Homebrew_PCBs

Someone was asking what types of software people use to manufacture their boards. My machine is not setup for milling. I have only used it for drilling holes in the boards and thus wrote my own program to do so. At the time, I could not get any useable information regarding excellon files or NC drill files, so I wrote the program to accept XY coordinate files. This is very time consuming for complicated boards to produce the original file, but if you are making several of the same board, it is quite efficient. Actually, some CAD programs can output the XY coordinate file and thus most of the work is already done.
Lately, I have given some thought to adding on a conversion program so that the program will accept the NC drill files produced by the standard CAD programs (still in the research stages).

In my research I came across a webpage with a tutorial on what is in a drill file (excellon). I thought others on this group would also be interested in this. It is at http://www.excellon.com/applicationengineering/manuals/program.htm
This site is packed with a lot of information.

-Mike



[Non-text portions of this message have been removed]

--- In Homebrew_PCBs@yahoogroups.com, "Mike Putnam" <circuit@g...>
wrote:

> Someone was asking what types of software people use to manufacture

their boards. My machine is not setup for milling. I have only used
it for drilling holes in the boards and thus wrote my own program to
do so. At the time, I could not get any useable information regarding
excellon files or NC drill files, so I wrote the program to accept XY
coordinate files. This is very time consuming for complicated boards
to produce the original file, but if you are making several of the
same board, it is quite efficient. Actually, some CAD programs can
output the XY coordinate file and thus most of the work is already
done.

> Lately, I have given some thought to adding on a conversion program

so that the program will accept the NC drill files produced by the
standard CAD programs (still in the research stages).

>
> In my research I came across a webpage with a tutorial on what is

in a drill file (excellon). I thought others on this group would also
be interested in this. It is at
http://www.excellon.com/applicationengineering/manuals/program.htm

> This site is packed with a lot of information.
>
> -Mike
>

Although I have not done it for PCB's. I spot points on my CAD
program and can save it as a text file, similar to a DXF, but
readable by a word processor.

I pull it in to Excel to make a G-code file out of it and run Turbo-
CNC to drill holes.

The neat thing is that you can use DIP outlines and just plop caps
and resistors and whatever package you want on the drawing, then just
save the layer with the points that represent the center of the
circle.

Dave

>
>
> [Non-text portions of this message have been removed]

Mike,

I am very interested in this subject since I want to convert several
table top drill-router machines to PC control. Does your machine read
directly from the CAD system or is another program needed to correct
the data? I have experimented with the TurboCNC program and it looks
like it could do the job but needs a little bit of editing to take
straight XY drilling commands. Can you give us more details on how
you run your system? I think everyone in this group has an interest
in this. My weakness is software but I'm willing to learn.

When I ran Excellon CNC-6 machines they would respond to all of these
commands but we used just a few of them. Here is a simple program to
drill several holes:

M48
T01C0.0292
T02C0.035
T03C0.125
%
T01
X01234Y01234
T02
X02Y03
T03
X0456Y0789
M30

The data between the M48 and % tells the machine what drill sizes are
used. For example, T01C0.0292 means tool 1 has a diameter of .0292
inches. XY coordinates between the % and M30 will be drilled and then
the machine stops. Many of these commands are left over from the
paper tape days with the M30 telling the machine to stop and rewind
the tape until it reaches the % command. When the cycle start button
is pushed it starts over. The M48 "header" is normally read once per
job.

The CNC controller also has what is called a "DIAP" page for setting
tool size vs. spindle speed and feedrates. The DIAP page settings can
be in ranges or a setting for every individual tool size can be
entered and the CNC will find the proper speeds and feeds. In the
paper tape days the drill files deleted trailing zeroes to conserve
paper tape and is still used today to conserve CNC memory. For
example, X02Y03 is the same as X020000Y030000. Most Excellon files
are in a 2.4 format, X12.3456 etc. with the decimal point implied.
Many CAD systems get fancy and try to "help" by inserting all kinds
of commands that end up confusing the CNC machine and operator which
results in extra editing time.

Dave mentioned TurboCNC and I hope he can also tell us more about his
experience with this program. I sent an Excellon programming manual
to Dave Kowalczyk who wrote TurboCNC and he said he is considering
writing a version tailored for PCB machines. Maybe he will have this
available in the future. I'm hoping both Mike and Dave can tell us
more about their experience with setting up these machines. Thanks!!

Tom

--- In Homebrew_PCBs@yahoogroups.com, "Mike Putnam" <circuit@g...>
wrote:

> Someone was asking what types of software people use to manufacture

their boards. My machine is not setup for milling. I have only used
it for drilling holes in the boards and thus wrote my own program to
do so. At the time, I could not get any useable information regarding
excellon files or NC drill files, so I wrote the program to accept XY
coordinate files. This is very time consuming for complicated boards
to produce the original file, but if you are making several of the
same board, it is quite efficient. Actually, some CAD programs can
output the XY coordinate file and thus most of the work is already
done.

> Lately, I have given some thought to adding on a conversion program

so that the program will accept the NC drill files produced by the
standard CAD programs (still in the research stages).

>
> In my research I came across a webpage with a tutorial on what is

in a drill file (excellon). I thought others on this group would also
be interested in this. It is at
http://www.excellon.com/applicationengineering/manuals/program.htm

> This site is packed with a lot of information.
>
> -Mike
>
>
>
> [Non-text portions of this message have been removed]

> Dave mentioned TurboCNC and I hope he can also tell us more about his
> experience with this program. I sent an Excellon programming manual
> to Dave Kowalczyk who wrote TurboCNC and he said he is considering
> writing a version tailored for PCB machines. Maybe he will have this
> available in the future. I'm hoping both Mike and Dave can tell us
> more about their experience with setting up these machines. Thanks!!
>

Tom,
<< sorry for the length, but you asked ;-) >>
My program just uses a data file which is standard information in the
"xx","xx","xx" format. The program takes the quote information and loads it
into variables and text boxes. For example, the file would have a particular
name, like a:\plot.dat. You would be able to open this file with a text
editor if you want and it would look like the following:
"0001","0.001","0.015"
"0002","0.015","0.200"
"0003","0.115","0.200"
etc....

This simple example will tell the machine that hole #1 is at 0.001,0.015,
hole #2 is at XY coordinate 0.015,0.2, and hole #3 is at 0.115,0.200. It
does not matter if you have any leading or trailing zeros or if you do not
have any at all. The program recognizes them as numbers. I do not know what
the standard format is from a CAD program, so I cannot comment on the
compatibility. If it is XY coordinate, then it would not take much to make
it adaptable. I also made a template in Microsoft Excel that already added
the hole numbers and quotes and commas so that I could use a basic parser
program to convert it into the DAT file in the example. Once a DAT file is
loaded into the software program, there is a screen where you can edit the
hole locations and re-save the file in case you find that you need to change
a hole location.
Although it sounds somewhat complicated and time consuming in explanation,
it was a fairly quick procedure to write a data file. Keep in mind that all
this was done with lack of information on normal NC drill file outputs and
was a great example of re-inventing the wheel. I would go about this very
different today. In fact, as I mentioned in a previous post, I will make
some changes when time permits.
The information from the DAT file is converted to stepper pulses and
transmitted through the parallel port of the PC to the Drill machine.
-Mike