A well-known gear manufacturer in the United States had an application they were currently using conventional hobbing methods on. They had three main objectives which were cost, productivity, and quality of the part. What the customer required from Vargus USA was a faster more reliable tool to manufacture their splines. “The previous method was slow and cumbersome,” says Mike Trimble Vardex product manager. “The new process is faster and more cost effective.
TMSD gear milling tools solved all of the customers’ needs for the application. First, the price was five percent cheaper than the cost of the current hobbing methods. Secondly, the productivity of the TMSD was almost 75 percent faster than the current tooling. Third, the reliability met all class requirements for the spline. “The customer was very happy and all the requirements of the test satisfied. Subsequent orders have been placed,” says Joe Magee, gear milling product manager.
The main improvements the customer received as an added bonus, but did not expect were the tool life and part finish both were considerably better than the current method. “The finish was better than a 64 Ra (roughness average), competition was 125 at best, 250 on average,” Magee says.
As for the overall project summation the customer was able to move the parts from a secondary operation on a hobbing machine to the part they were now completing on their machining center; reducing handling, extra set up and utilization time on the extra operations.
The Vardex Gear Mill is suitable for medium and large batch size spline and gear manufacturing and is faster, simpler, easier to use and much more economical than existing HSS/HSS PM cutters. With its state-of-the-art design of PVD coated fine substrate carbide, the Gear Mill offers absolute price/performance advantage over existing technology.
TMSD is suited to the machining of both straight and helical teeth gears, and gear modules from 1 mm to 6 mm. All materials can be accommodated, from very soft to hardened steels of 60 HRC. Each insert profile in the TMSD portfolio is supplied with the appropriate module shape of one, two or three cutting corners (special forms can be supplied), and the ability to achieve a full profile in accordance with Class 7 DIN 3962. Importantly, because the tooling focuses on carbide inserts located in ‘standard’ tool bodies for end, shell and disk milling on three-axis CNC milling machines (the cutting edge is subject to relatively low loads), TMSD is affordable for companies of every size across all industry sectors.
This is in stark contrast to the usual need for ultra-expensive hobbing machines and tooling (which also needs recoating after regrinding) with their inherent lengthy set-up times. Likewise, traditional milling disks are often only suitable for rough machining on softer materials. TMSD, therefore, alleviates the cost and potential quality problems for many companies where relatively small batches do not justify the expense of a dedicated machine – and for manufacturers, especially, the TMSD route eliminates the cost and time involved with sub-suppliers.
The benefits of Vargus TMSD tools are clear: in one case, involving a 40.5 mm diameter 42CrMoS4V gear with 52 teeth, a TMSD milling operation took just five seconds to produce each slot. TMSD also produced similar savings in one spline milling application, reducing gear rack production from 10.7 min to only 3.3 min. Similar benefits have also been achieved with plastic gears.