b'\x1b\x1a\x19 \x1f\x18\x1d\x17\x16Ask the Grinding DocVERTICAL SPINDLE BLANCHARD-STYLEBy Jeffrey Badger = 0.006/20 = 0.0003". the grit penetration depth to get 2. The wheel/segment is going tobetter self-sharpening.D earDoc:Youdontwritedevelop two tapers: a larger taper5. Increasing the plunge veloc-much about vertical spindleon the outside and a smaller taperity will increase your grit penetra-Blanchard-style grinding. Why ison the inside. The larger taper heighttion depth.that? will be about two-thirds the effective6. Increasing the plunge velocity The Doc replies: I havent writ- depth, and the inside taper will bewill increase your workpiece surface ten much because Blanchard-styleabout one-third the effective depth. temperature.grinding drives me nuts. There just3. The two tapers will converge7. Increasing your bed rpm will not arent a lot of options to play withquickly to a point, which means thatchange your grit penetration depth.when that vertical spindle (solidyour surface finish Rwill be high.8. Increasing your bed rpm will awheel or segments) plunges downThats why Blanchard-style is con- decrease your workpiece surface onto workpieces mounted on thesidered a stock removal operation,temperature.rotating magnet. not a high-precision or fine-surface9. Workpieces farther from the Having said that, here are someoperation. bed center will have a higher grit observations and general trends: 4. Try to keep the grinding powerpenetration depth.1. The effective depth of cut issteady. If your power is increas- 10. Workpieces farther from the calculated by plunge velocity in ipming gradually, followed by wheelbed center will have a higher sur-divided by bed rpm. If youre plung- screaming, followed by no scream- face temperature.ing at 6,000 a minute on a bed rotat- ing, then youre not self-sharpening11. A slower wheel rpmsome-ing at 20 rpm, thats effective DOCyour wheel well enough. Increasetimes possible, sometimes notThe wheel/segment is going to develop two tapers: a larger taper on the outside and a smaller taper on the inside. The larger taper height will be about two-thirds the effective depth, and the inside taper will be about one-third the effective depth.J. Badger16SEPTEMBER 2023 GrindingDoc.indd 16 8/15/23 1:07 PM'