W8: Computer-Controlled Machining

Group members

Group assignment

Test runout, alignment, speeds, feeds, and toolpaths for your machine

Work description

Test I: Alignment, speeds, feeds, and toolpaths for your machine

At the beginning of the week, we had an introductory session with the local instructor this week, Eino Antikainen.
He guided us through the design of a 3D model in Fusion 360, how to get the toolpaths in CAM workspace and, finally, how to prepare the machine and cut the model. Our group assignment is based in this work.

First, Eino guided us in creating the 3D model, and while preparing the setups for the design, he explained us the different values.

Defining the toolpaths for the piece

Some explanations for the different values

The piece we cut:

The piece

After cutting we measured with the digital calibrator.

Outer part

Measuring outer part

Result Test I


Here is the files of test part.

The machine setup was: 8 mm 2 flute milling bit, Feerate was 80 % of the maximum 6000 mm/min -> 4800 mm/min. Spindle speed was as well 80 % of the maximum 15000 r/min -> 12000 r/min.

The measured and target values were quite close to each other. Biggest difference was 0.17 mm and the smallest difference was 0.03 mm.

Measurement Measured length [mm] Target values [mm]
Width 1 149.89 150
Width 2 150.09 150
Inlay rectangle 1 119.92 120
Inlay rectangle 2 100.17 100
Inlay rectangle 3 119.93 120
Inlay rectangle 4 100.12 100
Inlay circle 1 79.97 80
Inlay circle 2 59.94 60
Inlay circle 3 79.93 80
Inlay circle 4 60.06 60

Test II: Runout

For measuring runout we made another test piece to measure the diameter of the cut line and compare it to the diameter of the milling bit. The results were very accurate.

We cut the test piece with spindle speeds of 20 % and 40 %. The cut quality was a little bit higher with 40 % spindle speed. With 20 % spindle speed surface was more rough than the 40 % speed.

We cut the test piece using spindle speed 20% and 40%

We used 8 mm 3 flute milling tool for the runout test. The measured flute diameter was 8 mm.

Foam piece was attached to sacrificial board with double sided tape.

The measurements were taken from four different positions. The positions are marked on the foam piece, which can be seen in the image. X1 is taken from the area where the spindle speed was 20 %. All the rest of the measurements are taken from the area with 40 % spindle speed.

Measurements were taken carefully with as little force as possible to avoid the caliper from pressing in the foam. The measured cut was 8 mm in all of the positions. Because we took measurements from x and y directions we can determine that the tool angle against the surface was 90 degrees from both directions, because the measurement was same as the tool diameter.

Result Test II

Manual test run using the manual controller of the machine.

Measurement location Width [mm]
X1 8.00
X2 8.00
Y1 8.00
Y2 8.00