Ask most shop owners what the number one reason is for new molds failing their first sample and you will most likely hear “material sticking in the ribs.” It is not uncommon for a tool to have its ribs and slots repolished two, three or more times before the tool works cleanly. The following is [...]
Few people within the moldmaking industry will argue that cleaning and maintenance are critical processes for maintaining the life and reliability of expensive equipment and ensuring the quality of the end product. […]
Ask any polisher what the hardest part of his/her job is and most will tell you the same thing – stoning. It doesn’t have to be that way. Here is a simple technique that not only makes stoning easier and more enjoyable, but actually cuts 30 percent off the time it takes to do a [...]
Indexable-insert ballnose endmills for high-speed finishing of molds can be purchased as individual units from a standard endmill catalog, or assembled from components of available modular end-milling systems. […]
To provide the high-performance results demanded in today’s moldmaking, many indexable-insert ballnose endmills use PVD-coated, precision-ground, micrograin- carbide inserts. Experience shows that such inserts perform best with sharp edges, which represents a departure from the conventional wisdom that extra-strong edges are required to stand up to hardened materials at very high feedrates. […]
Within this decade, advanced carbide cutting tools used with constant-chip-load CNC cutting strategies have dramatically increased material-removal rates in roughing of mold cores and cavities. The combination of these tools and strategies also results in dimensions closer to near-net shape, which favorably impacts subsequent finishing operations. As impressive as these roughing approaches have been, however, [...]
Both solid-carbide and small indexable-insert ballnose endmills are capable of the speeds and feeds required for high-speed finishing of molds. Moldmakers should keep in mind, however, that the indexable-insert tools offer important cost advantages – starting with a much lower replacement cost and no regrinding. […]
Checking for Positive DraftOn occasion tool marks can be so deep that they reduce the draft or the polisher accidentally takes off the draft. The key is to always check for positive draft by putting a six-inch scale on the wall and comparing the angle it makes to the parting line. It takes just a [...]
If we consider the primary metal of steel, which is iron, there are a number of features that we can observe immediately about the metal: […]
Of all the tasks polishers face in the moldmaking trade, texture and its related problems are probably among the most challenging. Getting hand texturing to match up perfectly with acid bath texturing is a skill entirely unto itself, but with a few tricks of the trade, almost any polisher will be able to stand up [...]