Halloween PVC Fence Toppers

thingiverse

This comes from DYNE and Finial Tetra (for PVC Halloween Fence) Thank you Dyne. You can use the finial with either schedule 40 (white) or schedule 80 (grey) PVC. It won't matter which of these standards you use. The outside diameters are identical; only the inside diameters differ. Since the finial fits over the pipe as a cap, we only care about the pipe's outer diameter. Grey is usually significantly cheaper, but it also comes with a short bell on one end, so you lose a few inches of the length. There's also black schedule 40, which could save you some painting, but it's more expensive. This finial was designed to fit a 3/4 inch PVC pipe, which I chose as a compromise. It's more common to use 1/2 inch PVC for the fence posts, but to use larger PVC for the ends of each section of fence. So you may need to scale the finial up or down from its default size. The default finial is nearly six and a half inches tall. Due to cable management issues on Wanhao style print heads, I would have to mod my Z axis (e.g. AzzA's Z extensions) before I could print that height. Scaling for a 1 inch pipe would be even worse; the finial would be more than 205 mm tall, well over my Maker Select's theoretical max build height of 180 mm. "We're gonna need a bigger printer." *(cue __Jaws__ theme)* Deltas and larger cartesian printers might fare better. If you do need to scale the part for a different pipe size, though, some things to keep in mind are that 1) you are scaling to fit the model to the new pipe's *outer* diameter (plus a bit for tolerance), 2) the name of the pipe bears little resemblance to [any actual measurement you'll get off of it (see http://www.engineeringtoolbox.com/pvc-cpvc-pipes-dimensions-d_795.html if you don't believe me), and 3) you need to compensate from the "ideal" scale factor to keep the tolerance more or less constant. For the pipe standards mentioned above, here are a few common scales: * 3/4 inch pipe = The model's base has an Inner Diameter of 1.08 inches. This equals the pipe's standard outer diameter of 1.05 inches, plus a designed clearance around the pipe of 0.03 inches (a bit more than three quarters of a millimeter). That clearance seems sufficient for a relatively snug fit. Of course, printed parts have some dimensional variance depending on calibration and material, and the pipe also has some accepted variation, so Your Mileage May Vary. * 1/2 inch pipe = 0.84 inches O.D. The exact scaling factor from 3/4 inch to 1/2 inch pipe is 80% (0.84 / 1.05). Probably the actual number you will need to scale by will be a little larger; you are shrinking the tolerance as you scale down, so the finial may not fit if you go all the way down. 81% is a good starting point as it seems to fit snugly in my tests. * 1 inch pipe = 1.315 inches O.D. The scaling factor from the default pipe size to this pipe is 125.24% (1.315 / 1.05).