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AFAIK

OK, I figure out IMHO, FWIW, TIA, and a few others, but this one I do not
get! Anyone know where to find an NG-addict's acronym dictionary?

As Far As I Know - Sorry, I debated using this acronym and laziness won out
over clarity.

Matt

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Folks,
Want full Autocad compatibility (except solids). You can get it
FREE (good price huh?) at www.cadopia.com - That's where Intellicad hides
now days. The Free version doesn't have photorealistic shading, or VBA -
If you want those, it's less than a C note. It is AutoLisp compatible


Charlie


At 08:29 PM 2000-05-04 -0400, you wrote:

I use Lt both at home and work. I switched from full Acad to Lt as I was
tired of the excessive cost of the upgrades when 99.99% of my work was 2d.

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Matt Shaver wrote:

AFAIK

OK, I figure out IMHO, FWIW, TIA, and a few others, but this one I do not
get! Anyone know where to find an NG-addict's acronym dictionary?

Carlos Guillermo
VERVE Engineering & Design

I use Lt both at home and work. I switched from full Acad to Lt as I was
tired of the excessive cost of the upgrades when 99.99% of my work was 2d.
Yes, I miss the Lisp capability and the many Lisp routines that I had
written, but it gets down to $$$. Release 9 does what I need to do; but
they keep changing the stupid file format with each release and that for me
was the only real reason to upgrade versions. I have been using Lt for
about 3 or 4 years now (time flys when your having fun) and have gotten
fully accustomed to its look and feel. Now there is the possibility of the
Lisp add-on so may be looking at that to gain back that protion of the
capability where necessary although, some of the built in functions are
look a likes for the Lisp routines that I built.

I would say go ahead and give it a try.

Art
At 07:23 PM 5/4/00 -0500, you wrote:

List
Has any one used Auto Cad Lt, if so what do you think of it.
I have access to it at work ,and was thinking about learning it.
Jim

A. G. Eckstein

axtein@...

Eric writes:

I see the real machinists using
CNC more than non cnc maybe because it is new, but also because it is really
easy.

Last year I was out in California working on a project for a foundation
who's primary product is publicity. One of the PR people was taking
pictures of me making a part on a Bridgeport. I said that surely she had
something better to take a picture of than someone turning cranks on a
mill, but no, this in now quaint and artisinal, that most real machining
takes place now by pushing buttons outside of a closed box.

As for me, I am in the process of getting a CNC mill, but I was told in no
uncertain terms that I should keep my manual mill as well, rather than do a
retrofit, because I was going to need it.

David M. Munro

List
Has any one used Auto Cad Lt, if so what do you think of it.
I have access to it at work ,and was thinking about learning it.
Jim

From: Tim Goldstein <timg@...>
Interesting...

When I talked to Matt Shaver about his Bridgeport conversion he said he was
able to get 60 ipm if I remember correctly. Makes you wonder why he managed
3X the speed you are getting??

54ipm to be exact, perhaps it's because I was using a scale of 4000, I don't
know for sure. That said, Darrell is right, the stepper pulse output of the
EMC, even using freqmod, isn't good enough for some machine configurations. I
think it's a combination of things:

1. The machines Darrell and I are trying to retrofit have much more mass in
each axis to sling around than a mill drill or Sherline, or even a Shoptask,
although they're closer to Bridgeport size than most hobbiest machines.

2. The motors Darrell and I are using are old technology. Most hobbiests use
newer motors with greatly superior characteristics.

3. People who buy a Bridgeport retrofit expect rapid feed rates of at least
100 ipm (the stock machine would do 120 ipm), while most Sherline operators
could probably get by with 50 ipm ;) .

AFAIK the existing control programs that are capable of high output steps
rates _AND_ close grained frequency control of the step rate _AND_ negligible
jitter use external hardware (outside the standard PC) to generate or somehow
control the step pulses. Examples of these are AHHA, and Flashcut. For
reasons that take about a page of typing to explain (see the archives),
software only solutions break down at high step pulse rates. The one possible
exception to this is Indexer LPT, although I don't have personal experience
with it (does anyone here use it?). I would love to know if anyone has done
any experiments to measure the performance of I-LPT, specifically I'd like to
know the granularity of the frequency control from DC to it's maximum output
rate and the guaranteed maximum jitter (however they would like to specify
it). If it turns out that I-LPT achieves all the three above mentioned
performance goals _AND_ still allows the user interface to operate normally
while the machine is in motion, then it's definitely worth the price charged.

The approach I would use (will use if I ever do anything else with steppers)
would be to employ an external programmable frequency generator, probably in
the form of an Intel 8254 CTC that would be controlled by the EMC software.
The step signals (from the 8254's output) and the direction signals (from a
general purpose digital I/O port) would go to the stepper motor drive
circuitry and also be fed back into a counter circuit (like the LSI Logic
7266) that would accumulate the position count for each axis. To the EMC this
would look just like a servo system. The EMC would send out velocity commands
to the 8254 and read back position data from the counter. This servo loop
would be processed at a kilohertz or so just like any other servo system. In
fact, you could get position feedback from a linear scale if you would prefer
and that wouldn't change anything in the software (actually there are a few
issues such as the difference in resolution between one stepper step and one
encoder count, but this could be worked out). It's interesting to note that
this is exactly a mirror image of the approach taken by Bill Wainwright with
his Servo-Lite setup.

