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| Troubleshooting |
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Tool Breakage
Excerpts from the Amana Tool catalog technical information page. |
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There are two main causes of tool breakage. Vibration and wear. Here are a few suggestions to help you get the most tool life and cut down on breakage.
First, never let a tool get too dull. Heat has probably the most damaging effect on the cutting edge. Once a tool starts to get dull heat increases on the cutting edge softening the edge allowing it to dull even faster. This dull edge increases the torque required to penetrate the material putting more pressure on the bit eventually causing it to snap. Cutting tools that are properly sharpened and maintained will cut faster, better and longer, and will be safer to use. In addition, less horsepower is required (both machine and operator) when sharp tools are used. Second, tool vibration is the other leading cause of breakage. Proper collet condition is of extreme importance. Worn, scored or out-of-round router collets do not provide adequate holding power and will increase run-out and vibration. Multiply these factors by the router R.P.M. (22,000 and greater) and you will realize why we must emphasize the importance of proper collet condition. Dark marks or grooves in the router bit shank usually indicate slippage and a worn collet, which should be replaced immediately. Router bits should always be completely inserted into the collet and backed off slightly (approx. 1/16"). Never partially insert the bit into the collet. Always use the shortest cutting edge available that will meet the requirements of your application. Excessive cutting edge length and/or overall length compounds vibration and deflection - a leading cause of tool breakage. Always use the correct size collet for your router and avoid using reducing sleeves or bushings. Reducers only add to vibration and run-out, and they do not provide the necessary holding capabilities as with a collet alone. Deciding on Feed Rates Excerpt from the Safranek Enterprises technical information. |
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A wide range of variables - such as the router RPM's, the depth of cut, the diameter of the router bit, the material you are routing, et cetera - affect the required feed rate. When any of these factors change, your feed rate may need to be adjusted.
Here are some basic guidlines to keep in mind when figuring your feed rate. A greater depth of cut requires a slower feed rate. The deeper the cut the more material removed and the more heat and side pressure generated. When heat and pressure reach the critical point the cutter will break off. Smaller diameter cutters should be fed at a slower rate than larger diameter cutters - although smaller diameter cutters require faster RPM's. This is a point of confusion for many because, when using the same diameter tooling, the rule of thumb is a slower feed rate for slower RPM's and a faster feed rate for faster RPM's. The material being routed affects the required feed rate. Balsa wood, for instance, will machine much easier than rock maple or other hard woods. Real woods need a slower feed rate than engineered woods. Plastic materials require even slower speeds due to the risk of melting. For maximum life, start at a "safe" feed rate, say 400" per minute, and then increase until you determine an upper limit where you are still getting a good cut. If the feed rate is too fast, the tool can break. If the feed rate is too slow, the tool can burn. Usually, the faster a bit is fed, the longer the cutting edges will last. Moving the cutter into cool material helps to keep the cutting edge from overheating. If you stop, the cutter will burn. When plunging use a slower feed rate. Don't get attached to a magic number. Each combination of factors give rise to a unique situation. When it comes to determining feed rate, nothing can substitute for the intuitive know-how of an experienced woodworker. What's so important about carbide tooling running cooler? Bottom line, longer tool life. Too much heat will dull the carbide edge prematurely. Some tooling is designed to reduce heat build up by creating their own air draft when being used. Most carbide tooling can benifit from having an air draft when in use. Wood chips remaining in a cut add heat to the tooling. The friction of cutting is where most heat is generated. Click here for Amana Feed Rate Chart
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