Service Tip: 7 Things You Need to Know About Gibs, and Why You Should Care
September 30, 2013
Here are 7 things to keep in mind about gibs:
The gib on a CNC machine tool is an often forgotten and neglected component that, nonetheless, performs an important function. In most cases, the saddle, table and knee of the machine ride along slides. As these parts wear over time, the gib can be adjusted, via set screws, to compensate for this wear so the machine tool can maintain the level of precision necessary for close tolerance machining.
An experienced technician should adjust gibs to insure proper positioning. If the gib is too loose, the machine will not perform accurately. If the gib is too tight, the slide won’t move correctly and the parts will wear prematurely.
The best way to monitor the condition of the gib is to periodically remove and examine it for wear spots. When the gib surface becomes too shiny it means there are not enough low areas for oil to collect. Without enough oil on the gib’s surface, the machine will eventually seize up.
Excessive gib wear indicates a lack of lubrication that may be the result of plugged oil metering pins, a malfunction of the oil metering system, or a clogged hose. In some cases, the oil delivery system is compromised by contaminants that find their way into the system. This condition is often the result of poor habits such as removing the strainer when refilling oil, or leaving the cap off of the oil reservoir.
Another source of gib wear is traceable to damaged or missing scrapers or wipers designed to keep chips, filings and other debris away from moving parts. If these abrasive particles get between the gib and the other components, they can cause severe damage.
If the gib is damaged or worn, a trained technician may be able to scrape the gib to restore flatness and oil pockets. In many cases, however, the damage is too great and the gib must be replaced. The new gib must also be expertly scraped to insure an accurate fit with the sliding components to millionths of an inch.
Replacing a gib and repairing damage to other machine components can be costly. That’s why every machine tool should have a planned, preventative maintenance program that includes inspecting machine wipers and scrapers and replacing them as necessary. Also vitally important is regularly checking the lubrication system components and following proper procedures when adding oil.
If you have questions about how to properly maintain and extend the life of your CNC machine’s gibs and other critical parts, contact Gosiger’s technical service department. They can provide training for your internal maintenance staff and design a planned preventative maintenance program for your specific requirements. Gosiger also offers complete preventative maintenance plan packages that make it possible to get the maximum life out of your CNC machine tools.