Making a Carbon Fiber/Aluminium D3. (1st Part)

From time to time, I like to work out permutations of already made dice. One day, while working on D3, I wondered how would a hollow D3 look like, and to wich extent could it be hollowed.

After a par of trials, I made one with 0,25mm thick walls (on the sides), but it was clear that that die had no practical use, and in fact, on a mild accident, it got torn apart.

After a while, I revisited the idea, and remembered that there is something called “fiber sock”. You can find a lot of materials in that shape (fiberglass, kevlar, carbon fiber) and it’s nothing more than a flexible tube of interwoven fibers, that can adapt to various diameters through stretching or compressing it.

In a two part post, i’ll explain how a carbon/aluminium die is made. The first part will cover the making of the aluminium cage, and the second part, the carbon reinforcement.

1.- Make a nice D3 on the mill.

I already had this made some time ago, because it’s more profitable to make 3 of something, than 1. That way you only have to clean the machines once.

The only difference with a normal D3, is the more holes and that all are made with a square mill, not a round one.

2.- Up to the lathe.

Now, at the lathe, you start roughly hollowing the die with progressive bigger drill bits, from 4mm out to 10mm.

That will leave big marks on the inside of the die, but it’s not a problem, we will finish that lather. Now, the thinnest part of the die is almost 2mm thick. That means plenty of aluminium to withstand normal use, altough it will make a funny sound like a tin can, when thrown.

After the last drill (10mm) we proceed with the dangerous part of the operation.

Using a boring bar instead of a drill bit means that we can turn the piece a lot faster (2200rpm vs. 300) and also leave a better finish on the inside. At the tool limit of internal diameter cutting (note how little space is between the boring bar and the spinning metal), we proceed to increase internal diameter from 10mm to 11.5.

Also, we can remove very little material on each pass, avoiding stress on the increasingly thinner metal frame. That leaves us with the die reaching it’s wall thickness of 0,25mm. Now, it probably won’t stand normal storage with other dice, being crushed to death by randomness. ^^

The next process is a thorugh sanding of the internal, external and hole walls. leaving an exterior smooth finish and a coarse interior, perfect for resin adhesion.

(On the next chapter, carbon, resin and finishing of the die.