J&L is remembered mostly for its lathes, but they also produced several other noteworthy products. The grinder branch of the company produced grinders for various tasks, including thread and form grinders. Grinders are basically used to machine hardened items, using an abrasive wheel, or in some cases, multiple wheels. Because of advances in turning tool technology, a lot of hardened items are now machined on lathes, using “hard turning” techniques (if surface finish is not of paramount importance). But a grinding machine is still indispensable in many instances.

The grinder engineering department was a small group of veterans, some of which were reaching retirement age. So when I transferred into it, I was the young one. The Grinder Engineering Manager was Clyde Quimby. Clyde kept track of all the department tasks on little pieces of paper, which he reviewed every morning. It worked for him. In the beginning, I worked with some of the older engineers on small tasks, to familiarize myself with the product line. But because of the increase of orders, it wasn’t long before I picked up my own projects. Most of the time these were the “Special Tooling” items that were required to be used on the machine order. The basic machines were already engineered, so no work was required from us on them, just write up the order and build it. The “Special Tooling” might include a work holding device (chucks, mostly), perhaps a special tailstock center, or diamond dresser items. Grinding wheels need to be kept sharp, and the only way to do that is with an industrial diamond dresser. These might be just a single point diamond traversed across the grinding wheel face, or perhaps a diamond impregnated roller to dress out a complex shape. The diamonds remove the dull portion of a grinding wheel, exposing new, sharp cutting edges.

J&L had a couple of older model manual thread grinders that they were still selling in the 60’s, one was the 6×36 and the other was the 12×45. The numbers refer to the machine capacity, the first being the largest work diameter, the second being the longest work piece length. These grinders used single point diamond dressers to (usually) dress a single wheel to the shape of the thread form being put on the work. Most of the time the job was to grind threads or grooves on hardened shafts (like an automotive transmission shaft). If threads were being ground, the wheel head could be tilted to the appropriate angle to match the helix angle of the thread. The work slide would traverse at the rate necessary to achieve the proper thread lead, using change gears.

Another grinder product was the E2 and E3 form grinders. Basically plunge grinders to grind annular grooves on automotive shafting. The E2 had a rather limited wheel width capacity, the E3 could mount multiple wheels, with spacers in between, depending on the job. The wheel  adapter could be upwards of 12″ in width, so long shafting with multiple grooves could be accommodated. We also had a line of tap grinders; a specialty grinder to grind the “Christmas Tree” forms on jet engine turbine blades. The latest grinder in the product line was NC controlled, the 1040 shaft and shoulder grinder. This was being developed in R&D when I joined the group.