Cutting circuit boards

[M.Daughtry]

Ok, so I've tried using a thin abrasive cutoff wheel (ala Dremel) on a small
home built "table saw" to cut my PCB material, but it really rags out the
positive coating. It does a tolerable job on the copper, but leaves a lot to
be desired. I'm thinking about investing in a table top type shear to do the
job, but being the cheapskate that I am, I don't want to spend big $'s on
it. I found a good looking unit across the Big Pond in the UK, but cannot
find a comparable unit in the US.
(URL of UK machine):
http://www.megauk.com/cgi-bin/mega/lp.pl?page=http://www.megauk.com/company.
html

About the closest thing I've come across in the US is this:
http://www.amazon.com/exec/obidos/tg/detail/-/B0000DD1GM/sr=1-5/qid=10958122
94/ref=sr_1_5/103-7863735-3310216?%5Fencoding=UTF8&m=A2LM8ZC59IT9RX&n=396061
1&s=merchant&v=glance

Any suggestions or comments are welcome.

--
Best regards,
Mark Daughtry, SR

[Nicholas O. Lindan]

Post by M.Daughtry
Ok, so I've tried using a thin abrasive cutoff wheel (ala Dremel) on a small
home built "table saw" to cut my PCB material, but it really rags out the
positive coating.
Any suggestions or comments are welcome.

A small (~$100) table-top band saw with a fine tooth blade works tolerably
well with phenolic. Use a shop vac(s) for the dust.

The standard one-of method is to score the board on both sides with a
Stanely knife and crack it over a sharp edge.

[Tim V.]

Post by Nicholas O. Lindan
The standard one-of method is to score the board on both sides with a
Stanely knife and crack it over a sharp edge.

Like cutting tile?

[Nicholas O. Lindan]

Post by Tim V.

Post by Nicholas O. Lindan
The standard one-of method is to score the board on both sides with a
Stanely knife and crack it over a sharp edge.

Like cutting tile?

The same principle: put a stress riser in the material (a pinch point,
weak point ...) and then add stress right at the riser.

Fiberglass gives way rather slowly, phenolic is reasonably quick,
blue perf-board goes with a snap. You use gentle even hand pressure
to break the board, not an impact as with tile.

The sharp edge of a table works as a cracking edge. Sometimes it
helps to lay a length of wood over the held piece of board. For small
pieces try a smooth-jaw vice.

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.
Remove spaces etc. to reply: n o lindan at net com dot com
psst.. want to buy an f-stop timer? nolindan.com/da/fstop/

[sycochkn]

Post by Nicholas O. Lindan

Post by M.Daughtry
Ok, so I've tried using a thin abrasive cutoff wheel (ala Dremel) on a small
home built "table saw" to cut my PCB material, but it really rags out the
positive coating.
Any suggestions or comments are welcome.

A small (~$100) table-top band saw with a fine tooth blade works tolerably
well with phenolic. Use a shop vac(s) for the dust.
The standard one-of method is to score the board on both sides with a
Stanely knife and crack it over a sharp edge.
--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.
Remove spaces etc. to reply: n o lindan at net com dot com
psst.. want to buy an f-stop timer? nolindan.com/da/fstop/

Router table?

Bob

[James Varga]

Has anyone ever used a paper guillotine? Not a bit one but something like a
A4 sturdy paper one?

Post by M.Daughtry
Ok, so I've tried using a thin abrasive cutoff wheel (ala Dremel) on a small
home built "table saw" to cut my PCB material, but it really rags out the
positive coating. It does a tolerable job on the copper, but leaves a lot to
be desired. I'm thinking about investing in a table top type shear to do the
job, but being the cheapskate that I am, I don't want to spend big $'s on
it. I found a good looking unit across the Big Pond in the UK, but cannot
find a comparable unit in the US.

http://www.megauk.com/cgi-bin/mega/lp.pl?page=http://www.megauk.com/company.

Post by M.Daughtry
html

http://www.amazon.com/exec/obidos/tg/detail/-/B0000DD1GM/sr=1-5/qid=10958122
94/ref=sr_1_5/103-7863735-3310216?%5Fencoding=UTF8&m=A2LM8ZC59IT9RX&n=396061

Post by M.Daughtry
1&s=merchant&v=glance
Any suggestions or comments are welcome.
--
Best regards,
Mark Daughtry, SR

[Christopher Ott]

Post by M.Daughtry
Ok, so I've tried using a thin abrasive cutoff wheel (ala Dremel) on a small
home built "table saw" to cut my PCB material, but it really rags out the
positive coating. It does a tolerable job on the copper, but leaves a lot to
be desired. I'm thinking about investing in a table top type shear to do the
job, but being the cheapskate that I am, I don't want to spend big $'s on
it. I found a good looking unit across the Big Pond in the UK, but cannot
find a comparable unit in the US.
http://www.megauk.com/cgi-bin/mega/lp.pl?page=http://www.megauk.com/company.
html
http://www.amazon.com/exec/obidos/tg/detail/-/B0000DD1GM/sr=1-5/qid=10958122
94/ref=sr_1_5/103-7863735-3310216?%5Fencoding=UTF8&m=A2LM8ZC59IT9RX&n=396061
1&s=merchant&v=glance
Any suggestions or comments are welcome.
--
Best regards,
Mark Daughtry, SR

I've had my best luck using a tile saw with a diamond blade. Be sure to put
water in the tub. It'll be messy, but it does a good clean job. Harbour
Freight typically has tile saws very cheap.

I've attempted to build a router setup using a Dremil tool and a special bit
(a diamond coated burr especially for FR4, purchased from Travers Tool) but
the bit would grab and pull the board in undesirable directions. I almost
took off my finger(s) more than once. The burrs are expensive, and standard
carbide bits could only cut about 2" of FR4 before having their edges
completely rounded over. The HHS (Dremil wood router bits) were completely
worthless and would shear in half in just a few seconds.

I've used a jigsaw with some success. The blades would round over pretty
quickly (1" - 2" of FR4) but they still cut good enough to do several feet
of cutting before needing replaced.

I've never been able to cut FR4 with a utility knife regardless of how hard
I scored the board.

Chris

[Nicholas O. Lindan]

Post by Christopher Ott
I've never been able to cut FR4 with a utility knife regardless of how hard
I scored the board.

Score heavily twice on each side; you need to be well through the copper.
Place the score over a sharp edge - usually a table top - hold the board to
the table and press down on the free end. With fiberglass you may want to
'loosen' it and then turn the board over and bend the other way to complete
the break.

I can imagine this being a problem if the stock was 2"x12" and you were
cutting off a 1"x12" strip - no leverage - but normally it is like
falling off a bicycle: requires neither brains nor effort.

Fiberglass 'gives' first before coming apart. Phenolic cracks.
Perf-board does either/both.

Clean the edge with a bastard file. A lip in the copper cladding will
interfere with good contact if you are going to expose the board (gee, how do I
know this ??). Clean it off with the file or you will have 'choking':
skinny fuzzy traces, no holes in the pads.