got caught and don't want to get yelled at by
the admin again! I am thinking a trip to Home Depot or ??

Thanks!

I wonder if anyone here has ever tried a scoring knife (essentially a
single tooth file that you pull along a guide) as a way to make break
lines in PCB material. I think I may have to get one of these and
experiment with it. At least it is fairly easy to resharpen.
http://www.epinions.com/Stanley_Scoring_Knife_Shop_Tools

 

[Karl Uppiano]

I wonder if anyone here has ever tried a scoring knife (essentially a
single tooth file that you pull along a guide) as a way to make break
lines in PCB material. I think I may have to get one of these and
experiment with it. At least it is fairly easy to resharpen.
http://www.epinions.com/Stanley_Scoring_Knife_Shop_Tools

I've always done this. I bought a knife 22 years ago, that was designed for
scoring Formica. It has a carbide tip. A take few swipes with that thing
along a straight-edge, and snap the board along the score. I score the metal
side on single-sided boards. A little sanding smoothes everything right out.
Works much better than sawing freehand.

 

[John Woodgate]

I score the board on the copper side with an exacto blade and then break
it over a table edge. You need to first make a 2 inch cut making a 2 x 6
and then cut that in half to make a 2 x 3.

Drill a very small hole at each end of the score line and score both
sides. The holes ensure that the two scores are closely aligned. This
allows the inside of the bend to compress and the fibres at the outside
are not there to stretch, so the force needed to break along the line is
greatly reduced.

 

[Yukio YANO]

How do you guy's do this, I have bare PCB that is 6x6" and I am building a
board of 2x3", what do you use to cut the boards. Before this I used the
paper cutter at the office but got caught and don't want to get yelled at by
the admin again! I am thinking a trip to Home Depot or ??

I use a "Jeweller's Saw" for smaller projects. A fugitive from my
Lapidary days, perfect for cutting, sawing small objects like circut boards
..

Yukio YANO

 

[James T. White]

How do you guy's do this, I have bare PCB that is 6x6" and I am building a
board of 2x3", what do you use to cut the boards. Before this I used the
paper cutter at the office but got caught and don't want to get yelled at by
the admin again! I am thinking a trip to Home Depot or ??

Jim,

I've used a table top jigsaw with reasonable results. Good points are that the
saw kerf is really small so you don't waste a lot of board material. Bad points
are that FR4 is a bit tough on the blades (at least they are cheap) and the
small blade tends to want to follow the lay of the fiberglass which can make
"straight cuts" difficult at times.

While I've never tried it, I always thought the ideal way to cut PCB material
would be a band saw with a fine tooth, carbide tipped blade. Using a panel
cutting jig so you could clamp the PCB material down and cranking the blade
guide down would make cutting even small PCB's pretty safe.

As I have access to them, I also thought about using a table saw or power miter
with a fine tooth carbide blade but never did due to the amount of waste in the
saw kerf. FR4 is relatively hard and brittle so the chipping might be excessive
even with a fine tooth carbide blade designed for cutting wood. Using a
non-ferrous metal carbide blade with a negative rake angle might solve this but
still removes about 1/8" of material. Table saw safety would dictate using a
panel cutting jig with clamps for the PCB. With the power miter you could just
clamp the PCB down to the saw table.

I'd be interested if you figure out any better ways to cut PCB material. Good
luck and be safe.

 

[John Woodgate]

I read in sci.electronics.design that James T. White

As I have access to them, I also thought about using a table saw or
power miter with a fine tooth carbide blade but never did due to the
amount of waste in the saw kerf.

There was a small PCB maker in UK who used these. The saws were less
than 3 mm thick, but I don't know the thickness. Proper guarding is
essential because the odd blade can disintegrate suddenly.

 

[Jim Thompson]

Jim,

I've used a table top jigsaw with reasonable results. Good points are that the
saw kerf is really small so you don't waste a lot of board material. Bad points
are that FR4 is a bit tough on the blades (at least they are cheap) and the
small blade tends to want to follow the lay of the fiberglass which can make
"straight cuts" difficult at times.

While I've never tried it, I always thought the ideal way to cut PCB material
would be a band saw with a fine tooth, carbide tipped blade. Using a panel
cutting jig so you could clamp the PCB material down and cranking the blade
guide down would make cutting even small PCB's pretty safe.

