开云体育

--- In CAD_CAM_EDM_DRO@..., "jcc3inc" <jccinc@o...> wrote:

Gentlemen:

I have been considering adding a manual pulse generator to the CNC
controller which I have built. My questions are:
1) Will ONE MPG be used to operate all (3) or (4) axes?
2) Are the pulses multiplied by 1, 10, 100 or ??
3) Is there a max feedrate applied to the MPG input?
4) If the speed is fast, is accel and decel applied in the system?

Thanks for your comments here.

Merry Christmas to you all,
Jack C.

Depends what you want.

if you are looking for testing, then there is no real needs.

if you are making a manual handwheel, then all of the above.

if you are just jogging the machine, then a manual selection switch
for the axis is approprate.

ditto for speeds max feedrate is that of the machine. a seperate
button for rapids would be desired.

and yes on accel and decel.

Dave

Hi,

I'm using Yeager's CNCPRO software and stepper motors.

Shelby

Not sure which software you are using, but nornmally the home

command

sends the machine to some known position (which does not have to

be

0,0,0 in programs like TurboCNC - which I think you might be using
from your description of the slow movement during homing). From
there you move to the work zero using G00 (assuming you have a jig

or

something to hold the stock in a known position) and then rezero

the

machine using G91 (I think from the top of my head - I don't have

G

code manual handy)

HTH
Nigel
Shelby:

Actually, the home command (often G74 but is different with

different

controls) sends the machine to the MACHINE reference. This is

usually set with limit

switches and a zero/home pulse on the encoder. You would then

send the

cutter to whatever new zero position you would like and use a G92

command (again

this can be different with controls) to set the new program zero.

G90=absolute

position, G91=relative positoning, G00=rapid positioning,

G01=linear

positioning, G02=clockwise circular positioning, and G03=counte

clockwise circular

positioning. These are standard G codes for almost every control

out there.

Other G codes will change from control to control so you would

need to refer to

the instructiions for your particular controller.

Randy Abernathy
4626 Old Stilesboro Road
Acworth, GA 30101
Ph / Fax: 770-974-5295
E-mail: cnc002@a...

I furnish technical support, repair, and other related services

for your

industrial woodworking machinery. My background as Senior Service

Engineer for the

SCMI Group for nearly fifteen years with factory training,

combines with my

extensive background in electronics, mechanics, pneumatics,

electrical and CNC

machinery to offer you needed support for your machinery.

Gentlemen:

In my previous post I forgot to ask if anyone knows of a source for an
MPG; who makes units with detents, and what are toe prices? We
hobbyists are always looking for low cost answers.

Regards,
Jack C.

While it will reduce the speed of drilling, I would advise using
carbide masonry bits, but not using the percussion mode of a
hammerdrill. If there is a cleave line in the stone, you run less
of a risk of fracture. If you want advice in working granite, you
might go to your local tombstome manufacturer (they work with the
material all the time).

Jeff

--- In CAD_CAM_EDM_DRO@..., "ballendo" <ballendo@y...>
wrote:

Hello,

How about flatness, stiffness, temperature stability, damping

mass...

Ballendo

P.S. Several recent posts tell how to attach machine parts to

Granite.

--- In CAD_CAM_EDM_DRO@..., "Ray Brandes"

<RBRANDES@G...>

wrote:

Dave,
I wouldn't know how to attach machine components to granite. I

am

sure

it can be done though. Aside from the stability offered by the

weight,

I don't see any advantage over aluminum jig plate.
Regards, Ray

Gentlemen:

I have been considering adding a manual pulse generator to the CNC
controller which I have built. My questions are:
1) Will ONE MPG be used to operate all (3) or (4) axes?
2) Are the pulses multiplied by 1, 10, 100 or ??
3) Is there a max feedrate applied to the MPG input?
4) If the speed is fast, is accel and decel applied in the system?

Thanks for your comments here.

Merry Christmas to you all,
Jack C.

As Jon mentioned, some of the extraudinailary high priced PCB
machines use granite for the base.

For a home mini (router/pcb/etc) the granite offers some benefits
that aluminum and steel don't.

One is that it is FLAT, so that makes it easier to start with.

