Thanks for posting this! I used to work in a machine shop but never saw how rotors were machined. Just did a brake job where the rotors were machined and now I understand why one of them was returned to me with .010" runout!
You have a few things incorrect in this video. But some good tips also. For starters never wear rubber gloves when operating a brake lathe. One of my customers caught his hand on the spindle wearing rubber gloves and broke all his fingers so I never recommend wearing a rubber gloves. Another thing don't turn the spindle all the way out to the right come back at least one turn on the crank wheel then lock everything down. It's a reason being is if it's extended all the way out to the right you're putting extra load on the bearings in the drum gearbox and extra load on the motor also. Always come in one turn in. Also when setting up those silencer arms it's best to but one pad on the top of the rotor and one pad on the bottom of the rotor not side by side. Some of those silencer assemblies have one short arm and one long arm just for that reason. Another thing never take two thousandths of a cut. That is too light of a cut the heat will not transfer on the bits and you wear your bits out faster. Always take four to six thousandths.
great video for those of us you have gaps in our knowlege as you said in a previously stated attend an instructor guided work shop or class before attemping to use brake lathe.
This is a very good instructional video but I'm curious why he didn't finish the job by giving the rotor a non-directional finish which is the last step before removing the rotor from the lathe. Also, after machining drums and rotors it is good practice to wash them with soap and water or at least in an aqueous parts washer to get rid of any small filings that might be on the friction surfaces or caught inside of the cooling fins of the vented rotors.
thank you Mark for the very well presented demo, but if I may, you forgot to make you initial scratch cut to determine if the adapter set up is correct.
When machining a rotor you want to reduce vibrations as much as possible. The self-aligning spacer ensures that any indifference between the lock nut and the drive plate even out to reduce vibrations. It works on the same principle as the anti-vibration pucks. He placed it in the wrong position (watch again at the 2:15 mark on the video), and the self-aligning spacer should butt up against the outer drive plate. Please keep in mind that not all machining procedures will require a spacer.
Too much, we replaced our brake lathe with one very similar to the one used in this video and we paid over $4,000.00 US for it. Rotors are so inexpensive these days that many shops opt to replace them over machining due to the labor costs incurred when machining rotors.
