8. Computer controlled machining¶

Inkscape¶

For this week, I wanted to make a Seagull assembly. I tried using Inkscape to do this design. I went through several tutorials such as Inkscape Tutorial 3 & Inkscape Parametric.

Then I collected several images & started tracing them.

I tried to improve the tail design a bit by redrawing it.

Then I used simplify feature to improve the design & to avoid problems in cutting. I used Linked Offset to create offset for the body of the bird.

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But since the tail design was not symmetric, my instructor helped me & showed me how to do it by deleting half of it then mirroring it to create this tail version.

Then, I tried creating the joints & this is the final result before laser cutting.

& made the stroke width 0.001 in for laser cutting.

Laser Cutting¶

This was the result after assembling.

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I found out that some joints needed some modifications before the CNC cutting.

CNC testing & settings¶

This is the CNC machine we used.

For testing we used 3mm bit

We fixed the board using nails.

Machine buttons

Before cutting we adjusted the origin settings for all vectors. Setting Z origin:

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We tried testing different cutting settings & pucketing. We used VCarve Pro software to design & do the cutting settings. After designing, we selcted each element in the design & set the toolpath settings for it & then clicked on “Calculate” button. We did that for all elements then merged them & saved the file to be used in the cutting program. After ensuring that the origins are set correctly, we clicked on “Cut” button, then it requested us to click on the green button & “Enter”.

Tool settings changes depending on several factors such as material type & thickness. Some refrences Makezine & ShopBot Feeds & Speeds Charts.

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For the first one we used:

2D Profile Toolpath
6mm cutting depth
One pass 3mm, 2 passes in total
Machine Vectors: Outside/Right

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Pocket Toolpath
3mm cutting depth
One pass 3mm, 1 passes in total
Clear Pocket: Offset
Cut Direction: Climb

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For the second one we used:

2D Profile Toolpath
6mm cutting depth
One pass 3mm, 2 passes in total
Machine Vectors: Inside/Left

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Pocket Toolpath
3mm cutting depth
One pass 3mm, 1 passes in total
Clear Pocket: Raster
Cut Direction: Climb

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For the third one we used:

2D Profile Toolpath
6.5mm cutting depth (at first we tried 6mm but it didn’t cut 6mm depth)
One pass 3mm, 2 passes in total
Machine Vectors: On

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Female Inlay - Pocket
1mm cutting depth
One pass 3mm, 1 passes in total
Clear Pocket: Raster
Cut Direction: Climb

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Result:

The second sequare (Machine Vectors: Inside/Left) was smaller than the rest

Seagull CNC Test Cutting¶

After doing some modifications to the design after laser cutting like increasing the size of the wings & tail in Inkscape & VCarve Pro. I had to save Inkscape files in dxf format so that I can open it in VCarve Pro. We tried to cut some of the parts to test the joints. The board thickness was 4mm.

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