5 ms·

I'm a Windows dev at build, but I know nothing about 3D printing. If you can you give me an idea what G-code is, then I'll ask or look at the SDK.

by gecko 13y ago

deleted 13y ago
[deleted]
Mikeb85 13y ago
G-code converts a 3D model into printing instructions for a 3D printer. http://reprap.org/wiki/G-code http://reprap.org/wiki/G-code
- Someone 13y ago
  No, it describes how to make an object with a CNC machine. I hadn't heard about G-code until 5 minutes ago, but from what I see, there is a huge mismatch between G-code and the way 3D printers operate. Who cares about the zillion times one has to cut away a piece of wood using a lathe to create a sphere if one uses a device that _adds_ material to the object? Yes, it is good that there is software that understands G-code for 3D printers, but using it as _the_ data format? Ridiculous. That would be as if one used plotter instructions to print in 2D; instead of "here is a rectangle; fill it with pure red", one would have zillions of "move pen to x,y; draw to x,z; move to x,y+0.01; draw to x,z+0.01; move to x,y+0.02,…" instructions. Also, I don't even think G-code is that good of an idea for generic CNC files. Suppose your file says "use a 10mm bit", while your CNC machine only supports bits up to 5mm. You can sort-of emulate the larger one, but it will be inefficient and lead to lower quality cuts.
  - tmuir 13y ago
    G-code is indeed an old language, but it's the industry standard because it's better than all of the alternatives. There are complex G-codes, such as threading, which allows you to define the pitch, thread depth, cutting style, the distance to move away from the material between passes the distance to cut the thread, etc. But a lot of G-code files do consist of thousands of discrete lines. The reduction of a 3d shape to motor signals will eventually come to a stage that deals with lots discrete vectors, regardless of how you represent the data, G-code or not. G-code files consisting of thousands of lines are usually created by a CAM software anyways, not by hand. Your strawman argument of a 10mm bit when only a 5mm bit is available extends to just about any type of standardized process that consists of instructions being evaluated.
    - Someone 13y ago
      Yes, descibing a product in terms of motor signals will be tedious. That's why I think a good description tries hard to describe what must be produced, not how it must be produced. And yes, it applies to any process that consists of instructions. Again, that's why I think that is a bad way to describe a 3D object for a generic printer interface.
  - jacquesm 13y ago
    G-code describes movements and tooling parameters, it does not describe how to make an object with a CNC machine. That's why you can use G-code both for additive and subtractive processes.
  - angersock 13y ago
    Well, let's look at it this way. Having a language which simply describes the movement of your tool through space is nice--there is less chance that a later vendor decides to add overrides to your "red rectangle" to be more of a blue circle. There is also much less chance for hardware vendors to screw up their implementations and introduce incompatibilities: move this bit here, at this speed. It makes the firmware much simpler, and makes the shelf-life of files much longer. It seems to be a pretty good solution, though with not as great a shiny factor as others.
  - adestefan 13y ago
    That is how plotters work. Lookup HP-GL or DPML
  - jotux 13y ago
    >it is good that there is software that understands G-code for 3D printers, but using it as _the_ data format? People don't really write G-code anymore, it's generated from a 3D model. G-code is like the compiled version of the model made for execution on the printer. >Also, I don't even think G-code is that good of an idea for generic CNC files Why make such a ridiculous assumption when you just said you heard about this only 5 minutes ago? You're making a blanket statement about a technology that's been around for more than 40 years based on 5 minutes of googling.
bagels 13y ago
G-code is a language used to describe the movement of a tool. I think the first uses were for cutting tools, like CNC lathes and milling machines. It describes things like movements of a tool on linear or rotational axis, cutting tool rotational speed, operation of auxiliary equipment (heater on/off), etc.
