FreeCAD and CNC machining - Basic profile and pocket toolpaths

hello internet hello folks in this video i will use the open source software freecad and prepare a milling job for my chanmitsu 4030 cnc the aim is the miller profile and the pocket tool path we will design a simple 3d object prepare the model for cnc machining create a tool path prepare the post-processing and exporting the grbl-based g-code and finally mill the pocket with my cnc okay let's have a look how it turns out [Music] i'm using freecad an open source parametric 3d model modeler made for the design of real life objects of any size freecad is designed to fit a wide range of uses including product design mechanical engineering and architecture our cad model is kept very simple and should be easy to follow here is my workflow so we are in a part design workbench create a body as a starting point with the body selected this is the default setting create a sketch use the x y plane as the baseband for your sketch and then with that sketch in place you can create a 3d object or modify an existing model in 3d space afterwards use the circle tool to draw a circle starting from the center point of the plane then insert an arc constraint to define the radius that's all for our first sketch close the sketcher now use the padding tool to create a 3d object in this case a cylinder please note that i am extruded in the negative direction so there is a checkbox reversed um this will make it easier for us to create the milling path afterwards as the origin point is on the top level surface of the workpiece now we want to create the pocket therefore we create a new sketch on the cylinder as i already explained and create a circle as in the example before after you closed this additional sketch you can use the pocket tool to create a pocket with this we have created our basic object now we start to define the machine processing to do this we use the following steps first we switch to the path workbench then we use the chop icon to create a new job and select the design object to be processed from the model tree in our case it is the cylinder body creating a new chop free cut immediately jumps to the setup dialog for the stock material here i can define the stock dimensions we will start milling directly on the top side of the material so no addition on the top side is required if you like you can add additional stock material on the left and right and the bottom side it's up to you in output tab you can define the postprocessor format i have a grpl based controller therefore i select grbl code in the drop-down i also defined an output file pattern using some of the freecad variables but this is optional in the tools tab add the tools that you want to use for the job i used a straight router bit with two flutes and three limit and a three millimeter diameter i picked the feed rate of 150 millimeters per second horizontal and 100 millimeter per second vertical speed and i set the spindle to 12 000 rpm the work plan tab will later include a different tool pad operations close the job dialog and press the ok button now let's define the tool path for cnc machining as a first step i create a profile toolpath i selected the outer face of the cylinder and used the profile tool to create a path now i look at the different tabs profile dialog the base geometry is the outer phase of the cylinder as the next step i changed the depth parameters the startup is the maximal set value where we start milling each of the depth fields contains predefined variables that can be edited using the setup sheet which is located in the model tree you can also delete the predefined values and insert your own settings directly the only thing i changed here was the step down value and again i picked two millimeters let's say sixty percent seventy percent from my tool diameter normally you can have a step down depth that has the size of the diameter of your root a bit but this was too much for me with this stock material this plywood is pretty hard i still figuring out how the machine behaves and step by step i push the limits a little bit further to create a pocket tool path i selected the bottom surface of the pocket in my model then i also adjust the step down and the final depth in tool path settings we can use the default settings as they are already set we will the direction is clockwise no extra offset necessary and no special start point for this task this was my my first basic setup i did not define any tabs to hold the work piece assuming the double sided tape will hold the cutted piece in place okay so far so good with the pocket toolpath in place i decided to run a simulation to see what my final product would look like and i saw in the pocket to path that there are some left there is some left over material from the zigzag pattern to have a cleaner edge toolpath i changed the pattern to zigzag offset which also cleans up the edge geometry i also added a ramp movement to the profile and also to the pocket toolpath um with the ramp movement the router bit does a little bit of a zigzag movement while going down into the material part dress ups can be used to add additional behavior to the tool path you find the dress up menu item under the top level menu path and path dress up now i simulate the toolbars one last time before i start to building my workpiece to export the grblg code select the job and use the post process icon to export your code keep in mind set the correct post export data format using the output tab of the job settings otherwise your cnc controller will not work as expected after i exported the g-code i loaded the g-code in my g-code sender application in my case i use scandal which comes with the chain mitsu 4030 to fix the stock material on the machine i used double-sided tape okay with the stock material in place i marked the center point of my workpiece and and define the origin of the work coordinate system the x and y position and i use the set probe to define the set position [Music] [Music] [Music] to fix the stock material on the machine i used double-sided tape and it failed i had to abort the milling as you can see maybe if i change the order starting with the pocket but without taps it is easy to break your router bits when a part becomes loose during the milling okay back to free cut yeah freakout offers a nice solution here it's very easy to modify existing tool path by using a tool pad dress up you can find the dress ups under the top level path menu and i used tech dress up for the profile path in combination with the ramp dress up have a look at the created pad to see the effects and i did also use a ramp dress up for my pocket tool path to add a little bit of movement while the router goes down into the material and it should prevent the router bit from overheating for example but have a look at the created pad to see the effects you see that okay with the path dress up in place i run a final simulation and then the same procedure export the g-code file load it in the g-code sender in which i use candle which controls my and then let's see what the outcome looks like as you can see in the first simulation there were some artifacts left on the inner side of the pocket therefore i changed the pocket tool path pattern to zigzag offset and it created a nice path along the inner side of the pocket maybe you can change this maybe you can also change the step over percentage maybe you can also change the step over property um and change it to 70 to have some overlapping of your tool path it takes longer for the milling process but also creates a cleaner surface [Music] [Music] um uh [Music] [Music] so [Music] [Music] [Music] foreign [Music] [Music] um this time it worked and the milling was done cleanly i'm happy with the result and i'm using it as a starting point for a number of smaller milling projects freekah did a pretty good job even though the path workbench is still in an early version but for a freely available open source software the result is very respectable and a large part of projects could be realized with it i will do some more tests and post them on my channel as always suggestions and questions just write them in the comments i don't need to repeat that like and subscribe thing but i'm happy about that too it would be super good to get some feedback on this video so that's it for today have fun with your projects thanks for watching bye freedom [Music] you

Channel: UMLOOAD

Views: 18,234

Keywords: CNC milling, Freecad, freecad path 0.19, freecad path profile, freecad path 3d, genmitsu cnc router machine proverxl 4030 review, genmitsu cnc proverxl 4030, genmitsu cnc 3018, toolpath software, toolpath simulator, toolpath cnc, toolpath generation, GRBL, grbl cnc, grbl controller tutorial, grbl software tutorial, gcode for cnc, g code, candle gcode sender

Id: tWthv-HCS9U

Length: 19min 31sec (1171 seconds)

Published: Sat May 21 2022