While the TNC product line was being quoted and built, J&L was working on a new improved model; even as the original TNC was selling well, there were many areas that could be improved. The original TNC lathe lineup consisted of three basic sizes: the original “B” size, a somewhat larger “C” size, and a “D” size for the big boys. The new product line would be called the “Delta” TNC’s. “Delta” is a Greek letter signifying change. So the new products would be known as the “Delta line”.

One of the limitations of the original TNC line was the time it took to index the turrets (and tools). Each index consisted of unclamping the turret, indexing one tool station, and reclamping. If the program called for using a tool in station #1, and then skipping to station #3, you still had to unclamp and reclamp station #2 to get there. Because of the inherent design, index could only move one station at a time (the index itself was by hydraulic cylinder and rack and pinion gearing). The new Delta designed turrets used an electronic servomotor connected to a worm and wheel to enable multi-station indexing without having to clamp at each face. This was possible in part because of advances in electronic servomotors and their feedback devices. This was a huge improvement for the customer, helping him to cut machining time (and per piece cost) down.

The Delta series improvements included the servomotor index setup mentioned above, along with better guarding to meet the current OSHA regulations. The headstock drive was improved to include infinitely variable spindle speeds which translated into more optimum cutting tool metal removal rates (this was referred to as “constant surface footage”). The older TNC’s had just a few specific spindle speeds, and you could hear when the RPM’s jumped from one to another. The new setup provided seamless speed increases. The basic spindle sizes remained the same. The “C” size TNC was redesigned with the petroleum industry in mind (what we referred to as the “Oil Patch”). Everything was made larger, and we had the steepen the slide angle to keep the overall machine width narrow enough to fit on existing flatbed trailers.

Unfortunately, these Delta “C” machines were brought to market just as the country was entering a recession. Unemployment and inflation sent the economy reeling. After much development time and money, J&L sold very few of these machines. I believe the first two were sold to Cameron Iron Works, a petroleum based Texas outfit that made large threaded oil pipe couplings and such. At this point in time there was also a banking crisis, especially in Texas. Many banks were failing, and their involvement in the real estate market just compounded it. Oil workers were losing their jobs (and homes) and leaving the Southwest.