The assignment for the week includes the following;

1. Carry out lab's safety training
2. Test runout, alignment, fixturing, speeds, feeds, materials, and toolpaths for CNC machine at Lab

For this week;s assignment we had to make something big using the CNC machine. The CNC machine in out lab is the shopbot ---. Before we bagan operating the machine, we were briefed on some safety rules when inside the shopbot room. Some of the safety rules were as follows;

• When using the CNC machine, one should be attentive and should avoid doing multiple tasks to ensure no issues occur.
• ALways wear all the protective gear when using the CNC machine. The portective gear includes ear muffs, protective googles and lab coats.
• All the girls to tie their hair neatly
• Never put your hands on the machine bed when the machine is running.
• Never leave the machine unattended when the machine is operating / to be present after feeding the machine to carry a task
• To keep the machine clean of saw dust to avoid breakage of fire
• ALways keep your hands on emergency stop button to aoid mishaps.

Machine Description

The CNC machine available at our lab is the shopbot.Shopbot is a 3-axis with a bed dimensions of 4x8 feet. It also has two emergency switches to turn off the machines if issues occur. The macine can be used to cut wood, plys, sofe alumnium etc.,.

• Material:For the individual assignment we used plyboard of thickness 18mm to create something big while for the group assignment we used rubber wood of same thickness.
• Cutting Speed: 4000 rotations per minute (4000rpm)
• Alignment:The XY-Axis is aligned using the Machine Console Shopbot3. For Z-Axis we had manually align (Zeroing). For the bed alignment, we did it manually and a sacrificial layer must be put under the actual material.
• Fixture:We use clamps to hold the sacrificial layer and screws to hold the material
• Toolpath:To create the machine toolpath we use the Aspire software. We created drilling toolpath for the screw holes and profile toolpath for the design cutting

To check the runout, fixtures, alignment, feed etc., we made a simple design and cut it using the CNC machine at our lab. We made a simple parametric design incorporating strating cuts, holdes and curve cuts. The design files and the machine cutout are shown below;

In the design files the dimensions mentioned were as follows;

• Length: 185mm
• Width:130mm
• diameter of circles:15mm

However in the cutout the dimensions were as follows;

• Length: 185mm
• Width:130mm
• Diameter of the circles: 12mm