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BobWarfield
02-02-2010, 11:18 AM
As promised, here is what little you have to know to run a CNC mill like a Manual Mill with DRO's and power feeds:

To move quickly to a location on the DRO, you enter:

G0 X123 Y456 Z789

That's G+Zero not "Go". Enter appropriate X, Y, and Z coordinates for the 123, 456, and 789.

You need only enter the G0 once and the machine will remember. After that, just enter X, Y, and Z's. If you want to move in one or two dimensions/axes, just enter those. The machine remembers the one you didn't enter and leaves it alone.

To move at a feedrate to a given location, you enter:

G1 F123 X456 Y789 Z101112

G1 tells it to move at feedrate 123. The feedrate is in inches per minute. "F3" is therefore 3 IPM.

X, Y, and Z coordinates are just like for G0.

That's basically it for the simple motions you could make on a mill fitted with DRO's and power feeds on all axes. You could put that on a card and tape it to machine.

There are similar simple commands for turning the spindle on/off, making it go clockwise/counterclockwise, and setting the spindle speed.

If you have a toolchanger, there are simple commands to pick a tool.

Lastly, there are simple commands to turn your coolant on and off.

It's dead easy to use a CNC mill just like a manual mill. Consider yourself armed and dangerous if you encounter a CNC, LOL.

Cheers,

BW

Evan
02-02-2010, 11:54 AM
It's even easier than that for many things. If I need to drill a string of holes with a 1/2 inch spacing I set the jog to .5", set the feed rate to what I want and then jog along the line a half inch at a time using the jog to drill to the right depth at each half inch interval.

CNC drilling is amazing. I recently made a wire drawing die plate and the smallest hole is .030 in a quarter inch plate. I set the machine to drill about .030 per peck on a fast peck cycle and away it went easily drilling the hole with no difficulty.

vpt
02-02-2010, 12:48 PM
You lost me at G.

Toolguy
02-02-2010, 01:12 PM
I got a Milltronics CNC for doing prototypes. It's the best of both worlds. It has a Bridgeport type head and full 3 axis function. There is an electronic handwheel that can be used just like the manual machines. Just push an axis button - X,Y or Z and turn the handwheel. The handwheel is marked in 100 increments for one revolution with a click for each mark. There are on and off buttons for spindle and coolant. There are dials for feedrate and spindle speed.
It has a 3 axis readout to one tenth increments.It is very easy to use the mill just like a Bridgeport with no programming at all. It also has conversational programming that is WAY faster and easier than G code. I will never buy a CNC machine that doesn't have conversational programming.

beanbag
02-02-2010, 01:38 PM
I don't like to type in these commands for these quickie cuts. I would only use the jogging at a controlled feed rate (i.e. pressing the arrow keys) so that it will leave a nice surface finish. Doing something very quickly is something I try to avoid on the CNC because it is too easy to type in something like G0 Z-2, and suddenly realize you are in g91 and not g90 mode. If you want to do something quickly, you'd better be able to stop doing it quickly as well.

BobWarfield
02-02-2010, 02:06 PM
You'll get past it eventually beanbag. Typing in those MDI commands is no biggie. Just look at them before you press Enter, same as anything else.

Cheers,

BW

PS You know it's funny, but once you screw it up, it is burned in but good. Heck, even once you hear about and imagine the degree of destruction possible it is burned in good. I've never left a key in a chuck of any kind and turned on the spindle, but I cringe even looking at pictures of keys in chucks.

Scishopguy
02-02-2010, 03:36 PM
I got a Milltronics CNC for doing prototypes. It's the best of both worlds. It has a Bridgeport type head and full 3 axis function. There is an electronic handwheel that can be used just like the manual machines. Just push an axis button - X,Y or Z and turn the handwheel. The handwheel is marked in 100 increments for one revolution with a click for each mark. There are on and off buttons for spindle and coolant. There are dials for feedrate and spindle speed.
It has a 3 axis readout to one tenth increments.It is very easy to use the mill just like a Bridgeport with no programming at all. It also has conversational programming that is WAY faster and easier than G code. I will never buy a CNC machine that doesn't have conversational programming.

Back in the early 80's I went to a SME tool show in Orlando and saw a Wells Index knee mill with this type of conversational controller. I wish we could have talked our department into buying one. It was really easy to use and could also be programmed with G codes. That was a really neat machine.

Dawai
02-02-2010, 04:03 PM
OR?

get a keyboard emulator, a arcade joystick. each axis of the joystick "the emulator" throws a keystroke according to jog in that direction..

You can stand there with the joystick in your hand and cut manually.

This is a simple way to build a pendant.. or.. jog wheels?? they are simple encoders that pulse the software.. You can weight a jog wheel and spin it alike a old fooseball table.. (illegal to do in the rules)

If that is too fancy? just use the arrow keys.. soon they will be too black to read the lil characters on them tho.

