On Fri, 01 Oct 2010 17:55:43 -0400, Rick Collins gnuarm.2...@arius.com
wrote:
Oh, I almost forgot, NEVER ask a PhD anything to design PCBs. What
the heck are you thinking???
Are you trolling, or just ignorant?
Peter
--
Peter Brett pe...@peter-b.co.uk
Remote Sensing Research Group
Surrey
John Doty wrote:
On Oct 1, 2010, at 3:55 PM, Rick Collins wrote:
Oh, I almost forgot, NEVER ask a PhD anything to design PCBs. What the
heck are you thinking???
Speaking as a physicist, let me comment.
1. Learning to do a variety of engineering tasks is an important part of an
experimental
Rick Collins wrote:
At most you might want to verify that the data in the XYRS file
matches the Gerber files for a small number of representative parts.
Why do you think you need to verify the results by reverse engineering
the code??? That is the stuff I am talking about over thinking the
Rick Collins wrote:
I'm guessing here, but pick and place machine have to orientate the
part very fast, so it is important that they pick the component from
a principal axis of inertia. It is not always easy to determine where
the axis lies when the component is asymmetric, which is frequent
Steven Michalske wrote:
As you guys continue to debate this... Look at how pcb makes the xyrs data
files. You'll findout that it generates it from the pcb file not the library.
It takes the center of the part from the pins and pads. Then it puts pin 1
somewhere consistent. See the
Rick Collins wrote:
At 05:34 PM 10/1/2010, you wrote:
Rick Collins wrote:
If for whatever reason the designer used 2 different footprints for
the same part occuring
several times on a board, if the footprints are position/rotation
inconsisten...
I have no idea why anyone would do that.
Real
Kai-Martin Knaak wrote:
I think registration marks help a lot. Attached you find my favourite
mark, that regrettably can't be converted into a footprint, because it
contains polygons.
I converted it to a footprint anyway ;-)
Nice work, thanks
At 08:24 AM 10/3/2010, you wrote:
Rick Collins wrote:
I really have no idea how things work in the gEDA/PCB world. With
FreePCB the library has a default orientation for parts and there
is a centroid vector to allow the pin 1 orientation to be set
compatibly with the Gerber files. If you
Rick Collins wrote:
I really don't know what you are talking about. The footprint will
show up on your layout in some orientation. That is the orientation
it will have on the board in the Gerber files. How will the
transformations affect that? What you see is what you get.
This
Rick Collins wrote:
At 08:24 AM 10/3/2010, you wrote:
Rick Collins wrote:
I really have no idea how things work in the gEDA/PCB world. With
FreePCB the library has a default orientation for parts and there is
a centroid vector to allow the pin 1 orientation to be set
compatibly with the
At 06:09 PM 10/3/2010, you wrote:
Rick Collins wrote:
At 08:24 AM 10/3/2010, you wrote:
Rick Collins wrote:
I really have no idea how things work in the gEDA/PCB
world. With FreePCB the library has a default orientation for
parts and there is a centroid vector to allow the pin 1
On Mon, Oct 04, 2010 at 12:09:22AM +0200, Armin Faltl wrote:
Rick Collins wrote:
At 08:24 AM 10/3/2010, you wrote:
Rick Collins wrote:
I really have no idea how things work in the gEDA/PCB world. With
FreePCB the library has a default orientation for parts and there
is a centroid vector
At 10:23 PM 10/3/2010, you wrote:
On Mon, Oct 04, 2010 at 12:09:22AM +0200, Armin Faltl wrote:
Rick Collins wrote:
At 08:24 AM 10/3/2010, you wrote:
Rick Collins wrote:
I really have no idea how things work in the gEDA/PCB world. With
FreePCB the library has a default orientation for parts
FYI gerbv will put the xy file generated by pcb onto your gerbers.
Steve
On Sat, Oct 2, 2010 at 10:42 AM, Steven Michalske smichal...@gmail.com wrote:
As you guys continue to debate this... Look at how pcb makes the xyrs data
files. You'll findout that it generates it from the pcb file not
How does that work? I'd like to try that. I guess it will only work
for an XYRS file generated by PCB. What is that format? Maybe I can
convert my XYRS file into that and check it.
Rick
At 03:56 AM 10/2/2010, you wrote:
FYI gerbv will put the xy file generated by pcb onto your gerbers.
Rick Collins wrote:
Where I want to get us, is being a consistent customer, for whom they
no longer need to think about step b).
From what I can tell, they don't bother with the two steps. The
machine picks the part from the feeder and before placing it, the
operator verifies it is oriented
At 02:47 PM 10/1/2010, you wrote:
Rick Collins wrote:
Where I want to get us, is being a consistent customer, for whom they
no longer need to think about step b).
From what I can tell, they don't bother with the two steps. The
machine picks the part from the feeder and before placing it,
Armin Faltl wrote:
I think registration marks help a lot. Attached you find my favourite
mark, that regrettably can't be converted into a footprint, because it
contains polygons.
I converted it to a footprint anyway ;-)
The central corner can be done with square pads. The pads are exposed
Rick Collins wrote:
If for whatever reason the designer used 2 different footprints for
the same part occuring
several times on a board, if the footprints are position/rotation
inconsisten...
