I had some free time today since the team isn’t meeting, so I decided to use it making a series of fittings to assemble the REEF pipe and BRANCHES out of old 1.25" PVC pipe from my garage. The goal was to make them strong enough for some abuse, easy to print, and matching the geometry of the real parts without any external fasteners or parts. These internal fitting is what I came up with.
There is one fitting design for the T branches, and another design for the S bend. Each fitting is split in half to allow easy printing and alignment of the layers for maximum strength. The pipe lengths came out just a bit odd so I rounded to the nearest 1/8" with the understanding that this build method simply isn’t that accurate. The bottom piece length is based on the assumption of a 3/4" base plate for the correct height, so add that length if this will rest on the ground directly.
Glue everything together with hot glue if you want it fast, or a slower curing glue to make sure everything is aligned properly. I recommend assembling on a flat table or the floor to ensure everything is planar. I printed the sample pieces out of ABS with 3 perimeters and 15% infill, which seems to provide plenty of strength and fits well.
To assemble one full pipe/branch unit you will need:
(2) 35 degree T connector half prints
(2) mirrored 35 degree T connector half prints
(2) level 4 offset half prints
(2) mirrored level 4 offset half prints
(1) 23.125" length of 1.25" schedule 40 PVC (add 0.75" if you are sitting directly on the ground)
(1) 13.875" length of 1.25" schedule 40 PVC
(1) 12.25" length of 1.25" schedule 40 PVC
(1) 8" length of 1.25" schedule 40 PVC
(1) 6.875" length of 1.25" schedule 40 PVC
(2) 10.5" lengths of 1.25" schedule 40 PVC
One 10’ length of pipe will create 1 assembly with a little over 2 feet of extra remaining.
Note that the team build element plans have a 1/2" plywood base and a 1/8" hardboard under the bored out 4x4. That would be “most” of the ~3/4" delta in lengths…
I added a version in the OnShape model that embeds a 54" long piece of 3/4" steel EMT conduit for stiffness. The T fittings and the lower S fitting have a very slightly oversized hole for the conduit to pass through. I don’t have any 3/4" EMT handy to test fit currently, so buyer beware.
I’ll add chamfers and maybe a couple of glue channels when I get some time tonight. The fit in the pipe was just snug enough to force most of the hot glue out when I assembled one.
I’m only on my phone at the moment, but are you selecting the part “name” over in the left side text area? (Not the part itself in the 3D geometry pane.)
The team printed this on Bambu Labs A1 mini. Strength setting with infill reduced to 15%. Add a chamfer to the ends 1/16”. The result was great. It’s a light hammer fit. No glue used anywhere. Thank you for sharing the design.
2706 is printing the fittings on my Bambu Lab A1 Mini (cranking out one pair at a time) and I have cut up all the 1.25" pipe and some 3/4" EMT conduit.
Unfortunately I did find that the cutout for the nominal dimension of the EMT was a bit too small. I will ream out the parts I already made with a Dremel or some such, and I have adjusted the model with a wider channel to suit the EMT that I have.
I discovered tonight that the model parts print successfully without supports, though I did use tree supports for the first few.
The parts were glued together with Gorilla Super Glue Gel and then hammered into the ABS pipe.
I made a slight tweak to the CAD file last night, adding 0.1" extra clearance at the peak of the “arch” of the EMT pocket to combat sag while printing. Fit seems great with PLA off my X1C so I’ll roll that into the printables page tonight when I’m at my computer.
