I wanted some nice flange-joinged pipes for my Stuart No. 4, so I've been playing around with making pipe flanges, and thought folks might be interested, and have useful feedback for me!
I got some copper pipe from the hardware store (the type used for refrigerator waterlines), in 3/16", 1/4", and 5/16" diameters (that's an external diameter) to play with.
My first problem was knowing how big to make the flanges, and I underestimated on my first, "freehand" attempt. So some internet research on full-sized flanged fittings suggested that the diameter of the flange is about 2.5x the pipe diameter. Using half that diameter for the diameter of the central "boss" where the pipe screws in seemed about right. The boss ended up with a length of about half the pipe diameter, and I guesstimated the flange thickness as about 75% of that.
Here's one flange underway, turned from some 3/4" brass bar. I've turned the back side, and now I'm drilling for the tap:
I'm using 26TPI BSB taps. After threading, it's parted off, leaving a flange of the right thickness:
I finished the parting with a hacksaw (taking care not to mark the flange face). Here's my first attampt at flanges for 1/4" pipe before cleanup:
To cleanup the mating faces, I threaded the end of a bit of 1/4" brass rod and used that as a mandrel:
After turning, the part can get pretty stuck on the mandrel. Here's my new favorite shop accessory, a bit of non-slip rug pad material which is great for unscrewing slippery parts
Threading the pipe, which is held gently in the 3-jaw?but not so gently that it revolves under the threading force, leaving nasty gouges (ask me how I know):
Progress so far: 2 sizes, 1/4" pipe at the top, and 5/16" pipe at the bottom. Top left flange was not threaded deep enough.
I'll silver-solder the flanges onto the pipes, after drilling holes for bolts. I think I'll use 6 bolts on each. I did struggle with a 10BA die today trying to make some studs for this, but making 24 teeny nuts will drive me crazy so I ordered some 8-10BA nuts and bolts to give me a size range to play with
I guess I should trepan a groove for an O-ring on the faces (any tool suggestions for doing that?).
Simon