What are the different types of cutting bits used on brake lathes, and when should I use each?

Brake lathes typically use either carbide or CBN (Cubic Boron Nitride) cutting bits. Carbide bits, like the Ammco-Coats positive rake bits for Kwikway lathes, are a good general-purpose option for many rotor materials. CBN bits are harder and more heat-resistant, making them ideal for harder or heat-treated rotors and drums, where they can maintain a sharper cutting edge for longer. Always consult your lathe manufacturer's recommendations to ensure compatibility with your specific machine and the type of material you're working on. Also, always inspect your bits for wear before each use.

What is the purpose of the different grit levels available for brake lathe stones?

Brake lathe stones come in various grits, each serving a specific purpose in the resurfacing process. Coarser grits, such as 60 grit, are used for roughing or removing significant material quickly to correct deep imperfections. Medium grits, like 220 grit, are used for finishing, to refine the surface and achieve a smooth, even finish after using a coarser grit. Using the correct grit sequence is crucial for achieving optimal brake performance and minimizing noise. For example, Ammco-Coats offers both 60-grit roughing stones and 220-grit finishing stones.

How do I choose the correct arbor size and accessories for my brake lathe?

Selecting the correct arbor size and accessories is essential for accurate and safe brake lathe operation. The arbor size must match your brake lathe's spindle diameter. Consult your lathe's manual for the correct specifications. You'll also need appropriate adapters and cones to securely mount different rotor and drum sizes. Ensure all accessories are in good condition and properly tightened before operation. Using mismatched or worn components can lead to inaccurate cuts and potentially dangerous situations. Verify the compatibility of any new accessories with your specific lathe model before use.

What safety precautions should I take when using brake lathe accessories?

Safety is paramount when operating a brake lathe. Always wear appropriate personal protective equipment (PPE), including safety glasses and gloves. Ensure that the workpiece is securely mounted and that all guards are in place before starting the lathe. Never reach over or near moving parts, and be aware of the potential for flying debris. Regularly inspect accessories for wear or damage, and replace them as needed. Consult your lathe's manual for specific safety guidelines and operating procedures. Also, be mindful of the materials you are working with, as some may create hazardous dust when machined.

What is a 'gear shear' for an Ammco brake lathe, and what does it do?

A gear shear, like the Ammco-Coats gear shear for Ammco 4000/4100 lathes, is a small but crucial component that protects the lathe's feed mechanism. It's designed to break or shear under excessive load, preventing damage to more expensive internal gears and components if the cutting bit encounters too much resistance. If your lathe's feed stops unexpectedly, the gear shear is a likely culprit. Replacing it is a simple repair that can save significant downtime and repair costs. Always use the correct replacement shear for your specific lathe model.

How often should I replace the cutting bits on my brake lathe?

The lifespan of cutting bits varies depending on the material being cut, the depth of cut, and the overall condition of the lathe. Regularly inspect your bits for signs of wear, such as chipping, dulling, or breakage. Replace them as soon as you notice any degradation in cutting performance or surface finish. Using worn bits can lead to inaccurate cuts, increased vibration, and potential damage to the rotor or drum. Keep a supply of replacement bits on hand to minimize downtime. For example, Ammco-Coats offers carbide bits in convenient 10-packs.

What can cause chatter or vibration when using a brake lathe, and how can I prevent it?

Chatter or vibration during brake lathe operation can be caused by several factors, including loose or worn bearings, improper tool setup, excessive cutting depth, or an unbalanced rotor. Ensure that all lathe components are properly tightened and in good working order. Use sharp cutting bits and avoid excessive cutting depths. Consider using vibration dampers or support arms to minimize movement. If the problem persists, consult a qualified technician to diagnose and repair any underlying mechanical issues. Also, ensure that the rotor or drum is properly cleaned before machining to prevent contamination from affecting the cutting process.