18mm Soft Attach Block / Pulley

I started with [Bedzplane's version](https://www.thingiverse.com/thing:3525442) but found myself needing to modify it a bit for my purposes.

I'm using this on a catamaran to route the 3/16" (4.7mm) shock cord used for the trapeze system underneath the tramp. The original version had some hard edges so I rounded everything over a bit to keep chaffing to a minimum. I also sized it to use [this 3/16" stainless steel tubing](https://www.amazon.com/gp/product/B004XN9E8Y/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1) for the axles.

All of the parts push fit together and the becket then helps to hold it all together. I then run a small line through the back of the shell and becket which locks it all together. This has the effect of pulling the parts closer together as it is tightened, and the higher the load the tighter it is held, which makes it quite strong when printed at 50% infill or more.

**Single Block**
Cut your stainless tubing to 10.4mm lengths and print the following: