Precision is the single-most important trait when it comes to mass production of machine parts. After all of the time and effort is spent in research and development of the parts and process, and all of the wrinkles are ironed out of the manufacturing process, the next – and possibly the greatest step, as the legacy of your brand and product hangs upon it – is precision. Falling under the oft-heard category of “quality control”, ensuring that every part produced falls within the prescribed tolerances is imperative, especially in today’s age when any individual can take to their keyboard and publicly denounce your company for an ill-fitting, poorly machined part.
In an effort to dramatically improve its game, SBT, Inc (Short Block Technologies, Incorporated), out of Clearwater, Florida, it recently acquired a Crysta-Plus M Series 196-Manual-Floating Type CMM (Coordinate Measuring Machine). Atypical for manufacturing outside of the OE (original equipment) manufacturers, the level of precision that this machine is capable of is staggering. The Watercraft Journal spoke directly with Quality Control Manager Jerry Xiong of SBT, who said, “The machine is capable of measuring to within millionths of an inch (0.000001). Critical internal engine parts tolerances are typically measured in a tenth of a thousandth (.0001), so having at least one or two decimal points more accuracy in the machine is important for consistent measurements.”
Above: SBT’s Quality Control Manager Jerry Xiong demonstrates how a single part is pulled from production to be measured against the prescribed tolerances set for this particular piece. The “clamp” (or wand) is manually positioned where it can set digital waypoints before conducting is program.
Opting for a manual floating type CMM allows Jerry and his team the ability to manually guide the mobile clamp for one-touch clamping on each axis by hand. The one-touch air clamp articulates smoothly as it rides on high-precision air bearings and lightweight moving components, providing high-accuracy measurements as it generates a continuous fine feed over the entire measuring range. Best of all, the Crysta-Plus M is suitable to measure a wide range of applications by using a high-performance linear encoder for detecting axis position. So why was all of this so necessary for SBT? Jerry continued, “The complexity of our new parts lines, especially our new engines and heads, drove the investment.”
We asked what parts offered by SBT were measured/checked by this machine, Jerry noted matter-of-factly, “Any part that varies by less than 0.001-inch or has complex critical surfaces. As it simplifies critical measurements, most parts that aren’t easily done with calipers or micrometers are measured on the CMM. Parts are batch-produced and each batch is sampled thought the production output and compared against the average. If any part has a variance issue, the entire batch is 100-percent inspected to ensure high variance parts are taken out and new batches are of the part are put under a higher level of sampling.” And don’t think this is a high dollar item that is rare used. Jerry laughed, “[We use it] every day. Users rotate usage time in windows, so [it’s] probably running 4-to-6 hours a day.”
Above: As Jerry described, because of the high levels of precision necessary in today’s finely tuned personal watercraft, SBT, Inc. saw it necessary to acquire the CMM to ensure that the products leaving SBT’s Clearwater, FL facility were factory-fit correct.