Metalwork - Assembly
Putting the items we manufacture together is one of the most important things we do in Metalwork. There isn't much point in making loads of things and then just leaving them lying around the workshop. This is where the topic of Assembly comes into its own.
At this stage you have probably assembled many things already by a variety of methods but here we aim to give you more information on the many different types of assembly methods and the pros and cons of each in differing situations.
One of the first major decisions that a designer has to make is between Permanent and Temporary joining methods. The category of Permanent joints covers those that you use when you do not want component parts to be dissassembled after manufacture. The category of Temporary joints covers those which allow a person to take items apart after manufacture.
Lets look at the car for an example of how the type of joining method you choose is important. The chassis of a car is permanently joined by a method called welding. Whether is is the old style 'ladder-chassis' design that you can see on the left, or the more modern 'monocoque' design, viewable on the right, the basic requirements are the same. We want and need rigidity for good handling, good shock absorbtion and so that we are still sitting in a car when we get where we want to go. Now consider a designer who would like to use nuts and bolts to hold the different parts of a car chassis together .... would you buy a car like that ? Can you think of a few reasons why it might be a bad idea .... (a clue, compare Irish roads and swiss cheese !) Nuts and bolts don't like vibrations.
But we couldn't make a whole car using Permanent joining methods, it just wouldn't go, wheels could not turn, pistons couldn't go up and down, gears couldn't turn, etc. So Temporary joining methods can have the advantage of allowing parts to move .. always good in an engine. (That's a V8 on the left by the way).
Another major advantage of Temporary joints is that if, in the case of an engine, a part breaks, we can remove it easily and repair or replace the broken part. Engine covers are screwed into place, (even though a sealed engine could work fine), for this very reason. Imagine the expense that would result, if every time a car engine broke down, the whole thing had to be replaced ..... scary !
As a result of the major difference between Permanent and Temporary joining methods we have broken this topic down under these two methods. Below you can see links to the various topices in each section.
The decisions don't stop there though, other deciding factors include type of materials to be joined, cost of joining method, size of joint, thickness of materials .. the list goes on. Read on to find out more .....
Permanent Joining Methods
Temporary Joining Methods