Hi guys,

Im into aluminium engraving.  I must engrave a lots of letters (words) on big aluminium plate and some of letters are very far from each other.
My question is:

Is there any option in Mach3 where I can set up that my CNC machine go faster when it is above material and slower when it is in material ?

For example I want 1200 mm/s when my mill is into material I want to engrave and 2400 mm/s when it is above material (mill is going to another letter).
Whit that I would be able to reduce my time a  lot.

Thank you !

Yes!  G0 and G1.  G0 runs at the maximum configured motor speed and would be used when the tool is above the material.  Then G1 is used for the cutting moves and can be programmed for a different speed with the "F" word parameter.  That is actually what these two commands were designed for.  G0 for rapid moves and G1 for cutting moves.

Hope that makes sense.

Stephen "Highspeed" Kruse

What is the maximum speed your machine is configured for? It may be going slower simply because it cannot go any faster

Motor Tuning -> Speed for X & Y axes.

As mentioned above, is your G-Code using both G0 & G1 moves?

Well guys thanks for fast replay's !

At the moment my Velocity is set to 500 in MACH3.

I don't know what is maximum speed my machine can go, but it certainly can go faster than that (500).

Where do I set G0 and G1 parameters ?

I suppose if G1 is used for cutting moves it can be set in Motor Tuning under Velocity tab.

But where do I set G2 speed ?

Cheers
 

If its at 500 then that is your current max speed with ANY code, that does not mean it is all it can do though, who set that speed?

To go higher will need testing and tweaking unless you know for a fact that it can do it, not hard just tedious

If you look at your G-Code file, you should see lines beginning with G0, G1, G2 etc these are the moves, G0 is a rapid and never used for cutting, G1 is a cutting move - straight at a feed speed commanded by the F parameter on or near that line, G2 is clockwise circular cutting again with an F parameter maybe and so on, these are all documented - Google Mach3 G codes and you will get a document that explains it all.

Now, there is no point in the code asking for a speed of say F1000 if your machine is pegged at 500 - it will be limited to 500 for cutting OR rapids.

To increase the speed you change the settings in motor tuning, increase in small amounts say 100 at a time, save it then jog the machine at full rapid (shift & jog) if it screams you have gone too fast and the motors are throwing in the towel, if ok then advance some more, at some stage it WILL give up, at this point you need to back off maybe 20% and start testing for lost steps - this will cause circles to come out square and other lovely cock-ups

Its an art to get right as every machine is totally different, but can be done, just make sure you note what you are doing.

Once you have found the sweet spot, set the acceleration to 1/10 of the speed and start testing again for lost steps etc.

Definitely get the book on G-codes though, there is also a smaller on on M-Codes

Also a little more info on the machine would be good

G0 and G1 are modal commands, meaning that once set it is the active mode until a different modal command is set.  As an example:

G0 X0 Y0 Z0
X1
Y2
G1 Z-0.5 F50
X4 Y5 F600
X3 Y7

In this rather basic program, the machine is set to rapid movements (G0) and positions the tool at zero for all axes, then moves (still at rapid movement) the X Axis to 1 followed by a movement of the Y axis to 2.  (These two moves can be combined into one line and the tool would then traverse at a diagonal line from 0,0 to 1,2 rather than a straight move along the X axis and a seperate move on the Y axis.  Next, a cutting move (G1) is made on the Z axis to -0.5 at a feed rate of 50 followed two cutting moves (still in G1 mode) at a feed rate of 600 to various points on the X and Y axis.  These last two moves are diagonal moves since the X and Y values are on the same line and the feed rate (F600) is set until changed by a different F word so both of the last two moves are made at a feed rate of 600.

In Motor Tuning, adjust the Velocity to the speed at which your machine is capable of running RELIABLY.  This velocity is what is used for G0 moves.  You'll also need to adjust acceleration accordingly to get smooth starts/stops as well as keeping it high enough so that corners don't become rounded.