adestefan 13y ago
Think of G-code like PostScript. It's a description language that tells a multi-axis machine how to move in 3D space.
- seanmcdirmid 13y ago
  I was hoping for something a bit more vector based. G-code seems more like Logo than PostScript.
qwerty_asdf 13y ago
https://en.wikipedia.org/wiki/G-code https://en.wikipedia.org/wiki/G-code The first implementation of high level numerical control programming language was developed at the MIT Servomechanisms Laboratory in the late 1950s. The main standardized version used in the United States was settled by the Electronic Industries Alliance in the early 1960s. During the 1970s through 1990s, many CNC machine tool builders attempted to overcome compatibility difficulties by standardizing on machine tool controllers built by Fanuc. Siemens was another market dominator in CNC controls, especially in Europe. Numerical control (NC) is the automation of machine tools that are operated by abstractly programmed commands encoded on a storage medium, as opposed to controlled manually via handwheels or levers, or mechanically automated via cams alone. Most NC today is computer numerical control (CNC), in which computers play an integral part of the control. G-code is the common name for the most widely used numerical control (NC) programming language. There are other codes (Letter addresses which span the entire alphabet); the type codes can be thought of like registers in a computer. Some letter addresses are used only in milling or only in turning; most are used in both. Bold below are the letters seen most frequently throughout a program. A Absolute or incremental position of A axis (rotational axis around X axis) B Absolute or incremental position of B axis (rotational axis around Y axis) C Absolute or incremental position of C axis (rotational axis around Z axis) D Defines diameter or radial offset used for cutter compensation. D is used for depth of cut on lathes. E Precision feedrate for threading on lathes F Defines feed rate G Address for preparatory commands H Defines tool length offset; Incremental axis corresponding to C axis (e.g., on a turn-mill) I Defines arc center in X axis for G02 or G03 arc commands. Also used as a parameter within some fixed cycles. J Defines arc center in Y axis for G02 or G03 arc commands. Also used as a parameter within some fixed cycles. K Defines arc center in Z axis for G02 or G03 arc commands. Also used as a parameter within some fixed cycles, equal to L address. L Fixed cycle loop count; Specification of what register to edit using G10 M Miscellaneous function N Line (block) number in program; System parameter number to be changed using G10 O Program name P Serves as parameter address for various G and M codes Q Peck increment in canned cycles R Defines size of arc radius, or defines retract height in milling canned cycles S Defines speed, either spindle speed or surface speed depending on mode T Tool selection U Incremental axis corresponding to X axis (typically only lathe group A controls) Also defines dwell time on some machines (instead of "P" or "X"). V Incremental axis corresponding to Y axis W Incremental axis corresponding to Z axis (typically only lathe group A controls) X Absolute or incremental position of X axis. Also defines dwell time on some machines (instead of "P" or "U"). Y Absolute or incremental position of Y axis Z Absolute or incremental position of Z axis
tmuir 13y ago
Heres some sample G-code: N10 G00 Z0.25000 N20 G00 X0.00000 Y0.29975 N30 G01 Z-0.50000 F2.00 N40 G01 X0.00000 Y1.03725 F5.00 N50 G02 X1.12000 Y1.03725 I0.56000 J-0.37323 N60 G01 X1.12000 Y0.29975 N70 G02 X0.00000 Y0.29975 I-0.56000 J0.37323 N80 G00 Z0.25000 N90 G00 X0.00000 Y0.00000 N100 G00 X1.5200 Y0.29975 N110 G01 Z-0.50000 F2.00 N120 G01 X1.5200 Y1.03725 F5.00 N130 G02 X2.64000 Y1.03725 I0.56000 J-0.37323 N140 G01 X2.64000 Y0.29975 N150 G02 X1.5200 Y0.29975 I-0.56000 J0.37323 N160 G00 Z0.25000 N170 G00 X1.32000 Y0.668625 N180 G01 Z-0.50000 F2.00 N190 G00 Z0.25000 N200 G00 X0.00000 Y0.00000 The N field is a line number and is disregarded The G field describes the motion type. G00 is a rapid line. G01 is a feedrate line. G02 and G03 are arcs, one CW, the other CCW. The X, Y, and Z fields describe geometry The F field is the feedrate, or the tool's speed

