Accuracy of Renishaw laser tool setter.

[balnh]

We have new Renishaw laser tool setter and Probe on a Vertical machine. I am told by the owner that our tooling can not be set accurately and now wants to get his money back. The tooling in question are basically 60 deg chamfer/engraving tools that come to maybe .003 web at tip. Without getting into the application of these tools we have 2 that we blend together in Z. I was told that they are .008-.006 off. Before I take a look at it today it it's still on the machine, what kind of accuracy can I expect on tool length? Thanks

[Guest]

We do FAR better than that.......any adjustments we make after laser the tool length is less than .001"

 

Now, when it comes to chamfer tools.....lets' say your tool has a .004" - .006" radius at the nose of your tool.....if that was programmed to tip depth that was sharp, guess how  much your program is going to be off?

 

Is that the presetter issue or is it a setup issue?   It's a set up issue not the laser, the laser told you what was there but the tool selected most likely doesn't match the program

 

Typically, if a blend is "that" critical, I will ball mill to be certain

 

JM2C

[balnh]

This is exactly what I was thinking. We do ball mill then use these custom ground tools to clean out a sharp corner.

[balnh]

Also tools are theoretically sharp, or as close as it can be.

[Guest]

Also tools are theoretically sharp, or as close as it can be.

 

Which is normal, but any deviation in the tool itself is going to show up at that time.....

 

The laser is almost certainly perfectly fine

[YoDoug®]

We used to pick up the tool radius of the chamfer at two given Z depths with the laser, then with a little trig you can adjust the TLO to be the exact point the tool would make. We could blend multiple chamfer cutters seamlessly by doing it this way.

[robk]

Personally when using a laser, I never set the TLO at the sharp point of a chamfer tool. I always set it at the cutting diameter.

[htm01]

not to mention the angle  on the cutter has a tolerance

[YoDoug®]

Personally when using a laser, I never set the TLO at the sharp point of a chamfer tool. I always set it at the cutting diameter.

 

I used to set them at the major diameter as well but then I was at a shop replacing and re-calibrating physical touch setters tips a few times because they used both lasers set major diameter of angled tools and machines with physical setters that touched tools off at the tip. The operators were so confused about TLO they scrapped parts and broke touch setter styli often.  

[balnh]

To be honest I came in today to try and sort the thing out and was told not to. Renishaw was called and the owner wants his money back. I called bull xxxx on the laser being off that much. These tools angles and diameters are all custom ground to super tight tolerances. I think it's a case of an old dog not wanting to learn new tricks.

[balnh]

Thanks for replies everyone

[Sticky]

That sucks. It's frustrating working with or for people that have no interest in getting to the root of the problem.

[Guest]

You can expect lasers to be accurate to the accuracy of the machine PLUS the accuracy of the laser. (Typically .0003" or so) In practical terms though some tools' geometry, shape, and insert finish can cause deviations from that. For example, AB Tools' Shear hog... (I hate those things BTW... The chips from those things drie me nuts. But I digress) The high polish and insert geometry cause issues with laser beam deflection so I've always had to adjust those.

 

For your situation though, make sure the tip diameter matches what was used in your program. Sharp tip tools can report wrong lengths because the beam itself is about .2mm and the tool needs to block the beam completely in order to report a length.

 

HTH

[soymilk]

At my old shop on one of our vertical machines, we noticed that coolant pooling at the tip would cause the laser to be inconsistent.  We adjusted the air and it helped a lot.

 

Over here we get on average within .0005 of our external tool setter.  Usually repeatability within .0002.  Are the tools always off a certain amount?

[Redfire427]

We hold .0001" to .0002" without any problem with our lasers, but we use a Blum A2 laser system, but I am sure a Renishaw would be equal in performance. Small tools are our specialty. The easiest way to check your accuracy would be to touch the tool off the laser and then send the tool to a position 1.0" above the top of your part and then take guage blocks to measure the true gap. If the gap turns out to be 1.0", then it is your tool geometry or program that is incorrect.

 

Carmen