OK, so for this post I will describe a recent job, which although simple will hopefully demonstrate the design and make process of a project from start to finish.
The job was to make a modification to a hay baling machine.
The baler has a chute at the rear of the machine from which the bales are discharged. Occasionally the baler tows a bale accumulator which collects the bales, and arranges them in blocks of 8 or 12 to simplify the process of collection from the field. When the accumulator is in tow, the discharge chute has to be unbolted and a separate towing frame fitted in its place to pull the accumulator. The task was to create a simple method of fastening the chute to the towing frame, enabling the towing frame to remain permanently attached to the baler. This picture shows the accumulator towing frame and the discharge chute. A few minutes thinking time produced a couple of design ideas. No need for sophisticated CAD for this job. Then it was down to work. From these basic dimensions some plate was cut and prepared to form the brackets. Some round bar was cut and machined to form bushes which were welded to the bracket plates. Now, it was necessary for the chute to simple to remove and refit to the baler, and that no tools should be required. Given that remit, and remembering that this is 'agricultural' engineering, the following method was adopted. The brackets were designed to hang from 'flat bar' pins. Not especially elegant from an engineering best-practice perspective. However, by slotting the bushes, the brackets are simple to lift off and refit. As the following images show. Bracket in 'lift off' position, simply slots over the pin. Bracket in running position, held securely. In practice these hinges are only moved once during an operating period, therefore the crudity of the arrangement is of less significance than the ease of 'no-tool' fitting. So a couple of minor adjustments later and the accumulator frame and bale chute were as one. Then back to the field to check on the hay baler. Job complete, subject to paint, and another separate modification to the towing frame. A quick and hopefully long lasting modification.