| A large diameter tubing can be used for aerospace | | | | out is 9.42 inches, and the finished tube length is 18 |
| ducting hot or cold air to various places in the aircraft. | | | | inches. To each of the 9.42 inch ends add one inch to |
| There are two types of tubing used for this purpose: | | | | make the joggle and locking seam. |
| One is flexible and the other is rigid. On modern | | | | Once the joggle and seam are bent, release the slip |
| aircraft, flexible aluminium tubing is not used as often | | | | roller and lock the flat sheet into place in the middle. |
| any more because it is being replaced with specially | | | | After the slip roller is locked into place, adjust the |
| treated fabric covered ducting. However, the use of | | | | rollers to begin the initial curvature of the tube. Crank |
| rigid tubing still serves a valuable purpose because it | | | | the rollers back and forth and roll the tube from one |
| can take more abuse than soft flexible ducting. | | | | end to the other until the tube begins to take shape. |
| Aerospace Ducting Of Aluminium Tube. | | | | Each time you roll, gradually increase the tightness of |
| Either type, heat treated or non-heat-treated | | | | the rollers until the tube is completely rolled into |
| aluminium alloy in the annealed condition, is best suited | | | | shape. Release the slip roller and remove the tube |
| for the making of rigid tubing. The tool used to make | | | | from the roller. Check the diameter and seams for |
| tubing or duct pipe is a set of slip rollers. The smallest | | | | alignment. Once the seam is joined, slip it over a pipe |
| diameter that can be made using a slip roller is | | | | clamped in a bench vice and begin flattening the |
| determined by the size of the rolling machine. When a | | | | seam. This action will lock the seam into place. |
| tube diameter larger than the roller is called for, the | | | | If more joint security is needed you may want to |
| rollers can be adjusted to make a larger diameter | | | | install soft aluminium rivets (AN470A3-6) along the |
| such as those needed for leading edge construction. | | | | seam. The holes for the rivets are drilled by slipping |
| The construction of aluminium alloy tubes requires | | | | the tube over a pre-formed 2 x 4 clamped in a |
| knowing the diameter, length and type of locking | | | | bench vice. The rivets can be bucked using the same |
| joint to be used. Suppose that 3-inch diameter | | | | pipe you used to lock the seam. If this piece of |
| finished aluminium tubes will be made. The | | | | tubing is going to be fitted into another piece of |
| circumference of the tubes is the length of metal | | | | tubing, the rivets used to secure the seam must be |
| needed to roll the diameter of the tube. With a | | | | countersunk (AN426A3-4). |
| diameter of 3 inches times 3.1416, the length of roll | | | | |