CAM Assignment 2

Above is a video showing the simulation in Delcam for SolidWorks of the machining of a block as part of the CAM module. The aim is to design a block that can be machined, and using Delcam generate the CNC code for that block. After generating the code, the procedures and tools are optimised so that the block is machined with speed in mind. After first generation, the time for the machining of the block was around 60 minutes. With manual arranging of the operations the time was reduced to around 35 minutes.

This process was improved upon by changing the features delcam is machining. The features of the block were selected as sides with the appropriate boundary conditions. This method reduced the machining time to around 25 minutes and  CNC code by around 1000 lines. The video for this improved process is shown below.

More Delcam

This weeks brief was to create CNC code which made use of two different tools, the 4 and 6 mm flat drill bits. To do this, a model was created and Delcam was used to plot the features and tool paths. The paths Delcam created were then edited to use the 4 and 6 mm bits only. The 6 mm bit was mainly used for the rough cuts and the face cut, as this larger bit reduced the overall time for the completed block. The 4 mm bit was used for the finishing cuts and any cuts that needed a finer tool such as the narrow circle cut in the “Cross Block.”

The Roland CNC machine does not have an automatic tool change function, the tool need to be changed manually. Delcam creates code which assumes the tools change automatically, therefore, the code needs to be edited further before transferring to the Roland CNC machine. The tool paths are arrange so that the same tools are grouped together, and then one tool path is suppressed (in this case the finishing tool path was suppressed, leaving the rough pass running). Delcam then only displays the CNC code for the running tool path. This code is copied into a text file and saved appropriately. This process is repeated for the finishing tool path, and the code copied into a separate text file.

This method generates several text files depending on the number of tools used, in this case two. The files can be loaded into the CNC machine an run, one at a time, to achieve the desired model.

Delcam machining simulation

Block design

Cross Block

Delcam simulation

Delcam for SolidWorks

Using SolidWorks 2015 I designed a 100 x 100 mm block with several features and a facing cut.

The shapes are different depths

Isometric view

Using Delcam for SolidWorks, the CNC code was generated and a simulation of the cutting machine run. There was a little trouble with the rough cuts for the two circles, due to the width of the circles and the size of the selected cutting tool. This issue was sorted by manually overriding the finishing allowance from 1.25 mm to 0.25 mm.

The code was programmed to cut all features using a 4 mm drill bit. This code was generated for a Roland RotoCAMM CNC machine and contained 495 lines of code.

The CNC machine in action

The finished block

The design was cut into a 100 x 100 x 52.5 mm foam block (recycled from another student, hence the extra few cuts). The final block measures 100 x 100 x 50 mm thanks to the face cut which removes the top 2.5 mm of material.