开云体育

From: Bob Bachman <bobach@...>

OK,

I'm sold!

Where do I find this $30 RH Linux 5.2 book and cd. Who publishes it? Name
of the book?

Bob
I mentioned the Redhat distribution or boxed set. It is sold by redhat
software and is available from


I failed to mentioned the most important part of the boxed set... A boot
floppy. It is essential to an easy install and only comes with the boxed
set. You can make one yourself in DOS from the CD, but it is a pain the
first time around.

The $30 price is one I saw at "Best Buy" a regional electronics super store
that also sells software. Since it is an older version it should be quite
cheap now. Note that the book is an installation guide NOT a linux guide.
Linux mall also has books on linux also.

Be careful of $3 linux cd's. They include all the software (a copy of the
disk from the $30 boxed set), but if you lack linux knowledge, they can be
difficult to install. Just buy the boxed set until you have installed a few
versions and know linux well.

You want redhat version 5.2 NOT version 6.0. RTlinux is released in a
stable form for the linux 2.0.36 kernel, the 5.2 version of redhat linux
uses this kernel. Redhat 6.0 is new( and now costs $79) and the RT linux
stuff for it's kernel is still in beta testing.

PS there are other "flavors" of linux but they differ only in packaging and
the install procedures. I choose redhat because it is the most popular and
if you have install problems ( and buy the full $30 version) they give free
email support to help you. I doubt you will need it since people on this
list are probably better qualified anyways.


dave

I have a 3 axis stepper controller from eggert electronics and I am
trying to
write some software for it. I have everything working except one part
that I can't
figure out. Perhaps one of the programming gurus here can help.


The controller is somewhat smart in that you send it a command such as
move X axis
1000 steps ccw and the Y axis 7000 steps cw at so and so speed. All
pulses are generated inside the controller.

when setting up the controller a base speed is set for all motors. This
would be the
fastest speed that all the motors can run reliably. When sending speed
commands to the
controller in preperation for a move a divisor of the base speed is sent
to each motor.

a divisor of 1 is base speed / 1 (full speed)
a divisor of 2 is base speed / 2 (1/2 speed)
a divisor of 3 is base speed / 3 (1/3 speed)
.
.
.
a divisor of 255 is base speed / 255 (1/255 speed)

Therefore if I needed to move the X axis 10000 steps and the Y axis 5000
steps I would
divide 5000/1000 and come up with .5. So Y axis needs to run .5 times
the speed of the X axis giving me X divisor = 1 and Y divisor = 2.
Simple enough.

Now for the problem. The above example works fine because the division
works out even.
If I need to move X axis 10000 steps and Y axis 7256 steps I get
7256/10000 = .7256
or Y axis needs to move .7256 times the speed of the X axis, but that
number can't be sent to the controller so I will have a rounding error
on all moves that don't come out even. One axis will finish before the
other axis.

Any suggestions (besides throw the controller in the trash)

I can always use it as a drill controller since any moves on the X and Y
axis will be with the tool up and it will not matter if the axis' do not
arrive at the same time.

I hope my explaination of this is somewhat clear.

Thanks
Bill

Matt Shaver wrote:

From: "Matt Shaver" <mshaver@...>

From: John Grant <grantjoh@...>
I have nine units that I think are good and two that might be
repairable. I will give them to people in sets of two or three.

I would love to have three of them to use for a servo retrofit on my manual
Bridgeport. I've already got amps, and I'm hot on the trail of some surplus
servo motors, so this would just about do it. I'm happy to pay the shipping
of course.
Matt Shaver
mshaver@...

