Here's another 3D model you can download for free from Thingiverse and print on your 3D printer.
This 3D object is a transition from Este BT-55 to BT-60 tubing. The distance between the two sizes of tubes (transition taper length) is 2.2 inches (55.88mm). It is similar to the Estes TA-5560 (P/N 70028) transition/adapter.

There are eight models:
1) Solid,
2) Solid with a 3.2mm hole to allow for screw eyes to be fastened to it,
3) Hollow,
4) Hollow with end caps.
5-8) End caps fit the ends of the Hollow2 transition. One has 1/8 inch (3.2mm) holes for the attachment of eyebolts and the others do not.

https://www.thingiverse.com/thing:4962698