Week 7 - Computer-Controlled Machining

 Make something big out of ply or foam

Shopbot – CNC milling machine. A shopbot is a large CNC router that uses a bit like the Modela to cut files. It is necessary to screw the board down onto the bed and essential that the bit does not hit these screws when routing.

I decided to use this opportunity to work on my final project. Starting with Partworks  to draw up and  prepare my designs to cut out on the Shopbot. Having not used Partworks before this took some time but actually was quite straight forward. Having prepared the design I then went on to using the Shopbot.

Tool data set in Partworks below

File formats I used

2D Inkscape save as PDF

3D designs save as STL

Partworks saves as a CRV file

Shopbot saves paths as an STV file

Materials

12mm plywood 2440 x 1220mm

My settings for the Shopbot

I used a dowcut 6mm bit at spindle speed of 18,000rpm

I prepared 2 different pathways.  Pocket cuts for milling out shapes at a depth of 2mm and Profile cuts at a depth of 14mm for cutting out the outlines

SAFETY NOTES – be clear on 3 ways of turning Shopbot off in emergency

Space bar   Big red button  mouse

Remember to add tabs carefully spaced on all parts to be cut out

add tabs for all pieces that are being cut out

Work with a friend not on your own

Wear safety goggles

Workflow

Set up board on milling table secured with screws check position of screws and if others needed

Choose bit 6mm downcut, collete 5 – 6mm tighten and setup

Set zero   x,y axis see below

Set z height for 6mm drill

Practice moving the bit around the board without spindle on to get confident using the control panel

Check toolpaths – I noticed I needed to add ramps and set toolpath cutting order for the profile cuts to be last and pockets first

Run a preview – at this stage I noticed a mistake, I hadn’t saved all the files so short delay while all files were added and another preview made

Spindle on with key

Check spindle speed, extractor on

Goggles on

Start job

When job finishes turn off spindle, then  extractor and check job, I then added another toolpath at this point.

 I have enjoyed using the Shopbot and hope to use it again soon.

First prototype of  structure for robot face below and picture of lines next to it not matching up with cut - I need to work this out for next

What next

I would like to try creating a 3D version of my final project using 123D Make and will continue to improve and refine the design and hope to create several other versions using the Shopbot.

Files I used

Partworks