You are second on the list

John Grant

Hi Fred
How about a mention of this list on the EMC web page.
Mo

Al,
In my last post about putting the PSU in the driver enclosure I forgot to
mention that the PC parallel port cables should be routed into the enclosure
as far way from power section as possible specially if your parallel cable
to the PC is longer than 2 meters.
Mo

Hi Al
From my experience with similar drivers, it is OK to use the same enclosure
as long as you apply some simple rules of good design. Keep the transformer
and any high power bridge rectifier (get quite hot) a reasonable distance
away from the driver (5" is good) and allow for good ventilation of the
power section (without making it easy for swarf, metal dust and any coolant
spalsh to get in. A fan near the power section would be a good idea too.
If your space is very tight, a peice of sheet metal or copper clad PCB board
used to seperate the power supply and electronics would not hurt.
The large smoothing capacitor(s) for the power supply should not be exposed
to high temperatures so don't put it next to the bridge rectifier - high
temps will shorten its life.
If you think along those lines you should end up with a reliable setup.

Mo

Hi Joseph,

EMC running on a PC is the equivalent of the computer already on your CNC
lathe.
EMC reads G-Code input and then controls the motors accordingly.
This is the exact same function of the controller already on your system.
EMC is designed for those with manual systems (or retrofits) needing to
implement the
same function which you already have - the difference being that your system
is fed the
code from a serial port or keypad and EMC gets its input from a file on a
disk.
There is PC communications software out there that can spoon feed files to
your controller from a PC and
even CAD-CAM design software with serial output. If you need links to any
of these let me know.

Mo

Does anyone know if Linux/EMC can be used to run an Emco Maier Compact 5

CNC

Lathe.
It has one RS232 (serial) port on it.

From what I understand this port can be used to load code from a computer

and also save to a computer.
The machine has a computer built into it. Entries are input via a numeric
keypad.

Hi All,
Does anyone know if Linux/EMC can be used to run an Emco Maier Compact 5 CNC
Lathe.
It has one RS232 (serial) port on it.
From what I understand this port can be used to load code from a computer
and also save to a computer.
The machine has a computer built into it. Entries are input via a numeric
keypad.


L8r
Blue Knight "Machinist Due It With Precision"
AKA Joseph P. Mucenski
Tucson, AZ
josephm@... <mailto:josephm@...>

Hello All,
Fred Proctor from NIST mentioned this list as discussing, amongst other
things, the EMC experiences. Is there a list archive where I can read
past mail? If so how do I access that archive?
Thank you
Regards
John Craddock

Just curious, I'm in the process of constructing on of Dan's 5A stepper
drivers and was wondering if it's ok to put the transformer/power supply
components in the same enclosure. I'm new to all of this stuff and was
wondering if the AC current in the enclosure would end up creating a lot
of noise that would affect the stepper driver operation.

Thanks,
Al

EMC Users/Victims,

Thanks to all of you who have posted replies to the CAD/CAM mail list to
questions that I should have answered. I was suffering email paralysis
and couldn't summon the will to attack my inbox.

For those of you on the emc@... mailing list (see
for subscribing), you should
note that the CAD_CAM_EDM_DRO@... mail list has become the place
for EMC experience sharing. Apparently nobody on this list sleeps. I'll
post any EMC stuff to both lists in the future.

As Tim Goldstein noted, I put a new release of the EMC code on the FTP
site. It's at:

ftp://ftp.isd.cme.nist.gov/pub/emc/emcsoft/linux_2_0_36

with files:

emc-08-Jun-1999.tgz (tar file of new release)
emc-08-Jun-1999.txt (copy of RELEASE_NOTES)
emc-08-Jun-1999.log (result of install script, for comparison)

If you install this and notice problems, LET ME KNOW ASAP. I've tested
this on my stepper motor test stand on a desktop PC and a laptop, and it
worked, but we'll see.

I've appended a description of the fixes at the end of this message.
Basically they have to do with setting the default and max feed rates,
honoring them when they're set, and setting the stepper pulse rate.

