Orbit Saturn III Sprinkler Spray Nozzle Insert

thingiverse

This insert allows you to alter the flow rate of an Orbit Saturn III gear drive spray head. These are budget-friendly lawn sprinkler heads available at big-box stores like Home Depot and Lowe's, as well as online at Amazon. I was replacing two heads on an existing zone, but the stock nozzle had too much flow, creating a swimming pool and causing excessive pressure drop. There is a set of replacement inserts available from Orbit with different flow rates that can be special-ordered through Home Depot for under $2, although delivery takes a week. Alternatively, they are available on Amazon Prime for $6, but it's the holiday weekend, and I need to complete my sprinkler project so I can enjoy the rest of my vacation. Since I was interested in reducing flow, the inserts slide inside the existing stock nozzle as shown in the pictures. The target outer diameter is 6.82mm. The nozzle has a slight taper to facilitate fitting. The fit should be snug but not too tight. There may be danger if it's too loose, as it could get sucked back into the gear drive when pressure is turned off, although this is unlikely. Once the insert is in place, push the entire nozzle back into position. Be careful that it goes all the way in so that when the spray adjust screw is reinstalled, the screw doesn't grab the green nozzle and crush it. I've completed this project, but it's easy to modify the FreeCAD file. Adjust the nozzle diameter to your desired setting and tweak the Z position of the nozzle taper to leave at least a 0.5mm lip on the exit section of the insert orifice. This is an obvious candidate for OpenSCAD. One possible tweak in addition to the orifice size is adjusting the exit angle to shoot a higher arc. You can also experiment with square orifices. The stock nozzle has two nubbies in the exit stream that probably create some close-in spray. In my case, I was still seeing over 15 feet of throw, so I had to use the spray adjust screw to dial back the range and achieve ample local coverage. Another possible tweak would be to replace the entire stock green insert with a 3D printed part. I don't think it needs as thin wall sections as the stock piece. There were several reviews on Amazon where people forgot to reinstall the spray adjust screw and blew out the green stock nozzle into their lawns. What was Orbit thinking? I have no idea how long ABS will hold up. Printing in Nylon is another possibility, but it soaks up water like a sponge. I'm not sure about PLA degradation. Print Settings: Printer: Highly Modified KS Robo3D Rafts: No Supports: No Resolution: 0.2mm Layer Height Infill: 70% Notes: 3 perimeters, 2 top/bottom layers, 2mm brim, Slic3R 1.2.7. Print with SUN ABS at 250C and Elmer's Xtreme Glue Stick at 110C bed temperature for the first layer. Use full fan speed after the first layer and 90C bed temperature with a 2mm brim. The part will require some cleanup after printing. Remove any blobs and scale the part as necessary to achieve the target outer diameter of 6.82mm. I was able to hit the target on the first print, but the inner diameter may be smaller on most printers. With my E3D V6, the 3mm orifice printed at 2.5mm. You can also tweak it after printing with a drill.