7 - Computer-controlled machining
The design process for the CNC machine milling machine. Test runout, alignment, speeds, feeds, and toolpaths for your machine. Make (design+mill+assemble) something big
How can I use this in my final project?
- Before I thought i could not use this. But now i finisched it I found out the beaty of the wood structures are so mutch better than the painting frames i have at home. So For my final project I would like to make a photoframe. (Or 3 to match it in my kitchen)
The steps for this assignment
- 1. Group: find the specific of our CNC machine
- 2. Safety instructions - How to operate our CNC machine
- 3. An overview of the functions
- 4. Replacing a Mill
- 5. Fusion 360 - Designing for the CNC milling machine
- 6. Illustrator
- 7. VCarve Pro - Prepare a file for the Shopbot software
- 8. ShopBot
- 9. The Final result - the panels
- 10. The Final result - putting it together
- Files & conclusion for this week
1. Group: find the specific of our CNC machine
Test runout, alignment, speeds, feeds, and toolpaths for our machine read all about this group assignment
2. Safety instructions - How to operate our CNC machine
1 | Don’t get to close to the machine when the machine is on. | |
2 | Keep the machines and surrounding clear | |
3 | Don’t operate the machine when: | You are not calm, So Start in Time, Don’t rush. You have loose long hair, or wear anything loose, possible getting cough by the mill |
4 | Beware of the emergency exit | |
6 | Wear glasses | |
7 | Beware of the Fire extinguisher | |
8 | Be aware for fire in the bin (Dust collector)! If you hit a Screw with the Milling Bit. Or you smell a burn: ALWAYS check the BIN/Dust-collector. | |
9 | In case of smoke or any doubt put the bin outside the building! | |
10 | Loose/wobbly milling bit: check if the bit rotates evenly before you start hitting the material | |
11 | Don’t hit a screw: Make the material dimensions in VCarve Pro smaller than the actual wood, so you will never hit a skrew on the side |
3. An overview of the functions
1 | Axes of movement of the machine | |
2 | Milling system | |
3 | Dust collecting, at the mill | |
4 | Dust collecting, from machine to Bin | |
5 | The keyboard should be sideways | |
6 | To have proper mapping with the axes |
4. Replacing a Mill
1 | Loosen the Wing nut to lower the skirt | |
2 | Only use Metric Mills | |
3 | Find the right mill for a collar, the nr on the collar correspondents with the mill nr | |
4 | 6 is the Mill size, 25 is the nut size | |
5 | First press the collet in the Nut, then put the mill in | |
6 | Tighten the NUT, MILL, COLLET using the tools | |
7 | Put the tools back where they belong |
5. Fusion 360 - Designing for the CNC milling machine
I have only 8 hours for the design & get the files ready to be milled… So here we go!
Dogbone Joints. Inspired me to make the dog-bones a part of the design. I dropped this because I was running out of time. Frontier Design inspired me to make a stackable system with different sizes. From a spiral design point of view I could start wit simple elements. But all should be parametric, so not the simplest I can Do.
1 | Create a parametric handle was a lot of work | |
2 | I had to use co-sinus to get the math right | |
4 | When entering other dimensions, the handle rotated a bit. | |
5 | I added fingers for the pres-fit in the 3D environment | |
6 | Used the Combine > Cut procedure to take the fingers out of the fitting material | |
7 | When adding appearance, some mistakes became visible | |
8 | Most of the time only loose parts, caused by the combine command | |
9 | Use the combine > Join commands to fix the loose parts |
First I create all the panels in one sketch in Fusion 360. When ready I wanted to add fingers.
I found this video explaining how to make parametric finger-jonts in fusion 360.
I copied all the sketches to 3D placing all the sketches on the face of the 3D object. When all the panels are ready I stared to make the Fingers. When Some where ready I tried to export the separate panels to 2D. Export As DXF.
But this was impossible! I could only export the sketches, and the sketches doesn’t contain the improvements/cuts/fingers. All is made in 3D!!
I really panicked since time was running out. I Hit Google but all manuals just gave me a way to OR, create 2D sketches and send those to CNC.
A few hours I banged my head against the 3D wall.
Than I thought I could try to trace the faces as a sketch, This would result in a failure but still better than nothing. Than I started searching for ‘convert faces to sketch’. I’m not the only one, It is not a feature but from a face you can create a sketch simular to the face!
THANKS: to this post explaining how to export to dxf via the face of 3d
My global evaluator (Yuichitamiya) gave me antother fine tip I really want to record for future reverence:
- Use Shaper Utilities to export to SVG.
- This extension is for Shaper Origin.
How to export Fusion 360 to DXF
- Click an face of an object en ‘create sketch’
- Finish
- Rename this new sketch
- Click on sketch (layer) and ‘export as DXF’
Mistakes/mental notes I was really stressed during the design because of the unclear design process and the extreme timepressure. So I made mistakes and really froze from panic two times that day.
