GPS antenna wall mount

I made a mount for my gps antenna that I can screw into the wall. The design was made using Openscad

Looks very much like this model a Boat GPS Navigation External Antenna (5m Cable)

At first glance it seemed that I just need to make openscad make an M26 screw. Actually, it wouldn’t help since it it not a standard screw size (M24 and M27 exist), so we would still need to custom define it.

Googling yields this which seems correct. So we will go for 1 inch and 14 TPI, ie. pitch 1.814 mm

A bit More googling tells me that this is standard for marine antennas.

Screw

I initially looked at boltsparts, but failed at defining my own screw.

BOSL2 worked out better for me.

Download latest and extract to $HOME/.local/share/OpenSCAD/libraries (cf openscad wiki)

Note that file -> show library content... will reveal where Openscad imports from.

You can set all screw parameter as you wish. See the wiki for details

The connector screw was made like this

include <BOSL2/std.scad>
include <BOSL2/screws.scad>

spec = [["system","ISO"],
        ["type","screw_info"],
        ["pitch", 1.814],
        ["head", "hex"],
        ["head_size", 36],
        ["head_height", 10],
        ["diameter",26],
        ["thread_len", 25],
       ["length",35]];
screw(spec,tolerance=0);

The wall mount

The final design looked like this

The issues I had with the screw came in handy with the mount, since I could just use the same library to add M4 screw holes.

module mount_plate() {
    translate( [0, mount_arm_w/2, -mount_arm_l/4] ) {
        difference() {
            // actual back plate
            hull() {
                ...
            }

            // two holes for screws
            translate( [mount_arm_h/2, 0, 0] )
                rotate( [0, 90, 0] )
                    screw_hole("M4,40",head="flat",counterbore=0,anchor=TOP);
                
            translate( [mount_arm_h/2, 0, mount_arm_l] )
                rotate( [0, 90, 0] )
                    screw_hole("M4,40",head="flat",counterbore=0,anchor=TOP);
        }
    }
}

I also added a slit for the antenna cable along with a guide for a cable tie.

Files are available on thingiverse