Hi robert,
Hadn't thought of using servos for this, just steppers. But that is
an interseting idea. For hobby robots, the servos are modified for
continuous rotation. May just be possible.
The picaxe has built in servo routines and is programmed in BASIC.
Should be easy to hook up a couple of servos to the screws to try it
out.
Myc
--- In Homebrew_PCBs@yahoogroups.com, Robert Hedan
<robert.hedan@v...> wrote:
> 1st: if Eagle doesn't produce a DRILL file, chuck it, I can't
remember if it
> does.
>
> 2nd: if you are going to go into programming, might as well follow
the
> conventional technique using steppers, that way you can copy
existing code,
> same thing for the stepper motor control circuits.
>
> 3rd: you can use the same technique as the others, but drastically
reduce in
> size everything, that in itself will make a LOT of things easier,
for
> example, a 12" rod of aluminium 1/4" thick will be plenty for
you. Same
> thing with the screw, a 1/4" diameter screw would be fine.
>
> 4th: make it all out of wood, REAL easy to cut & drill, using
holes in the
> wood as bushings for the rods.
>
> 5th: polish the aluminium rods slightly, just to give them that
extra shine,
> which translates into less friction (maybe a little dab of
lubricant).
>
>
> Myc, I've looked at a lot of ways to skin this chicken, and if you
have a
> DRILL file, can program PICs, can download the file, can assemble
a basic
> stepper controller like this one:
> <http://www.xavierkamial.com/Videos/Stepper%20Motor%
20Controller.htm>, then
> steppers are the way to go.
>
> Everything is out there for a rinky-dink system, I am just looking
for
> something with a little more ooomph. But for drilling, el-cheapo
steppers
> cost no more than $5. Using servos, you'd be all alone in left
field, with
> probably no samples from the web to get ideas from. With
steppers, you'd
> get pretty darn close to the same precision as a lot of us will
get. The
> only difference is that we will be able to maintain that precision
over a
> longer surface; which you don't need anyways.
>
> Robert
> :)
>
>
>
> -----Message d'origine-----
> De : Homebrew_PCBs@yahoogroups.com
[mailto:Homebrew_PCBs@yahoogroups.com] De
> la part de mycroft2152
> Envoyé : juin 11 2005 20:10
> À : Homebrew_PCBs@yahoogroups.com
> Objet : [Homebrew_PCBs] PCB Driller - Looking for comments
>
>
> Hi Guys,
>
> I've been following the pcb driller discussion. I've been wanting
to
> build one for a long time. But so far the designs seem too
complicated
> or too heavy duty for my needs. And too expensive too. I want to
throw
> out a couple of ideas. I'd appreciate any thoughts on them. (Yes,
> Stefan, I wouldd like yur thoughts too, as long as they don't
include
> anything about a chicken grill. :)
>
> I use EAGLE free version for my boards. That means they are under
3" x
> 4". When drawing the layout, I set EAGLE at a 0.10" grid
(sometimes I
> cheat and go 0.05"). I lay out my components to fit this grid.
This
> works well, but I don't like to manually postion the board for
driling
> on my drill press.
>
> It occurred to me that what I needed was something that could
drill
> holes on a 3" x 4" grid. At 0.10" spacing the grid would be 30 by
40,
> and on 0.05" spacing the grid would be 60 x 80.
>
> I will say, for now, I am not interested in milling, just drilling
> holes. And I would be willing to "pull the handle" on the drill
press.
> My boards are small enough with not too many holes. So what would
it
> take to build a grid based driller.
>
> My first thought was converting an old printer. Attaching a small
> dremel to the print head. I would move the print head across the
page
> stoping at the appropriate spot and the pulls the handle. Afte all
the
> holes on one line were drilled, go to the next line. After all if
you
> cn print a grid of dots on a page, you could move the print heaad
with
> simple commands.
>
> The second idea I had, after looking at all the drivers chps and
> software and discussion about half stepping and choppers, was that
the
> driller could be very light duty due to the size of the board and
the
> coarseness of the steps.
>
> Looking at the old Nasa stepper design, that uses 2 flip flops and
a
> couple of nor gates, I realized that 2 lines would be all that i
> really need for single stepping.
>
> I've been playing woth the PICAXE chips. They are programmed in
basic
> and only need a 3 wire cable for programming. Best of all they
(the
> 08M)are only about $3 each, and has 5 i/o lines.
>
> I've been thinking about using one of these as the controller. If
I
> download the coordinate of the holes, program, The PICAXE could
> convert the coordinates to steps I could position the drill using
just
> 4 of the 5 lines. The 5th line would be an input to start or go to
the
> next holes. A driver chip or transistors would be needed for the
power
> to run the servovs.
>
> For the driller bed, a light duty X-Y table about 6" x 6" could be
> driven by some small servos and screws.
>
> It would be a small, inexpensive, semi automatic pcb driller.
>
> What do you see as the pitfalls with these two ideas?
>
> Myc
>
>
>
>
>
>
>
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and Photos:
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>
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