Print PDF
Favorite
Email
Do you want an ice ball maker like those sold online, but don't have $800+ to spend? Then make your own!
Don't know what an ice ball maker is, or how it works? Then check out the last page of this Instructable for a video of it in action.
You'll need access to a machine shop, and specifically a CNC machine. TechShop provides all the equipment you need for a monthy fee. I made it at TechShop, and you can too.
Ice ball makers work by melting a large block of ice into the proper shape. It accomplishes this by having two large blocks of aluminum (aluminum has high heat conductivity and capacity), each with a hemisphere carved into a side, slide together to form a single continuous chamber on the inside. What's left is a perfect sphere.
Don't know what an ice ball maker is, or how it works? Then check out the last page of this Instructable for a video of it in action.
You'll need access to a machine shop, and specifically a CNC machine. TechShop provides all the equipment you need for a monthy fee. I made it at TechShop, and you can too.
Ice ball makers work by melting a large block of ice into the proper shape. It accomplishes this by having two large blocks of aluminum (aluminum has high heat conductivity and capacity), each with a hemisphere carved into a side, slide together to form a single continuous chamber on the inside. What's left is a perfect sphere.
Remove these ads by
Signing UpStep 1Materials and Equipment
The basic material is two large blocks of aluminum. You'll need to pick a size based on the size of the ice ball you want.
You'll need blocks that are in total at least 10 times the volume of your sphere. This is so the aluminum properly melts away the rest of the block. My ice ball maker produces 70 mm diameter ice balls, and the aluminum blocks are each 125x125x75 mm. That's a 13-to-1 ratio, and works pretty well.
You'll also need stainless steel rod. These serve as the bottom vertical guide shafts. I used 3/8" SS rod.
Last, you'll need plastic rod of a larger diameter. This piece slides over the stainless steel rod. I used 3/4" teflon rod, but teflon turns out to be hard to machine. I hear that Delrin machines well.
The only extra material is whatever you think will make the final product easy to use. I added rubber feet and a cabinet knob for lifting the top.
For equipment, you'll need a CNC mill and a lathe, and basic tooling. The inner hemispheres will be cut with a ball end mill, and you'll want as large a diameter here as possible. I used a 1" ball end, but smaller diameters will work as well. You'll also need a tap and die set.
You'll need blocks that are in total at least 10 times the volume of your sphere. This is so the aluminum properly melts away the rest of the block. My ice ball maker produces 70 mm diameter ice balls, and the aluminum blocks are each 125x125x75 mm. That's a 13-to-1 ratio, and works pretty well.
You'll also need stainless steel rod. These serve as the bottom vertical guide shafts. I used 3/8" SS rod.
Last, you'll need plastic rod of a larger diameter. This piece slides over the stainless steel rod. I used 3/4" teflon rod, but teflon turns out to be hard to machine. I hear that Delrin machines well.
The only extra material is whatever you think will make the final product easy to use. I added rubber feet and a cabinet knob for lifting the top.
For equipment, you'll need a CNC mill and a lathe, and basic tooling. The inner hemispheres will be cut with a ball end mill, and you'll want as large a diameter here as possible. I used a 1" ball end, but smaller diameters will work as well. You'll also need a tap and die set.
| « Previous Step | Download PDFView All Steps | Next Step » |
If I make another I may try out using round stock. It's actually pretty hard to make a perfectly square block, even on a good mill!
Thanks for the support!
I managed to do the first 4 sides without much trouble but the final 2 sides were more difficult. I ended up fiddling around with an L-block (is there some better name for that?) to get a side perpendicular to both axes, but I'm sure there's a better way.
One small problem is that the CNC machine is only available in 4-hour increments. Although with an optimized process I probably could have finished a full block in that time, with me learning as I went it took much longer than that. Given this, and the fact that I needed the blocks to be square in the end anyway, I decided to make that the first step in the process.
If I do it again, I'll probably look into doing the squaring, planing, hemisphere boring, and drilling all in one pass.
A doubt: the holes in the photo of step 5 seems out of phase. It is to say that joining the hemispheres, the holes don't match. Does you changed them?
Although I didn't incorporate the hole drilling into the program, I was able to use the Tormach for both the hole drilling and tapping. I did this separately from the hemisphere cutting, but that is not a big deal--the hemispheres could be a couple thous off and no one would notice. But each pair of holes did need to be the correct distance apart and so I did those in one step.
If I do make another, I'll see if I can incorporate the drilling into the program. I was using peck drilling since the holes were so deep and there was a lot of volume to remove, and it became quite tedious (and error-prone) after a while.
You're right that there isn't a huge amount of Z travel on the Tormach, but it was sufficient for my purposes, even with my 2" height gauge.
Thanks for the advice on the spotting drill. It seems that there is some debate as to whether center drills are appropriate for this application or not, but in any case spotting drills are a good choice here.
I saw the pieces simply rotating around a vertical axis, the holes do not match, but I realized now that as they are perfectly symmetrical, you also have to rotate them horizontally.
http://www.instructables.com/id/How-to-make-crystal-clear-blocks-of-ice/
I've since made a "quad" unit that can freeze 4 blocks at once, each the correct size for use with the ice ball maker.
just wondering cause it has a better heat conductivity than aluminum
I did make a nice copper cylinder on the lathe as part of a mini element collection. It's the prettiest element of the ones I have to far, and nice and dense too--although tungsten beats it there!
at least i think so.
That I did not know!
Anyway nice instructables man!
1 cent alternative: Fill balloon with water, freeze in bowl to retain a relatively spherical shape, remove balloon and form into a sphere by melting the outer layer and moulding with your hands in a bowl or bucket of water.
Plus these ice balls are primarily used for high end liquor, and I don't really want to use "balloon" ice in my scotch.
Check out spcutler's other instructable on how to make clear ice, although you can use a regular cooler in a pinch.
I have tried the molding technique but the results are inferior. The only way I've found to create clear ice is the way I described in my other instructable (linked on the last page). There is no way to use that method for an ice ball; the best you can do is a cylinder. And you'll never get close to a perfect sphere with your hands.
I won't claim that this device is practical for most people, but for anyone interested in CNC machining, I'll say that this is a fun project to start with and gives quite good looking results.
There are cheaper sources than OnlineMetals, but they are convenient, have an excellent selection, and haven't let me down yet.
Thanks.