Historically, grinding applications in the manufacturing industry used a rotary device for hand grinding pins placed either in a v-block or 5C Collet which was designed into the unit. This is a dry grinding operation with the fixture being spun by hand. The indexes were set up on a sine plate, indicated in and stops set.
This grinding operation evolved to a motorized option, eliminating the need to spin by hand. The motor delivers steady speeds so the operator can concentrate on grinding. This is also done dry.
Further innovation came by manufacturing the same fixture in stainless steel with ceramic bearings. The stainless steel construction allowed indexing functions in the wire EDM. The ceramic bearings resulted in a tool that could be used in all EDM operations as the ceramic bearings isolated the bearing race from electrical discharge.
Further development to use this unit while submerged opened the potential to also spin and burn in the EDM environment. These solutions were always considered an add-on option. The results were often limited due to the challenges of successfully submerging a small, high torque, high rpm motor. Usually at best 2 of the 3 above requirements were met.
Hermann Schmidt decided to redesign the product to meet today’s new demands for a device of this quality and flexibility while also addressing the changing workforce that the industry is experiencing.
We see a trend where manufacturers tend to have fewer toolmakers and more specialty operators in an area. As a result, broad-base experience is diminished and many employers make this up with more sophisticated systems.
Stainless Steel Rotary Index Fixture in the Grinding Area
In the grinding area the RIF-S improves on all abilities of previous products as follows:
- Compactness of design maintained.
Face diameter of 4″ and maintaining thru hole capacity of 1″ allows customers to use previously developed face tooling.
- Ceramic bearings allow a higher preload without generating heat.
Previously as a unit was spinning the ball bearings would warm and expand. As a result lower preloads needed to be used. The end result is tolerance on the spindle can be held tighter.
- The output from the rotary encoder allows the setting of indexing stops without indicating a position on a sine plate.
This is significantly quicker than previous products. This also allows a less skilled operator to set up the fixture to toolmaker tolerances. Output can by in either decimal or degrees-minutes-seconds, eliminating the need for calculations.
- The unit is submersible.
If flood grinding is required, the internal motor option allows spinning. The applications for this are usually seen in high-pressure oil type grinding or when flood grinding chromed materials.
Stainless Steel Rotary Index Fixture in the EDM Area
In the EDM area our RIF-S – along with optional high RPM internal motor – changes what has been previously available to the industry. Many work pieces previously ground can now be EDM’d. Tighter tolerances with smaller details can be manufactured with greater repetition of accuracy.
- Compactness of the design allows flexibility of placement in EDM.
Small size also allows easy movement from machine to machine.
- Ceramic bearings isolate the unit from electrical discharge.
This prevents the any damage to the bearing race during EDM. The ceramic bearings also allow for a heavy preload, maintaining high precision with heavier work holding fixtures and work pieces installed on the spindle face.
- The digital readout allows setting of the indexes while the unit is installed in the machine and squared to the machine travel.
Previously the unit would need to be uninstalled, indexes set up and reinstalled.
- The high-torque and high-rpm internal motor gives precise control up to 1800 RPM.
This combination has not been available until now. The high torque is required so proper face tooling options can be utilized at the high rpm required on smaller diameter work pieces.
Flexible, Expandable Options
The face tooling options can be purchased as required by the customer when their needs change. None need to be added to the spindle at the time of purchase.