TIW Machined Die

In this instructable, you will make your very own machined aluminum die! We will be using the manual mill to do this. If you are making this project at Texas Inventionworks (TIW), all materials can be found in the machine shop. If you're interested in following this instructable but don't attend UT Austin, no worries! All supplies are listed in the following section.

Manual JET Mill w/ DRO

1. Edge Finder
2. Collet Set
3. Parallels

Drills

1. Standard set of drill bits

Other

1. Aluminum rectangular/cubic stock
2. Level
3. Calipers

You will need approximately a 1" thick and wide aluminum stock. If completing this instructable at TIW, ask if you can use some stock in the machine shop. Otherwise, order some from onlinemetals.com.

The first step is to size the aluminum stock to the size of the die you want. To do this start off by measuring each of the edges of the stock and calculate how much you need to take off. For example: if I had a perfect 1" stock all around and I want my die to be 0.75" on each side, I need to take off 0.25" from each phase. Since we need to smoothen out all of the sides, I will take off half of 0.25 from each side. Therefore, from each surface I will take off 0.125".

Next, calculate the number of passess needed on the mill to take off 0.125" from each surface. At TIW, we reccommend never taking off more than 0.015" at a time. Hence, it will take a little over 8 passes. On the first go at the mill, only do half of this (4 passes) and then remeasure the die for the remaining half.

Now that we have everything measured, we will align the stock in the mill using parallels. To get the smoothest finish, we will only be using end-mills on the side edge of the stock and not on the top.

Place the stock on top of the parallels in the vice and make sure there is enough overhang off the side for the end mill to take some material off. Once it is placed on the vice, use the mallot to hammer the stock in the place. Use a level at the end to make sure the top surface is fully flat and parallel. If it is not level, use the mallot to adjust the positioning of the stock.

We will be using the 1/2" end mill to smoothen out the stock. Using the 1/2" collet, put the end mill into the mill. Align the teeth of the end mill with the side surface of the die and make sure it covers the whole surface. Turn on the mill at 1200 rpm. To zero the part, make a small touch off on the surface of the end mill and click the 'zero' button on the DRO. Move the part out of the way in the y-direction (in front of the end mill) and adjust the endmill to where the DRO shows -0.015 in the x direction. Slowly start maually, or using the autofeed to speed 0.7, move the part backwards.

Do this 4 times on one surface and then reposition the part to a new surface and repeat the steps till you do it all around the cube.

Now that you are halfway done with prepping the body of the dice, its time to recalculate all the measurements to make sure you took off an appropriate amount of material. Start by measuring each surface of the cube. They should all be exactly equal. If one or more surfaces is larger than the average, make a seperate calculation of how much material to take off to make it even across all 6 surfaces. Ideally, every surface should be around 0.94". Since the remaining 0.065" cannot be taken off in 0.015 increments, this will require 4 passes taking off 0.015" and 1 pass taking off 0.005". Repeat the process from step 2 to finish prepping the whole body of the dice.

Now that the entire body of the dice is prepped and smoothed out, we can move on chamfering the dice. To do this, you will need a v-block and a cyclinderlical shaped stock. Place the dice on an edge in the v-block and use the cyliner to make sure it its in place in the vice (use the image above as reference). For chamfering we will be using 1 3/16 inch end-mill at 1800 rpm. We will be doing 2 passes for each edge so start with the dice in front of the mill for the first pass. Repeat for each of the edges.

For the last and final step we will add the holes to our die for each of the numbers. Using calipers, a scribe and a center punch, measure each surface for the appropriate number and center punch the placement for each dot. Use a sharpie to mark it to make it more visibe. Using a 0.078 inch drill bit, slowly drill a little bit into the material, just enough to make a visible dot in the surface. Repeat for each surface. Thats it, now your machined dice is completely done!