Solving Common Router Problems
Solving Common Router Problems
1. Vibration
First check your collets. Ina production CNC operation collets should have a life of 800 to 1,000 hours or 5 to 6 months of 40 hour weeks. This is about as far as you should push them and then only if the shop is clean and the equipment is very well maintained. Often the collets are worn and dirty. Occasionally the collets were the wrong size when inserted. Much more common is to find a collet that has worn to be too loose. After the collets, check for an unbalanced tool or tool holder. Finally check the spindle. Remember that a worn collet can damage the tool and tool holder. This can eventually affect the spindle. The best solution is to clean and replace the tool and tool holder, then replace the collets with the correct size.
2. Burning or melting material
First check your rpm and feed rate to make sure you have the proper chip load on your tool.
A. RPM’s = feed rate (inches per minute) / (number of flutes x chip load)
B. Feed Rate = RPM x number of flutes x chip load
C. Chip Load = feed rate (inches per minute) / (RPM x number of flutes)
If your chip load is too high you are not clearing it out of the way fast enough. This is related to chip removal. Chip removal problems occur when the chips are the proper size but are not removed from the cut. You generate a lot of heat because you are plowing through a lot of chip crud in either case. The solution is to use a correct tool and make sure your chip removal is spot on. It takes very little obstruction to seriously interfere with a gravity or vacuum chip removal system.
3. Part movement
Start by checking your fixturing and/or hold downs. You might need to change your tool. In a CNC application switching to a downshear bit can solve this problem. Check your chip load. Exceeding a proper chip load puts a lot of pressure on the tool and the material being cut. You may be trying to cut parts that are simply too small to hold properly.
4. Short Tool Life
This can be caused by; improper chip load, vibration, inadequate chip removal, using the wrong tool configuration or worn equipment such as collets, tool holders and spindles.
5. Poor Cut Quality
Are you using the right tool and is it in good shape. A 30x lens does a beautiful job for inspection. Check the chip load and similar calculations to make sure you are not trying to run too fast. Check the tool runout and make sure the tool is in good shape. Check your fixturing; hold down, vacuum, etc to make sure your parts are not shifting. Check for vibration especially from worn or dirty equipment.
6. Tool Breakage
If you are using the correct tool then you are probably pushing it tool hard. Check your feed rates and your chipload. Then check your equipment.
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