Harvey,
Makes sense. I always like self aligning procedures like this.
Thanks!
Rick
-----Original Message-----
From:
Homebrew_PCBs@yahoogroups.com [mailto:
Homebrew_PCBs@yahoogroups.com]
On Behalf Of Harvey White
Sent: Sunday, January 06, 2013 3:58 PM
To:
Homebrew_PCBs@yahoogroups.comSubject: Re: [Homebrew_PCBs] Re: circuit board drilling question
On Sun, 6 Jan 2013 14:52:25 -0700, you wrote:
>Baxter,
>
>Your insights are very helpful. I had the same problem with too much
>light washing out the beam and too little light not letting me see the
>area and drill bit. I now understand why a laser is needed and a high
>intensity LED is not bright enough. It is too bad the laser beam
>couldn't be narrow enough to match the diameter of the drill. Then
>there would be no question about where it would hit.
Take a small piece of aluminum and drill a hole in it the size of your
expected hole (and drill bit). Put this a little under the board, far
enough below the point of maximum drill penetration. This mask sets the
size of the laser beam on the underside of the board. You can make this an
exact alignment by drilling a hole in a spare piece of board and adjusting
the mask for maximum brightness through the hole.
Harvey
>
>I did think about some electrical way to tell when the drill was
>centered in the hole. But it would require me to move a probe to each
>trace and that would be a PITA. I wonder if something like a sewing
>machine foot could work. It would be a half circle supported by a
>spring arrangement. The goal is to minimize parallax and speed up the
drilling.
>
>Rick
>
>-----Original Message-----
>From: Homebrew_PCBs@yahoogroups.com
>[mailto:Homebrew_PCBs@yahoogroups.com]
>On Behalf Of bebx2000
>Sent: Thursday, January 03, 2013 1:59 PM
>To: Homebrew_PCBs@yahoogroups.com
>Subject: [Homebrew_PCBs] Re: circuit board drilling question
>
>
>
>Rick,
>
>I look down at the board at about 45deg in subdued room lighting. When
>the beam is hitting copper you don't see any thing. when it shines on
>etched areas you see a spot. When it is under a pad with an etched hole
>you will see the spot. Then adjust the board in the horizontal plane
>with tiny movements for the greatest spot intensity; then drill.
>
>This drilling setup is not an original idea. I came across the concept
>from a forum post using a cigar box. I use a Proxxon drill stand with a
>Proxxon hand tool and there wasn't enough room for the cigar box so I
>adapted it to a smaller box (4" x 3" x 1 1/2"). I am using a $5
>dealExtreme red laser module directly hooked to 3 AA cells. A $2
>Staples steel ruler was cut to fit in the bottom of the box and glued.
>The laser is held with a large paper binder clip which is fastened to
>the the ruler with small button Neodymium magnets. The 45 deg mirror
>was fashioned from a piece of 1/2' 90 deg extruded aluminum stock with
>a craft store 1/2" strip mirror glued to one face. The mirror is held
>in place perpendicular to the laser with double sided sticky tape. I
>used magnets to secure the laser to make it easier to adjust it
>relative to the mirror and the hole in the top of the box. This is a real
jury rig, but it seems to work ok.
>
>Baxter
>> I put my drill press rather high and sat on a low chair so my eyes
>> are about even with the pull handle. How do you sit so you can see the
action?
>
>
>
>
>------------------------------------
>
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>
>
>
------------------------------------
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