week 7

Computer Controlled Machining

ASSIGNMENTS:

  • Explanation of how the files are made for machining.
  • How I have made something BIG. Setting up machine , selecting end mill, cut depth etc.
  • Problems and their fix.
  • Inclusion of design files and ' hero shot' of the final product.

weekly work

designing the

'c2' table

final project

For this assignment we had to design something big and I got the chance to design myself a Coding + Calligraphy table. A convertible table  that can be used for my laptop and an extra keyboard; while not using it can be used as a flat desk for calligraphy with a place on the side for the pens, inks, USB sticks and other stuffs like an Arduino Uno.

contact

First I made it of changing heights but later stuck to a standard height  for ease of assembly and use. Further I developed the design in Rhinoceros 5.12 and produced the drawing from it only. The pockets in the side are made in accordance with Pilot Parallel pen, automatic pens, calligraphy handles and Arduino Uno and Raspberry Pi.

I generated the drawing from the 3D and nested. It looks like this.

producing the

fabrication data

From the 3DM, I have exported the file to DXF to worked with Partworks 2D which will convert the design data to machine code. Its a software from Vectric.

This the welcome screen from which I chose the New File options.

Set the bed size as 1200 * 2400mm and set the material thickness as 12mm with the origin point. This is because we have a PRS Alpha of 96" X 48" bed size. Now its time to import the files.

This is the screen it comes while importing with all the vector operations.

With the Cutting vectors in 2 Layers.

  1. Pocket Cut
  2. Profile Cut

Here I set the parameters for the Cutting. The settings are as follows:

  1. 1/8th inch Upcut 2 Flute End mill
  2. 7000 RPM
  3. Feed Rate 1.5
  4. Plunge Rate 1.5

This settings I have given becasue having worked the Bit and 12.5mm MDF.

 

The tool setting can be downloaded and used in any other ShopBot with same endmill.

The file can be downloaded here.

Preview. And these are the further preview of the other Cuts.

For the other vectors gave the profile cut as necessary.

And this is the all the toolpath combined.

Further step was to save all the toolpath to Shopbot Inch Toolpath.

setting up

machine

To turn on the ShopBot Alpha, there are some specified steps. Those are illustrated below.

We need to turn up the single phase motor and single phase power.

Flip the RED switch on.

Turn the key to Engaged. Now, the spanners are connected to the key, so it means one cant change the bit with the machine on. This is for a safety precaution.

Made sure these 2 Switched are not pressed.

This is the 1/8 th inch bit I have chosen, with the collet and the fastening ring.

Screwing the board to the base.

Tapan is ensuring the board is perfectly on the sacrificial layer.

Its time to fire up ShopBot to start cutting of the parts. By simply clicking on the Shopbot menu the software starts running and it looks like this:

It loads up the last XYZ location from the last file. So the first thing is to be done is to set the XYZ ; to do that Keypad is called.

Using the Arrow Keys or the Arrow button one keypad it can be moved in X and Y axis. Page Up and Down arrow is required for setting te Z axis. now it is set as Zero in the Zero Axes button.

Now in the Cuts menu. C5 Spindle warmup routine is activated. It will rotate the spindle at 9000rpm to prepare it for cut .

Now the pendant looks like this and ready to cut part. So now I load the SBP files one by one to the ShopBot at cut them.

One thing to keep in mind that, put the vaccum on and connected to the CNC machine and the material is either clamped or screwed on the sacrificial layer.

First all the pocket Cuts were done, then the small grooves and then the Profile cuts are performed so that the pieces don't move.

I had fixed a GoPro onto the spindle to check make a video of the cuts. the set up looks like this.

The quality of chip load also came like chips and dust.

Progress:

final product

This week's working feel can be downloaded from here.

 go to WEEK 8 >>

Avishek Das   |   2017   |   FabLab CEPT