BobWarfield
02-02-2010, 05:07 PM
"Soon they will be too black to read the little characters"

I know just what you mean!

Course the chips getting buried in the keyboard will mean it needs replacement soon anyway.

Best,

BW

PaulT
02-02-2010, 05:30 PM
As promised, here is what little you have to know to run a CNC mill like a Manual Mill with DRO's and power feeds:

To move quickly to a location on the DRO, you enter:

G0 X123 Y456 Z789


Yikes. On the practical machinist forum a while ago, they had a thread about the worst (and most expensive) crashes people had ever seen, and 90% of them were due to mis entry of an MDI command, leading to hitting the GO button and then watching an expensive big bang occur.

After reading that thread, I realized that most of the crashes I had so far on my CNC machine were also due to bad MDI entries, either typos or not thought out well enough, typically in a hurry to get a part done.

I stopped using MDI for any machining at all. Instead I wrote a set of G code macros for the common "manual" type things I do, ie drilling, tapping, surfacing, trimming ends. These macros are parameterized, and after I enter the parameters in a macro I single step through the part where the parameters are set as a double check on the parameter values. If that looks good, I hit the go button.

No more major crashes have occurred since moving to this method.

My other big crash eliminator is the following. If at all possible, never setup your workpiece so that Z0 is below the vice jaw edge. This was my second largest contributor to crashes, typically pausing, jogging away from the part to do some inspection, hitting the start button again but forgetting that the rapid path from the current spindle location wouldn't clear the vice top.

Paul T.

S_J_H
02-03-2010, 09:38 AM
What Bob said and I also extensively use the jog flyout in Mach3 along with a USB gamepad. I do not miss turning a handwheel 1 iota.

BobWarfield
02-03-2010, 12:57 PM
Or, if you're very afraid of MDI, just never use g0. Always use g1 and a slow feedrate. That way, you've got plenty of time to e-stop.

My power feeed didn't really go nearly as fast as my CNC even maxed out. Also, FWIW, have crashed a manual power feed too. It doesn't take a computer to make those kinds of mistakes, just an idiot at the controls, LOL.

Cheers,

BW

Dawai
02-03-2010, 05:59 PM
IF it ain't a real big program, I always lower the table and run the program through ..

I ain't perfect.. typos bust $35 end mills.

MY SPECIAL manual cutting software, I had a flight simulator joystick rigged up to manually cut.. a 2hp dremel tool I had there.. whoopiieee.. till.. the crappy subroutine for accel-decell blowed the geckos up in smoke rings. I blamed Geckodrive, it was the heavy table and no proper decel, pump up voltages.

Neat thing? it was recording each move for "replay".

A pendant simplifies it all.. jog wheels.. a clarostat optical encoder.. simple to do, it explains it all in Mach3 manual.

It ain't nothing anybody here does not have the brains to figure out.. I ain't that smart, I am however one of the most stubborn people here.

I highly suggest to all to purchase a tabletop cnc mill and join this century of machining. It can be ran in manual too.

Dawai
02-03-2010, 06:29 PM
By the way...

Linuxcnc.org has cnc simulators you can MDI movements and see the movements of the endmill on the screen.. No busted endmills, no errors can break anything.

Also, Mach3 can too.

doctor demo
02-04-2010, 01:07 AM
Just when I was getting comfortable knowing that I was as dumb as a bag of door knobs, this thread comes along and now I have to down grade to a box of rocks:D .
Roller balls, joy sticks G codes:eek: I can't even play pong on My machine:) .

Steve

gmatov
02-04-2010, 02:53 AM
Doc,

I am wondering how many of therm are active gamers, too. All they talk about is playing with their joysticks. I imagine there are lots of firing buttons, too.

Shoot alla them vermin out of space.

I won't say they should learn to crank a handle, but just maybe.

Cheers,

George

gnm109
02-04-2010, 07:44 AM
You lost me at G.


That's nothing. He had me at Hello. :)

Evan
02-04-2010, 07:55 AM
There is no reason to be intimidated by G-Code. It isn't like computer programming. There is no fancy computer logic involved. It is just like a set of instructions to find a treasure.


G0 X 10 (go ten units positive X at full speed)
G1 Z -1 F3 (lower the cutter 1 unit at Feed 3 units per minute)
G1 Y2 F3 (go two units positive Y at Feed 3 units per minute)
G1 X -2 (go negative X 2 units, still at F3)
G0 Z 1 (raise the cutter one unit at maximum speed, G0 is the rapid move command)

Dawai
02-04-2010, 08:25 AM
Think of it as a DRO, with power feed of variable rate. All you people who "make fun of technology" perhaps should remove the DRO. It is nothing to be intimidated by, nor motors on the handles.

Crank a handle.. geeze my poor soft hands might develop a blister...

(yeah.. my hands are not that soft, and my head is as hard as a billy goat.)