cnc turned parts-Machining a hole in a block

 
As mentioned previously, the rings machined on the faceplate are guides to help you set up the work. This will do if the work is a round component, but we need a different method if the work is square. Take a block of metal, for example, that has
been machined all over. We want to machine a hole in it 2in from one edge and 1in from another edge. Mark out the position of the hole and centre punch it. Put a dead centre into the tailstock, hold the block onto the faceplate, bring the tailstock
up towards the chuck and lock it. Wind the tailstock barrel and centre up to the component and engage with the centre pop. Lock the tailstock barrel. Clamp the block to the faceplate using some packing pieces and four clamps on the block.
The hole is now on centre and we can machine it in the correct place.
 
If we need more than one hole placed accurately in the component we can use toolmaker’s buttons to ensure the holes are in the correct place. Toolmaker’s but- tons usually come in sets of four. One button is usually longer than the rest so you
can still clock the diameter when it is close to another hole. Sets are often available second-hand on eBay; while they probably have an obscure American thread, you can clamp them to the block using your own BA or metric screws, together with a
Washer