OK on the quiet vacuum and the dust scoop, Harvey.
I looked at the drill press/camera device and found it
interesting. I downloaded the info and will take a good
look at it. Thanks!
Charlie
>Thanks for the advice Harvey...I'll look into the methods
>you
suggested.
>I have a very quiet vacuum, so it is on all the time with an air
scoop
to remove the board swarf.
>
>Yeah, the swarf from the board is a problem...have a
vacuum
>at hand, but some kind of automatic "vac as you go"
method
>would be best.
I have a very crude (but quite workable) air scoop made from the
crevice tool of a regular vacuum. Works surprisingly well.
You can get very very close with a vertical alignment drill press, and
not so close when you have to match the hole at an extreme angle.
Harvey
>
>Charlie
>
>mosaicmerc@...
[Homebrew_PCBs]"
>>> I use resharpened carbide in my dremel 395 with
1/8" shanks for PCB
>>> work. They work fine....I go down to around
0.31 mm. I can go smaller
>>> but bit breaking happens every 10
holes or so.
>>
>>>Me too, but I rarely break bits since I
switched to a home-brew drill
>>stand that seems to eliminate any "hand
wobble" from causing breakage.
>>
>>>My CNC machine can
drill lots of holes with resharpened carbide and a
>>Grizzly
pencil-style die grinder.
>>
>>>Perhaps rigidity in the
holding of the dremel is more important than
>>runout? Or at least,
∗lack∗ of rigidity is more common as a cause of
>>breakage?
>>
>>>Posted by: DJ Delorie <
href="mailto:dj@...">dj@...>
>>
>>I
purchased a drill stand from Sears quite a few years ago. It
>>had
run-out, but I cured that by tightening/adjusting all the
>>critical
screws that caused the run-out. Works just fine since
>>then, and no
breakage of carbide drill bits either. I'm using
>>a Dremmel with the
collets, mostly the 1/8" size. I gotta say
>>though that the stand sure
is CHEAPLY made....lots of plastic
>>parts. Once when using the stand,
the sector gear that raises/lowers
>>the drill carriage broke!! (Cheap
plastic!!!) I made another gear out
>>of some thick aluminum and it's
been good ever since.
>>
>>My bigest problem is positioning
the PC board on the exact
>>center of the pads. My drilling is close
but most of the time not
>>dead-on especially if the pad's center holes
don't get etched
>>away. I installed a 12v light bulb under the stand
and
>>that helps to illuminate the pad locations, but
still.....
>
>You're looking at parallax as a problem. You're not
looking straight
>down on where the hole should be.
>
>One
option would be to put a webcam under the board, illuminate the
>bottom,
and drill from there. Your only problem would be the swarf
>from the
board.
>
>Mine is upside down, with the camera above and the drill
from the
>bottom. It's a bit more complicated mechanically, and involves
some
>programming and a stepper motor.
>
>However, a top drill
press with a bottom view (and a vacuum sucking
>off the swarf) would be a
possible good idea.
>
>You drill from the side where the pads are.
>
>A good set of movable crosshairs (if there's any play) and a
test hole
>when the drill is changed ought to get you very very
close.
>
>Harvey
>
>>
>>On my drill stand I
made a larger platform out of some
>>1/8" smooth hardboard so I could
use a homebrew
>>moveable fence that clamps to the edges of the
hardboard.
>>Using that sure made drilling easy when I needed to
neatly drill
>>holes in a row like for IC's.
>>
>>Charlie
>
>