b'\x1b\x1a\x19 \x1f\x18\x1d\x17\x16 Machinists CornerART OF THE GROOVEBy Brandt TaylorI n this article, Ill talk about mak-ing grooves for V-belts on a lathe. The first photograph shows a two-groove cast-iron sheave with 34-de-gree grooves in the manufactur-ing process. I use a brazed-carbide T-type cutoff blade for this work.I put a full-radius nose with a pos-itive rake angle on the carbide. The positive rake angle makes for faster metal removal and a nice surface finish. When I make a groove, I make a rectangular cutout that forms the depth of the groove, and then I cut the flank angles. I make a few par-allel plunges to get to the width at the bottom of the groove. Then the flanks of the groove are formed.I make the rectangular cutout in steps. First, I plunge the tool along the x-axis to a depth four times the width of the tool. Next, I retract the tool and move on the z-axis three-fourths the width of the tool, stay-ing in the rectangular cut area. Then I make a cut to a depth eight times the width of the tool. For the next cut, I retract, move on the z-axis an-other three-fourths the tool width and cut to 12 times the tool width. I repeat this procedure until the groove depth is reached and there is a bumpy bottom to the groove, then I move in the z direction toB. Taylorclean the groove bottom. Shown is a two-groove cast-iron sheave with 34-degree grooves in the manufacturing process.This technique is handy when parting off a large-diameter piece. Make the parting groove width 1.75about the author times the tool width by moving theBrandt Taylor is owner of Berlin, Massachusetts-based Taylor tool back and forth in the grooveEngineering, a machine shop and manufacturer of lathe and taking progressively deeperchuck jaws. He can be reached at [email protected]. It saves trouble from a toolcom. For more information about the chuck jaws, visit www.jamming in the work and possiblystopjaws.com.10JULY 2023 MachinistCorner.indd 10 6/15/23 11:57 AM'