This is a fun littel print project to create your own castle dice roller. The nice part is, after you are done gaming it collapses down into a small box, full contained, holding your dice, if you want. When gaming, you drop the dice in the top of the tower and they tumble down the inside, bouncing off three paddles and then shoot out into the tray. This tray contains the dice so that they don't roll into your game pieces. You can drop any number of dice down the tower at once, typically 1 to 15 or so. You may use dice up to the size of a typical D20. The dice roller is about 3.8wide 5.9 long x 4.5tall (when open) and 2 tall (when closed).
When closed, it makes a completely sealed box. You can store up to about 20 dice inside by closing the tower and then dropping the dice into the tower top. Once your dice are in, remove the Slide Tray and rotate it on the long axis 180 degrees and re-insert it onto the roller tray (now upside down) onto the rails. Will will just clear the closed tower. You can then seal the box with the Rear Door. To open the dice roller, pull the Rear Door up out of the slot, set aside, pull the slider tray off the Roll Tray, rotate the Slider Tray again and insert it onto the Roller Tray. Lift the castle up and re-insert the Rear Door to hold it in place at the back. Now you are good to go.
Initial assembly is as follows. I printed the slider tray with the merlons facing up. Print the roll tray on short end, with the open end up. Print the tower in the normal up orientation for a tower. Once you print all the parts, take the three Dice Paddles and insert them into the slots inside the tower, with the largest paddle in the bottom slot, and the other two into the slots they fit into easiest. Push the tower down the side or the Roller Tray until the two dimples drop into the round dimple holders in the Roller Tray. Insert the two Guard Towers onto the hex blocks on the Roller Tray (each one fits properly onto only one side, so just try them and if they drop on, that's the correct Guard Tower for that hex block. I'd glue them in if I were you, they don't need to be removed to close the entire dice roller up. Insert the Rear Door into the slots included on the Slider Tray. You're all done.
I printed the example on a 100 micron accuracy printer (Markforged)