Garbage In Garbage Out: Mistakes in the Wire EDM are most often made before the start button is pressed. As the operator, you are often pushed to get the machine cutting, because when it’s not cutting, it’s not making money, right? WRONG! What if in the process of setup, your touch-off was dirty or not square? You are now cutting scrap, and may not know it until the part is out of the machine and into inspection—which may be hours or days away, so the machine was losing money all that time.
As we set up the machine, we also should think ahead a bit and plan for a re-setup. This might be for several reasons:
- the part needs a second operation
- the part needs to be inspected mid-process
- the part needs to be removed for an emergency part for another job
- the one we all think will never happen: we have a crash
Most of these unforeseen issues can be avoided by good WEDM tooling. If you look at the cost first, though, it is high! But think about the cost of that part that cut all day and was not located or picked up properly; you just paid for the tooling. Look for good quality tooling that has features that will eliminate the issues you expect or want to prepare for.
Some things to consider:
- Will you be using a robot in the future to change workpieces? Unless you’re going out of business this year, the answer should be yes.
- Will I need a setup station? This is extremely useful but not required.
- How often will I be changing the workpiece on the table?
- Do I want to move the workpiece do a different machine still mounted in the tooling?
- Will I inspect the workpiece in the holder on a CMM?
- Especially important: does the tooling have known pickup locations with recorded X and Y?
- Will I mount to a tooling rail or a table receiver? Maybe both.
Another option is to make your own holding system. Although this works in some cases, it usually will cost more in the long run, and adding to the system makes it difficult at best.
Tool changing and work holding are parts of automation and can make setup and work holding predictable and accurate. This is the best way to ensure that mistakes in setup are stopped before the start button is pushed. Never time to do it right but time to do it twice. Work holding is cheap compared to the time it takes to cut the part again.