Poor Modular-Fixturing Uses
Just as conventional machine tools are better suited for some tasks than numerically controlled machines, the selection and application of workholders is determined by the work to be performed. Modular workholders are not intended for every job. Two limiting factors of modular workholders are the frequency of production runs and the size of the workholder.
Regularly repeated jobs. The choice of fixturing method depends more on the frequency of production runs than on the number of parts per run.
Modular workholders are usually disassembled after each job. Each time a job is run, the modular fixture requires reassembly. Permanent workholders are normally built for a complete product run. If a job repeats on a regular basis, a permanent fixture is the better choice. Modular fixtures could remain assembled between production runs, thus becoming a permanent workholder, but this negates the economy of reusing modular components.
|
|
When fixture compactness is important. Another factor to consider in the selection of a workholder is the size of the completed fixture. Permanent workholders are normally built from custom-made elements and base plates that permit a smaller, more-compact workholder. Modular components are intended for a variety of applications and are larger than comparable custom-made components. So, when space is limited, such as with multiple-part setups, modular workholders may prove to be too large.
|
