An upcoming step in building my current Springer involves making hefty handrails. The tubing is .094 diameter (the Springer is 1/18 scale) so a little more pressure is needed to bend this size tubes versus the usual smaller diameter tubing commonly used on model boats.
My idea here is to use a small one-piece (no moving parts) hand tool designed and printed in 3D modeling. This would make the curves consistently the same as well as getting the center to center distance correct where one piece of tubing has more than one bend in it.
The linked video shows how this works.