Week 7: Computer Controlled Machining

Group assignment

. Complete your lab’s safety training

. Test runout, alignment, fixturing, speeds, feeds, materials and toolpaths for your machine

. Document your work to the group work page and reflect on your individual page what you learned

The group assignment page is here.

The ShopBot CNC Router's safety features

Ensuring safety is paramount when using ShopBot CNC Router machines, which are capable of producing accurate cuts and designs on a range of materials such as wood, plastics, and metals. Despite their efficacy, as with any industrial equipment, caution must be exercised while operating them.

Test Runout:

When the cutting tool wobbles or vibrates, it is known as runout. To gauge runout, a dial indicator can be employed to detect any movement in the tool during its rotation.

CNC Speed:

To avoid tool breakage, it is recommended to adjust the machine speed based on the material being worked on. For hard surfaces, a lower speed is advisable, while for materials with high friction, a medium speed should be used.

Feed rate:

The feed rate of a CNC machine determines the speed at which it moves to the next line. For optimal results, it is advisable to set the feed rate at a low percentage, such as 15% or 30%, depending on the material being used.

Materials & Toolpaths:

Our machine can work with various types of materials, including wood (such as MDF, plywood, cherry, maple, and OBS), metal (thin layers of aluminum), and plastic. There are also multiple toolpaths that can be utilized, such as pocket profile drill, 3D rough and smooth, V-carve, and many others.

Fixturing:

Fixturing is the process of securing the workpiece in place during cutting. Adequate fixturing is crucial to prevent the workpiece from shifting or moving during the cutting process, which may cause imprecise cuts or harm the machine.

Individual assignment

. Make (design+mill+assemble) something big

Design of a table to hold a Saachi Coffee Maker and/or Laptop Computer

1.) Modeling the table leg part in solidworks as show on the following pictures:
Firstly: I started my design from sketch, and I added its dimensions.

Secondly: I did feature editing and extruding.

Thirdly: After cutting the through rectangle of the above indicated dimensions, I made reflection to another side and extrude throught all.

Finaly: This is the modelled table top part.

2.) Modeling the table top part in solidworks as show on the following pictures:
I started my design from sketch, and I added its dimensions.

I did feature editing and extruding.

I have cutted the edge of the top view of table leg rectangle to provide the interlocking and fittig to the top and the button section.

This is the modelled table leg part.

Below here is the modelled table in solidworks:

From the above generated model, now I am going to use VCarve Pro to generate toolpaths for CNC machines, including V-carving, engraving, and drilling.

See the generated toolpaths to instruct the CNC router on how to cut

CNC Cutting

A CNC (computer numeric control) tool is used in prototyping and full production for cutting, carving, machining and milling in a variety of materials including wood, mdf, plastics, foams and aluminum.

CNC machining is a manufacturing process that uses computer-controlled machine tools to remove material from a workpiece to create a finished part or product. The process involves programming a computer to control the movement of a cutting tool, such as a drill or milling machine, along multiple axes to shape and contour the material into the desired shape. CNC machining is widely used in manufacturing, prototyping, and toolmaking for a variety of industries, including aerospace, automotive, medical, and consumer products, among others. The precision and repeatability of CNC machining make it a popular choice for creating complex and intricate parts with high accuracy and consistency.

I started by fixing the plywood sheet on CNC bed, I inserted screws to fix it so that it stays stable:
ShopBot move a cutter aroung a big table (X and Y axes)
I moved the spindle to the desired starting position, then click on "Set Home" and enter the values for X, Y, and Z axis in the controller's software in order to set the origin.

Here below: see the ShopBot tool while cutting

Here below: see the assembled made table

Finaly: see the table I made to hold a Saachi Coffee Maker and/or Laptop Computer

• Used file can be found here