This is quite a beefy clamp/holder to attach an umbrella/parasol/sunshade to a horizontal railing post. As you can see the stand I got on my balcony is not really tasked to hold a big umbrella but I also don't want to waste a lot of space so this half-slab stand and a clamp like this is a perfect feature for me :)

Feel free to adjust everything to your dimensions - step and parameteric f3d files included :)

The two clamps slide onto the connector piece so that the clearance between the parasol and railing post can be adjusted with the slotted holes in the connector from 165mm to 180mm.

The two clamps feature two different diameters:

Clamp Umbrella: 38mm

Clamp Railing: 42.5mm

To attach everything you need a few bits of hardware:

8 Pcs. of M5 x [16-20mm] e.g. DIN 912 (I used M5 x 16mm)

8 Pcs. of M5 Hexnut e.g. DIN 934

The assembled clamp on the pictures is printed in PAHT-CF (from Bambulab) @0.16mm with 6 perimeters and 30% infill on a Bambulab X1C. But I guess every material that can stay outside and withstand the sun (UV and temperature-wise) is fine with such strong print settings.

Supports are only needed for the slotted holes in the connector and only if you want them to print super clean (they are most likely not visible assembled though).