3/4" U Barb

Download folder: File:Upipe.tar.gz

U-barb for making tight u-turns with 3/4" irrigation pipe or other poly pipe for the purpose of heat exchangers. This u-turn goes inside the pipe sections that are to be joined. Poly pipe should be heated to allow easy application. The current application is u-turns for 500' of 3/4" black poly tubing - a 3.5kW heat exchanger for heating aquaponic ponds on solar radiation and some heat from the ceiling of the greenhouse. Download STL - File:Upipe.tar.gz

Notes:

• There is a defect in the file - one of the 2 legs is a little shorter than the other. We recommend printing with the curved side on the bottom, or laying flat. If printing like shown in the picture, you need to use a pad and support.
• STL file is the printing file. It has a thick wall.
• File was generated and exported from FreeCAD.
• The Sweep Tool was used in Part workbench. A circle was swept along an elliptial line. Since only solids and shells are possible using this tool in FreeCAD, I created one solid, and a smaller solid, then subtracted them. This worked by merging the solids into the final FreeCAD file. The only way this worked was when I cloned the solid BEFORE merging the two files. Otherwise, a merge of a non-cloned entity did not work. It was not sufficient to create a solid - only a clone of the solid worked for the Boolean operation.
• This worked for the original 2 solids. Then I tried a larger inner solid (to make a thinner shell). That did not work for some reason. You can play with the files above to see if it works for you.