Going through the mail list, I notice a couple of hot items that I'll be
working on in the next few weeks. These are:

1. An EMC User's Guide. Installing Linux and RT-Linux is a pain, and so
is installing and configuring the EMC, so this guide is intended to
cover how to get and set up an EMC PC. I will work with Matt Shaver to
get a draft that I will post to the FTP site, and if anyone feels like
commenting (or contributing) let me know.

2. A part program verifier. There is actually one of these already, in
emc/plat/linux_20_36/bin, called "rs274ngc". Tom Kramer here at NIST who
wrote the interpreter uses this. I'll clean it up and make it easier to
use. I just ran it, and got:

me> cd emc
me> plat/linux_2_0_36/bin/rs274ngc
name of tool file => tool.tbl
name of setup file =>
1 N0 USE_LENGTH_UNITS(CANON_UNITS_INCHES)
2 N0 SET_ORIGIN_OFFSETS(0.0000, 0.0000, 0.0000)
3 N0 SET_FEED_REFERENCE(CANON_XYZ)
4 N0 SET_ORIGIN_OFFSETS(0.0000, 0.0000, 0.0000)
5 N0 SET_FEED_REFERENCE(CANON_XYZ)
6 N0 SET_ORIGIN_OFFSETS(0.0000, 0.0000, 0.0000)
7 N0 SET_FEED_REFERENCE(CANON_XYZ)
8 N0 SELECT_PLANE(CANON_PLANE_XY)
Cannot open tool.tbl

so you see it needs some work. I'll ask Tom how to use it.

Regarding the incredible pickiness of the interpreter with regard to
cutter compensation corner radii, circular move start and end radii,
etc., I'll ask Tom how we can set this up to not die horribly when you
are half an angstrom off.

3. Contouring, so you can run that 2 MB racecar part program that comes
with MasterCAM. I had a grad student from the Netherlands work on this
and we've cut a bunch of wax cars. I don't know if any of you have tried
running dense G code programs but it doesn't work well in the current
release.

The fixes in the new EMC release I mentioned earlier (thanks to Tim
Goldstein, to whom this list was originally directed) include:

1. The INI file parameter [TRAJ] DEFAULT_VELOCITY is used to set the
initial value for the jog speed in the xemc GUI. Note that the units on
this in the INI file are in units per SECOND. We decided to keep all
time units to seconds in the INI file. If you have set your units to
inches (e.g., [TRAJ] LINEAR_UNITS = 0.03937...), then setting [TRAJ]
DEFAULT_VELOCITY to 0.5 will yield an initial value of 30 IPM.

2. The INI file parameter [TRAJ] MAX_VELOCITY is used to set the rapid
(G0) rate, and as an upper limit for the jog speed in xemc. The units
are the same as in (1) above. More importantly, the motion system will
clip all velocities to this max limit, even if the feed rate override is
above 100% (e.g., INI file parameter [DISPLAY] MAX_FEED_OVERRIDE = 1.5,
for 150%). So, if your stepper system can't run faster than 45 IPM, for
example, you can set the INI file value to 0.75 and you should never be
able to run faster than this, even with 150% feed rate override. Note
that this will make feed rate overrides above 100% appear not to
function for rapid moves or programmed moves at close to the rapid rate.

3. The stepper motor pulse rate used to be set via a compile-time
parameter set to 400 microseconds maximum pulse period, which is 2.5
kilohertz. Now, the INI file parameter for [AXIS_0,1,...] CYCLE_TIME is
used. There is a single stepper motor pulse task, so it's run at the
rate for the fastest axis (smallest CYCLE_TIME). I make all the
CYCLE_TIMEs the same. Note that making the CYCLE_TIMEs shorter yields a
faster maximum pulse rate, and a faster achievable maximum velocity.
Making it too fast may cause the steppers to malfunction, or may consume
too much compute time and starve out the other tasks. You should set
this rate to be the maximum your motors can take. Apparently the 2.5
kilohertz default was too fast for you, which was causing motor
malfunction and the need for the MAX_VELOCITY described in (2) above.

