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Documentation

This page describes functions of blender CAM. It is a stub, but will be improved in the future.

it is handy to know a bit of blender, see the documentation to learn some basics of the interface.

samples file:

you can download a file full of simple samples here. It shows how to set up most of the strategies.

panels description:


CAM operations panel:


Calculate path
- this calculates the operation which is currently selected

Calculate path in background - it is important to save your file before using this function. It calculates the path, while you can continue working on setting up other operations.

Simulate operation - works for 3 axis operations, but not for all. It creates a new object which shows the simulation - the subdivision of the object can be increased, and the resolution of the simulation also depends on simulation sampling raster detail, which is in the optimization panel

Operation name

File name - name of the gcode file. The file is automatically saved after the computation of the operation, in the same folder where you save the project.

Source of data - this can be either 1 object, a group of objects, or an image.

  • Object - select the object. write it's name in the field, it should auto-complete
  • Group - select all objects you want to use, and hit Ctrl+G to create a new group. Then type name of the group in the field(Group will be the name of the first group you create)
  • Image - open an image, put the name here


CAM info and warnings

this panel will show any trouble found during the computation, estimated operation time, and chipload data


CAM operation setup

Strategy - sets one of the strategies.

various strategies will combine these parameters:
distance between toolpaths - also called stepover in other applications
distance along toolpaths - how dense will be the operation path. This can influence accuracy of the machining.
angle of paths - this rotates the parallel and cross strategies by the specified amount. Note that e.g. rotating by 90 changes the basic axis from X to Y
parallel step back - this function is only for finishing pass, where you still have to cut some substantial amount of material, and want also to save the cutter. If you set up to climb movement, it goes with climb into material, then goes in the other direction one step back - this uses the back movement of the machine for finishing the surface. Note that this also means the cutting into material will happen with a rate which is 2x of distance between toolpaths If you don't know what this all means, don't use this function.
Skin - usefull for roughing, leaves a layer on the surface for finishing
Inverse milling - used if you want to mill a form directly from positive of the object. Does not work in exact mode. only works for 3 axis strategies.
Direction - for block and spiral strategy, decides if the path progresses from inside or from outside
Carve depth - decides how deep below the surface will go the carve operation
Dont merge outlines when cutting - for cutout strategy. Does never merge outlines - this results into cutting in the object area! It is usefull when milling PCBs, where you don't need exact shape but need to separate areas with engraving.
Use bridges - for cutout operation, places automatically bridges by the rules set by options that will appear after this is enabled: width, height, minimum per curve, distance.


CAM optimisation

this panel is crucial for performance of blenderCAM.

Use exact mode - exact mode is related to the strategies that are fully 3d - parallel, cross, block, spiral, circles, waterline, outlinefill, carve. It's a very important setting.

  • Non exact mode: In non-exact mode, an image is used to estimate the cutter offsets, and the Sampling raster detail is used to estimate the resolution of the image. Non exact mode is good for high poly meshes, several milions of polygons shouldn't be problem for it, but the sampling raster detail setting is crucial then. Memory overflow can happen if you use e.g. default blender cube that you have by startup, since the cube is 2 meter in size in blender units. For artistic use with high poly meshes, non exact mode is good for most of the cases. 
  • Exact mode: a real collision simulation is used, so the collisions are exact. But the speed goes down with increasing number of polygons. It is recommended in these situations: Your model is too big for the non exact mode, you need high precision, your model doesn't have too many faces.

Reduce path points - reduces number of commands in the operation, so the resulting gcode is shorter and can run smoother on the machine
Reduction threshold - points with smaller distance to the path direction will be reduced
Sampling raster detail - this parameter is crucial for memory use and mainly speed of blender CAM. In non-exact mode, blenderCAM uses an image to compute the cutter offset positions. If the raster detail is 0.1mm, then a 10x10 cm object will use a 1000x1000 image. If the object size would be 1m, the image would be 10000 x 10000 pixels, which will probably fill the memory of your computer. Check your object size before computing operations.
Simulation sampling raster detail - same as sampling raster detail, but only for simulation
Detail of circles used for curve offsets - exactly what it says


CAM operation area

Use layers - sets up layers for roughing. 
Step down - specifies thickness of the layers for roughing
Ambient - how much space surrounding the object will be used for the milling
  • all - a rectangular area will be used
  • around - object silhouette will be used, with a radius specified by Ambient radius
Depth from object - takes object depth and sets up the total depth of the operation from it. Otherwise, you can use Operation depth to do the same manually.


CAM  material size and position

Estimate from model - will assume the workpiece has the same size as the model, with radius around model
Material origin and Material size are used in case when the material is not the same as model.
Position object - this will move the object to positive X and Y and negative Z.


CAM movement

Movement type - is supported only for some of the strategies, sets up how the cutter moves into the material
  •  Meander - sometimes also called ZigZag , this means you don't care which direction the cutter goes into the material. 
  • Climb - the default movement, and mostly used when doing CNC machining. 
  • Conventional - 
Spindle rotation - this parameter is not exported, but it is used when setting up the movement type, because with the spindle rotating CCW, all operations go in opposite direction.
Free movement height - how high will the cutter travel when moving between toolpaths
First down - for cutout strategy. If on, the paths are cut one by one to the full depth(all layers), otherwise first all the silhouettes are cut on layer 1, then 2....
Ramp contour - for cutout strategy, instead of going layer by layer, it goes down all the way on a ramp.
Ramp out - also going out is performed on a ramp, to prevent burning of the finished piece by staying on one place in XY axes.
Stay low if possible - tries to not lift the cutter when going from 1 path to other, when the paths are closer to each other than the cutter radius, which means no extra material will be cut during this travel move.
Protect vertical - when the angle of the path is above verticality limit, the move will be made vertical. this way vertical surfaces won't get a slope because of the distance between the path points.


CAM feedrate

feedrate/minute - How much will the machine travel in 1 minute
Plunge speed - the feed speed gets reduced when the slope of the path is above the Plunge angle
Spindle rpm - spindle revolutions per minute



CAM cutter

Tool number - this parameter is exported with toolchange command
Cutters - supported types are now following:

  • Ball
  • Cylinder
  • V-carve - width is the maximum width of the cone. 

Cutter diameter
Cutter flutes - this parameter is used only for chipload computation



CAM machine

this panel sets up your machine and the settings are common in the whole file.
You can also set up your machine and then save your default file with Ctrl+U command. This way you will always start with the settings you need.

Post processor - this defines the formating of the output file. If you machine is not in the list, you can try the Iso code, which is standardised g-code
Unit system - Metric or Imperial
Work area - if the operation has a larger area than this, you will get a warning in the info panel
Feedrate minimum/maximum - this will limit your feed speeds set up in the feedrate panel.


CAM chains

this enables you to chain operations. It is usefull for simulating more operations, or exporting a chain of operations, if you have automatic toolchanger or use the same tool for several operations. 


2 comments:

  1. Images on this site are not displayed... :(

    ReplyDelete
    Replies
    1. wow, that's strange. Thanks for telling, will fix that.

      Delete

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