I'm a Windows dev at build, but I know nothing about 3D printing. If you can you give me an idea what G-code is, then I'll ask or look at the SDK.

by gecko 13y ago

I'm a Windows dev at build, but I know nothing about 3D printing. If you can you give me an idea what G-code is, then I'll ask or look at the SDK.

deleted 13y ago

[deleted]

Mikeb85 13y ago

G-code converts a 3D model into printing instructions for a 3D printer. http://reprap.org/wiki/G-code http://reprap.org/wiki/G-code

Someone 13y ago
No, it describes how to make an object with a CNC machine. I hadn't heard about G-code until 5 minutes ago, but from what I see, there is a huge mismatch between G-code and the way 3D printers operate. Who cares about the zillion times one has to cut away a piece of wood using a lathe to create a sphere if one uses a device that _adds_ material to the object? Yes, it is good that there is software that understands G-code for 3D printers, but using it as _the_ data format? Ridiculous. That would be as if one used plotter instructions to print in 2D; instead of "here is a rectangle; fill it with pure red", one would have zillions of "move pen to x,y; draw to x,z; move to x,y+0.01; draw to x,z+0.01; move to x,y+0.02,…" instructions. Also, I don't even think G-code is that good of an idea for generic CNC files. Suppose your file says "use a 10mm bit", while your CNC machine only supports bits up to 5mm. You can sort-of emulate the larger one, but it will be inefficient and lead to lower quality cuts.
- tmuir 13y ago
  G-code is indeed an old language, but it's the industry standard because it's better than all of the alternatives. There are complex G-codes, such as threading, which allows you to define the pitch, thread depth, cutting style, the distance to move away from the material between passes the distance to cut the thread, etc. But a lot of G-code files do consist of thousands of discrete lines. The reduction of a 3d shape to motor signals will eventually come to a stage that deals with lots discrete vectors, regardless of how you represent the data, G-code or not. G-code files consisting of thousands of lines are usually created by a CAM software anyways, not by hand. Your strawman argument of a 10mm bit when only a 5mm bit is available extends to just about any type of standardized process that consists of instructions being evaluated.
  - Someone 13y ago
    Yes, descibing a product in terms of motor signals will be tedious. That's why I think a good description tries hard to describe what must be produced, not how it must be produced. And yes, it applies to any process that consists of instructions. Again, that's why I think that is a bad way to describe a 3D object for a generic printer interface.
- jacquesm 13y ago
  G-code describes movements and tooling parameters, it does not describe how to make an object with a CNC machine. That's why you can use G-code both for additive and subtractive processes.
- angersock 13y ago
  Well, let's look at it this way. Having a language which simply describes the movement of your tool through space is nice--there is less chance that a later vendor decides to add overrides to your "red rectangle" to be more of a blue circle. There is also much less chance for hardware vendors to screw up their implementations and introduce incompatibilities: move this bit here, at this speed. It makes the firmware much simpler, and makes the shelf-life of files much longer. It seems to be a pretty good solution, though with not as great a shiny factor as others.
- adestefan 13y ago
  That is how plotters work. Lookup HP-GL or DPML
- jotux 13y ago
  >it is good that there is software that understands G-code for 3D printers, but using it as _the_ data format? People don't really write G-code anymore, it's generated from a 3D model. G-code is like the compiled version of the model made for execution on the printer. >Also, I don't even think G-code is that good of an idea for generic CNC files Why make such a ridiculous assumption when you just said you heard about this only 5 minutes ago? You're making a blanket statement about a technology that's been around for more than 40 years based on 5 minutes of googling.

bagels 13y ago

G-code is a language used to describe the movement of a tool. I think the first uses were for cutting tools, like CNC lathes and milling machines. It describes things like movements of a tool on linear or rotational axis, cutting tool rotational speed, operation of auxiliary equipment (heater on/off), etc.

adestefan 13y ago

Think of G-code like PostScript. It's a description language that tells a multi-axis machine how to move in 3D space.

seanmcdirmid 13y ago
I was hoping for something a bit more vector based. G-code seems more like Logo than PostScript.

