SMALL AND VERY SMALL BALL BARS— SHORT AND VERY SHORT BALL BARS— LITTLE BALL BARS— TINY BALL BARS— SMALL CMM MACHINE CALIBRATION— BALL BARS FOR SMALL C.M.M.’S— MINI BALL BARS

Calibrating small and very small C.M.M.’s, requires unique equipment. To quality as a small machine the up and down (z axis) clearance is less than 14 inches. Much shorter Ball Bars are an obvious and quite simple requirement, but the rest of the support equipment must be carefully selected. For extremely small machines our device, the mini Ball Bar can find some use, but this device is not very utilitarian. Standard Ball Bars and the mini Ball Bar clamp are fairly universal piece of small Ball Bar mounting hardware, but beyond these essentials, customers must make the other hardware choices based on their preferences. There are two general approaches, to the small Ball Bar mounting hardware.

The conventional approach is to use an anchor and standard collar system. This will mount the Ball Bar as well as the gage block clamp. If you decide to use the anchor system, you have to decide whether to mount the anchor by screwing it down to the threaded mounting holes in the C.M.M. table, or to mount the anchor on top of the Mini Trivet, part number MT-7. The limitation to screwing the Anchor down to the C.M.M. table, is there are a limited number of locations available and there is also the extra time, that is required to unscrew and rescrew the anchor down to the table. Using the Mini Trivet, is a much more versatile approach. Using this device, the anchor can be positioned anywhere on the machine table. The anchor system has the added advantage, of using the standard trimount collar, which has three surfaces to mount artifacts on. The alternative to using the anchor system, is to use the “crown.” This very simple device is limited to a single mounting surface.

The crown has no up and down adjustment, which can be a major drawback. Basically the crown is a larger version of the Mini Ball Bar, that will hold larger artifacts. The crown can be mounted directly to the table of the CMM, using a simple cap screw and washer, or it can be attached to the Mini Trivet so that the crown with attached hardware can be moved anywhere on the CMM table. Developing an effective but economical approach to small CMM calibration can be greatly enhanced by using a new version of the Hammer, Ball Bar mounting approach. The “new hammer” provides a totally new approach to versatility. It opens up expanded use of the crown, with its simplicity. The long handle of the New Hammer actually provides, considerable up and down adjustments of the Ball Bar held by the crown. Another big plus is the fact that the Dual Gage Block Clamp can be attached to the opposite end of the new hammer’s handle. This feature overcomes many of the crown’s limitations.