As I have access to them, I also thought about using a table saw or power miter
with a fine tooth carbide blade but never did due to the amount of waste in the
saw kerf. FR4 is relatively hard and brittle so the chipping might be excessive
even with a fine tooth carbide blade designed for cutting wood. Using a
non-ferrous metal carbide blade with a negative rake angle might solve this but
still removes about 1/8" of material. Table saw safety would dictate using a
panel cutting jig with clamps for the PCB. With the power miter you could just
clamp the PCB down to the saw table.

I'd be interested if you figure out any better ways to cut PCB material. Good
luck and be safe.

Reminds me that friend DOES use a small-bladed, carbide-tipped, table
saw to cut FR4.

I've also, on rare occasions, used a small hand-held rotary tile saw
(Makita) with a diamond blade. Cuts the FR4 cleanly, but tends to
"mooosh" the metal edge when you cut across a ground plane.

...Jim Thompson

 

[Jim Douglas]

I found heavy duty scissors at WalMart for $6.00 that cut right through the
stuff. The are made by RubberMaid, go figure. I went shopping with board
material in hand and tested alot of different products, this was the least
expensive tool I found that worked easily. The ones made for metal did not
do good cutting the PCB material.

I like the score and snap idea and will try that next time, I do have one of
those scoring type knifes! Thanks for all the input!

 

[John Popelish]

I've always done this. I bought a knife 22 years ago, that was designed for
scoring Formica. It has a carbide tip. A take few swipes with that thing
along a straight-edge, and snap the board along the score. I score the metal
side on single-sided boards. A little sanding smoothes everything right out.
Works much better than sawing freehand.

Excellent! I didn't find one with a carbide tip, but just bought one
with a replaceable steel tip.

Now I have to make a cutting board out of a square of plywood with a
strip of laminate glued to the near edge as a board stop and a second,
narrower strip glued on top of that as a guide for the steel square
(set back a bit so that the knife doesn't have to hit it when it
reaches the edge of the board) and I will ready to clamp that to the
work bench the next time I need to cut a board.

 

[JeffM]

I bought a knife 22 years ago, that was designed for scoring Formica.

Excellent! I didn't find one with a carbide tip,
but just bought one with a replaceable steel tip.
John Popelish

http://www.google.com/images?q=carbide-tipped-scribe ?

 

[keith]

Reminds me that friend DOES use a small-bladed, carbide-tipped, table
saw to cut FR4.

What about a table-mounted router (or roto-zip)? AFAIK, the biggies use
such high-speed widgets to cut FR4.

I've also, on rare occasions, used a small hand-held rotary tile saw
(Makita) with a diamond blade. Cuts the FR4 cleanly, but tends to
"mooosh" the metal edge when you cut across a ground plane.

Wrong direction of cut. The bit should "rout", rather than "saw".

 

[Brane2]

keith wrote:

Wrong direction of cut. The bit should "rout", rather than "saw".

I have tried with tabletop scrollsaw from Proxxon-"DSH" (No:28092) and I
can say that it works very well, but not with blades that are meant for
it (No:28740-No:28744).

I had to use harder blades (No:28106) that are pain to mount in the saw,
but they work very well and seem to take FR4 abrasion much better than
serial ones. Quality of the cut is perfect and blade cuts closer to
straight line, so there is much less need for "course corrections".


Regards,


Branko

 

[John Popelish]

http://www.google.com/images?q=carbide-tipped-scribe ?

Those are scribes. A scoring knife has a slight hook and is sharpened
on the handle side of that hook, so it peels a thread of material off
when pulled.

 

[Guy Macon]

I just use my lightsaber to cut PCBs...

I've also, on rare occasions, used a small hand-held rotary tile saw
(Makita) with a diamond blade. Cuts the FR4 cleanly, but tends to
"mooosh" the metal edge when you cut across a ground plane.

This shouldn't be a problem; copper shouldn't be allowed to reach
the edhge of the board.

 

[Barry Lennox]

How do you guy's do this, I have bare PCB that is 6x6" and I am building a
board of 2x3", what do you use to cut the boards. Before this I used the
paper cutter at the office but got caught and don't want to get yelled at by
the admin again! I am thinking a trip to Home Depot or ??

Depends on the size and accuracy required. Options I have used are:
(#3 is the current choice)

1. Scoring both sides with a custom tool, basically a hook in an old
piece of heavy-duty bandsaw blade, then snapping it.

2. A metal shear, but I understand it does the blade no good.

3. A scrollsaw then clean up the edge with a light touch on a belt
sander. Odd shapes I cut out with a cheap air-nibbler.

Barry Lennox