I moved to a new office at work where the dry erase board has no tray to hold the markers. I want to make a holder that is held on to the board with a magnet. The first design took about 20 minutes. It had a singlemagnet in the center of the holder. Printing took an hour, and upon testing it on the fridge in my apartment, I found that the magnet is not quite strong enough to hold two markers. Also, with the magnet in the center, the marker has to be perfectly centered or else the holder tips to the heavy side. I could use a command strip instead of a magnet, but I want the ability to move the holder around on the board if I need to, so magnets are a must. To fix the stability issue, I doubled the width of the holder, added another magnet recess, and moved the magnet recesses out toward the ends of the holder.
Using the original design, it took an hour to print two units. The modified design took an hour and 20 minutes to print a single unit. I saved some time by printing on two printers at the same time. I printed the blue one on the Airwolf3d v5.5 and, the red one on my modified Prusa i3. They finished within minutes of each other, and both work very nicely. With the two holders, I have the capacity to hold 4 markers on the board. The design file is available on Thingiverse.com as thing 675232. The design file is also available at redpah.com product 1318.
This original design was not stable. The markers had to be carefully placed in the center of the holder
Very stable dry erase marker holder #Abstract2Actual: 3:40