easy-to-read, staked, angled number plates

This project is for when you want to label plants (or whatever) with large, easy-to-read two-digit numbers that are visible from both sides, tilted upwards slightly, and mounted on a stake. The digits are 40mm tall and the wedges mount on ⅜" re-bar (sometimes called #3). The project also includes a pair of soft jaws to assist with gluing the number plates onto the wedges.

The source CAD is in this Onshape document.

In addition to the prints, for each label you will need: (1) M5 square nut, (2) M5×16mm hex-drive screw, and (3) ⅜ inch rebar of appropriate length (I used 4 feet). For the soft jaws, you will need 16 magnets total, of size 10×5×2mm.

Assembly procedure is roughly:

1. Print the soft jaws, inserting a pause just before the magnets get covered so you can put them in.

2. Print one wedge.

3. Print two number plates for the desired number, one for each side of the label. Note color change so you can read it.

4. Glue the first number plate to the wedge and clamp it in a bench vise using the soft jaws. The plate being glued goes on the “direct” jaw (the one without a lower lip).

5. Turn the wedge around and glue the other number plate on. You should need to open the jaws only a few cm.

6. Insert an M5 square nut into its slot from the bottom.

7. Insert an M5 screw through the nut and but not into the re-bar mounting hole.

8. Insert the re-bar through the mounting hole, with a few centimeters protruding above the wedge.

9. Tighten the screw.

10. Take the label to the desired location and pound it into the ground. If indoors, you will likely need (1) a pilot hole and (2) to wait until your spouse is not home.

Repeat steps 2–10 until you have enough labels. I was able to print 8 number plates or 8 wedges per job.

Gotchas/tips:

• Printing:

  • I had successful prints in both PETG and PCTG, with the second working better. I did use PLA for the soft jaws to avoid overheating the magnets.

  • The models assume 0.32mm layers in a few places. I’m not sure how much this matters.

  • The number plates were pretty warpy for me. Printing with a single bottom layer and few top layers helped, i.e., more infill layers to provide flexibility. Less than three top layers made the digits weird.

• Glue-up:

  • I used Zap-A-Gap medium CA glue.

  • Take it easy on the glue, as if it leaks out it can glue the assembly to the soft jaws, and there are some sneaky places where it can do so. I found that a grease or tape barrier on the indirect soft jaw helped but did not fully solve the problem, but just being more reasonable with the glue did solve it.

  • Be careful to put the number plates on right side up, as they do fit both ways.

  • Similarly, it is easy to get the soft jaws aligned oppositely with one another. If I were smarter, I would have marked the alignments in the models. You may wish to compensate for my error with a marker.

• Re-bar insertion:

  • Insert the re-bar before placing the label. Pounding the re-bar into the ground can mushroom the tip so it no longer fits the wedge.

  • If it’s hard to get in, vise-grip pliers can help, or just hold the assembly by the wedge and pound it on the floor. Make sure it’s not colliding with the screw first.