In the current manufacturing environment it is small things that can add up quickly to be either hidden costs or savings. I tend towards simpler is better when at all possible because time is money. Inaccuracies that take you over a tolerance cliff also cost money and identifying where the last little bit of tolerance stack up took you over the edge can be a problem. The best way is to eliminate the things you can ahead of time and reduce the number of negative variables that affect what you make. I am going to talk about one of those ways here.
One of the great things about HSM is the tool generation process. The capability to quickly “make” a tool and in the same order features are cut have them assigned to a pocket on my tool changer. I never leave assigned tools to one location as I just don’t have this type of production here. I do not want this individual CAM plan to have any relationship with tool data elsewhere since the very next job will see me start over with a fresh new tool setup and order on the mill. It just goes too quickly to want to work any other way as far as this owner is concerned. Other CAM programs probably do things this way or very close so I am not claiming the HSM way to be revolutionary or unparalleled. What I am saying is that this is the very best way to do it for almost all the shops I have direct contact with and indeed the way I do it by choice.
There is also another important aspect of operating like this. Cutter manufacturers are often getting into resharpening services nowadays for those tools they have manufactured. If I have five or more 1/2″ end mills for instance Hanita will take them in and recut the geometry and recoat to factory specs. The practical life of your endmill may be extended by as many as four or five lives if you don’t beat them up between resharps. But none are true original size end mills anymore.
I like Haas Mills. I know the debate rages about what is best and why but there is a reason Haas is so large and so many people make lots of money day in week in and year long. They are good machines and one of the key things that helps to make them so is the best bargain in new CNC equipment. The Haas Renishaw probe. Accurate easily to less than a tenth according to the Renishaw guys I have spoken to it is better that the claimed repeatability of of the mill itself when brand new. And it lends itself perfectly to the idea of the tool library system I describe above.
Now about that tolerance stackup I mentioned above. Until you have a probe and you start measuring the true diameter of your endmills you have no idea of how often you have introduced tolerance problems right from the very start with endmills that say .500 on the box but really are .4985 or some other variation. All these add up after all and two sides of a cavity is double the difference between .500 and .4985. In addition just how do you measure three and five flute endmills anyway without a probe? OK before some smart alleck gets in here there and points out this is not the only way and that expensive metrology equipment will do this too I will say sure, and probably cost more than the probing system on the mill and be no where near as handy and limited to one function. The combination of quick new tool creation or existing tool editing if need be inside of HSM is perfect for accounting for the use of the true correct size of the endmill in question and no fooling around with libraries. The probe will also account for any out of round condition in the holder to which is another important step in error reduction. I am slowly replacing all of my cat40 tool holders with Schunk Hydraulic holders with sleeves for all high speed tools paths and precision cutting. The faster you push adaptive tool paths the more concentric your cutting needs to be with the spindle centerline for best end mill life. The additional benefits are better accuracy and finishes.
Join with me today as I show not revolutionary stuff but the right stuff for quick and easy tool generation that will save you time and produce better parts.