Then it is solid so as you assemble, there are no sections that don't
fit just right.

Then there is the mass of the unit to keep it from moving.

If you have the $$, Starrett will drill whatever holes you want on a
special order plate. If you have a concrete drill you can drill your
own.

For mounting the rails, I would mount one side by drilling the holes,
and using a epoxy secured bolt. Then using one side as the
reference, secure the other side.

Another benefit is that with the cheap import stuff, a Granite
surface plate will not cost too much. A 12x18 from Enco is about 30
bux.

Dave




--- In CAD_CAM_EDM_DRO@..., "Ray Brandes" <RBRANDES@G...>
wrote:

Dave,
I wouldn't know how to attach machine components to granite. I am

sure

it can be done though. Aside from the stability offered by the

weight,

I don't see any advantage over aluminum jig plate.
Regards, Ray
If your post isn't off topic, I don't think my reply should be

either!

--- In CAD_CAM_EDM_DRO@..., "turbulatordude"
<davemucha@j...> wrote:

Hi All,

I checked my T-Tech PCB mill and found it was based on a 1/2

aluminum

plate, ground flat, and then added the linear rails.

Hello,

How about flatness, stiffness, temperature stability, damping mass...

Ballendo

P.S. Several recent posts tell how to attach machine parts to Granite.


--- In CAD_CAM_EDM_DRO@..., "Ray Brandes" <RBRANDES@G...>
wrote:

Dave,
I wouldn't know how to attach machine components to granite. I am

sure

it can be done though. Aside from the stability offered by the

weight,

I don't see any advantage over aluminum jig plate.
Regards, Ray

From: "Tim" <luvindaddy@...>
Subject: Manual Pulse Generator (Handwheel) for EMC

Hey Everyone,
I've got a question for Jon Elson & Ray Henry..... and anyone else
that may know??????

Jon, Does your "Universal Stepper Controller" handle input from a
manual pulse generator? Selector switches for axis & step rate,
handwheel for direction?

Jon & Ray, Is "EMC" capable of handling this type of external input?
or does "EMC" really not care/or have anything to do with it?

Hi Tim

Certainly Jon's encoder board will read an encoder or quadrature based
handwheel -- not all of them are. EMC will treat that as an ordinary
axis so you will need to set the soft limits and following error very
large so that it does not expect much control over whatever is "driving"
that encoder.

What you do with the position maintained for that axis is another
question. We were able to get electronic gearing written into the motion
code last summer but we don't have easy access to it from the GUI just
yet. That has kinda been hanging fire until the low level rewrite - EMC2
- is completed. IMO electronic gearing is the only way to run a
handwheel. Well the only way that would satisify a machine service guy
like me.

For now it would be possible to run a handwheel from a GUI like "mini" if
we added a process that read the offsets for the handwheel axis and
formed proper mdi commands from them. This process would also need to be
able to ignore handwheel offsets when it was not being used. We'd need
to add some buttons or keyboard bindings to control the pulse multiplier.
With a bit more work we could also make machine speed responsive to the
size of the handwheel offset as well. This would not be real time but it
would be there.

Ray

Hi group

I am runing EMC with default startup code as G21
I have seen that if you use emc with default startup code as G21
and exit the program then it cant store and recall the work offsets
correctly.
for examle if workoffsets were x=-1 y=-1 z=-1 (all in mm)
when you exit and reopen emc then work ofssets are set to
x=-25.4 y=-25.4 z=-25.4

And sometimes i have noticed when you run program using G54 then
all the three axes start to travel towards an unknow position to
touch there hard limits. i think this may be due to the problem with
workoffsets storage problem.

There is another troubles if EMC is used in metric (mm) units (that
is if your default startup code is G21 or you enter G21 from MDI)
the SetCordinates dialog box found in scripts menu doesnt works.


i would suggest people to please set the default startup code to
G21 in ini and experiment with EMC to check these bugs of the
software.

