Internal grinding, also known as internal diameter (ID) grinding, is a method through which grinders finish off the interior of a workpiece. It generally indicates the use of specific grinders to produce precise bores or holes. Often considered the most difficult types of grinding, ID grinding produces accurate results. However, problems can and do arise.
Three Basic Problems in ID Grinding
ID has a narrow focus. It must be precise and highly accurate in its approach. Yet, when operators rapidly, accurately and efficiently remove miniscule quantities of metal, errors may occur. These fall under two major categories:
1. Workpiece inaccuracy: This falls into 2 types:
a. Out-of-round work: This is the result of one of two issues: the grinding operation is itself flawed, or the dressing for the wheel is incorrect.
b. Out of cylindricity: Causal factors are: flawed grinding operations and unsuitable wheel specification
2. Burn and/or cracks: Multiple issues may be the cause, including the grinding operation is imperfect, problems with coolant flow, too slow work speed and to fast wheel in-feeding.
It is possible to correct these problems. The operator has to note the cause before deciding what is the best solution. When it comes to faulty wheels, the solution may be to redress the wheel face. The operator may switch to a wheel of a harder or softer grade – depending upon the problem. The former is for an issue resulting from shedding; the latter if the wheel acts too hard. Other solutions may be as simple as adjusting the work chuck or wheel head, increasing the wheel width size or changing the quill material Adjust wheel head angle and infeed rate.
ID grinding demands precision from the machinery and the operator. It is exacting and not without its problems. While alignment presents one problem, others include burns and/or cracks and inaccurate workpieces. Internal grinding operators understand what they are facing and easily correct such issues.