[sdiy] Non-chemical PCB production???

[Merv Thomas]

It's an interesting thought Ray, not sure it lends itself to the kitchen
table though :)



Happy trails . . .


Merv


----- Original Message -----
From: Raymond Wilson <rwilson at fhmsi.com>
To: <synth-diy at dropmix.xs4all.nl>
Sent: Wednesday, August 27, 2003 9:08 PM
Subject: RE: [sdiy] Non-chemical PCB production???


> Non-Chemical PCBS
>
> Is there a process that perhaps involves sand blasting? The pattern would
be laid down with a masking material and then the blasting material would
take off the copper. This might work with a really light-weight copper (1/2
ounce maybe).
>
> I'm certain I have seen some type of dry process and when I remember what
it was I'll write again.
>
> Ray
>
> -----Original Message-----
> From: Merv Thomas [mailto:mervynt at mezzie.demon.co.uk]
> Sent: Wednesday, August 27, 2003 1:54 PM
> To: synth-diy at dropmix.xs4all.nl
> Subject: [sdiy] Non-chemical PCB production???
>
>
> Hey Obe-Wans,
>
> Here's a DIY (not synth specific) question for you concerning the
> non-chemical production of small PCBs. As far as I can tell, the only
> non-chemical method of producing PCBs is to mill contours around traces
and
> lands - I'm sure you've all seen the LKPF, or is it LPKF? - I can never
> remember. It produces nice looking little boards in a reasonable time, but
> it costs a small fortune. So I got to thinking . . . hmmm, could I get
> something close to this using alternative means.
>
> Over last weekend, a swoop on a local car boot sale resulted in me now
being
> the proud owner of an HP7475A pen plotter. You know this puppy is sitting
> there and I'm wondering could this thing be converted into a weapon of
board
> construction?
>
> As a plotter it moves the paper in the Y direction (front to back) while
the
> pen moves along the X axis (side to side). The stepper motors are beefy
> enough to move the couple of ounces a piece of copper clad would weigh,
the
> accuracy is good enough for home brew but I'm not sure how I would make
the
> cutting 'head' to sit in place of a pen . . . I would guess at some sort
of
> little pin chuck and a small, high speed motor arrangement but that's
where
> my engineering knowledge leaves the building.
>
> Anyone ever seen/done anything like this before? Problems I can see: the
> speed of the thing . . . it'd need to be slowed down some to cut rather
than
> draw. I had a look at the controller board - ain't it wierd, the first
thing
> you do to a new piece of kit is take it to bits to see what you got :)
The
> controller is a 4MHz 6802 based thing . . . changing the crystal would
slow
> it down maybe? There's probably a means of slowing it down
programmatically
> too but I've no manual. Another problem is the lack of Z axis control -
the
> HPGL it uses as a control language has pen up/pen down and that's it. The
> actuator that moves the pen up and down is a rather crude affair - a lever
> on the end of a solenoid - but it works.
>
> If there are any engineers out there who could make suggestions, I'd be
> grateful.
>
>
>
>
> Happy trails . . .
>
>
>
> Merv
>
>