- I made All drawings in One sketch
- I wanted to finish the sketches 2D
The result
6. Illustrator
Since the tests we did with the group assignment showed the size of the wood after cutout (outer line) is 0.8 to 1.1 mm bigger. | ||
1 | I made all inner diameters of fingers 0.8 mm bigger. I hope this will be snug enough and sometimes even press fit. | |
2 | I did’nt like the finger hole to be so close to the edge, so I moved it | |
3 | And I had to move all the fingers 5 mm too | |
4 | Save the file as Illustrator 8 |
Mistakes/mental notes
- I tried to open
- I wanted to finisch the sketches 2D
The result
7. VCarve Pro - Prepare a file for the Shopbot software
1 | Open the Ai file (I used AI 8) | |
1a | Double check the dimensions of the file | |
2 | Job setup: Set material Thickness, Dimensions, Material Z must be on top. No offset. XY datum position, lower Left. Modeling resolution is only the way you view a file | |
3 | Press OK, the panel will get to the right. set: Z zero = top. XY Left bottom. De-select use offset | |
4 | Click on a path (in your drawing and configure the tool-paths). Start dept = 0, Cut dept is material thickness + 0.1 mm!. Click “Select” | |
5 | Select the ‘End Mill 5MM two flute’ | |
6 | Set passes to 6 | |
7 | Machine vectors settings | |
8 | Add Tabs to the tool-path, Click on your drawing, click again to remove | |
9 | Press Calculate when ready |
Shortlist (for my next time)
- Open file
- Set up dimensions (smaller than your actual material to be save)
- Create separate tool-paths (inner cuts, outer-cuts and cutout)
- select path (Profile etc) for the same toolpaths
- choose ‘cut’ etc
- Drill settings
- Add Tabs
- Name toolpath
- Repeat for all toolpaths
- Calculate toolpath
- Add dog-bones - Fillets (icon in the Edit Objects - left panel)
- Calculate every tool-path again
Mistakes/mental notes
1 I forgot to move the fingers of the inner panels
8. ShopBot
1 | Insert the spindle | |
2 | Turn on the Shopbot with BIG turning swith on the side | |
3 | Open the Shopbot software and strike ‘k’ on the keyboard. | |
4 | Manually move the mill to 0,0 material (zero X = 0 and the Y = 0, lower right corner) | |
5 | Make a picture | |
6 | Set xy zero: [Z]ero > ‘Zero 2 Axes [X & Y]’ | |
7 | Move the mill to the center of the material. Put metal plate under the Mill (not turning!). | |
8 | Automatically Set Z zero: [C]uts > ‘C2 - Zero Z axis w/ ZZero Plate.’ | |
9 | Remove the metal plate and check if the machine is free (around and on the workspace) | |
10 | Check if the Skirt is fixed (can it move up or down?) | |
11 | Turn on the Vacuum (Knob next to the green light bulb & turning Knob at the front of the CNC) | |
12 | Turn on the spindle with the key (attached to the tools) | |
13 | ‘Open file’ - Find your toolpath | |
14 | Double check all and press Start, Keep your hand above the spacebar for the first minute |
Change shopbot settings during operations
You can change the moving speed during operation
1 | If the Mill is up, press ‘SPacebar’ on keyboard | |
2 | Click ‘Enter Command’ in the popup | |
3 | Press ‘k’ on the keyboard | |
4 | Click the fields and change settings. I changed to this: | |
5 | Pres the ‘esc’ button | |
6 | Click “resume Job” in popup menu |
9. The Final result - the panels
1 | All the panels | |
2 | I didn’t sand the panels. My plan was to hammer them in and do the sanding after putting it together. It was made to fit, not to sand… | |
3 | The fingers on both sides did’nt fit. I changed the fingers in illustrator, but forgot two panels | |
4 | So I needed to take some of the finger to fit the panel. |
Lessons learned:
- Don’t change the design in illustrator, I will make mistakes
10. The Final result - putting it together
1 | Mistake 1, love text on the inside | |
1 | The top panel fits like a glove | |
1 | This should fit, probably It didn’t since I refused to sand | |
1 | Mistake 2, the misplaced finger. some damage from hammering it without sanding. | |
1 | Bottom is a decent fit | |
1 | Final result, some mistakes and really rough without any sanding |
Files & conclusion for this week
The files
- Fusion Parametric file
- 3D file
- DXF exports from Fusion. One DXF per panel
- Illustrator file, with all panels
- VCarve Pro save .crv file (too big for FabAcademy)
- Exported VCarve pro file .sbp
Biggest Mistakes and lessons this week
- Don’t start if you don’t know what your process will be. Same mistake as last week!
- Don’t try to make a CNC design in 8 hours if you never did it
- Check the fingers before printing
Wat I really liked
- The parametric designing, and the 3D design in Fusion was fun
- Putting the box together was fun to do, Hammer time!
- I really had fun about my mistakes, BIG mistakes are more fun!
My concerns
- I did not handle the stress very well.
- Will I be able to use the (almost unusable) software on the CNC machine next time?
- I made nothing in line with my final project.