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

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

1Don’t get to close to the machine when the machine is on.
2Keep the machines and surrounding clear 
3Don’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
4Beware of the emergency exit 
6Wear glasses 
7Beware of the Fire extinguisher
8Be 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.
9In case of smoke or any doubt put the bin outside the building! 
10Loose/wobbly milling bit: check if the bit rotates evenly before you start hitting the material 
11Don’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

1Axes of movement of the machine
2Milling system
3Dust collecting, at the mill
4Dust collecting, from machine to Bin
5The keyboard should be sideways
6To have proper mapping with the axes

4. Replacing a Mill

1Loosen the Wing nut to lower the skirt
2Only use Metric Mills
3Find the right mill for a collar, the nr on the collar correspondents with the mill nr
46 is the Mill size, 25 is the nut size
5First press the collet in the Nut, then put the mill in
6Tighten the NUT, MILL, COLLET using the tools
7Put 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.

1Create a parametric handle was a lot of work
2I had to use co-sinus to get the math right
4When entering other dimensions, the handle rotated a bit.
5I added fingers for the pres-fit in the 3D environment
6Used the Combine > Cut procedure to take the fingers out of the fitting material
7When adding appearance, some mistakes became visible
8Most of the time only loose parts, caused by the combine command
9Use 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:

How to export Fusion 360 to DXF

  1. Click an face of an object en ‘create sketch’
  2. Finish
  3. Rename this new sketch
  4. 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. 
1I made all inner diameters of fingers 0.8 mm bigger. I hope this will be snug enough and sometimes even press fit.
2I did’nt like the finger hole to be so close to the edge, so I moved it
3And I had to move all the fingers 5 mm too
4Save 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

1Open the Ai file (I used AI 8) 
1aDouble check the dimensions of the file 
2Job 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
3Press OK, the panel will get to the right. set: Z zero = top. XY Left bottom. De-select use offset
4Click on a path (in your drawing and configure the tool-paths). Start dept = 0, Cut dept is material thickness + 0.1 mm!. Click “Select”
5Select the ‘End Mill 5MM two flute’
6Set passes to 6
7Machine vectors settings
8Add Tabs to the tool-path, Click on your drawing, click again to remove
9Press Calculate when ready 

Shortlist (for my next time)

  1. Open file
  2. Set up dimensions (smaller than your actual material to be save)
  3. 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
  4. Calculate toolpath
  5. Add dog-bones - Fillets (icon in the Edit Objects - left panel)
  6. Calculate every tool-path again

Mistakes/mental notes

  • 1I forgot to move the fingers of the inner panels

8. ShopBot

1Insert the spindle 
2Turn on the Shopbot with BIG turning swith on the side 
3Open the Shopbot software and strike ‘k’ on the keyboard. 
4Manually move the mill to 0,0 material (zero X = 0 and the Y = 0, lower right corner)
5Make a picture
6Set xy zero: [Z]ero > ‘Zero 2 Axes [X & Y]’
7Move the mill to the center of the material. Put metal plate under the Mill (not turning!). 
8Automatically Set Z zero: [C]uts > ‘C2 - Zero Z axis w/ ZZero Plate.’ 
9Remove the metal plate and check if the machine is free (around and on the workspace) 
10Check if the Skirt is fixed (can it move up or down?) 
11Turn on the Vacuum (Knob next to the green light bulb & turning Knob at the front of the CNC) 
12Turn on the spindle with the key (attached to the tools) 
13‘Open file’ - Find your toolpath 
14Double 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

1If the Mill is up, press ‘SPacebar’ on keyboard 
2Click ‘Enter Command’ in the popup 
3Press ‘k’ on the keyboard 
4Click the fields and change settings. I changed to this:
5Pres the ‘esc’ button 
6Click “resume Job” in popup menu 

9. The Final result - the panels

1All the panels
2I 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…
3The fingers on both sides did’nt fit. I changed the fingers in illustrator, but forgot two panels
4So 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

1Mistake 1, love text on the inside
1The top panel fits like a glove
1This should fit, probably It didn’t since I refused to sand
1Mistake 2, the misplaced finger. some damage from hammering it without sanding.
1Bottom is a decent fit
1Final result, some mistakes and really rough without any sanding

Files & conclusion for this week

The files

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.
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