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7. Computer-Controlled Machining – Group Kuriyama

This is group assignment page of Computer-controlled cutting (Kuriyama Student) :

Group assignment

  • Do your lab’s safety training

  • test runout, alignment, speeds, feeds, materials, and toolpaths for your machine

What we’ve done this week

  • vcarve-pro

  • ShopBot


This time we used vcarve-pro as CAM software

The material used was Lumber-core (1830mm x 916mm x 15mm)

First, we needed to know the kerf of the lumber core to be used in the individual assignment,so we made a measure based on Doyo sensei’s kerf tool to measure the kerf of the 15mm Lumber-core.

In actual machining, the corners are output with the bit diameter rounded off. In this case, the rounding is equivalent to the end mill radius.

For this reason, a fillet called a dogbone is added at the joint.


Reference: Doyo-sensei kerf checker

Import DXF file

Set “Job setup” and “Job material” as follow

The mill settings used are as follows

Toolpath settings as follow

Added tabs as follow

The key is to add tabs along the grain of the wood. It can be easily removed later when cut it off.

Toolpath (Vector)

Toolpath (Drill)

After calculation, Toolpath can be displayed as follows. In this case, displaying the toolpath of the kerf tool and the marker of the place to be biz-fastened.

Save it ready for processing by shopBot and done!


Machine : ShopBot PRS Standard

Material : Softwood plywood 15mm thickness 910x1820mm

Mill : Solid Carbide router, 2 flute, downcut extreme heavy duty

Setting the mill

Take off the collet and collet screw from machine.

Setting the mill to collet.

Be careful not touching your finger to blades.

Set to machine

First screw by hand,

Second screw by tools.

Make sure to screw tight!!

Turn on the machine

Setting origin on ShopBot3 application.

Click the icon of XY.

XY is already setting. So automatically move to front right corner of bed.

The bolt is guided of XY.

It stop when it touch the bolt.

You can move with KeyPad and Key board on the computer when KeyPad is opened.

So make sure it’s closed when you don’t use it.

Set the Origin of Z.

Set the metal plate under the mill and clip anywhere metal part.

Input 1 is on when you touch the metal plate at mill

Leave the metal plate under the mill and press Z icon on the PC.

Automatically down the mill and set the Z origin when it touch the metal plate.

We also check the same number with actual measurement and application panel.

Turn on the mill when you set and turn the key.

Always check the Preview and air path before cutting.

Select the “1-3D Offset” in Offset in 2D or 3D to air path.

Setting the Z position around 50mm high. (MAKE SURE mill is not touching the material)

Press the “START”!! Start the air pass.

You can stop it seems okay.

Turn on the Air duster. Press the green button.

Now select “0-No Offset” at Offset in 2D or 3D

Press “Start”


Inside cutting was 105mm

Outside cutting was 118mm

15.3mm was perfect fit for this material with this mill.

We set the following values

Feeds and Speeds
Spindle Speed Feed Units Chip Load Feed Rate Plunge Rate
16000 r.p.m inches/sec, 0.0047 inches 2.5 inches/sec 1.25 inches/sec

“Feed rate” was set to “inch/min” by default, but changed to “inch/sec” because it is difficult for beginners to understand

“Chip load” is the amount of material that the blade shaves off at one time. “Chip load” is recommended between 0.001 inches and 0.01 inches.

We found the following

Material clearance kerf
Lumber core 15.3 mm 0.3 mm


Last update: April 12, 2022