CAD program origin points?

[Michael]

I have a simple little freeware CAD program for doing chassis etc. that I
like called A9CAD.

The one thing I'm not clear on with regard to the software though is the
"point of origin" in the piece you're working on.

Let's say for the sake of simplicity that I'm drawing a simple 6" x 6"
aluminum rectangle with a couple of holes in it.

The starting point of the drawing (the origin point?) is the bottom left
hand corner with all the measurements taken from there.

The problem is....with this software that I use (and I've see this in other
programs also).....is that, if you want the origin point at X=0 and Y=0 then
you have to draw starting in the middle of the screen.

This is a pain because the zoom and view options are few and I have to
scroll the drawing all the time.

What I would like to do is start the drawing at the very left hand corner of
my drawing screen (which would show
negative values for the X and Y starting point).

My question is.....

As long as my drawing dimensions are what I want, does it matter to the DXF
information that is being exported or the fabrication house that this
"origin point" is NOT at zero? Would the DXF file be ok to read
regardless?

THANKS

 

[Ned Simmons]

I have a simple little freeware CAD program for doing chassis etc. that I
like called A9CAD.

The one thing I'm not clear on with regard to the software though is the
"point of origin" in the piece you're working on.

Let's say for the sake of simplicity that I'm drawing a simple 6" x 6"
aluminum rectangle with a couple of holes in it.

The starting point of the drawing (the origin point?) is the bottom left
hand corner with all the measurements taken from there.

The problem is....with this software that I use (and I've see this in other
programs also).....is that, if you want the origin point at X=0 and Y=0 then
you have to draw starting in the middle of the screen.

This is a pain because the zoom and view options are few and I have to
scroll the drawing all the time.

What I would like to do is start the drawing at the very left hand corner of
my drawing screen (which would show
negative values for the X and Y starting point).

My question is.....

As long as my drawing dimensions are what I want, does it matter to the DXF
information that is being exported or the fabrication house that this
"origin point" is NOT at zero? Would the DXF file be ok to read
regardless?

THANKS

I can't imagine it would be a problem. Your part will probably not be
set up with its origin point at the (0,0) of whatever equipment it's
running on, so somewhere along the line an offset to the corner of your
part will need to be determined anyway.

Ned Simmons

 

[John2005]

Hi Michael,

I usually try to put the origin point somewhere on the part, because it
makes it easier for the CNC programmer to program the part. However,
with most cad programs it is very easy to either move the part to the
0,0,0 origin, or to move the coordinate origin point to the part (you
can do it both ways in AutoCAD). So, the CNC programmer may have an
easy way to put the part wherever he/she wants.

I would think most shops could handle it either way without too much
trouble, but you should try to make it as easy on them as possible, and
locate the origin somwhere on the part, usually at an important datum
or reference point.

Hope this helps.
John

 

[JR North]

You should have 2 sets of coordinate readouts. 1 set for cursor
{FROM}origin and one set for current active drawing operation from
initial point X. No? Poorly written program. Zoom should be slaved to
the cursor position and + - keys. No? Poorly written program. Origin
should be shiftable to any cursor position with a {shift/X} keystroke
function. No? Poorly written program.
DXF doesn't care what, or where the "origin" of the drawing is.
"Origin" is a reference point for the objects in the drawing, and for
the cursor position. It is not a specified absolute as to relative
position to the drawing (IE: left/lower corner).
JR
Dweller in the cellar

I have a simple little freeware CAD program for doing chassis etc. that I
like called A9CAD.

The one thing I'm not clear on with regard to the software though is the
"point of origin" in the piece you're working on.

Let's say for the sake of simplicity that I'm drawing a simple 6" x 6"
aluminum rectangle with a couple of holes in it.

The starting point of the drawing (the origin point?) is the bottom left
hand corner with all the measurements taken from there.

The problem is....with this software that I use (and I've see this in other
programs also).....is that, if you want the origin point at X=0 and Y=0 then
you have to draw starting in the middle of the screen.

This is a pain because the zoom and view options are few and I have to
scroll the drawing all the time.

What I would like to do is start the drawing at the very left hand corner of
my drawing screen (which would show
negative values for the X and Y starting point).

My question is.....

As long as my drawing dimensions are what I want, does it matter to the DXF
information that is being exported or the fabrication house that this
"origin point" is NOT at zero? Would the DXF file be ok to read
regardless?

THANKS

--
--------------------------------------------------------------
Home Page: http://www.seanet.com/~jasonrnorth
If you're not the lead dog, the view never changes
Doubt yourself, and the real world will eat you alive
The world doesn't revolve around you, it revolves around me
No skeletons in the closet; just decomposing corpses

 

[ATP*]

I have a simple little freeware CAD program for doing chassis etc. that I
like called A9CAD.

The one thing I'm not clear on with regard to the software though is the
"point of origin" in the piece you're working on.

Let's say for the sake of simplicity that I'm drawing a simple 6" x 6"
aluminum rectangle with a couple of holes in it.

The starting point of the drawing (the origin point?) is the bottom left
hand corner with all the measurements taken from there.

The problem is....with this software that I use (and I've see this in
other programs also).....is that, if you want the origin point at X=0 and
Y=0 then you have to draw starting in the middle of the screen.

This is a pain because the zoom and view options are few and I have to
scroll the drawing all the time.

Sounds like you are wasting your time using a freeware program with limited
capabilities- why not acquire an old version of Autocad for next to nothing?

 

[Michael]

Thanks JR....I'll look into that although the setup feature seem to be
limited.

I'm getting the hang of this program better now....maybe a bit hasty in my
post......like any other software the "more you use it"...etc

Actually, I didn't choose it because it was freeware, I had bought some
other programs and for an infrequent user like me the A9cad is really
decent.

Especially considering I can get a DXF file out of it.