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Using the N-scale Streetlight tube Bending Tool
This tool is designed to allow step-by-step forming of of the tubing shown in the picture of the building light above. We also have a kit (NK016) which includes enough parts to build 8 of these lights. More information about the kit can be found here.
The first step in building this gooseneck light is to flare the end of a segment of the .018” tubing. The complete procedure for doing this can be found here (under cold flaring).
Once the tubing has been flared, the next step is forming the gooseneck shape and that is where this tool is used. Following is the step-by-step procedure:
Bending the tubing
The tool (pictured below) consists of an aluminum block which contains 4 holes, and 4 pins which fit into the holes. The holes are located in a pattern that with pins inserted, provide a bending pattern that the .018" tubing can be formed around to achieve the curved top of the streetlight.
The diagram below shows the tubing in position in the tool.
Note that the flared end of the tubing is aligned with the bottom edge of the pin #2. A line could be scratched in the fixture surface to assist in alignment as well. All pins are .125" dowels. The first two pins can be a left in the fixture as they will not need to be removed. Pins 3 & 4 are a slip fit in the fixture and they will be inserted as stated below.
Once the tubing is removed, inspect it for uniform shape. If slight distortion occurred as a result of the support wire removal, it can be gently reshaped using slight pressure with your fingers to straighten any distortion.
Important note: The .012" wire can be lightly coated with thin oil prior to inserting it into the tube. This will facilitate easier removal from the formed tubing, HOWEVER... the remaining oily film inside the tubing will make pushing the magnet wire through the bent tube very difficult. If oil is used, squirt some type of cleaning solvent through the tube and thoroughly dry it before proceeding.
In all cases, the way we've found easiest and quickest to cut tubing to length is to simply snip it slightly oversize in length (using ordinary side cutters) and then, using a Dremel and sanding disk sand off the crimped ends until the tube is round and to the length you need. The .018” tube inside diameter can easily be deburred using a #80 drill bit in a pin vise. The external diameter is deburred using an Arkansas stone or fine sand paper.
This completes the use of the N-scale streetlight tube bending tool.
© 2011 Ngineering