b'Boring Ending removes half the stock and then ishe recommends a diametrical stock taken out of the bore so a probe canallowance equal to or slightly more be inserted to measure the hole. Thisthan the insert nose radius of the tool. and a reamer can work together.data is sent to the machine control,For holes with extremely tight toler-Hacker pointed out that fine bor- which uses it to calculate the devia- ances, he said the stock allowance ing provides better positional accu- tion from the required bore diam- should be reduced and inserts should racy than reaming but is a compara- eter. Based on the calculated devi- have a sharp cutting geometry.tively slow process and does no bet- ation, process parameters then areTegelman believes that in re-ter than reaming when it comes toadjusted so boring will be even morecent years, fine boring has gotten roundness, straightness and surfaceprecise in the second step, when thea boost from the appearance of finish. So shops can start by mak- tool is reinserted in the hole to re- boring heads with a digital display ing a pilot bore with a fine boringmove the other half of the stock. to show adjustment increments. toola depth equal to the boreHacker said this two-step finishToday, he said, BIG KAISER Preci-diameter or even less is often suffi- boring process can be particularlysion Toolings EWE digital fine bor-cientand then switch to a reamerhelpful in situations in which there areing heads can communicate with with six or more teeth to quickly fin- unknowns upfront about the work- software not only to display and re-ish the hole. piecefor example, the exact hard- cord offset adjustment information When cycle time is not a primaryness of the material, which can affectbut to use the last measured bore consideration and the workpiecethe hole diameter cut by the tool. diameter value to determine the is a valuable one that the manufac- When it comes to finish boringoutput diameter of the next cut and turer can ill afford to lose due to aquality, Tegelman said, the No. 1then show where that diameter lies boring error, he recommends a two- issue I deal with is improper stockin the applications tolerance band.step process in which twice the nor- allowance, which results in poorThe company currently is work-mal amount of stock is left in the holesurface finish. ing on closed-loop boring tools for fine boring. In the first step, a toolFor most standard applications,that adjust themselves using back-The EWA is a fully automatic fine boring tool that doesnt require manual adjustments.BIG KAISER Precision Tooling34JULY 2021Boring.indd 34 6/17/21 11:04 AM'