I had managed to lose the plastic guy ring for my portable antenna mast during the last field day and despite searching all over I couldn't find a replacement plastic one. So I decided to make some! I knew the material would need to be cheap and easy to work with as I don't have access to a laser CNC or molding equipment, after searching various vendors I accidentally came across the cutting board in the Kitchen...
Step 1: Materials and Tools
The material used is 8mm Polyethylene sheet, fortunately this is really easy to get hold in the form of the Legitim cutting boards from IKEA ( https://www.ikea.com/gb/en/products/cookware/knives-chopping-boards/legitim-chopping-board-white-art-90202268/ )
8mm Polyethylene Sheet
Small Self tapping screws
Various hole saws
8mm wood drill
Step 2: Measure and Cut
Start by measuring and drawing two intersecting lines on the board, be mindful to stay within a few millimeter of the edges of the board in such case the center point to the edge should be slightly more than the radius of hole saw used.
Before making any holes or cuts to the board make sure it is well secured using spoil boards and clamps.
The easiest method to cut the holes is to find a bit closest to the required inside diameter, another for the desired outside diameter and finally one that is between the two. This final bit will be used to score (not cut!) a circle that will aid in locating the guyline holes later on along with drawn marks to insure equal distribution.
Start drilling the board working from the smallest bit upwards, whilst it is possible to start from the largest first you will find it difficult to secure the board effectively
Chuck up a suitable sized hole saw and cut the piece using the center point drawn, whilst polyethylene is easy to work with it is critical to not let the saw heat up too much, I found the best method was to pulse the drill and apply little pressure. Once a piece has been cut remove it carefully from the hole saw.
Once a piece has been successfully cut away from the board, use the guide lines and score to drill the four 8mm holes for the guy lines.
Step 3: Fitting and Securing
If the fit is too tight for the mast gradually remove some material using sandpaper, however if it too loose then it is possible to make the ring slightly adjustable;
Mark off a straight line between the inside and outside of the ring and using a hacksaw cut along it to make a 'slice', depending on the fit required you may need to use a larger saw with a thicker blade width or simply place two cuts close together and remove the excess material. Use a utility knife to carefully notch out on one side of the cut as pictured, this notch should be at least 10mm from the cut and will be used to place a suitable sized screw to act as the 'adjuster', be sure to pilot a hole for the screw to prevent damage to the piece.
For additional security a hose clamp can be place on the mast below the ring to prevent it sliding.