BEST PRACTICES FOR MACHINING LARGE CAST PARTS Machining large parts, especially castings, is not for everyone. The generalization ‘parts are
parts’ does not apply in this case. To be proficient requires commitment
to constant process improvement, equipment evaluation and investment.
And to top it off, mistakes are very expensive.
cnc precision machining parts There are unique challenges associated with machining large parts,
today. Customers are demanding ever tighter tolerances, parts are large,
heavy and quite often castings. Increasing quality and efficiency is a
tall order – how can you do both? TCI Precision Metals approached the
challenge by analyzing variables of the machining process that directly
affect quality and consume the greatest amount of time. The result
focused on three key areas: 1. Cutting metal more of the time 2.
Reducing part movement 3. Maintaining a digital workflow When machining
large parts such as composite mold tooling for aerospace, or large
castings for oil and gas, there are typically large surface areas
involved. Compensating for high spots on a wing mold or variances
between castings can result in cutting air for hours, days or even
weeks. Being too aggressive or a miscalculation can result in tool
crashes or worse. The goal is to keep the tool cutting more often.
Moving a large part from the machining center to the quality inspection
room, then back to the machining center, then re-fixturing and aligning
for modification takes considerable time. Not to mention the chance of
damaging the part and risk of injury associated with moving large parts
around the shop. If you can place a large part in the machining center
once and remove it only when it is completed and verified, you will save
considerable time and effort. Machine Operators will remain focused on
completing the part at hand and avoid distractions associated with
switching out parts, re-fixturing, alignment and all the potential for
error that goes along with it. Closing the loop on digital workflow is
the key to improving the quality inspection and reporting process. The
CAD process is digital, the CAM process is digital, so it makes perfect
sense that the quality inspection and reporting process should be
digital too. By comparing inspection data back to the original 3D CAD
model, the loop is closed and the digital integrity is maintained.