Matt

For example, Drilling and Tapping a single hole. I guarantee that I can do
this faster on my Bridgeport than on any CNC machine.

I am wondering if this is the type of work the hecklers were thinking of
when they were talking about CNCing one off parts, I kind of doubt it.

I work in a very small shop (one full sized commercial cnc machine and
several table top retrofits) where we do mostly one offs and very small
prototype runs of parts. If anyone is interested, you can see some samples
of the types of parts I machine at:


Bill Griffin
www.grifftek.com/links.htm

On Thu, 04 May 2000, you wrote:

And while we are on AcuRite note that it is a 2D machine, and part of
why simple jobs are faster there is because there is no motor on the Z-
raising and lowering a quill to change from center drill to drill to
drill to reamer is a big pain with a Z motor. That is exactly why my
Grizzley mini mill will not get a z motor.

ron

My Rong Fu RF-45 has the Z-axis movement tied to the column. The quill is
still stock- so it's great to be able to run the table around and then manually
drill and tap a hole fast. If I have to drill 80 holes, then I use a canned
drill cycle.

Dan

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Hi,
Sorry for any of you who receive this more than once

Due to the increase in email viruses , all e-mail that I send out from this
time forward will be PGP signed. Any e-mail from me that is NOT PGP signed
should be considered suspect, in that it was probably sent without my knowledge

Charlie
- -->
RKBA!
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Hi,

I know I shouldn't laugh but I find that two people, both intelligent, appear to have to defend their view to this degree. You both have a valid point.

Terry.


>Then we had Fred smith pushing CAD/CAM, and even making a foolish statement
>that anyone making just one or two parts shouldnt be using CNC at all.
>He did get soundly shouted down on that statement!

For those of you who missed the little CNC discussion forum and
presentations, I was not pushing Vector at all (it was in the title, but not
the words). I merely showed when it is best to use CNC as opposed to manual
machining. Most of my discussion was about the $100,000 CNC lathe I watched
wreck itself & a statement to be safe when using CNC machines.

Hi,

I concur with the comment below and would add that if I understood the code words, used by those that use this system, what is a GUI.

Terry



The 5 minute install for EMC would make it vastly more popular with
hobbiests! I'd even give it a shot...

Hi,

I trained as a draughtsman and finished my Indentures in 1973. I still own drawing instruments and drawing boards. On discovering ACAD at version 10, I thought there is no reason to learn this new technology as it was unwieldy and very difficult to use. Them came 14 and 2000, now even sketching is done on the puter. The days of white paper syndrome have gone with anything being put on the screen and moved around until the design appears.

Last night I designed the track of a DRO in fifteen minutes. This morning I changed it beyond recognition saving over half the cost in the metal used and a great deal of fabrication time. If this had been drawn the old way the design would not have been changed because it was too much trouble.

Anyone want to buy the old gear :-)

Terry.




>I don't care how smart you are, there is no getting around the fact that
>this is more efficiently done by cranking handles.
(rest of message CNC vs Manual Machining snipt for brevity)

Seeing as this mailing list concerns CAD as well, I would like to ask the
list the following:
Assuming equal proficiency with a drawing board and a CAD system, is there
any type of drawing that is suited to the manual process, as opposed to the
CAD process?

Personally, I find manual drawing a chore, so I opt for the easy way out
whenever possible.

Interesting...

When I talked to Matt Shaver about his Bridgeport conversion he said he was
able to get 60 ipm if I remember correctly. Makes you wonder why he managed
3X the speed you are getting??

Tim
[Denver, CO]

Ron Ginger wrote:

And while we are on AcuRite note that it is a 2D machine, and part of
why simple jobs are faster there is because there is no motor on the
Z-
raising and lowering a quill to change from center drill to drill to
drill to reamer is a big pain with a Z motor. That is exactly why my
Grizzley mini mill will not get a z motor.

Well, what really happens is you find a new, better way to do things.
On a manual,
because it is hard to repeat an XY position, you center drill, drill
through, ream,
countersink and tap, all before moving to the next hole position. All
that spindle
start/stop and tool changing takes a LOT of time. On a CNC, you put in
the
center drill, and spot all the holes. Then you change tools, and drill
ALL the holes
through. Then, change again, etc. This actually can save a LOT of
time, making
some of these one-off jobs go TWICE as fast!

So, you might find that a Z axis can also speed up the one-off work,
once you
find the way to make it work for you.

