Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Monitoring the wear of tools

Monitoring the wear of tools

Monitoring the wear of tools

Hi all,

Today I helped a coworker in doing some tests of a system he designed that is able to measure the size of big objects. For example, the tickness of walls. This brought me to think if there is anything similar which cam be used to monitor the wear of tools of cutting machines, so that an alert when the tool is worn out can be deployed to the user. Probably, something with that purpose already exists which relies on load cells or a torque applied by the motor (I'm not sure). But which other approaches could be used?

RE: Monitoring the wear of tools

I think some CNC machines can monitor spindle motor current or vibration. I'm not sure how well they work; I'd guess it depends on what you're doing with the tool.

Many CNC machines have a Renishaw touch probe that's used for setting the zero/offset of the tools. Basically the machine creeps up on the probe until the probe signals that the tool is touching it. You could conjecturally re-check the tools' position when they're being changed, or in between workpieces. The touch cycle adds to the cycle time without making money, so again you might or might not add the touch test to the regular cycle; again it depends on what you're doing...

I think some outfits measure each workpiece right after producing it, using a touch probe as a tool. The machine should then be able to flag a produced surface that's not in the correct location. Again, the inspection time is not making money, but it's probably faster and cheaper than adding a process step involving a separate CMM machine.

Mike Halloran
Pembroke Pines, FL, USA

RE: Monitoring the wear of tools

Renishaw toolsetter probes are the bees knees but only measure geometric size changes. This is a great function but does not cover all wear situations. As @MikeHalloran notes, there are spindle sensors that can detect common symptoms. Typically spindle load is used to detect tool condition. Tools in good condition will only require 'x' horsepower to continue material removal. If that trend line starts to creep upward, a boundary can be set whereby the machine automatically switches to a backup tool, or throws and alarm or whatever one deems necessary. This method is probably the most common.

There's also the old fashioned, manual way. If you're running a part for a long time, using a fairly controlled process and material, you'll develop a memory of how parts a certain tool/insert is good for, and can preventatively change it out.

Skipping past in-machine inspection: There are also semi-recent advances where separate CMM or measuring machines can communicate back to the machine controller with particular dimension results, and adjust cutter compensation offsets or provide the data necessary for the tool wear monitor to switch to a backup tool. I'm still undecided on that method, mostly because of lack of experience with it. I'm not sure I'm keen on relying on dimensional results to dictate tooling action - it seems to measure something too far removed from the actual root cause, and does not account, on its own, for all possible conditions.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


White Paper - Reshoring Prototyping and Production
In this whitepaper, we'll provide insight into why and when it makes sense for U.S. manufacturers to reshore prototyping and production, and how companies can leverage the benefits of working with local design, prototype, and manufacturing partners during the pandemic and beyond. Download Now
Engineering Report - Top 10 Defect Types in Production
This 22-page report from Instrumental identifies the most common production defect types discovered in 2020, showcases trends from 2019 to 2020, and provides insights on how to prevent potential downtime in 2021. Unlike other methods, Instrumental drives correlations between a variety of data sources to help engineers find and fix root causes. Download Now
White Paper - Addressing Tooling and Casting Requirements at the Design Stage
Several of the tooling and casting requirements of a part can be addressed at the design stage. If these requirements are not addressed at the design stage, lot of time is spent in design iteration when the design reaches the die caster. These design issues lead to increase in time and cost of production leading to delay in time to market and reduced profits for the organization. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close