NOAH Series Machines: Gear Hobbing Made Easy

UCAM had a humble beginning with a small job shop back in 1986 and then diversified into rotary table manufacturing in 1994. Having begun with the noble vision of becoming world leaders in manufacturing of Rotary Indexing Tables, has now become synonymous with rotary tables in Indian Market. Our technologies, innovations and developments in the Machine tools led in development of three newBusiness verticals. And one of the verticals is Nimble Machines.

Being a Rotary table manufacturer, we consume many gearswhich calls stringent quality standards. To meet this requirement of quality and range of gears, only few manufacturers were ready to offer such Gear Hobbing Machine. And these machines being customised, were very expensive. This necessity got our teams together and gave rise to the development of our very own first CNC Gear Hobbing Machine in 2004, as a backward integration.

The performance of this machine impressed many of the customers. And one such impressed customer placed first order way before launching Nimble Machines vertical. With the satisfied performance of the machine supplied, the customer had repeated the order. This boosted the confidence level of the team, which led to formation of new dedicated machine building vertical called “Nimble Machines “in the year 2015.

Hobbing is basically a special milling process to cut the gear profiles on the blanks using a special cutting tool called Hob. This is a highly efficient process used to manufacture gears such as spur, spline, sprocket, worm wheel. The machining process in hobbing involves rotation of workpiece and the hob in relation to each other. Hence, the precision synchronization between the workpiece & tool is very critical. The material removal in hobbing process being very high, the rigidity of machine also plays a very vital role in the quality of the parts produced.

Challenges during development of machine.

When there is a need for high performance machine in terms of quality & productivity, Indian customer are not having many choices, but to look for imported suppliers, which are very expensive. Understanding this UCAM has strategically decided to build the machines, which will be import substitute and meet the demands of the market. Achieving this there were many challenges such as technology, performance and competitiveness.

To compete with international brands, it was decided to build the machine with the latest Direct Drive technology and EGB. With the Direct Drive technology, the machine can run at very high cutting speed and produce gears at shortest time and give highest productivity. The latest DDR motors which offers high torque will eliminate the gear reduction requirement in work head and spindle, this intern makes it more accurate and maintenance friendly.

In the conventional gear hobbing machines the synchronisation between the spindle & worktable was achieved through gear trains, but it had its own demerits such as higher in-accuracies due to more linkages and setting of the gear ratios needed the skill of the operator. With today’s CNC Controller this gear train is now replaced with EGB (Electronic Gear Box) which improves the quality of synchronisation between spindle and work head and in turn leads to higher quality of gear output. The EGB automatically sets the gear ratio between the spindle & work head, using the gear data entered in the CNC controller and making it user-friendly.

The working of EGB can be better understood using below block diagram.

Electronic Gear Box (EGB), is a virtual gear box wherein the gear ratios are set between the Hob spindle and the work table. In this configuration the spindle acts as a master and the worktable, as slave based on the gear ratios set on the EGB controller.

In today’s competitivity market scenario, the cost per piece is very critical and for which the productivity of the machine is of paramount importance. To meet this requirement Nimble Machine’s NOAH series of gear hobbing machine are built to offer higher cutting speeds. The loading / unloading of components plays vital role in the productivity of the machine. And to address this, the machine is equipped with high speed ring loader for quick change of parts as well as component magazine & robot arm options, are available to minimize the human interference during the production of the component.

To compete with the global brands, the reliability and performance is vital. UCAM believes that it can be achieved, only through highly innovative & mature design. To make this possible, UCAM has invested in sophisticated design & analysis software’s and highly qualified design team. The software’s had helped us in optimising the design through various analysis such as static analysis, modal analysis, vibrational analysis, thermal analysis even before the product is released for manufacturing. Selection of raw material and quality of input components was given maximum importance to ensure the highest quality of the product. To improve the quality of output, the controlling and dampening of vibrations is very critical, and this is achieved by using special composite material in the machine bed and column.

Being an Indian manufacturer, market demands our price to be much competitive than any imported brands, and this was one of the biggest challenges for UCAM. As, most of the critical input items are imported from the best-known brands. But, UCAM has successfully overcome this challenge through innovative design approaches, design for manufacturability and highly efficient component manufacturing.

 NOAH series of machines comprises of four models NOAH 150, NOAH 250 H/XL, NOAH 400 & NOAH 400 XL catering to components of modules up to  3 mm, 6 mm, 8 mm, 10 mm and diameters up to  150 mm, 250 mm, 400 mm & 500 mm respectively. These machines are capable of producing output gears of DIN7/DIN8 class accuracy, using suitable Hob cutters.

Features of the Machine

Our Machines are suitable for both gear type and shaft type components and equipped with number of features such as,

1.  The direct drive worktable, with zero backlash which enables to produce gears with no follow-up errors.
2. Servo driven Hob shift feature for optimum utilization of Hob life.
3. High-speed cutting capabilities of machine, which help improve the productivity multiple folds.
4. The HSK quick change hob clamping system and hydraulic support arm, benefits to reduce the Hob Arbor change over time.
5. For machining shaft components with multiple gears in single setup, our multi gear hobbing feature has been the key to customers, thereby reducing component & Hob change over time.

1. In high volume mass production environment, Our High speed ‘ring loader ‘automation option has been pivotal to increase productivity, reduce loading/unloading time by 70-80% and also increased consistency of output for our customers
2. User-friendly macros provided on the machine aids for quick creation of gear hobbing program using the drawing values, without need of high skilled operator. Different macro cycles facilitate easy offset corrections, crowning, taper hobbing and also allows multiple cut cycles with different combination of climb & conventional cuts.
3. Column retraction safety feature, helps retract the Hob head in case of power failure and prevents any possible tool & workpiece damage.

Customized work holding solution
We provide Different types of component specific, rigid and reliable work holding solutions, using various concepts such as:

• Hydraulic mandrel type
• Hydraulic chucks
• Quick change chucks
• Splined mandrel type
• Mechanical mandrel type
• Eccentric compensating chucks etc

Components produced on the machine

Our machines are known for quality, productivity & technologically advancement and are one-point solution to all hobbing requirements.

Customer Voice
Company:  Highway Industries Ltd
Mr. Narender Singh Thakur – AGM, Production

We are using Nimble Machines NOAH 250 machine for last 3 years. And it is producing the components with required quality and quantity at par with the existing imported machines. It has also given us benefit in terms of cost per piece, with much less capital investment as compared to other imported machines. Our productivity has gone up by 20-30% while working on this machine. Currently we are using two ‘Nimble Machines’ make ‘NOAH 250’ CNC Gear Hobbers at our factory, and we are producing around 3500 components per day, because of reduction in cycle time. This could happen because of ability of the machine (rigidity) to produce accurately at high speed.  Hob life has increased by using hob shifting feature in the machine. These machines have very low maintenance and almost nil Break downs. We are getting a very good teeth profile and parts are being produced with accuracy as per our standard.