Say goodbye to inconsistent results: troubleshooting router bits

For any user of a handrouter, there's nothing more frustrating than experiencing issues with your router bit during a job. From burning to tear-out and chipping, common router bit problems can cause a lot of headaches. However, with the right knowledge and techniques, many of these issues can be easily solved. With Tungsten & Tool expert tips, we'll explore common router bit problems or dilemmas and help you to solve them.

Burning

Problem: Burning is a common issue when hand routing. that occurs when there is a mismatch in the feed/speed relationship.
Take for example: a standard single speed router, irrespective of size, spins at approx. 20,000. With a 2-flute cutter, this means that the cutting edge contacts the material 40,000 times per minute or 666 times every second! Feeding too slowly causes the router to rub causing it to heat up almost immediately and burn the wood, leaving those unsightly marks.

Solution: Decrease the RPM and ensure your bit is sharp. Reduce the amount of material being removed with each pass and use a faster, more controlled feed rate.

Tear-out & chipping

Problem: Tear-out is when the router bit tears chunks out of the wood as it cuts, leaving a rough and uneven surface and chipping is when the router bit chips the edge of the wood, also leaving a rough and uneven edge.

Solution: If possible, use a shear cutting bit. Always use a sharp bit and take smaller passes to reduce the amount of material being removed at once. Adjust the depth of the bit and the feed rate to minimise tear-out. Additionally, using a backing board behind the workpiece can help prevent chipping. Going to a larger diameter router bit often helps as the cutting edge hits the material at a better, less aggressive cutting angle.

Snapping

Problem: Snapping is when the router bit breaks during use, which is dangerous and can be costly, not only in terms of bit replacement but damage to the project.

Solution: Ensure your router bit is undamaged, properly secured in a clean and undamaged collet and the collet is properly tightened. Make sure you have a good length of shank getting gripped in the collet, use the appropriate speed for the bit and make sure the bit is not being pushed too hard.

Wobbling & Vibration

Problem: Wobbling occurs when the router bit is not spinning evenly, causing the cut to be uneven and potentially dangerous. Vibration is another common problem that can cause chatter marks on the workpiece and an uneven cut.

Solution: The collet is the critical piece for this. Ensure the router bit is properly installed and tightened in the collet. Check that the collet is properly installed in the router. Make sure the collet is clean. If the bit is still wobbling, it is most likely the bit is worn or damaged and in need of replacement. 

Burning and melting plastic

Problem: When cutting plastic materials with a router bit, the heat generated by the bit can cause the plastic to melt and stick to the bit.

Solution: Use a router bit designed specifically for cutting plastics, as they have a different geometry and a specialised coating that helps to reduce heat build-up. Increase the feed rate and take lighter passes to minimise heat build-up.

Dust and Swarf/Resin build-up

Problem: Over time, dust and debris can accumulate on the router bit, affecting its performance and causing it to overheat.

Solution: Regularly clean your router bit and collet using a brass bristle brush to remove dust and debris. You can soak the dirty router bits in Gleiten-Clean overnight, this will also help the bearings to last longer. For a clean router bit and then use the DryUp aerosol spray to help prevent the resin from building up again. Use a lubricant to keep the bit cool and prevent it from overheating. 

Runout

Problem: Runout occurs when the router bit is not perfectly centred in the collet, causing it to wobble and cut unevenly.

Solution: Check that the collet is properly installed and tightened in the router. Use a bit with a shorter shank to reduce runout or invest in a precision collet to help keep the bit centered.

Do you have more questions?

Every day our team strives to boost your confidence, productivity and results through our accurate service and tailored support. Feel free to contact us at 0800 488 647 or sales@tungstenandtool.co.nz for more information on working with router bits.