Planter anchor for pedestal pavers

This mounting system anchors planters or any other objects to heavy pedestal pavers without drilling and without moving the pavers.

Use the SCAD file to generate your own bracket and anchor, and optionally the side covers. anchor.stl contains all parts with the default parameters.

How it works

The bracket is a hollow profile that is screwed to the planter and stands on the pavers over a joint between them. The anchor is a T-shaped rod: its crossbar is lowered through the joint and turned by 90°, so it bears against the underside of the pavers like a toggle bolt. The stem of the anchor comes up through a slot in the bottom wall of the bracket, and the handle at its top snaps into a seat in the bracket's internal ribs. The planter can therefore be neither lifted nor tipped over. Nothing is drilled or glued, so everything can be removed again.

The anchor is strong when it is pulled along its length, which is what holds the planter down. A sideways force (when the planter is pushed or slides) bends the thin plastic stem at the paver surface, where it can break. This is what the optional fastening pin and zip ties are for, see Hardware needed.

Usage

1. Install OpenSCAD — a recent release candidate is recommended.

2. Download the anchor.zip archive and extract it completely — anchor.scad must stay next to the BOSL2 folder.

3. Open anchor.scad in OpenSCAD and show the Customizer (Window ▸ Customizer).

4. Set or check all parameters in the Customizer (in particular anchor_underground_height, which is the paver thickness plus the rod diameter).

5. Use model_view = Assembly to visually check your parameters. It shows the parts assembled on a planter with pavers and dimensions the resulting paver thickness.

6. Switch model_view back to Print, then preview (F5), render (F6) and export the STL (F7).

Features

• Highly customizable — the bracket profile (width, wall angles, height, depth, wall thickness), the anchor (rod diameter, depth below ground, crossbar, handle), the screw grid, the zip tie and pin channels and the covers are all Customizer parameters.

• Prints without supports. The Print view lays all parts flat on the bed.

• No drilling, no glue — the anchor only uses the joint between the pavers and can be removed again.

• Holds the object firmly in all directions when the fastening pin and zip ties are used (recommended).

• Fits sloped walls — the angle between the ground and the wall screwed to the planter can be set from 45° to 135°.

• Countersunk screw holes in a configurable grid, with screwdriver access holes in the outer wall for the top row.

• Optional covers close both ends of the bracket and hide its inside. They are held by snap locks inside the bracket, and a recess in the outer wall lets you pry them off again.

Hardware needed

• Screws to fasten the bracket to the object. The holes are countersunk; the number of screws and the hole diameter are parameters.

• OPTIONAL (recommended): Fastening pin — a long screw or a steel rod (e.g. spring steel) with the diameter set by fastening_pin_diameter. It must reach from the bottom of the pavers up to the middle zip tie. The pin is pushed into the same paver joint right next to the anchor stem and comes up through its own slot in the bottom wall of the bracket. Once it is zip-tied to the anchor and the bracket, the steel pin takes the sideways loads instead of the plastic stem of the anchor, which could otherwise break at the paver surface.

• OPTIONAL (recommended): Zip ties — the vertical support (the rib next to the anchor stem) has a pair of holes at up to three heights: top, middle and bottom. Each zip tie goes through the two holes and around the anchor stem, clamping the anchor to the rib; the bottom and middle ties also go around the fastening pin. The zip ties lock the anchor in its seat so it cannot slide back out of the bracket, and they make the anchor, the pin and the bracket act as one rigid piece. The channel width is set by zip_tie_width.

Both the fastening pin and the zip ties need the vertical support (support_vertical, on by default).

Print instructions

• PCTG or PETG is strongly recommended. Nylon might be even better, but I have not had a chance to test it.

• Use enough perimeters to print the parts solid (100 % infill).

• The anchor is printed lying flat with its handle pointing up, so good layer adhesion (Z strength) is critical for a strong handle.

Assembly instructions

1. Screw the bracket to the object so that it stands over a joint between the pavers. The slots for the anchor and the pin are open at one end of the bracket only; the anchor is slid in from that end.

2. Lower the crossbar of the anchor through the joint and turn the anchor by 90°, so that the crossbar lies under the pavers.

3. OPTIONAL: If your configuration includes the fastening pin, push the pin (screw or rod) into the same joint next to the anchor, in line with the pin slot in the bottom wall of the bracket.

4. Slide the bracket (together with the object) over the anchor and the pin until the anchor stem snaps into its seat in the middle of the bracket.

5. OPTIONAL: If your configuration includes the zip ties, thread a zip tie through each pair of holes in the vertical support and tighten it around the anchor stem (and the pin).

6. OPTIONAL: If your configuration includes the covers, snap them onto both ends of the bracket.