PADS, ASCII output question: Scale factor?

Hawker wrote:

Joerg,
There is a way to interpret that, but I use an unsupported script under
VB scripts in Layout to make my X-Y sheet. Some 3rd party programs that
some assemblers use can directly read a PADS ASCII file, that is why
they asked for that, but apparently yours cannot so use the built in
script under VB scripts.
Click to expand...
My layouter wants to do something like that next time. He said he has
some conversion routines he can try out. Anyhow, too late now as the
boards are out of reflow and the remaining specialty items are being
hand-soldered on. The first batch is actually already on the UPS truck.


BTW I thought you were on the PADS ListServer as well. Probably get
better answers there than here.
Click to expand...
Sorry but I am not. Only on the Cadsoft Eagle server because I switched
to that software (but I don't do layouts except for some really nasty RF
stuff).

--
Regards, Joerg

http://www.analogconsultants.com
 
On 16 May, 23:47, Joerg <notthisjoerg...@removethispacbell.net> wrote:
Marra wrote:
Its the x and y coordinates

www.ckp-railways.talktalk.net/pcbcad21.htm

Sure, but what is the scale factor to get to inches, or millimeters?
When we measured by hand and using a Gerber viewer the results totally
did not corroborate the numbers in the PADS file.

--
Regards, Joerg

http://www.analogconsultants.com
Click to expand...
25.4mm = 1 inch

www.ckp-railways.talktalk.net/pcbcad21.htm
 
My machine can handle boards up to 12"x10", and passives down to 0603.
0402's take a special feeders which I don't have. I've never tried TSSOP's
on it, but I can place 50mil pitch IC's no problem. No BGA's or anything
requiring x-ray inspection though.

Incidentally, if you're ever shopping for a P&P machine, laser centering is
a must. Mine uses the older mechanical jaws to square the parts on the head
before placement. It's effective, but it's also the primary limitation when
placing smaller than 25mil pitch parts.

Chris
Click to expand...
Which machine do you have?

Andrew
 
"Andrew Tweddle" <sarason_not_me@alphalink.com.au> wrote in message
news:464e9fe0$1_1@news.chariot.net.au...
My machine can handle boards up to 12"x10", and passives down to 0603.
0402's take a special feeders which I don't have. I've never tried
TSSOP's on it, but I can place 50mil pitch IC's no problem. No BGA's or
anything requiring x-ray inspection though.

Incidentally, if you're ever shopping for a P&P machine, laser centering
is a must. Mine uses the older mechanical jaws to square the parts on the
head before placement. It's effective, but it's also the primary
limitation when placing smaller than 25mil pitch parts.

Chris

Which machine do you have?

Andrew
Click to expand...
It's a Manncorp ECM98.

Chris
 
On 16 May, 15:38, Joerg <notthisjoerg...@removethispacbell.net> wrote:
Hello Folks,

We weren't able to sort this out. The layouter said this is the usual
file that SMT assemblers use to program their pick&place machines but
the assembler said they can't use it since the scale factor or data
format for the coordinates is unknown. PADS was set to the American
dimensioning of "mils" (1/1000th of an inch). Contacting Mentor resulted
in no help. Here is one example from the ASCII file:

R75.2 R66.2
-190690500 289179000 1 381000 1024 TEARDROP N 90 90
-190690500 287274000 31 381000 512 TEARDROP P 90 90

What does "-190690500 289179000" mean in terms of mils, or millimeter?

--
Regards, Joerg

http://www.analogconsultants.com
Click to expand...
I would send them a file with a 1 inch square on it and let them work
out teh scaling factor.

www.ckp-railways.talktalk.net/pcbcad21.htm
 
Marra wrote:

On 16 May, 15:38, Joerg <notthisjoerg...@removethispacbell.net> wrote:

Hello Folks,

We weren't able to sort this out. The layouter said this is the usual
file that SMT assemblers use to program their pick&place machines but
the assembler said they can't use it since the scale factor or data
format for the coordinates is unknown. PADS was set to the American
dimensioning of "mils" (1/1000th of an inch). Contacting Mentor resulted
in no help. Here is one example from the ASCII file:

R75.2 R66.2
-190690500 289179000 1 381000 1024 TEARDROP N 90 90
-190690500 287274000 31 381000 512 TEARDROP P 90 90

What does "-190690500 289179000" mean in terms of mils, or millimeter?

--
Regards, Joerg

http://www.analogconsultants.com


I would send them a file with a 1 inch square on it and let them work
out teh scaling factor.

www.ckp-railways.talktalk.net/pcbcad21.htm
Click to expand...
They didn't want to experiment but get it done. So they entered it all
by hand. Guess what, no mistakes and the boards run just fine now.

--
Regards, Joerg

http://www.analogconsultants.com
 
On 16 May, 21:32, Joerg <notthisjoerg...@removethispacbell.net> wrote:
Hal Murray wrote:
They don't really need the P&P file. It just makes it a little faster to
program the machine.

Thanks, Chris. Maybe the layouter generated the wrong file. Anyhow,
since he's traveling now they went ahead and started programming the
machine by hand. Over 500 parts...

What's the error rate on "hand" programming?

Reducing sources of errors seems like a good idea to me.

It's surprisingly low. In the late 80's it was all hand-programming and
the errors were usually zero. But we do not have a choice here because
the layouter can't be reached right now and the stuffed boards must be
at the client Monday morning.

It's 80% analog and I'll find a stuffing mistake pretty quickly. The
only drag would be that we'd then have to correct it about 40 times.

--
Regards, Joerg

http://www.analogconsultants.com
Click to expand...
I had a company make errors on a pcb we sent to them so 0% is a bit of
an exageration.
The board came back with all the holes in the right places but not a
piece of copper etched !
 
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