This is a remix of the excellent pixel drilling jig by RiggsCasa used for drilling holes in 5/8" J-Channel from Lowes for mounting 12mm pixels. The original along with usage instructions is located on Cults3D and includes multiple spacing options - https://cults3d.com/en/3d-model/tool/christmas-j-channel-jig-for-ws2811.

This is an edit of the 2.8in version which fits a string of 50 nodes nicely into a 12' stick. The hole was slightly undersized and is enlarged to 12mm so that forstner and brad point bits can be used. A chamfer was added as well to help center bits for the initial usage in case it prints undersized. The hole is now cut through the entire jig (hook portion) so that step bits can be used. The hook tolerance was tightened up a bit to pull the hook out of the drill path as much as possible. The base was thickened so that the jig can be used upside down in a shallow drill press vise, ideally with a forstner bit. An alignment window was added at 1.4" to assist with drilling the first hole. Finally, fillets were added to all vertical edges.