by Mary Scianna
The Problem: Remaining competitive
The Solution: CNC gear grinder
CNC gear grinder moves shop into a higher league
The secret to success in the competitive job shop market is to set yourself apart from competitors. In the specialized gear cutting and grinding industry, you set yourself apart by finding the “sweet spot” of the size of gears you machine. For True Gear and Spline Ltd. in Cambridge, ON, that sweet spot is cutting gears up to 3 m in diameter and grinding gears up to 1.2 m in diameter.
Success though depends on investing in the right equipment. For True Gear and Spline, it meant investing in a Kapp Niles ZP 12 gear grinder capable of grinding gears up to 1.2 m in diameter, 1.4 m in overall length and 1 m face width with a weight capacity of 8,000 kg.
“The demand for this size of gear grinding is there and we have to remain competitive and move forward with new technology,” says Mark Bizjak, who runs the company with his brother Vinko. “And based on this demand, we had to purchase a new CNC grinder.”
The Kapp Niles gear grinder was purchased through the machine tool builder’s Eastern Canadian distributor, Machine Tool Systems Inc., Toronto, ON, run by John Manley.
Indeed, Vinko says the new Kapp Niles grinder, in addition to CNC shapers, hobbers and other specialized machines for gear cutting and gear grinding, gives the company a competitive edge.
“We have more work from existing customers who now know we have this new gear grinder and know we can do the work and we’re getting new business too. The feedback from customers is that they’re impressed with the work.”
The new Kapp Niles gear grinder replaced an old Niles grinding machine. It was installed in September 2014.
“The new machine is faster and much more accurate than our old grinder. It’s head and shoulders above the old machine and about six times faster, if not more,” adds Mark. “The machine is versatile and allows us to grind a wide range of gears from very small to very big pitches.”
According to John Manley of Machine Tool Systems Inc., the new grinder has a profile contact design instead of a single point of contact, which is “significantly more efficient.”
The gear making business
Gear manufacturing is a complex machining process that requires highly skilled machinists who understand
the nuances that can influence part quality. It’s not a business you enter lightly; most gear shops have a long history of experience, just like True Gear and Spline.
Founder Vinko Bizjak senior (his son was named after him) was a Slovenian-trained tool and die maker who formed his company in 1940.
“When he came to Canada, he was offered a job right away with a gear machining business here in Cambridge, just down the street from us now. The owner of that shop was from the Czech Republic and hired Europeans because he knew they were skilled tradespeople. My father learned about gear manufacturing in that shop and became an expert in it. He started his own business because he wanted to make a better life for his family,” says son Mark, who joined the company when he was 15 years old and learned the trade from his father and an engineer employed by the company.
Today, the 22,000 sq ft operation run by brothers Mark and Vinko offers complete gear machining processes including cutting, grinding, and splining. The shop also has the ability to reverse engineer gears.
Gear grinding has undergone many changes, with the most prevalent being a shift from manual grinding to sophisticated CNC grinders. Machine Tool System’s John Manley says the market for CNC ground gears is growing rapidly.
“Ten years from now you’re going to see dramatically more ground gears. What’s happening in the gear grinding industry is what happened in tool and cutter grinding; 15 years ago all tool grinding was done on manual machines and they had burn marks, inaccuracies and inconsistencies. People want higher class gears and you need CNC grinding machines to produce them economically.”
The machine was installed in September 2014, but True Gear and Spline’s machinists are still on a learning curve due to the sophisticated programming and monitoring capabilities of the grinder.
One of the biggest issues with gear grinding is that the upstream heat treating and machining processes are inconsistent. One of the features the Bizjak brothers like about the Kapp Niles is its ability to compensate for such issues. The machine incorporates two features that address this: grinding measure grind (GMG) and acoustic sensing.
GMG validates setup before completing the first gear. The machine grinds the first gap (tooth space) oversize but with finish wheel shape. It then measures the profile. The machine software calculates the deviation and prompts the operator to accept or modify the modification. Thereafter, the machine grinds the entire gear.
Acoustic sensing verifies the contact condition between the grinding wheel and dressing disc or between the grinding wheel and the workpiece. This helps to better understand the rough shape of the workpiece due to distortion and confirms when a wheel is fully dressed.
“At the end of the cycle, the probe measures the gear profile and lead, generating a gear chart that tells you the AGMA characteristics,” says Manley.
While the new CNC gear grinder has a lot of sophisticated software, the bottom line for True Gear and Spline is that the machine purchase is well worth the investment.
“The performance of the machine has been excellent and it’s amazing. We’re doing a lot of work on crane components but we’re looking to do more work with gears for wind turbines,” says Vinko.
Equally important has been the service, says Mark.
“We looked at different technologies presented to us but this machine suited our needs. In the end, even though there were a few other machines we could have selected, we knew we would get the service from John [Manley] and Kapp Niles. Service has been excellent and Kapp Niles is regarded as having one of the best machines in the market for gear grinding.” SMT