How to Machine All Around a Workpiece With Clamps in the Way

I think most of you are familiar with this issue:

Your workpiece needs to be machined all the way around so

• clamps would be in the way and crash the tool...
• but you also have no vacuum table...,
• double sided tape is too weak or messy...
• and holding tabs require much larger stock you don't want to waste...

But there is actually a very simple solution:

• Just clamp the workpiece down and instead of machining all around in one pass split it up into 2 individual operations:
  • First place the clamps on front and back to machine left and right...
  • Then move the clamps to left and right to machine front and back...
  • The only important thing is to move the clamps one by one so your workpiece cannot move and stays perfectly in place...

Step 1: Prepare the CNC Program

This is how you can do it in Estlcam:

• Instead of using the "Part" function to create the complete outside (picture 1) we use "Engravings" with tool radius compensation to create 4 individual sections for the left, right, front and back.
• The engraving in picture 2 will work - but have a look at picture 3. I've extended the engraving to start and end away from the workpiece. This is not necessary but helps to avoid burn marks on the workpiece and also lowers tool load.
• Save the CNC program after you created the left and right engraving (picture 4), then delete everything, create the front and back engravings and save as a different CNC program (picture 5).
• Have a look at this video - there you can see all the steps.