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

Introduction: 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.

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    Dui ni shuo de dui
    Dui ni shuo de dui

    6 years ago

    Nice instructable and great software. I just fail to see in this context how "engraving" is different from "part". In the "part" function it is also possible to create your own paths using the manual option too, so why using engraving instead of this?

    Also, if I understand correclty, we need to save 2 different projects. Could'nt it be possible to just add a pause after the first path are done, then the user just press the resume button after he moved the clamps?

    For now I'm just a beginner using the free version of Estlcam, but I'll buy it for sure soon, this software is awesome.

    Keep up the great work!

    Christian Knuell
    Christian Knuell

    Reply 6 years ago


    the part and hole functions require a closed shape - engravings can be open shapes and allow to set the tool radius compensation to either side (or none).

    As soon as we split the operation the shape is no longer closed and will only work with the engraving function.

    You can put the whole program in one file with a stop in between ("code" function in the "drill" group). But this is approach is far more risky - e.g. wrongly set machining orders will almost certainly kill your tool and damage your clamps.

    Dui ni shuo de dui
    Dui ni shuo de dui

    Reply 6 years ago

    Ok, I understand now, Thanks a lot for this very clear explanation.

    I might have to learn about whatever is the "tool radius compensation" though :D

    Again, great work, I love this software, super convenient to use.