No doubt EMC has lot of good features that are unmacthable to many
commercially available programs. In my country most people use metric
system (mm). If these problems are fixed then i think it will build
lot of confidence in people using them

regards

Asim



--- In CAD_CAM_EDM_DRO@..., "Asim Khan" <asimtec@y...>
wrote:

Thanks Ray and Jon for replying to my post about "G54,G55"

I have noticed (many times) that sometimes when you run a program

and

then you run another program next time (without closing and re
running) the interpreter runs this second program with a Feed value
which was being used in the last program. Although this second
program has the command for feed (for example F500).

Also I've noticed that sometimes G28 homes the axes at very slow

feeds

although the feed in program is much higher.

Sometimes when you run a program and interpreter encounters for
example "g01 x5 y10" and axis starts moving to some very strange
positions mostly towards hardware limits!

Another problem i've seen is that EMC displays old error message.

Like

if you had +ve limit on x axis once, and you get get -limit on y

axis

then EMC displays the old message that "+Ve limit on x-axis".
It seems as if the message boxes being displayed in EMC lag by on

Old

message.

I am using BDI-EMC version 2.16 and I had tried the previous

versions

also but all had these problem. I am using Servo2Go 8 axis Card.

and

my display program is tkEMC.

Please suggest what might be wrong?

regards

asim

[asimtec]

In a message dated 12/14/2003 9:26:05 AM Eastern Standard Time,
nigel.christianson@... writes:
Hi Shelby,

Not sure which software you are using, but nornmally the home command
sends the machine to some known position (which does not have to be
0,0,0 in programs like TurboCNC - which I think you might be using
from your description of the slow movement during homing). From
there you move to the work zero using G00 (assuming you have a jig or
something to hold the stock in a known position) and then rezero the
machine using G91 (I think from the top of my head - I don't have G
code manual handy)

HTH
Nigel
Shelby:

Actually, the home command (often G74 but is different with different
controls) sends the machine to the MACHINE reference. This is usually set with limit
switches and a zero/home pulse on the encoder. You would then send the
cutter to whatever new zero position you would like and use a G92 command (again
this can be different with controls) to set the new program zero. G90=absolute
position, G91=relative positoning, G00=rapid positioning, G01=linear
positioning, G02=clockwise circular positioning, and G03=counte clockwise circular
positioning. These are standard G codes for almost every control out there.
Other G codes will change from control to control so you would need to refer to
the instructiions for your particular controller.

Randy Abernathy
4626 Old Stilesboro Road
Acworth, GA 30101
Ph / Fax: 770-974-5295
E-mail: cnc002@...

I furnish technical support, repair, and other related services for your
industrial woodworking machinery. My background as Senior Service Engineer for the
SCMI Group for nearly fifteen years with factory training, combines with my
extensive background in electronics, mechanics, pneumatics, electrical and CNC
machinery to offer you needed support for your machinery.

Dave,
I wouldn't know how to attach machine components to granite. I am sure
it can be done though. Aside from the stability offered by the weight,
I don't see any advantage over aluminum jig plate.
Regards, Ray
If your post isn't off topic, I don't think my reply should be either!

--- In CAD_CAM_EDM_DRO@..., "turbulatordude"
<davemucha@j...> wrote:

Hi All,

I checked my T-Tech PCB mill and found it was based on a 1/2 aluminum
plate, ground flat, and then added the linear rails.

Thanks Jon, that's exactly what I needed to know.
I guess I'll start looking for new encoders instantly.

Mina F.
--- In CAD_CAM_EDM_DRO@..., Jon Elson <elson@p...> wrote:

Mina Aboul Saad wrote:

So, I got the breakout board, the Geckos 320 and the power supply

is almost

done.

Now, it's time to start wiring, I found out that my servo motors

have 4 pin

connection, how do I know which of the 4 wires is the Arm+ and

Arm- to be

connected to the geckos, or does this mean that my motors are

double

winding??

There is no "double winding" on DC brush motors. It is common for

these

to use 2 wires and 2 connector pins for each connection to the

motor.

Especially
on 4-pole DC motors, which have 4 brushes. In that arrangement,
diametrically
opposite brushes are connected together at some point, giving you

only two

wires to work with. If the motor is wired this way, you may have

to pull

the brushes and use an ohmmeter to figure out which wires are to

be

connected
together.

