Being the artistic type I am, I thought I could have a bash at making one - at least a prototype should I ever decide to make a more robust one in the future.
I had some balsa scraps and card stock to hand so got to it.
The principle of a dice tower is that inside it is a set of ramps to 'jiggle' the dice - and a ramp for them to roll out on (so they don't get stuck inside).
I started with a basic frame - three sheets of balsa attached to two bracing struts. Note that the ramps on one side need to be a bit narrower to fit between the two struts. This side we'll call the 'thinny'.
The other part of the tower is a chunkier piece (with a piece cut out of the bottom to allow the dice to exit) which fits between the two sheets and complete the box. We'll call this the 'thicky'
The inside with the 'thinny'.
The internal 'jigglers' and the exit ramp.
The jigglers need to be staggered so the dice tumble but still have room to fall and exit. I made these by cutting thick card to size. Each piece is roughly 10cm long - with 2cm each side to stick down and a triangle (6cm) bent in the middle. By using standard lengths it was easier to stagger to jigglers and to create roughly 90 degree angles on the triangles.
The 'thinny' side was trickier. I had to make a thin base with the jigglers and exit ramp on that would slide between the struts on the thinny side before being stuck down.
The 'thinny' side - the base made of thick lolly sticks to which the card triangles are attached.
I had some structural problems to overcome as I went. This included a small brace (see under the exit ramp in the picture above) to ensure the ramp could not bend under pressure. I also used bits of lolly stick to brace the card triangles to provide extra strength. I also stuck lolly sticks on the sides of the upright sheets to provide essentially a thin bracket for when the 'thicky' side was attached.
I then attached additional card (braced with matchsticks) to the triangles to ensure that there was an overhang, making sure the dice rolled from one jiggler to another (and so just didn't drop down to the exit ramp). This was important as this jiggling represents the shaking of dice - the whole point of the tower.
The triangles with additional card to create 'overhangs' and with matchstick braces.
Once all was in place the 'thicky' was attached to the upright sides and glued in place. I then moved onto the base. This is also balsa, with two more thick struts and another piece at the end (to stop the dice rolling off!). Once in place the tower was stuck in place - and a card top cut to shape with a hole to drop the dice in.
The finished article.
All that was needed to do now was test run it - to see if it did what it was supposed to do. I dropped 8 dice in, one at a time, with the '1' at the top of the dice (so if they all came out the same, then the jigglers would not be doing what they were supposed to be doing).
Dice test - randomness confirmed!
As you can see - a truly random result. Every number from 1-6 (5 excluded) in a fairly even distribution.
The second test was road testing a typical FOG scenario - loads of d6 chucked in to simulate combat.
Test 2 - satisfactory results
If you're aware of FOG you know that usually a 4,5 or 6 is required for a hit. The 16 dice here - 4 of each colour- delivered exactly 8 hits! So the 50% ratio expected was hit - exactly!
So there it is - a perfectly functioning dice tower for aout £2 in 'bits' and a couple of hours of time.
I'll aim to make a more robust one in the future - using wood, screws etc. It needs a bigger landing area as well. But for now, I'm very happy with my (albeit slightly flimsy) homemade dice tower.