As shown above, G1 moves are made at a speed determined by a feed rate command.  This can be set with F followed by a number or you can manually set it through the feed rate controls on the Mach 3 screen.  However, if you set it through the screen controls it can be altered by the program if an F command is encountered.  But again, to really summarize:

G0 - Rapid move at the velocity set in Motor Tuning
G1 - Cutting move at the currently set (via program or screen) feed rate.

Hope that makes sense.

Highspeed

G0 and G1 are modal commands, meaning that once set it is the active mode until a different modal command is set.  As an example:

G0 X0 Y0 Z0
X1
Y2
G1 Z-0.5 F50
X4 Y5 F600
X3 Y7

In this rather basic program, the machine is set to rapid movements (G0) and positions the tool at zero for all axes, then moves (still at rapid movement) the X Axis to 1 followed by a movement of the Y axis to 2.  (These two moves can be combined into one line and the tool would then traverse at a diagonal line from 0,0 to 1,2 rather than a straight move along the X axis and a seperate move on the Y axis.  Next, a cutting move (G1) is made on the Z axis to -0.5 at a feed rate of 50 followed two cutting moves (still in G1 mode) at a feed rate of 600 to various points on the X and Y axis.  These last two moves are diagonal moves since the X and Y values are on the same line and the feed rate (F600) is set until changed by a different F word so both of the last two moves are made at a feed rate of 600.

In Motor Tuning, adjust the Velocity to the speed at which your machine is capable of running RELIABLY.  This velocity is what is used for G0 moves.  You'll also need to adjust acceleration accordingly to get smooth starts/stops as well as keeping it high enough so that corners don't become rounded.

As shown above, G1 moves are made at a speed determined by a feed rate command.  This can be set with F followed by a number or you can manually set it through the feed rate controls on the Mach 3 screen.  However, if you set it through the screen controls it can be altered by the program if an F command is encountered.  But again, to really summarize:

G0 - Rapid move at the velocity set in Motor Tuning
G1 - Cutting move at the currently set (via program or screen) feed rate.

Hope that makes sense.

Highspeed

It makes perfectly sense. Thank you !
If i get it right the procedure is next.

I want my machine to move 500 mm per m when it is in material and i set that in mach 3 - motor and tuning - velocity tab.

I want my machine to go 1000 mm per m when it is not in material and for that I should go into G-Code with Notepad (for example) and change all G1 F's from 500 to 1000 (for example).

And that will make my machine goes 500 mm per m when it is in material and 1000 mm per m when it is above material. Correct me if I am wrong.

Not quite correct but you have the right idea.

I want my machine to move 500 mm per m when it is in material and i set that in mach 3 - motor and tuning - velocity tab.

You set that in Gcode with the F### command.

I want my machine to go 1000 mm per m when it is not in material and for that I should go into G-Code with Notepad (for example) and change all G1 F's from 500 to 1000 (for example).

You set that in Motor Tuning with Velocity.

Tweakie.

Not quite correct but you have the right idea.

Quote

I want my machine to move 500 mm per m when it is in material and i set that in mach 3 - motor and tuning - velocity tab.

You set that in Gcode with the F### command.

Quote

I want my machine to go 1000 mm per m when it is not in material and for that I should go into G-Code with Notepad (for example) and change all G1 F's from 500 to 1000 (for example).

You set that in Motor Tuning with Velocity.

Tweakie.

My mistake. I'll try that right away.
Usualy I make G code with ArtCAM.
Is there any software that can change G00 G01 speeds automatically instead of me doing it manually in Notepad ? 

Usualy I make G code with ArtCAM.
Is there any software that can change G00 G01 speeds automatically instead of me doing it manually in Notepad ?

The Gcode G00 / G01 moves are usually automatically taken care of by the post processor used in ArtCam.
Are you using their Mach2 post processor ?

Tweakie.