Regarding the encoders, they carry 17 pin connector, is there a

way to know

which wires for phase A and B, and also the +5V and the ground???
Is there some kind of standard for wire colors???

No, there isn't. If you can get info from the manufacturer, that

is

best. If not,
you may have to (VERY carefully) open up the encoder cover to

trace the

power wires. Usually there will be a capacitor directly across

the power

wires. If you are lucky, the capacitor will be an electrolytic

with

polarity
marked on it. Sometimes the circuit board will have a + marked

for the

power polarity. Once you have the power figured out, you can

figure

the rest with an oscilloscope on the signal wires. 17 is a lot of

wires.

I hope this is not really a brushless motor, which requires a few

extra

encoder wires to control motor commutation. Tht could account for

about

11 wires. A plain differential encoder with index would only need
8 wires.

Jon

Hi Shelby,

Not sure which software you are using, but nornmally the home command
sends the machine to some known position (which does not have to be
0,0,0 in programs like TurboCNC - which I think you might be using
from your description of the slow movement during homing). From
there you move to the work zero using G00 (assuming you have a jig or
something to hold the stock in a known position) and then rezero the
machine using G91 (I think from the top of my head - I don't have G
code manual handy)

HTH
Nigel

--- In CAD_CAM_EDM_DRO@..., "shelbyshepherd2002"
<cabrillo_shepherd@m...> wrote:

When I "HOME" the XYZ tables, it resets the software to X=0 Y=0 Z=0.

Most of the programs I see have the first lines "G00 X0 Y0 Z0,

which

I understand to be accelerates and positions to the coordinates
"X0 Y0 Z0".
This would mean it moves to very near the my "HOME" position.

I would like to move the work piece nearer the tool as G00 X=0 Y=0
means the table has to travel a lot of unneccesory distance, to do
this I would have something like "G00 X=95 Y=850 Z=0" for the first
line.

Is this the correct way to do it?

Shelby

When I "HOME" the XYZ tables, it resets the software to X=0 Y=0 Z=0.

Most of the programs I see have the first lines "G00 X0 Y0 Z0, which
I understand to be accelerates and positions to the coordinates
"X0 Y0 Z0".
This would mean it moves to very near the my "HOME" position.

I would like to move the work piece nearer the tool as G00 X=0 Y=0
means the table has to travel a lot of unneccesory distance, to do
this I would have something like "G00 X=95 Y=850 Z=0" for the first
line.

Is this the correct way to do it?

Shelby

--- In CAD_CAM_EDM_DRO@..., "cutthroatplasmaco"
<cutthroatplasmaco@y...> wrote:

1. What is the part number of the crydom?

The model # is DC60S3

DC Input model so thats ok

2. What are you using to turn it on?

I'm using a campbelldesigns.com breakout board to trigger the

relay -

12VDC

Should work

3. What is each wire of the crydom hooked to?

so, the +12Vdc from the breakout board is hooked to the positive

side

of the input on the relay, the gnd side of the breakout board is
hooked to the other (I guess it would be referred to as gnd) side

of

the input on the relay. +18Vdc side of the torch trigger is hooked

to

the + side of the relay output. The other side of the torch trigger
is hooked to the other side of the relay output.

I had originally purchased an AC SSR and it worked, wired basically
as I had wired this new crydom (except I wasn't using a breakout
board at that time). The problem with that was when I shut the

relay

off, it took up to a few seconds for the torch to shut off. So

after

reading those past messages from Jon and others explaining why that
happens, that's when I bought the dc relay... so, I'm fairly sure
that it's wired correctly...

As I not familiar with the torch trigger, does it supply the 18VDC?
I would expect that the minus side output of the ssr to be connected
to the return of the power source, and the plus side to the device
(torch) minus and the device plus hooked to the plus of a DC power
source. If the trigger plus is really the low side of the load then
what you described is ok.

4. What is the DC power source for the load you are switching.

Not exactly sure what you mean here?... The Plasma cutter has 18Vdc
on the ttorch trigger...

Is there an 18Vdc power supply that is part of the torch trigger?

Who/model of Trigger?

Mina Aboul Saad wrote:

So, I got the breakout board, the Geckos 320 and the power supply is almost
done.

