VLC 250 The flexible use of different technologies makes the machine suitable for a large range of applications.
VLC 250 with base unit for hob peeling
Internal gearing generated using the hob peeling process
"Hob peeling of gearings is proving highly productive, owing to process continuity," said an EMAG spokesperson. "Recently, users focus on this technology as an alternative to broaching and shaping, where the machine and tool have to be perfectly in tune to produce components of the highest quality. EMAG has succeeded in adapting the application for its standard turning machine platform. For pilot and medium size batches, internal and external gearings are machined at greater productivity rates, have better quality and, owing to the machine's universal use, greater flexibility.
"If one thinks of combining hobbing and shaping with a continuous axial roll-off, one gets an approximate idea of EMAG hob peeling. In theory, this process is nothing new, but proves efficient, as it achieves high cutting speeds with more teeth engaged at any one time, possible due to the diagonal arrangement of the tool and workpiece axes. Whereas hobbing is based on the worm gear drive, the principle of hob peeling is based on the helical gear drive, which EMAG studied thoroughly over the past two years with high expectations."
The objective was to adapt hob peeling technology for use on a standard turning machine, where better access and greater efficiency can be achieved, leading to trials and developments on a specific design for the tool spindle and on the clamping of the workpiece. "As the engineers soon found out, workpiece clamping was of great importance for the gear quality achieved," said the spokesperson. "However, they proceeded with the goal of utilizing a design with standard components. For instance, workpiece clamping tasks used a modified standard power chuck. The standard machine, the EMAG VLC 250 vertical turning machine, is capable of various manufacturing technologies that, in addition to the machining of gearings up to module 4, can also be used as a fully-fledged universal turning and milling center."
Philipp Ruckwied, Head of Technologies for the Defined Cutting Edge at EMAG, stated: "The universality of the machine and the productivity levels achieved using the hob peeling process are very encouraging. Our trials did, however, concentrate on the process itself. For instance, it generates great forces that must be controlled. On the other hand, we also felt obliged to deliver reproducible component quality and to offer the necessary quality control system to achieve it."
The spokesperson noted that the traditional EMAG customer is primarily a manufacturer of medium and large component batches. Hob peeling, however, has proven itself a process best suited for the manufacturer of one-offs and small or medium batch runs. This includes internal gearings that have, up until now, been generated using the broaching or shaping process. "Compared to shaping, the hob peeling process is two to three times more productive and the lifetime of its tools is two to three times better," said the spokesperson. "Tool life expectancy is also higher than with broaching, despite that process' costly tools."
For these reasons, manufacturers that produce gears in appropriate quantities express interest in this technology; whereas the automotive industry is holding back and awaiting further developments - a situation that, according to Philipp Ruckwied, will soon change: "We are seeing successful advancements in tool technology, i.e. the tool manufacturers have, for some time now, been busy developing new substrate and coating combinations for the hob peeling gears."
Another advantage of hob peeling is that both rough- and finish-machining operations can be carried out in the same set-up. "With the turning work completed in one set-up, reclamping errors are avoided and runouts are, to a large degree, eliminated," said the spokesperson. "Based on this conviction, EMAG, who can already machine workpieces with diameters of 70 to 250 mm, has successfully concluded a large number of customer trials, is ready with its pilot series and is already quoting the machines. Provided tooling is soon available for the required dimensions for the substrates, the process will take off with manufacturers of large batch runs as well."
The spokesperson noted the following facts and information:
- High component quality through pre-machining of the tip diameter and subsequent gear cutting in one set-up
- Machining times are five times faster than those achieved with conventional turning and shaping on two machines
- No component logistics between operations
- No additional loading times.
VLC 250 standard technical data:
- Chuck dia., max: 250 / 315 mm
- Swing dia.: 350 mm
- Workpiece dia. (nominal): 250 mm
- Travel in X-axis: 1,600 mm
- Travel in Y-axis (optional): ±100 mm
- Travel in Z-axis: 300 mm.
VLC 250 specification for hob peeling technology:
- Spindle size: #8, with hydrostatics
- Milling spindle console: Adjustable up to 25°
- Toolholder (milling spindle): HSK 100 A.
For more information contact:
Peter Loetzner
EMAG LLC
38800 Grand River Ave.
Farmington Hills, MI 48335
248-477-7440
info@usa.emag.com
www.emag.com
Southwest
AR
David Fitzgerald
EMAG LLC
Charlotte, NC
248-595-1117
dfitzgerald@emag.com
www.emag.com
NM
Peter Loetzner
EMAG LLC
38800 Grand River Ave.
Farmington Hills, MI 48335
248-442-6590
info@usa.emag.com
www.emag.com
LA, OK, TX
Ric Lorilla
EMAG LLC
Houston, TX
248-595-1530
rlorilla@emag.com
www.emag.com
Southeast
AL, FL, GA, MS, NC, SC, TN, VA
David Fitzgerald
EMAG LLC
Charlotte, NC
248-595-1117
dfitzgerald@emag.com
www.emag.com
Northeast
NY, PA
James Petiprin
EMAG LLC
38800 Grand River Ave.
Farmington Hills, MI 48335
248-910-8413
jpetiprin@emag.com
www.emag.com
CT, DE, MA, MD, ME, NH, NJ, RI, VT
Jonathan Chomicz
EMAG LLC
Hartford, CT
248-497-8526
jchomicz@emag.com
www.emag.com
WV
David Fitzgerald
EMAG LLC
Charlotte, NC
248-595-1117
dfitzgerald@emag.com
www.emag.com
Midwest
MI, OH
James Petiprin
EMAG LLC
38800 Grand River Ave.
Farmington Hills, MI 48335
248-910-8413
jpetiprin@emag.com
www.emag.com
IL, IN, WI
Tod Petrik
EMAG LLC
Chicago, IL
248-470-2646
tpetrik@emag.com
www.emag.com
IA, KS, MN, MO, NE, ND, SD
Bill Konetski
EMAG LLC
Minneapolis, MN
612-804-0857
bkonetski@emag.com
www.emag.com
KY
David Fitzgerald
EMAG LLC
Charlotte, NC
248-595-1117
dfitzgerald@emag.com
www.emag.com
West
AZ, CA, CO, ID, MT, NV, OR, UT, WA, WY
Peter Loetzner
EMAG LLC
38800 Grand River Ave.
Farmington Hills, MI 48335
248-442-6590
info@usa.emag.com
www.emag.com