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CNC Machining - Glass - Windshields & Side Panels

  • Glass - Windshields & side panels
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CMS Brembana's focus in the automotive sector lies mainly in the custom and replacement market. Custom and small run production requires flexibility, deftness and strength. These are the characteristics for which CMS Brembana machining centers are noted. 

Typical projects Bremband's glass CNC machining centers are windshields, door glass, rear and roof panels for the auto industry, military vehicles, and flight chassis.  These projects are diverse in their material requirements.  Single pane glass is used for rear and door glass. While laminated glass is used for new and replacement windshields up to multiple-ply bomb proof, explosion proof, and transparent armor for military applications.

 

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Flat Glass

The use of 3 & 4 axes machines for flat glass processing

For flat glass, projects typically require the use of 3 or 4 axes CNC machining centers.  These include the series SPEED and JR families of machining centers.  These machines are cover the broad requirements of flat glass applications within this sector including rear, side and (pre-bent) door glass.  Most of these process applications only require a simple automotive grind but SPEED and JR machining centers are also capable of profiling, polishing and flat polish for laminated glass projects. Waterjet machines can also used in the processing of automotive glass. Some specialty applications require the use of waterjet.

The included video here illustrates the JR being used to process 50 mm thick glass, beginning with a coarse diamond grit wheel followed by upper and lower arrises. The process continues with a medium diamond grit wheel to bring the edge closer to its required finish quality. This is followed by the application of a fine diamond grit wheel. Lastly this is followed by the polishing wheel bringing the edge quality to a completely transparent finish.

Curved glass

Working with curved glass

Working with curved glass

Curved glass applications include all types of formed glass both single sheet and laminated.  Once bending is completed, glass may be held in custom fixtures for specific parts or by the use of articulated vacuum cups. 

Articulated vacuum cups are manually manipulated to fit various sizes and shapes of curved glass pieces.  Depending on the application, a fixed program may be used to machine the piece.  It is also possible that a special program may be created in which a probing system is used to find the orientation of the curved glass piece and apply the fixed program to the new orientation.

Images

Multi-layered laminated glass

Multi-layered laminated glass processing

Multi-layered laminated 50 mm think wedge of glass is being machined on a 5 axis MAXIMA. The finished edge has been through a process of a rough diamond grit wheel, followed by a medium grit diamond wheel, then a fine grit diamond wheel, with arrises to the top and bottom edge, and finally a polishing wheel to give a transparent edge.

Incremental Probe for bent glass

Incremental Probe for bent glass

The picture shows a "touch probe" which is used to detect the surface of the bent glass and then to compare it to the theoretical surface and make compensations to the program accordingly so that everything comes out correctly.

Blade type tools on 4 & 5 axes machines

Blade type tools on 4 & 5 axes machines

Blade type tools can be used on 4 or 5 axes machines to carry out processes involving the use of "saw blades".  This process can be quite useful when removing large amounts of material and where grinding would be prohibitively to slow.

Processing multiple pieces of bent glass

Processing multiple pieces of bent glass

The larger work tables of various machining centers can be used to set up multiple pieces of bent glass and reduce the time for load / unload operations.

In this way a "non-stop" cycle is created, so that the times for loading / unloading are actually "masked" within the cycle and do not add to it.

Articulated vacuum cup

Articulated vacuum cup

An "articulated vacuum cup" is shown to make it possible to hold non-standard bends of variously bent pieces of glass. The style cup is mounted to an aluminum vacuum plate and angled manually to adjust to the varying inclination of the bend on the glass' surface.

Videos

Processing curved glass

This video shows how curved glass can be processed which does not have a hard fixed position or a dedicated fixture.

The curved glass is placed on an adjustable fixture which features the use of "articulated vacuum cups" so that regardless of the varying surface of the part, it is held firmly.

The video also shows the use of the special probing system which finds the edge of the glass and then automatically "offsets" the program accordingly in all directions, so that a perfectly machined part is the result.

The processing operation also demonstrates how the 4th and 5th axes are interpolated to move through the varying surface presented by the curved glass. The final process machining completes the work with a standard "pencil" edge.