Total newbie to CNC.  In fact I don't even own a machine yet.   I am considering buying one of those cheap CNC 3020 routers on eBay.   Mainlly to etch PCBs.   I figure it will make a really cool toy.

I saw some articles on etching PCBs.   A really important step is to get the PCB really flat.   One trick to do this is to super glue the PCB to an aluminum plate (a little acetone and the PCB is free).  But would this make drilling an issue?  I think the people that do this, work with surface mount parts which require no drilling.

Is it possible to do this operation in two steps using Mach3?  Is there any way to set a "home position"  so the routing job matches up to the  drilling job?

I would imagine there would be similar issues with double sided boards.


 

I make quite a lot of relatively small and simple pcb’s – some are held using a vacuum table (holes drilled manually after engraving) some are held with double sided tape to the spoil board (with engraving and drilling as two separate toolpath operations) I have never seen the super glue idea but it sounds good.

For small batch runs I make a jig which holds the board but there are many different ways of pcb point location for double sided work etc.

This thread may be of interest. http://www.machsupport.com/forum/index.php/topic,22932.0.html

Tweakie.

Thanks Tweak, that thread shows how to do 2 sided PCBs which is wonderful.  What I was looking for was a way to mill using the aluminum plate / super glue method then switching to a spoil board for drilling (or visa versa).    Is it possible to do this?    If so how would you keep things lind up in the switch?   

I suppose the easiest way would be to have a straight edge fixed to the spoil board so the pcb always aligns square with the machine then have a small through hole in the pcb (perhaps near the centre) and use this as the datum (X0 , Y0) for each side toolpath.

Tweakie.

I have used super glue to hold SMALL stuff when engraving. Just depends on what your doing.  For small holes / very light high speed
end milling should work. Best to test and see  for what you are doing. Used carpet tape also, PITA to get off sometimes.

RICH