SQUARE CENTRED FLIGHTING

Many times in the past it has been requested that we produce a set of sectional flights to suit square tube/pipe. Which we had done successfully on the likes of up to 4 " dia with a 1 " bore. However, we were about to find out just how hard it would be to produce 12 " dia flights with an equal pitch complete with a square bore, Not knowing that the larger the flight the more research had to be done designing the blanks to insure a complete 360 deg turn was accomplished and that the match up would be achieved.

Our first attempt taught us that purely a square hole would not work, because of the forming process, the flights were creeping around the square tube/pipe roughly 390 deg, which also caused the bore to become incorrect. As the flight formed around the square tube/pipe the corners of the flight blank ended up not being in the right place. Our first decision was to insure we got 1 complete 360 deg turn from the blank, ignoring the square hole.

We utilized our Auto Cad drafting system and went about designing the part on the computer first. Looking at a computer drafted part help us to understand what we would have to do to produce a part that could be snapped on to the tube/pipe with ease and minimal labor incurred by our clients. Who are the people left trying to get the parts welded to the tube/pipe, When they are not right.

By using the Auto Cad we measured the length of the strip from the out side of the flight to the tube in 16 different rotations of the flight. This helped us to determine what shape would have to be formed to have the flight touch the tube/pipe all the way around.

We then started producing the parts as we had estimated they should be and found them still to be wrong. Due to the square bore we found that the blank was over forming at the corners of the tube/pipe and under forming along the flat section of the square tube/pipe. What we thought should be a square hole ended up being a both a square and a round combined to make it fit the tube/pipe.

After experimenting to produce the parts as they should be we then asked our Managing Director Mr. Gregory Bloxham (B.E.) to create a program which with the information we had gathered during the experiment would calculate the shape and dimensions of the flight blank by simply entering the O.D , the pitch and the bore size required.

This is a task that Greg has undertaken in the past when he created our blanks program to calculate all of our large range of flights, including tapered OD, ID or both, our strip and tag, and our notched flights which also creates a DXF file that is able to be down loaded to our profile cutting machine or simply plotted out on our Draft Master plotter for the other types of electronic tracing systems. These blanks programs that Greg has created are one of the engineering tools we use daily.

Another example of our ability to be innovative and a leader in our field was achieved back in 1989 when a potential customer approached us with the following problem: they required a flight that was leaning over at 8 degrees to the perpendicular (what we termed a cone flight). Their contact with other manufacturers of screw flights in Australia and Europe had come up with only crude answers to their problem. They wanted a product that they could weld on without the hassle of having to "work" after fabrication. We set about the task at hand and suprisingly came up with a more than satisfactory result within a fortnight. We produced the part by forming the blank into a cone shape and then with a different to normal routine we formed the helix. By doing this coning process, when the screw turns at it’s high speed under load, gravitational forces gave the impression that it would stand at a 90 deg angle to the shaft whereas the conventional flight had a tendency to appear to fold away. This artificial appearance of the flight standing at 90 degs to the shaft allowed the screw to be approximately 32% more efficient. Today this company is now one of our most prolific and valued customers.

We also give the same dedication to producing conventional types of flights which are able to be fitted to pipe with ease and with precision to speed up the manufacturing of flight on pipe process.