7. Computer controlled machining
📸 Hero Shots
😅 week story
hello!!!! ! 😀 Every week is better than the last one. As every week-end for my fab-lab journey i make travel of about 165km to my fablab. This week my travel to arrive at the fab-Lab was quiet but my depature to Job was castrophique. But i love to have every week a new adventure for learning.😅
💤 me at 02.00 AM wating for a car after work at fablab to reback to Datcha because at 7.00 AM all will be at work, and travel will take 3 hours
🎮 Assignement
this week we are invite to :
1-group assignment
- do your lab's safety training
- test runout, alignment, fixturing, speeds, feeds, materials,
and toolpaths for your machine
2-individual assignment
- make (design+mill+assemble) something big (~meter-scale)
- extra credit: don't use fasteners or glue
- extra credit: include curved surfaces
1️⃣ group assignment
we have fun with a large format CNC our (big bertha)
Link to group assignment page
The group assignment page can be found on the Energylab 2024 website here
it is also embedded directly in the webpage below.
2️⃣ Individual assignement
Requirements
Make (design+mill+assemble) something big
Workflow
For this week’s work, I’ll be cutting and assembling a design table.
Step 1: Modelisation
Autocad
For this work, 😎 i want an extra design. I try copilot to give me some idea but it not convience me. So i came to my dear friend Lisa to give me some art deco idea. It was amazing but with time i have, and material it was a little hard for me.!!!(sorry lisa)
So finally in lab, with the constraints of plywood i make a simple 😉 table, but using human body form to build my table legs, and a circular top design.
For the modeling, I have used autocad to make a .dxf file with line and courbe.
I think i was good, but my instructor talk me about ** No way of avoiding a radius to internal corners of parts cut using a CNC spindle ** We have to add “t-bone” or “dog bone” So i remake my work with “dog bone ” because i like dog 😂
fusion360
Gcode
After modeling, we need to generate its gcode so that we can import it into our CNC machine software for cutting. In the gcode we’ll enter the necessary parameters so that we can get a good result after cutting.
To generate the gcode with Fusion 360, I had to install a post-processor for Fusion 360.
Installation:
The post processor consists of a single file, mpcnc.cps.
It can be simply installed by selecting Manage->Post Library from the Fusion 360 menu bar; alternatively the mpcnc.cps can be copied into a directory and selecting each time prior to a post operation.
If there is an existing mpcnc.cps installed select it prior to installing and use the trash can icon to delete it
The desired post processor can be selected during a post using the Setup button and selecting Use Personal Post Library Use the Job: CNC Firmware property to select between Marlin 2.x, Grbl 1.1 and RepRap firmware
Adding MPCNC post processor to Fusion 360
- In Fusion 360 Manufacturing Mode; click on NC program in SETUP section
Click on select post processor from library
Next Click import in the library windows opened and click on import
Now In new File Explorer window will open prompting to select the post processor to import. Navigate to where you have extracted it and select it;
Now click Open
Make sur you clicked on the new post processor
And click select
Since this post processor Code for different firmware I have to make sure while generating NcProgram or Gcode to select Grbl1.1
Now that we’ve added the post processor to Fusion 360, we can generate our gcode.
To do this, go back to “Manufacturing” then “Configuration”.
Then this window will open
Here we can choose the type of operation we want to perform, as well as the different axes and other parameters required for our cut. Then click on Ok to confirm.
Next, we go to the 2D panel and click on “2D contour”, then this window will open.
Here we’ll select our cutting tool by clicking on “select” and a new window opens up.
We can then choose a tool from this window according to what we have available for cutting.
If no tool corresponds to what we want, we can make a modification to get what we want by double-clicking on the tool. This window then opens, and we can make the various modifications.
In the same way, we’re going to modify the other necessary parameters in the “2D contour” window.
Once we’ve made all the changes, click on “Ok” to confirm.
We can now generate the gcode
As the garbage can will be made up of several sides, I’ve duplicated the model to be able to cut several at a time and also optimize the space on the material to be cut. Here’s an image of the duplication.
And the different steps to generate our gcode remain the same.
Step 2: Cutting
File import into software
With our gcode we’re now going to use the CNC software to make the cut.
Now we’ll load the file into the software
Install cutting material on machine and start CNC
Now it’s time to install the material to be cut on the CNC and start cutting.
Touch-ups
At the end of the cutting process, I removed the cut parts from the machine.
Then file off the parts that need minor finishing.
Step 3: Assembly
After cutting, I assembled the parts.