b'\x1b\x1a\x19 \x1f\x18\x1d\x17\x16Ask the Grinding DocSURFACE GRINDING LARGE PLATESD ear Doc: We surface-grind largeas snakeskin chatter. Truing cor- width. (So for a 25.4 mm (1") wide (0.6 m1.2 m, or 2\'4\') tung- rects both issues. So how do youwheel, cross-feed about 22.9 mm sten-carbide plates, removing aroundtrue? Mount a brake-controlled de- (0.9").) This will reduce cycle times 1 mm (0.04") per side with a 180- vicethese are available for $400drastically and, if done properly, re-mesh, resin-bonded diamond wheel.on eBayor a motor-driven tru- duce your risk of chatter. If you do We dont true the wheel but just leting spindle on your machine, andstart to get chatter or max out your it self-dress. Its an ugly process. Thetrue your diamond wheel with aspindle power, dont decrease your machine moans, cycle times are long,silicon-carbide or aluminum-ox- cross-feed. Instead, decrease your and surface finishes are bad. Whatide wheel. Even every few days willtable speed.can we do? work. Brake-controlled devices are3. Periodically stick your wheel with a 220H white stick to reduce loading.4. Dont use gradual down-feed; use incremental down-feed. (The reason is explained in the June 2011 column of Ask the Grinding Doc, which is available at www.ctemag.com.)5. Dont use gradual cross-feed; use incremental cross-feed. (This is explained in the August 2019 col-umn of Ask the Grinding Doc, which is at www.ctemag.com.)6. If possible, take the last few tru-ing passes at the same wheel rpm that you grind at. Doing this will cor-rect any imbalance-induced eccen-tricityand even balanced wheels have some imbalance.Ive had people attend my course, return to their shops, implement just a few of these concepts and report back cycle time reductions of 75%.CTEJ. Badger Grinding wheels wear. It would be nice if they wore evenly (B), but they dont. They wearabout the author unevenly (C), causing snakeskin chatter marks. And they wear in lobes (D), causing wheel regenerative chatter. Truing fixes both problems. Jeffrey Badger, Ph.D., is an The Doc replies: Heres a list ofslower and more cumbersome, andindependent things to do, in order of importance. motor-driven spindles are quickergrinding 1. True your wheel. Lobes even- and easier to automate. Then, stickconsultant tually wear into it, which causesyour wheel with an Al Owhite stickcurrently offering wheel regenerative chatter. Also,to open it up. 2 3 his one-day CovidMania Zoom Courses your wheel wears unevenly, causing2. During rough grinding, cross- online. For more information, chunky-wear chatter, also knownfeed with almost the entire wheelvisit www.TheGrindingDoc.com.12JULY 2021 GrindingDoc.indd 12 6/17/21 10:40 AM'