NCPlot Forums

Hi, I'm a complete novice with regards to G-code. I can see that it is fairly simple , but what I'm having trouble with at the moment is "breaking the ice".

I have downloaded the Nc Plot v1.1 software but what I need is a very simple starting procedure, i.e do I need to define the workpiece somehow ?? , and then if somebody could post a very simple example of some code and how to run it it the plotting software that would be most helpful.
I have tried to define a simple tool movement , using G1 , and then defining my position and feed rates but not much is happening !!!

cheers Nick.

Hi Nick,

I don't really have any documentation that teaches G-Code, but I do have some links that may help you.

This is Mike Lynch's CNC Concepts website, lots of training related material.

www.cncci.com

HAAS has got some good material on their web site:

http://www.haascnc.com/custserv_training.asp#mill

You can also download and install NCPlot v2. There are some pretty good sample files that come with it. You can step through these and get a good idea of what each command does.

Thanks,
Scott

i figured this is where i should ask this.
just starting to mess around with the program. how do you use the G28 command properly. i want the z axis to move up from the part, it just moves to the axis origin though. ive tried changing the home position z value. im a complete programming newbie

Hi,

The G28 command is actually two moves. The first move is a position command *in the current work coordinate system*. The second move positions the commanded axes to their machine zero coordinate. Many programmers use the following command:

G91 G28 Z0

This command causes no motion for the first move because of the G91 (incremental move of zero). Then then second move brings the Z back to machine zero.

Of course, if you have no work offset set for the Z, then the work zero and the machine zero will be the same point. You have to go to the Machine Configuration and set a work offset coordinate for the offset you are using (probably G54).

Hope this helps,

Scott

hi scott, love the program
ya i use g91 on the machines at work, trying to use g90. i changed the z to 60 mm in the 54 home. smid talks about not switching from absoute to incremental, so trying to stay in absolute. so how do you set the home positions?

Most machines have their machine zero positions at the most positive end of travel. Which means that their G54-G59 offset will have a negative Z value.

The G28 command example I showed you is usually used at the end of the program when you want the Z to move back to home (machine zero). So you can still program in G90 and only use the G91 as part of the G28 command.

As an alternative, I use G53. This command allows you to position relative to your home position without the intermediate move. Take this command for example:

G00 G53 Z0.

This command will simply move the Z axis back to the machine zero position without using G91. This command ignores all work and tool offsets and positions relative to the machine zero.

Thanks,
Scott

i was looking at a program using two home offsets, but when i went to see where they were, in the machine config menu there were no numbers. is there a way to see the home positions in relation to the absolute home

I am a novice also so here is may first of many basic questions. I have imported a dxf file in 2-D and the top view is how the part will lay in a vise in the mill. How do I tell NC Plot the part is 1.5" tall (the Z axis)? When I try to chain the area I want to mill out I get an error message that the entities are not chained. The entities form a rectangular mill out on the end to the part. Not sure I am understanding the error message of not.

Tom,
The easiest way to chain the drawing is to just click the button for Chain All. When a layer has been chained you will see a small square that marks the start point of the chain and an arrow that indicates the cutting direction.

To set cutting depths you set the appropriate Z values under the layer settings tab. This tab is on the bottom half of the DXF Conversion Options window.

Thanks,
Scott

The block is finished on all four sides.I only want to mill clearance on one side. If I chain select all the tool path will go all the way around the part.

If I set the Z to 1.5" ( the part height) and I know my end mill can only go down 0.040" per pass how can I make several passes?

This is a very frustrating process to lean to use NCPlot. It seam this software only works if the geometry is a closed loop. I do not want to machine a circle. I have the circle and only want to machine out a piece of pie. I cannot get NCPlot to only choose the piece of pie it keep choosing the whole pie. I have a friend who has done these parts with Master Cam but I cannot afford Master Cam. Any help would be greatly appreciated.

Tom,

To use the multiple Z step function the geometry must first be chained. This does not mean that the geometry must form a closed loop, the chaining process simply looks for connected entities and makes sure that they are going in the same direction and in sequence.

You cannot edit the geometry within NCPlot, the DXF file should be edited to represent the desired tool path before you load it.

Thanks,
Scott