Jon

Tim,
I am running an AMD K6 II 400 and only require 2000 steps per inch. I am
running freqmod Feb 29 I believe. When I tried it on my Bridgeport, movement
started getting ratty at 15 IPM and maxed out at 20 IPM. Looking at the
pulse train with a scope, pulse jitter (timing between steps) got worse up
to 20 IPM and then smoothed out to near perfect at 30 IPM and then started
going bad again. At 20 IPM the pulse train was varying by as much as 3/4s of
the signal width. I talked to Fred Proctor and he agreed that timing in EMC
was the problem.
Using micro stepping and small motors would probably let you move much
faster but with 1100 oz in motors and full stepping on the Bridgeport it
requires a clean signal. I am used to getting 120 IPM.
I have used the Microkinetics 8010 drivers with good success and I think the
problems that users have been having on this group is directly related to
the poor step signal timing.
Darrell

Hey All,
Feel like this is my time to chime in as I had to do a little research on
this exact topic once and found out the following things as best I remember
along with my perspective:
1. Given equal skills, on a one off drawing; it will be a one to one ratio
as to how long it takes to make the drawing.
2. Given MY "skills"; Cad wins every time because:
a. I can't draw a straight line with a rule and a pencil
b. Cad makes my circles round.
c. The drawing is CLEAN when I plot it and there are no smuges or holes
from erasures
d. A lot of what I do needs "construction" lines to make the finished
product (see c.)
3. If I have a multi story building to do and the floors are fairly
"typical" but have only minor differences, I can copy a lot faster than
draw and then do the minor modifications.
4. I can't letter for a damn:-(]

Art

At 10:12 PM 5/4/00 +0800, you wrote:

-----Original Message-----
From: Fred Smith [mailto:imserv@...]
Sent: Thursday, 4 May 2000 9:10 PM
To: CAD_CAM_EDM_DRO@...
Subject: [CAD_CAM_EDM_DRO] Re: Names

I don't care how smart you are, there is no getting around the fact that
this is more efficiently done by cranking handles.

(rest of message CNC vs Manual Machining snipt for brevity)

Seeing as this mailing list concerns CAD as well, I would like to ask the
list the following:
Assuming equal proficiency with a drawing board and a CAD system, is there
any type of drawing that is suited to the manual process, as opposed to the
CAD process?

Personally, I find manual drawing a chore, so I opt for the easy way out
whenever possible.

A. G. Eckstein

axtein@...

I use 3D solids every day and find that it is absolutely perfect for
95% of what we do. I know people who belive it to be the be-all
end-all. Not Yet!
What is missing is the ability to create a solid without accurately
defining it. I had an emergency with a sheet metal stamping once. The
toolmaker came over with a lump of clay. We molded the clay on the
existing part and said, "make it look like that" and he did. Would have
taken a week with CAD.
There are alot of shops springing up that won't be able to make your
part if you can't model it in CAD.
Is there a point? Just the right tool for the right job.

As someone that makes his living making parts for others in qty. from 1
to several hundred, I can second this. By the time I've created
geometry, run it through CAM, cleaned up the code, transferred to the
computer running my MAX, proofed the program (visual run-through for
errant moves), and set up the part and tool offset(s), I can often be
done and on to the next part by being clever with manual setups.

Again, I sure wish I could get you in front of an AcuRite machine. All
you do there is create geometry by filling in blanks, enter the tool
size, and run it. The screen shows the part, the offsets are all figured
by the program, you dont even have the ability to clean up the code, its
not needed, and its all on one machine so no transfer is needed.

And, by the way, how about the modification to a part that needs to be
made when there are no drawings- a good CPNC lets you pick off points in
a 'learn' mode and run the job. Rollie makes a lot of money fixing parts
that people break or want modified.

ron

Jon Anderson wrote:

Fred Smith wrote:

I stand by my statement that the best way to machine a single
part is OFTEN and USUALLY by turning the cranks. As I pointed out

in

my talk, there are indeed shapes and contours that can more
efficiently be machined with CNC. There are however those that are
not best done that way.

As someone that makes his living making parts for others in qty. from
1
to several hundred, I can second this. By the time I've created
geometry, run it through CAM, cleaned up the code, transferred to the
computer running my MAX, proofed the program (visual run-through for
errant moves), and set up the part and tool offset(s), I can often be
done and on to the next part by being clever with manual setups.

Ahh, but there's the difference. I make a lot of instrument panels and
such stuff.
Very simple rectangular cutouts, holes drilled in various spots, etc. I
DON'T use
a CAD/CAM system for these, in almost all cases. I either write the
G-code
by hand, or use a couple of programs that write sections for the
rectangular
slots and such. Using CNC, I can do some real tricks, like boring round
holes
with the same end mill that cuts the slots, rather than having to change
drills
half a dozen times. These things are VERY low volume, like one stack of

6 panels is an entire production run. When I did this stuff by hand, it
was VERY
sweat-producing, as I would spend hours cutting the slots, coming up to
the
desired coordinate, and one moment's inattention, and 6 hours of work is

trashed! Now, I can do the whole batch perfectly in the time it would
have
taken me to do two of them by hand.

I'll NEVER go back to manual, although I DO miss the simplicity of
drilling a
hole by hand in some piece of material.

Jon