CNC Repair Tip #7: Avoiding Crashes Due To Incorrect Offset Adjustments on Machine with Fanuc Controls
Attention: Please read the Terms of Use for this site before proceeding.
If you know what the term “fat-finger” means, then you may find this post interesting.
For those that don’t know what “fat-finger” means, I would describe it as the incorrect entering of information on a CNC control operation panel due to an erroneous key-stroke. I guess that sums it up.
As you may know, many times the result of this erroneous key-stroke is the cutting of an “out of tolerance” part or maybe a crash of the machine requiring CNC machine services.
In many cases, the data that is being entered is a wear offset value for a particular tool. The primary use for a wear offset is to make a small adjustment to the tool offset to compensate for tool wear from cutting. Since we are only compensating for tool wear, the number that we enter for the wear offset would be a relatively small number (several thousanths of an inch, typically).
At some point as the machine runs part after part, there will be a limit to how much wear offset I can enter for a tool. The tool or insert doing the cutting will eventually become so worn that is no longer useable and must be replaced.
Now even if you know all about offsets, you may not know about Fanuc parameters 5013 and 5014. Their functions are as follows:
5013: Maximum value of tool wear compensation.
This parameter sets the maximum allowable tool wear compensation value. If an attempt is made to set a tool wear compensation value, the absolute value of which exceeds the value set in this parameter, the following alarm or warning is output:
Input from MDI:
“Warning: Too many digits”
Input by G10:
“P/S alarm No.032: Offset value is out of range by G10″
5014: Maximum value of incremental input for tool wear compensation.
Set the maximum allowable value for the tool wear compensation value, input as an incremental value. If the incremental input value (absolute value) exceeds the set value, the following alarm or warning message is output:
Input from MDI:
“Warning: Setting value out of range”
Input using G10:
“P/S alarm No.032: Offset value is out of range by G10″
In short, you can use 5013 to limit the maximum amount that can be entered as a wear offset, and 5014 to limit how much of a change can be made to wear offsets at a time.
These parameters are available on many newer (and even “not-so-new”) Fanuc controls. Of course, you will have to confirm that they apply to your particular control before using them.
When I look at these parameter settings on machines in the field, I usually find them set to “0″ and therefore they are not being used. It seems to me that using these parameters would be a great countermeasure to the dreaded “fat finger”.
Check out www.pinpointcnc.com for machine repair information, procedures and other products
Go to www.cncalarm.com for machine alarms and details
Go to www.toyookivalve.blogspot.com for information on Toyooki products
Go to Fanuc Control Central for all Fanuc related posts
Filed Under CNC Repair Tips, Fanuc Control, General Information | Leave a Comment
Tagged With cnc repair, cnc service, cnc services, crash avoidance, fanuc, Fanuc Control, fanuc controls, machine repair, offset, parameter