Monday, March 16, 2009

TOOLS AND TECHNIQUES - Part 1




CUTTING TUBING FOR REALISTIC STEEL MILL GAS PIPING
This will apply to basically any type of tubing, however, I have mostly been using wood dowels for fabricating bends and tees.  Plastic can be cut using the same saw, but the blade should be changed to a plastic cutting blade. 
Creating these parts from wood dowels isn't hard.  You just need to make a jig to hold the piping to be cut - and - you need to establish a reference line that you can use to align the piece in the saw and drill, and later, use these lines while gluing up the pieces.  
The Jig -


As you have seen in some of my earlier posts,
I don't believe in spending a lot of time or money building jigs or tools.  The jig for piping will wear out pretty quickly.  You will need to make one for each size pipe you wish to cut. 

  The jig is made from a scrap of 3/4" plywood and two hardwood fences -  The rear fence is about 1"x1"x the length of the jig (which is about 12" in this case but it doesn't really matter)   The inside fence needs to be exactly half the diameter of the tubing in thickness, in this case, 3/8" x 1".  

To assemble the jig - first, glue the rear fence in place along the edge of the board, use spring clamps to hold.   Then, using a scrap dowel as a gauge, install the inner fence using glue and spring clamps.  I don't use any metal fasteners, as they might damage the blade or drill bit.  

Reference Line - this is a simple thing, but important in terms of creating consistently sized parts and for aligning these parts while glueing them together.  Basically, just put the dowel in the jig and draw a pencil line across it,  using the inside fence as a guide.  Also mark the rear fence of the jig using a ruler, again at the half way mark. Rotate the dowel until the line across it lines up with the mark on the rear fence, and then drag a pencil across the front fence - at this point you should have two lines, directly on either side of the tube.  Whenever you cut or drill, always align one of these lines with the front fence.   When you glue up the tubing, align the reference marks and you will end up with no twists in the elbow

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