Shenoy Engineering Private Limited

Peenya, Bangalore, Karnataka

We have developed a 3 axes Milling Machine, which can also be used as a portable CNC milling machine. This machine has the capability of a large VMC at the cost of a small VMC. The machine is inbuilt with linear, circular and helical interpolation capability. Any kind of machining, be it slots, face milling, profile machining, thread milling, drilling or tapping can be executed on this machine. The technical specifications of this machine is given below:

We have developed an economical duplex milling machine which is very affordable and is a no frills attached machine. A brief description of this machine is given below:

Features and Specs:

• Base made of square section, with adequate ribbing to provide more than sufficient rigidity with light weight. .
• Atop the base, a slide is mounted in the middle.
• The slide is made of LM guides and leadscrew with a stroke of 700 mm to cut 330 mm of width.
• The slide is run by AC induction motor connected to worm reduction gear box which inturn will be coupled to ballscrew.
• The AC induction motor is coupled to a VFD to obtain stepless feed from 100mm/min to 2800 mm/min for rapid return.
• On the slide a fixture is mounted with manual toggle clamps.
• Two milling heads are mounted on either side of the slide.
• The milling heads are run by a 1.5 HP AC induction motor coupled to the spindle through timer belt and pulley.
• The milling head is provided with ISO-40 spindle taper capable of holding 63mm cutter.
• The milling heads are provided with all cast iron cross axis manual depth of cut setting, of 50 mm.
• The machine will be run through a relay based auto-cycle sequence.
• The sliding surfaces with be lubricated by a centralized lubrication with timer.

Sequence of operation:

• Load the component and clamp using manual toggle clamps.
• Press auto-cycle button.
• The component gets feed against the cutters, after stroke ends, the component returns in rapid and stops.
• Unload the component

• used a spm with single spindle and 2 vmc.
• component output on spm was one component every 45 seconds
• component output on vmc would be 10 components every 7.5 minutes apart from manual loading, unloading and clamping time.
• features and specs:
  • heavily ribbed, rigid, fabricated & stress relieved base.
  • a top the base a two axis slide system is mounted with servo driven axes
  • on the two axis slide, a fixture is mounted, which can house 4 components at a time.
  • adjacent to the fixture, a vertical column with vertical servo driven slide is mounted.
  • on the servo driven slide, a 4 spindle milling head is mounted. Each spindle is mounted with a 4mm end mill.
  • all the sliding surfaces made of lm guides and blocks. Drive is through servo motor connected to ballscrew through servo reducer and couplings.
  • recirculating coolant system is provided for easy chip flushing, improving tool life & for better finish.
  • hydraulic power packs and cylinders of our make.
  • complete machine enclosure is provided to contain the coolant and chips.
  • siemens sinumerik 808d advanced cnc controller is provided for machine controls.
  sequence of operation:
  • load the job onto the fixture and press auto-cycle. The job gets clamped
  • the milling head moves to mill the profile slot with the help of two axis servo slide system.
  • after one pass the vertical slide lowers the milling head and another pass is made.
  • all slides move to home and job gets de-clamped.
  • final conclusion:
    vmc:
    • component setup time is high.
    • machining time is high.
    • due to manual clamping, operation is prone to operators fatigue, which may lead to loss in efficiency of production.
    • an expensive vmc is used for low production output
    four spindle cnc profile milling spm:
    • no need of skilled operator. Cost of skilled operators is reduced.
    • uses 4 spindles for 4 components at a time.
    • the total milling time is 35 seconds, for 4 components instead of 7.5 minutes for 10 components on a vmc. Efficiency is more than 3.5 times/ 350%. Increases the productivity, increases profitability, increases the scrap generation rate.
    • due to cnc controls this has a flexibility of a vmc, but has the production capacity of spm

Duplex Milling Special Purpose Machines to end face multiple components, both from the front and from the back simultaneously. Hydraulically operated automatic clamping system, with a well designed job holding fixture, facilitates multiple components to get clamped simultaneously and quickly. Two milling heads, one in the front and the other in the back, simultaneously perform end facing operations on both the faces of all the mounted components simultaneously in one rapid go. Job clamping, rapid approach of the spindle, machining, rapid homing, rapid de-clamping etc will the part of an efficient auto-cycle, delivered by the combination of limit switches and PLC. The total cycle time for duplex end facing the multiple components, is a few seconds. The machine is designed for high productivity at low cost, consistent accuracy and with least dependency on the operators skill.

• An unique, portable, multipurpose, CNC VMC with amazing, multipurpose capabilities.
• Produces drilled holes, square & round bores, threads on ID & OD, mills and other operations with speed & accuracy.
• Can be used as a regular VMC for small batch production and also as a table top, portable machine
• Can be mounted in vertical or horizontal position.
• Affordable, faster delivery

CAPACITY:

• Drilling capacity: upto 24 mm steel
• Thread Milling: upto 300 on OD & 220 on OD through helical interpolation.
• Tapping: M20 through tapping attachment
• Milling: 63 mm cutter x 1.5 mm depth of cut
• Weightof the machine: 500 kgs in CI body/320 kg in aluminum
• Weightof the Electrical panel & Console: 150 kgs

THREE LINEAR AXES (X, Y & Z AXES):

• Stroke Length: 300 mm for longitudinal (X) & cross (Y) axes & 400 mm for Vertical (Z) axis.
• Guideway: LM Guides & Blocks
• Feed Rate: 30 to 6000 mm per minute
• Feedback: Motor encoder
• Ball screw: C3 class, ground, preloaded
• Positioning Accuracy: 10?m for 300 mm.
• Repeatability: 10?m
• Protection: Wipers for slide cover

SPINDLE HEAD & SPINDLE DRIVE:

• Tool clamping taper of spindle ISO-40
• Tool Locking system Through Manual Draw bar clamping
• Capacity of tool holder max 63 mm cutter
• Spindle Bearings: Match pair angular contact bearings, lubricated for life with special imported grease
• Spindle speeds 500 2800 RPM
• Spindle drive Timer belt driven.
• Main Spindle motor rating: 5 HP, VFD controlled AC induction motor

OTHER FEATURES:

• 5 M cable for Operators Control Station; extra for additional length.
• CNC controller Siemens Sinumerik 808 D
• Servo Motors Sinamic IFK6 series
• Spindle Motor: KEC/ABB 5HP, 1440 RPM, 3 Phase Motor
• Drive for axes: V70 series
• ABB make VFD, Teknic Limit Switches, Switchgear elements Schneider/ Siemens, SKF/RHP/FAG bearings, Cenlub centralized Lubrication system, Finolex cables,
• HIWIN make Ball screws & LM guides HIWIN, reputed make of MPG etc
• Laser Calibration: only at pre-dispatch inspection stage at our works

This is a 3 axes in-situ milling machine, built on the bed of a discarded lathe bed of 30 ft long. You may see a vertical column, mounted on the lathe bed. On the vertical housing, a horizontally mounted milling head and on the milling head a tilting type right angle head can be seen. This machine is in use L&T for more than the past 10 years. This machine is used for machining J groves on the giant size under-ocean pipes for weld-edge preparation, for which, L&T otherwise should have used a huge floor borer.