Homebrew PCBs

I have posted a photo of two boards one made commercially and one
homebrewed. I am not trying to reproduce the commercially made one
else I would just purchase them. It's the bottom one that I need about
25 more of. I did not make the homebrew so I have no idea how to cut
the card edge that is so critical for success. 

I have never made a pcb but would like to give it a try. Please look
at the photo under Richard M and give me some ideas.

Thanks in advance,

Richard

If it were me, I'd use my scroll saw, but that would go through blades
pretty quickly, unless it's phenolic.  FR4 is hard on saw blades.

If you start by drilling the holes at the bottoms of each cutout (11
big ones and 10 little ones) at least it would be all straight cuts
with the scroll saw.

Has anyone tried a Linoleum tile cutter/shear. I belive they
can be rented from Home Depot.
Del N5ZTW

----- Original Message Follows -----
From: DJ Delorie <dj@...>
To: Homebrew_PCBs@yahoogroups.com
Subject: Re: [Homebrew_PCBs] Cutting a pcb
Date: 29 Aug 2008 15:20:47 -0400

> If it were me, I'd use my scroll saw, but that would go
> through blades pretty quickly, unless it's phenolic.  FR4
> is hard on saw blades.
> 
> If you start by drilling the holes at the bottoms of each
> cutout (11 big ones and 10 little ones) at least it would
> be all straight cuts with the scroll saw.
>

I use a wet tile saw. The advantage with the wet tile saw is that
there is no dust kicked up because of the water. I think I paid about
$70 dollars for mine.


--- In Homebrew_PCBs@yahoogroups.com, "n5ztw@..." <n5ztw@...> wrote:

>
> Has anyone tried a Linoleum tile cutter/shear. I belive they
> can be rented from Home Depot.
> Del N5ZTW
>

On Fri, 29 Aug 2008, n5ztw@... wrote:

> Has anyone tried a Linoleum tile cutter/shear. I belive they
> can be rented from Home Depot.
> Del N5ZTW

Don't use a shear.  Every time I've tried that, I get splinters and the
copper near the edge delaminates.

-- 
David Griffith
dgriffi@...

A: Because it fouls the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?

Best way to cut it out most likely would be a CNC router.  

But most likely you need to do it by hand, so I would say the idea of
drilling the back of each slot with the correct sized drill bit and
then cutting straight cuts with a saw to finish making the slots, saw
by hand with a hacksaw would be one way, Scroll saw or band saw which
would be faster would be good ways,  a table saw with fine tooth
carbide blade or dry/wet diamond blade or the wet tile saw to make the
short straight cuts.  If you go with the table saw cutting dry you
will need a good Vac setup for fine dust.

Yes FR4 is tough on saw blades, and HSS drill bits.


Ben

javaguy11111 wrote:
> I use a wet tile saw. The advantage with the wet tile saw is that
> there is no dust kicked up because of the water. I think I paid about
> $70 dollars for mine.
> 

Those tile cutter saws go through FR4 board material like butter. They 
also leave a nice edge. The copper burrs a little but that normally gets 
etched away.

Hi David,
--- In Homebrew_PCBs@yahoogroups.com, David Griffith <dgriffi@...> 
wrote:
> Don't use a shear.  Every time I've tried that, I get splinters and
> the copper near the edge delaminates.

I've never had a problem with the shear I bought from Harbor Freight.  
This was the way we cut boards in the shop at college and how I cut 
them when I worked at HP Labs.

Must be a problem with the shear you used.  Maybe the blades were dull 
or the gap between the cutting edges was too large.

Regards,
Dennis

I also have a big harbor freight shear that I use for PCB's etc.

On it's first use, cast iron(?) base broke. I was able to weld  it( if 
you are careful, cast iron can be mig
repaired even though many people spout rhetoric otherwise. )  I realized 
that the shearing angle of the cutter
edge was not enough to create a scissoring action to get the cut 
started. I shimmed the table
to increase the angle and it has been a pleasure to use ever since. -Lee

--- In Homebrew_PCBs@yahoogroups.com, Lee Studley <indigo_red@...> wrote:
>
> I also have a big harbor freight shear that I use for PCB's etc.
...
>-Lee
>

I have one of the small shear/breaks that Micro Mark advertises.  They
can be ordered from Harbor Freight I believe, as well.  I don't
remember which I got mine from.  For my modest uses it works very
well.  It cuts FR4 cleanly.  

I do tend to stick to 0.030 and thinner stock.  I can't think of much
reason to use thicker material for most of my projects.  I like to
stick to euro-card sizes like 160 x 100 mm (6.3" x 3.9") and
especially 80 x 100 mm (3.15" x 3.9") for most projects as it reduces
the packaging issues.  But increasingly I use smaller boards than
that.  So flexing is less of an issue than weight and thickness. 
Anyway, for my purposes that little shear has been one of my best
investments.

-- Dave

Is it this benchtop shear at HF you guys are using?
 
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=90757
 
dave mc
 


      

[Non-text portions of this message have been removed]

Dave,
That's a nice unit you have. It looks well made, shouldn't have the 
issue that I had.

Once I shimmed mine, it works great. Did yours have an angle to the 
shear blade built in?

-Lee

Lee, I actually don't own that shear.  I'm just asking if this is the Harbor Freight unit you guys have been talking about.  How much did u pay for yours?
 
dave 


      

[Non-text portions of this message have been removed]

I think that is like the one Dave has.

The one I had to repair is:
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=5907

-Lee

Hi Dave,
--- In Homebrew_PCBs@yahoogroups.com, Dave McD <davemac2@...> wrote:
>
> Lee, I actually don't own that shear.  I'm just asking if this is the
> Harbor Freight unit you guys have been talking about.  How much did u
> pay for yours?

I've been using that shear for several years now.  I see that the price 
has gone up about 40% from when I bought mine.

I've been using it to cut 0.060" CEM-1 and FR-4.  It only handles stock 
up to 10" wide.

Regards,
Dennis