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• Other factors to consider when handling parts,

-are the parts sticky?

-are the parts fragile?

-are there any sharp edges?

-do the parts nest or tangle?

-are there any parts or tools that the operator must leave the work station to get?

DI:13.2.4.3 - Orienting Parts

•When parts are to be fed, automatically and by human, the task is simplified if certain features are added.

•Basically, symmetry is a major problem for automated feeders.

•In general, a part is easier to orient if,

1.The orientation is based on internal features, and there are external features that can be used for reference.

2.Extra features are added to change the centre of mass, or create holding points for features.

•Some examples of parts orientation are,

PROBLEM: The part on the left would be hard to locate

SOLUTION: If external features are added to allow orientation without examining the internal holes, the part can be fed easily.

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PROBLEM: The sheet metal bracket has no features that would make it easy to orient.

SOLUTION: A lip is added at the top of the part (assuming this won’t affect the function), allowing the part to be oriented by suspending it by a wire for part of its travel.

PROBLEM: The hole in the part to the left would be hard to separate locate left to right.

SOLUTION: By cutting a notch on one side, we can use a vibratory bowl feeder to sort the parts by centre of gravity or by track width.

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PROBLEM: The feature on the part to the left is not prominent enough to simplify orientation techniques.

SOLUTION: The part to the right will be somewhat easier to orient.

DI:13.2.4.4 - Locating and Aligning Parts

•When we try to thread a needle, the thread is smaller than the hole in the needle, but this does not make threading the hole simple. In fact the process of threading the needle is simplified by the rounded opening on the needle. If the opening of the needle were square it would greatly complicate this problem.

•Much like threading a needle, the problem of mating two parts can be simplified if the parts tend to align and locate themselves.

•If we consider that for one part to mate with another, it must travel along an approach axis. In fact, when the parts are mated the parts will have common axis. We can add guides to the parts to align the axis to be parallel, and to locate the axis so that they are colinear. Hence, the terms aligning and locating.

•Consider the cases given below, and the implications they have for alignment

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PROBLEM: We are to put a bolt (with a bearing sleeve) in a hole, but it is hard to get the bolt in the hole. At the far side, the bolt must enter a second threaded hole to secure it.

SOLUTION: Put a chamfer on any stage where the bolt must pass through, this will align it, and allow it to slip in..