I have no idea why anyone would do that.
Real world example:
PhD student Foo designs some super
At 05:34 PM 10/1/2010, you wrote:
Rick Collins wrote:
If for whatever reason the designer used 2 different footprints for
the same part occuring
several times on a board, if the footprints are position/rotation
inconsisten...
I have no idea why anyone would do that.
Real world example:
PhD
As you guys continue to debate this... Look at how pcb makes the xyrs data
files. You'll findout that it generates it from the pcb file not the library.
It takes the center of the part from the pins and pads. Then it puts pin 1
somewhere consistent. See the source for details.
On Oct 2,
On Sep 30, 2010, at 7:00 AM, Armin Faltl armin.fa...@aon.at wrote:
Yes and No. The number of practical orientations a board and part can have
are very limited,
but to check them, until now a human will be involved. True automation
readines requires
that you can feed the file into the
On Sep 30, 2010, at 7:43 AM, Rick Collins gnuarm.2...@arius.com wrote:
Trouble is that the machine doesn't know how the parts are oriented in the
feeders. Rather than trust that the system works if they get each piece
right, they manually run through an sample of each component type to
On Sep 30, 2010, at 7:43 AM, Rick Collins gnuarm.2...@arius.com wrote:
they manually run through an sample of each component type to make sure it is
placed on the board right. That is all they care about and you only do this
once for a given board. They call this setup and charge a
Steven Michalske wrote:
Would registration marks help with this? Three points forming approximately a
90 degree corner. Would give the ability to detect +x,+y
I know our smt lines heavily depend on these marks.
Steve
I think registration marks help a lot. Attached you find my favourite
Hi,
Rick Collins wrote:
At 04:53 PM 9/28/2010, you wrote:
For all those, that follow the discussion from here or vaguely
remember some other rotations:
Rick Collins wrote:
I had to go through all this some time ago and recently I wanted to
iron out all the difficulties so that the assembly
At 08:38 AM 9/29/2010, you wrote:
Hi,
Rick Collins wrote:
At 04:53 PM 9/28/2010, you wrote:
For all those, that follow the discussion from here or vaguely
remember some other rotations:
Rick Collins wrote:
I had to go through all this some time ago and recently I wanted
to iron out all the
At 07:00 PM 9/29/2010, you wrote:
Rick Collins wrote:
The point I wanted to make is, that there's nothing wrong with our
memories but
that the 2009 version of IPC-7351 contradicts the 2005 version
(probably 2003 as I see now),
maybe in order to conform to EIAJ/ANSI 481C. So this conformance
For all those, that follow the discussion from here or vaguely remember
some other rotations:
Rick Collins wrote:
I had to go through all this some time ago and recently I wanted to
iron out all the difficulties so that the assembly house could use my
XYRS file (location and rotation data)
At 04:53 PM 9/28/2010, you wrote:
For all those, that follow the discussion from here or vaguely
remember some other rotations:
Rick Collins wrote:
I had to go through all this some time ago and recently I wanted to
iron out all the difficulties so that the assembly house could use
my XYRS
I am curious about the reasoning for picking values of design
rules. I have not found the assembly houses to be very useful for
this sort of info. They seem to be willing to work with whatever
they are sent and will only give feedback when something causes real
trouble for them.
At 12:51
Just 10 minutes ago I had my 1st talk with my first assembly house.
Guess what! I'm asked to provide rotation data.
In the other mail I'm currently editing, I'm trying to provide
definitions on
where X- and Y-axis is on a part, including where X+ is on mechanically
doubly symmetrical polar
I had to go through all this some time ago and recently I wanted to
iron out all the difficulties so that the assembly house could use my
XYRS file (location and rotation data) directly without
alteration. That ended up being a fool's errand, but I did learn a
few things. IPC has a standard
Mask should be 3 mil away from copper, and slivers should be at least
6 mil wide. That means, if there's less than 12 mil between pads you
go with a gang-opening.
Where did you get these numbers? Did a manufacturer give this as
their capability limit?
Yes. I've found this to be the
On Mon, Sep 27, 2010 at 9:56 AM, Rick Collins gnuarm.2...@arius.com wrote:
They [Assembly houses]
seem to be willing to work with whatever they are sent and will only give
feedback when something causes real trouble for them.
You have to ask, unfortunately. When you send a new project in to a
I've done that. I go to the assembly house to test my boards so they
can be repaired before I accept delivery and talk with them all the
time. The only complaint they have is a connector that hangs over
the edge of the board which I can't do anything about unfortunately,
it is due to an old
Yes, the old library parts are pre-hires and the pads can be way off
and should be fixed. Thanks!
If we're hand-coding footprints, we could use 0.5mm instead of
1965 and preserve the *meaning* of the units. We lose some
compatibility with older PCBs, but if the purpose is to update the
current
DJ Delorie wrote:
[snip]
All QFN parts should have some visual aids to centering :-) On my last
board, I added four diagonal lines on the silk layer to align each
corner (like a big X), that worked out well.
During modifying library footprints, I found comments about placement lines,
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