This is a centre piece used to make wire dipole antennas for Amateur radio, usually HF but it could also be used for VHF and UHF antennas as well, this has been designed to take these binding posts from Amazon (https://www.amazon.co.uk/gp/product/B09TPFXP7H/), the corners have been rounded and holes have been provided for cable ties and other such support items

This will obviously need to be waterproofed before use outdoors, this should be done before inserting the binding posts.

The top plate of the binding posts fit in the deeper recess on the top, the bottom plate then fits on the bottom, this will protrude out but be flat against the 3D printed part, the threaded bar is a little bit of a snug fit and should be screwed in from the top, the top part of these binding posts has a recess that holds one of the nuts, insert the nut and screw the thread in, it should line up with the hole, it may be a little tight at first but it will go through the hole, after this it is a case of putting the other plastic plate over the bottom, placing the washer on and tightening the two nuts, the binding posts can go either way round on the piece

Connection to the binding posts can be made with ring terminals which are readily available from most electrical and auto parts suppliers, I wouldn't advise trapping the wires under the two caps, also the feedline would need to be connected to the opposite side, you only need to undo one of the rear nuts for this, don't undo the one closest to the coloured plate when connecting wires to that side, also if you use coaxial cable as the feeder then the centre conductor should go to the red and the braid to the black to help identify which side is which, also important if you build a vertical wire dipole using this as the element on the red terminal should face up.

I will be doing a YouTube video on building one of these in the not too distant future so keep an eye out for that one as well, I'll put a link up when it is available

Creality

Ender 3 Pro

Yes

100%

The 100% infill will aid with weatherproofing the piece but you should still add a coating post-print to protect it from the elements