Now, it's time to start wiring, I found out that my servo motors have 4 pin
connection, how do I know which of the 4 wires is the Arm+ and Arm- to be
connected to the geckos, or does this mean that my motors are double
winding??

There is no "double winding" on DC brush motors. It is common for these
to use 2 wires and 2 connector pins for each connection to the motor. Especially
on 4-pole DC motors, which have 4 brushes. In that arrangement, diametrically
opposite brushes are connected together at some point, giving you only two
wires to work with. If the motor is wired this way, you may have to pull
the brushes and use an ohmmeter to figure out which wires are to be connected
together.

Regarding the encoders, they carry 17 pin connector, is there a way to know
which wires for phase A and B, and also the +5V and the ground???
Is there some kind of standard for wire colors???

No, there isn't. If you can get info from the manufacturer, that is best. If not,
you may have to (VERY carefully) open up the encoder cover to trace the
power wires. Usually there will be a capacitor directly across the power
wires. If you are lucky, the capacitor will be an electrolytic with polarity
marked on it. Sometimes the circuit board will have a + marked for the
power polarity. Once you have the power figured out, you can figure
the rest with an oscilloscope on the signal wires. 17 is a lot of wires.
I hope this is not really a brushless motor, which requires a few extra
encoder wires to control motor commutation. Tht could account for about
11 wires. A plain differential encoder with index would only need
8 wires.

Jon

Thank you for the link to this site. I just looked at their RotoBot ( ) and it looks beautiful. It's inspirational! With the struts being a fixed length, it makes for an even more rigid structure, too...beautiful design!

Does anyone have any ideas on how to implement this approach, in a home built machine? I mean, I could probably go to a machine shop and have parts made, but that's just throwing money at it...I'm thinking in terms of the way we build other small routers, truly hacking a solution. And, would any existing programs be able to control it?

-- Chuck Knight

Hey Everyone,
I've got a question for Jon Elson & Ray Henry..... and anyone else
that may know??????

Jon, Does your "Universal Stepper Controller" handle input from a
manual pulse generator? Selector switches for axis & step rate,
handwheel for direction?

Jon & Ray, Is "EMC" capable of handling this type of external input?
or does "EMC" really not care/or have anything to do with it?

Thanks, Tim Bostic

I'm new here. I have recently started researching building a CNC router and converting mills to CNC. If any of the questions can be readily answered with a link please direct me.

I'm going to assemble a router to learn how the things work and to gain experience with the required equipment and software. I've been looking around and have seen some products which are commonly used by CNC at home people. I have a few questions.

I'm considering the Stepperworld FET-3 controller. To use with 3 PK266-03 steppers. This unit is affordable and seems to be good enough for routing. It does halfstepping and I'm wondering if there is much to be gained with 10x microstepping of the Gecko drives. Stepperworld does not list all the specs like max stepping frequency and a few others listed by Gecko etc.

How is the accuracy and size of the machine defined by the controller board and lead screws? It seems that the machine has certain size and speed limits based on the controller's limitations. Stepping frequency and screw pitch define speed to some extent. How many steps per inch before you're just reducing speed and not gaining accuracy? I've read that if you want to do circular interpolation you need to use the same screw pitch on X and Y axis. Is this a software or hardware(controller) limitation? Is this also true for the Z if you intend to do 3D contouring.

Software seems to vary from freeware to industrial standard at 1000's of dollars per license. Is there a site that weighs the pros and cons of several types of software? Are there compatibility issues with controllers and software? I guess that the software to operate the machine can be run from DOS, Linux, or Windows. Most of the Gcode generators would be Windows based? I'll be designing parts in SolidWorks.

My plan is to make a relatively accurate router, then find a larger tabletop mill to convert for cutting aluminum. I'd go ahead and buy a Sherline or similar to start with but the Y travel is not enough for what I want to do.

Thanks for the help. Some of you may recognize me from RCGroups.

Gregory Kamysz
Crystal Lake, IL
USA

Hi,

I have three panasonic msm022a2ue 200W brushless servos I got from
ebay. I find the shafts are very stiff. They have bearings only (no
oil seals or brake). Is this normal?

Andrew