Because of the way the stepper motor task works, you can get following
errors with stepper motors. This happens when the commanded motor speeds
exceed the maximum pulse rate. This can be seen easily by setting [TRAJ]
MAX_VELOCITY to something high, and jogging an axis at the max speed.
You will notice when you let up on the jog key that the motor keeps
going. It's because the commanded position has outpaced the stepper's
ability to keep up.

I recommend setting the [AXIS_0,1...] CYCLE_TIME to be less than the max
the stepper can take, and then setting [TRAJ] MAX_VELOCITY to be the
corresponding inches per second. You need to figure out the max pulse
rate by trial and error, unless it's documented.

--Fred

In a message dated 6/9/99 4:39:50 PM Pacific Daylight Time,
johncrad@... writes:

Is there a list archive where I can read
past mail? If so how do I access that archive?
Thank you
Regards
John Craddock

John go to the following and you will be at list center, and can go from
there.

<A
href="
37433">ONElist E-mail Communities
</A>


bill
list manager

OK,

I'm sold!

Where do I find this $30 RH Linux 5.2 book and cd. Who publishes it? Name
of the
book?

Bob Bachman - bobach@...

Just got a message from Fred Proctor and he has put a new build of EMC on
the ftp site.

From reading his message it looks like the newest version has some hop ups
for up stepper motor people.

Tim
[Denver, CO]

I communicate with Dan Hudgins a few times a year. I have finally given up
on dancam and Dan Hudgins. He was working on a new version of dancam but
I still could not convinvce him that it need to be a G code interpreter.
I still use Dancam/Danplot for a few things that I do. I use dancam to
drill PCB boards for my own use. I have a program that reads the excellon
drill file then optimizes the tool path, give a grphaical display of the tol
path, measures the optimized tool path vis a vis the unoptimized tool path
and then creates a dancam data file.
Jon Elson sent me a program that convert the tool paths to G codes. It
works fine but doesn't have all the bells and whistles that my program has.
So I decided to have my daughter in law update my program to generate G
code. It should only take an hour to make the changes but if you have every
worked with a programmer--- welll you know what I mean.
Dan Hudgins is a brilliant guy he just has problems. Sorry to see him
out of the loop.
Dan

I can telnet into the Linux machine, or use
FTP from either one to the other.

Jon,

That is how I started moving files between Linux & Windows also.

If you want to make your file transfer life even easier get Samba running on
your Linux machine. Once you have the Samba package loaded all you have to
do is edit the config file for it and you will be all set. Samba lets you
see the Linux machine on the network from a Windows machine as if it was
another windows machine. You can then go straight to neighborhood network or
Windows Explorer and drop and drag files and even create new directories,
rename and delete files, or open and edit them from your windows machine.

Tim
[Denver, CO]

The shoptask electronic threading indicator uses a reflective sensor and
indicates the relative spindle posistion. It is not nearly as accurate as an
encoder but will suffice to make threads and it beats the hell out of having
to reverse the motor to back the toool out of the threads.
Dan

Hi all,

I haven't had much to say lately so I thought I'd add my $.02 to the
discussion of homebrew encoders.

To quote an old phrase, "ya pays ya money takes ya choice". I opted to
buy my encoders and spent the bucks to get linear encoders with high
resolution, <.001" ( closer to .0001").

Yep, I probably have more money available than time. Basically, I deal
with computers and electronics at work and when I'm in the shop, I
prefer to make swarf. Just my opinion.

On another note. If you want high quality patterns for your encoders try
a place that specializes in photo-etch masks. These people routinely
make high resolution masks for the etching of very small patterns. Try
to find a vendor that provides mask for the microwave electronics
industry.

Regards,
Mac

"Try as much as possible to be wholly alive, with all your might, and
when you laugh, laugh like hell and when you get angry, get good and
angry. Try to be alive. You will be dead soon enough."
--William Saroyan