Homebrew PCBs

What is the most common size dill bit used in PCB work ?

John I noticed that in your G-code that you used the same size bit 
for both millimg and drilling  what size was it .I was thinking of 
useing a 1/16 bit but the machine I can use has a 3/32 as the 
smallest right now . I think that is way to big .I was thinking of 
useing a #55 dill size for the paths ( 1/16 is bigger I know ) and 
#60 for the mount points these may be to small any thoughts (John)
(Group)

What is the best to use   By the way I am makeing the 3amp driver 
from Steve Blackmore on his site . I have almost completed the files 
meeded to make the G-code . Now I know why G-code is so protected if 
you make one up .

John Brauweiler

Hi,
   Don't get confused. The milling bit only makes a tiny starting
hole in each pad. A mechanical etching bit is tiny on the end. Some
people put a tiny circle in their drawings. This lets the acid create
a starting hole for the drill. I used the same concept in my DXF file.
The depth of the starting hole is only as deep as you mill the board.
   I then drill my board with a N0.60 bit. I know this is a little
large but I have found this lets me put in all my parts with one
size hole.

                                             John  
   
                                            



--- In Homebrew_PCBs@y..., "marble_h" <marble_h@y...> wrote:
> What is the most common size dill bit used in PCB work ?
> 
> John I noticed that in your G-code that you used the same size bit 
> for both millimg and drilling  what size was it .I was thinking of 
> useing a 1/16 bit but the machine I can use has a 3/32 as the 
> smallest right now . I think that is way to big .I was thinking of 
> useing a #55 dill size for the paths ( 1/16 is bigger I know ) and 
> #60 for the mount points these may be to small any thoughts (John)
> (Group)
> 
> What is the best to use   By the way I am makeing the 3amp driver 
> from Steve Blackmore on his site . I have almost completed the 
files 
> meeded to make the G-code . Now I know why G-code is so protected 
if 

> you make one up .
> 
> John Brauweiler

--- marble_h <marble_h@...> wrote:

> What is the best to use   By the way I am makeing the 3amp driver
> from Steve Blackmore on his site . I have almost completed the
> files 
> meeded to make the G-code . Now I know why G-code is so protected
> if you make one up .

What? What? Who? Where?

This one?

http://www.pilotltd.net/cnc.htm

Doncha love Google? Time to add this one to the bookmarks.

Steve Greenfield

__________________________________________________
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http://taxes.yahoo.com/

Hi,
   I answered this one but it got lost in Yahoo. The DXF file
causes the Milling Bit to put a tiny dot in each pad. The dot
is only as deep as you mill. This dot is then drilled out with
a number 60 bit. I use a No. 60 because it lets me put all my
parts in with one size hole.
    When you etch with acid you can put a tiny circle in each pad
of your drawing. This puts in a starter hole during etching. The
hole is only through the copper.
     If you mill using a drill bit make sure it is CARBIDE! HSS
will not mill for long. PCB material is like sandpaper to a bit.


                                        John  



--- In Homebrew_PCBs@y..., "marble_h" <marble_h@y...> wrote:
> What is the most common size dill bit used in PCB work ?
> 
> John I noticed that in your G-code that you used the same size bit 
> for both millimg and drilling  what size was it .I was thinking of 
> useing a 1/16 bit but the machine I can use has a 3/32 as the 
> smallest right now . I think that is way to big .I was thinking of 
> useing a #55 dill size for the paths ( 1/16 is bigger I know ) and 
> #60 for the mount points these may be to small any thoughts (John)
> (Group)
> 
> What is the best to use   By the way I am makeing the 3amp driver 
> from Steve Blackmore on his site . I have almost completed the 
files 
> meeded to make the G-code . Now I know why G-code is so protected 
if 

> you make one up .
> 
> John Brauweiler

--- In Homebrew_PCBs@y..., Steve Greenfield <alienrelics@y...> wrote:
> --- marble_h <marble_h@y...> wrote:
> 
> > What is the best to use   By the way I am makeing the 3amp driver
> > from Steve Blackmore on his site . I have almost completed the
> > files 
> > meeded to make the G-code . Now I know why G-code is so protected
> > if you make one up .
> 
> What? What? Who? Where?
> 
> This one?
> 
> http://www.pilotltd.net/cnc.htm
> 
> Doncha love Google? Time to add this one to the bookmarks.
> 
> Steve Greenfield

Yes, thats the site.

mike

In a message dated 18-Apr-02 11:00:31 Central Daylight Time, 
marble_h@yahoo.com writes:


> I was thinking of 
> useing a 1/16 bit but the machine I can use has a 3/32 as the 
> smallest right now . I think that is way to big .I was thinking of 
> useing a #55 dill size for the paths ( 1/16 is bigger I know ) and 
> #60 for the mount points these may be to small any thoughts 

John:  In MY opinion, even 1/16" is much too big for MOST things, other than, 
maybe, the leads of some TO-220 and TO-208 devices, or 2 W. (U.S. made!) 
resistors, etc.  

For "most leaded devices in the DIP-IC and ¼ W. R. range", #56 is small 
enough that the gap between the lead and the pad - the space "flying solder" 
must span - is acceptable, yet large enough to accept on up to, say, ½ W. R's 
and "big capacitor leads", etc.  

For some "tiny stuff" I have gone as small as #72, but this is really rare 
and difficult.  #60 ought to be as small as any hobbiest should ever have to 
go.  Remember:  It is vastly easier to RE-DRILL with a larger bit than to 
UN-DRILL with a smaller one!

Jan Rowland


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