Abstract: A disk brake lathe has a pair of tool bits mounted to tool holders which are translatable parallel to a lathe axis to adjust the separation of the tool bits from a brake disk. A displacement gauge responds to changes in the separation between the tool holders. When the tool bits are in continuous contact with the disk, the separation indicates the thickness which would result from machining the disk. This separation can be compared to a specification to determine whether to machine or discard the disk. A method for machining a disk starts by mounting and aligning the lathe to a wheel hub on which the disk is mounted. The tool bits are each advanced until they are in continuous contact the disk surfaces, when the separation of the tool bits is measured and preferably compared to a specification. When the tool bits are sequentially advanced, variation in the separation can be used to determine depth of cut for each tool bit.

Abstract: A brake testing device evaluates the condition of a disk having a disk axis and first and second disk surfaces that are normal to the disk axis. The device has a pair of gauges, each having a sensing element for measuring the position of one of the disk surfaces along a line parallel to the disk axis. The gauges generate position signals corresponding to the measured positions of the disk surfaces. The gauges are secured with respect to each other so as to measure positions along parallel lines, and the device positions the gauges to measure the disk surfaces at points equidistant from the disk axis. The gauges are preferably configured to allow testing a disk surrounded by a wheel and a dust shield. The device may be part of a system which processes the position signals to determine the thickness and the lateral run-out of the disk. The system may additionally compare the thickness and lateral runout to manufacturer-specified standards.

Abstract: An alignment device to be mounted on an on-vehicle brake lathe to provide quick and easy lateral run out compensation. A concentric bottom plate, ring member and top plate are mounted onto the output shaft of the lathe prior to attaching the lathe to an adapter mounted on a vehicle hub/brake assembly. Two spring-loaded screws extend through the bottom plate, ring member and top plate and into complementary recesses in the mounting face of the lathe. The ring member includes an adjustment screw which, when engaged, and in combination with the tension on the center shaft of the lathe output shaft, will alter the planar alignment of the top plate and thus compensate for the lateral run out of the hub/brake assembly and allow for the precision machining of the brake rotor surface with the cutting tips of the lathe.