History of GMT - Surface plates and Bed Plates - Part-4

Bed Plates were developed where the plate design is different to that of standard surface plate. There was no change in ribbing. Bed Plates are kept side by side with a gap of 3 mm. The plates are offered in grade2 and grade3 accuracies. The plates are mounted on special Cast Iron stands. Depending upon customer needs stands are supplied with 600 mm above floor level or can be kept in a pit so that plate is in floor level.

Unique feature of the special plates are foundation arrangement, erection and commissioning. At our works the plates are matched and assembled and scraped to the required accuracies, They are dismantled and dispatched to the customers works. Fabricated stands are dispatched as a single piece wrapped in hay and gunny. 

 GMT bed plate - size - 6000X4000 mm (consists of 4000x1500– 4 Nos)

Foundation plan sent well in advance to the customer with instruction to prepare the foundation, size of foundation bolts, and other important details specified in drawings and documentation. On confirmation from customer that foundation is ready with our stand in position our team will visit customer site and erect and commission the plate, Minor touching up by scraping is done at customer end to ensure accuracies are maintained as per our inspection report.

I remember Vikram Sarabhai Space Centre, Trivandrum were so impressed with the design, stability and strength of our Special Surface Plate size 6000 x 1200 mm,  2 other divisions also bought similar sizes. When asked why not use the plate which is already available. The  Department Heads said that the plate looks so impressive they budgeted for their requirement and raised purchase requisition as a single tender and ordered for the same.
 

About the author : Shri. K Jagannathan - Executive Director – Sales & Marketing, Guindy Machine Tools Limited.
Sri.K.Jagannathan is synonymous with lathe chucks in the Indian machine tool industry. He has been with Guindy Machine Tools for over 5 decades. His vast experience and immense knowledge of workholding products is evident in some of the most complex workholding solutions provided by GMT.

History of GMT - Surface and Bed Plates - Part-3

Although our prices were high, we were securing a number of orders from Defence and Public Sector due to the ribbing design of our surface plates. The rigidity of the plate and capability to match and assemble surface plates together also worked in our favour. Notable users:

• Vikram Sarabhai Space Center 
• Nuclear Fuel Complex

We developed Portage Layout Table for precision measurements. Bendix US were making Layout Marking Machine. Bajaj Tempo and Hindustan Motors wanted such Tables. Size of the table 4000 x 2500 mm consists of 8 nos. 1000 x 1250 mm plates matched and assembled. The table top will have precision slots 12 mm width 250 mm pitch distance on length and breadth of the table. Bendix arm will travel on the slot manually. The plate is mounted on speciall. low height CI legs so that the height of the table from floor is max. 500 mm....to be continued

About the author : Shri. K Jagannathan - Executive Director – Sales & Marketing, Guindy Machine Tools Limited.
Sri.K.Jagannathan is synonymous with lathe chucks in the Indian machine tool industry. He has been with Guindy Machine Tools for over 5 decades. His vast experience and immense knowledge of workholding products is evident in some of the most complex workholding solutions provided by GMT.

History of GMT Surface Plates-Part 2

After GMT parted with Voltas (who were our sole dealer) we focused on business with Ordnance Factories. GMT developed good rapport with Director General Ordnance Factories. (DGOF). The sales team identified Ordnance Factories in several locations and started visiting each one. GMT's Sales Engineer based at Calcutta started his regular visits to DGOF and developed good rapport and collected information in regard to expansion and new investments. DGOF tendered for a big Surface Plate of size 9000 x 1200 mm. This plate was required for Ordnance Factory Ambhajari near Nagpur.(OFAJ) They were setting up a factory for manufacture of large aluminum sections used for building bridges to transport arms and ammunition across river.

DGOF floated tender and we quoted and got the order from DGOF for the first time. 3 plates 3000 x 1200 matched and assembled mounted on special MS Fabricated Stand. A highly engineered product at that time. Plates were made mounted on stand duly assembled and scraped to the required accuracy. As per order the plate has to be inspected by DGS&D inspector. The inspector visited and inspected and accepted the plate for flatness accuracy. However, he said the plate has to pass for deflection test. Indian Standard for Surface Plate did mention deflection test. PV (GMT founder) accepted inspector's point and GMT made a Beam Comparator which is used for deflection test. This was designed and made strictly as per standard. The deflection was measured and our plate conformed to standard. PV was very impressed by the inspector of DGS&D, Mr. V. Subramaniam GMT used his services after his retirement and bought a number of standards for our library viz. IS and DIN.

History of GMT Surface Plates-Part 1

GMT commenced manufacture of Cast Iron Surface Plates, as per BS 817-1957. After supply a number of Surface Plates we had problems in quality of castings due to Plate ribbing which were diagonal as per BS. P.Venkat Raman then studied DIN 876-1963, and found it has orthogonal ribbing and made new pattern for Surface Plate as per DIN. This ribbing pattern had distinct advantages in making castings. The plate is also quite rigid due to its ribbing pattern.

To be continued....

GMT history - 1980-1990

GMT was focusing on PS model Power Chucks and 300, 400, 600 and 900 mm Lapping Machines. In the 80s and 90s GMT again built SPM and Special Power Chucks and Hydraulic Cylinders for Escorts Patiala. 1500 mm Lapping Machine was manufactured for BHEL Bhopal for lapping White Metal Bearing Pad used in Water Turbine. GMT received order from BHEL although M/S Lawrence UK was a strong contender for the order for Lapping Machine. They supplied a machine to Mitchell Bearings one of the leading manufacturer of white metal bearing in UK. Engineers in BHEL had faith in Lapping Technology of GMT and the order came to us for the machine.

High Speed Hollow chucks, Hollow High Speed Cylinders were also developed during 80s. Belt Grinders i.e.  Single, Double Ended and Platen Grinders were also developed in the 80s. Platen Grinders were developed for MICO, Bangalore with dust extraction system.