RE[6]: emc really needs a copyleft cad/cam package

["Terry L. Ridder" <terrylr-at-blauedonau.com>]

hello;

i have lead a sheltered life in that i have
never used autocad. i still have my slide rule
and t-square. would someone be able to point to
user interface information for autocad.

additional comments are intermixed below.

On Sun, 19 Nov 2000, Matt Shaver wrote:

matt> 
matt> I. My Wishlist:
matt> 
matt>   A. "Must haves":
matt> 

<snip>

matt> 
matt>     2. DXF file computability:
matt> 

<snip>

i would assume that is a given. there is enough
gpled dxf code available to readily draw upon.

matt> 
matt>     3. Multiplatform capability:
matt> 

<snip>

matt> 
matt>       b. If we could make this program run on both Linux and Windows,
matt> we'd be able to spread it around to a wider audience.
matt> 

should not rule out apple power macs.
with macosx coming out shortly it should be rather
easy to support the power macs.

<snip>

matt> 
matt>     5. Object Snaps and Print Scaling:
matt> 
matt>       a. In an earlier post in this thread, Terry remarked that he
matt> preferred xfig to qcad. I looked at xfig, and I like the looks of the
matt> program, but it seems to lack two features that differentiate true cad
matt> programs from vector based drawing programs:
matt> 

<snip>

matt> 
matt>         ii. The print scaling feature means that you draw things at
matt> their actual size, whether they're atoms or galaxies, and the print is
matt> scaled to fit the paper. Most drawing programs (and qcad for that
matt> matter) show you the outline of the paper size you select, and you are
matt> expected to fit the drawing to the paper.
matt> 

i am not sure which version/release of xfig you are
looking at, but xfig will print multiple pages. i
use this frequently. the latest version/release is
3.2.3c. this version does show you where pages are
but you are not limited to a single page.

matt> 
matt>   B. "Nice to haves":
matt> 
matt>     1. Machining time calculation.
matt> 
matt>     2. Speed & Feed calculation.
matt> 

this is going to have to have a library of
physical properties of materials and what feed
rates are possible for that material. an older,
like 6th edition of the machinist's handbook
would provide this information. we would not have
problems with copyrights either. lindsay books
may also have something that is a reprint and
also beyond copyrights.

these books are also a source for information
about cutting tools. i would not give up my
6th edition of the machnist's handbook for
anything.

matt> 
matt> II. General Notes (in no particular order):
matt> 
matt>   A. 2D vs. 3D:
matt> 
matt>     1. I've never made a 3D drawing!
matt> 

my drawing days date back to t-square, french curves,
mechanical pencils, etc. my drawing work now is 50/50
between 2d & 3d.

matt> 
matt>     2. The CAM system I currently use gives you a "through the spindle"
matt> view of the milling table.
matt> 

that is how i currently use xfig.
i make 2d slices of the object and use the 'depth'
parameter to stack them. my perl scripts are written
to use the depth parameter to key off of. a second input
file provides the height/z-axis information. 

matt>
matt>     3. Depth of cut is a parameter you enter in a menu. In a pocketing
matt> segment you tell it the finished depth of the pocket floor, and the
matt> distance to step down for each pass through the pocket. For example, if
matt> you have a depth of .500", and a step distance of .249", the program
matt> will generate a section of g-code that goes through the pocket twice for
matt> roughing (at Z-.249", and Z-.498"), and once more to finish the bottom
matt> of the pocket at Z-.500".
matt>

with a little programming varkon would be able to do this.
btw, varkon is now gpled. warning varkon is unlike any cad
program you have ever used.

thinking of it i could modify my perl scripts to do this.
it would not take much work. i will have to put that on my
todo list.

matt> 
matt>     4. I could easily live with this type of interface if it was easier
matt> (and faster) to code than a 3D type interface. We could also use the 3D
matt> technology in the backplotter to give us a good simulation function.
matt> 
matt>   B. Possible Toolkits:
matt> 
matt>     1. QT:
matt> 

there is still alot of "bad blood" about the manner
in which troll handled the qt licensing. i would have
to really think about using qt long and hard.

matt> 
matt>     2. GTK:
matt> 

maybe, it would be useable for linux and macosx.
windows would be a giant question mark.

matt> 
matt>     3. TK:
matt> 

tk can be slow. x-cdroast is written in tcl/tk
and the author is rewriting it for using x-windows.
i like x-cdroast, but the interface is slow.

that being said, my daughter used gig3d under linux
for many of her projects in college, and the entire
user interface for gig3d was tk.

to bad gig.nl is no longer around. many of us pressed
them to release the source code under gpl before they
went under but they would not.

advantage is that is runs on linux, windows, and macos.

matt> 
matt> This is meant to be a list of stuff to promote discussion, not a carved
matt> in stone decree so please comment early and often. I'll try to write
matt> something about my view of the block diagram of the system later today
matt> (it's my birthday!).
matt> 
matt> Matt
matt> 

-- 
Terry L. Ridder
Blue Danube Software (Blaue Donau Software)
"We do not write software, we compose it."

digging deep, i feel my conscience burn
i need to know who and what i am
this hunger jolts me from complacency
rocks me, makes me meet myself
----kendall payne---closer to myself---