qwerty_asdf 13y ago

https://en.wikipedia.org/wiki/G-code https://en.wikipedia.org/wiki/G-code The first implementation of high level numerical control programming language was developed at the MIT Servomechanisms Laboratory in the late 1950s. The main standardized version used in the United States was settled by the Electronic Industries Alliance in the early 1960s. During the 1970s through 1990s, many CNC machine tool builders attempted to overcome compatibility difficulties by standardizing on machine tool controllers built by Fanuc. Siemens was another market dominator in CNC controls, especially in Europe. Numerical control (NC) is the automation of machine tools that are operated by abstractly programmed commands encoded on a storage medium, as opposed to controlled manually via handwheels or levers, or mechanically automated via cams alone. Most NC today is computer numerical control (CNC), in which computers play an integral part of the control. G-code is the common name for the most widely used numerical control (NC) programming language. There are other codes (Letter addresses which span the entire alphabet); the type codes can be thought of like registers in a computer. Some letter addresses are used only in milling or only in turning; most are used in both. Bold below are the letters seen most frequently throughout a program. A Absolute or incremental position of A axis (rotational axis around X axis) B Absolute or incremental position of B axis (rotational axis around Y axis) C Absolute or incremental position of C axis (rotational axis around Z axis) D Defines diameter or radial offset used for cutter compensation. D is used for depth of cut on lathes. E Precision feedrate for threading on lathes F Defines feed rate G Address for preparatory commands H Defines tool length offset; Incremental axis corresponding to C axis (e.g., on a turn-mill) I Defines arc center in X axis for G02 or G03 arc commands. Also used as a parameter within some fixed cycles. J Defines arc center in Y axis for G02 or G03 arc commands. Also used as a parameter within some fixed cycles. K Defines arc center in Z axis for G02 or G03 arc commands. Also used as a parameter within some fixed cycles, equal to L address. L Fixed cycle loop count; Specification of what register to edit using G10 M Miscellaneous function N Line (block) number in program; System parameter number to be changed using G10 O Program name P Serves as parameter address for various G and M codes Q Peck increment in canned cycles R Defines size of arc radius, or defines retract height in milling canned cycles S Defines speed, either spindle speed or surface speed depending on mode T Tool selection U Incremental axis corresponding to X axis (typically only lathe group A controls) Also defines dwell time on some machines (instead of "P" or "X"). V Incremental axis corresponding to Y axis W Incremental axis corresponding to Z axis (typically only lathe group A controls) X Absolute or incremental position of X axis. Also defines dwell time on some machines (instead of "P" or "U"). Y Absolute or incremental position of Y axis Z Absolute or incremental position of Z axis

tmuir 13y ago

Heres some sample G-code: N10 G00 Z0.25000 N20 G00 X0.00000 Y0.29975 N30 G01 Z-0.50000 F2.00 N40 G01 X0.00000 Y1.03725 F5.00 N50 G02 X1.12000 Y1.03725 I0.56000 J-0.37323 N60 G01 X1.12000 Y0.29975 N70 G02 X0.00000 Y0.29975 I-0.56000 J0.37323 N80 G00 Z0.25000 N90 G00 X0.00000 Y0.00000 N100 G00 X1.5200 Y0.29975 N110 G01 Z-0.50000 F2.00 N120 G01 X1.5200 Y1.03725 F5.00 N130 G02 X2.64000 Y1.03725 I0.56000 J-0.37323 N140 G01 X2.64000 Y0.29975 N150 G02 X1.5200 Y0.29975 I-0.56000 J0.37323 N160 G00 Z0.25000 N170 G00 X1.32000 Y0.668625 N180 G01 Z-0.50000 F2.00 N190 G00 Z0.25000 N200 G00 X0.00000 Y0.00000 The N field is a line number and is disregarded The G field describes the motion type. G00 is a rapid line. G01 is a feedrate line. G02 and G03 are arcs, one CW, the other CCW. The X, Y, and Z fields describe geometry The F field is the feedrate, or the tool's speed