Ice Ball Press

[rwm]

OK. I am going to try to make an ice ball press. It has been done here with CNC.
I first needed to make a concave radius tool to machine a concave hemisphere into the stock. I can't use my regular radius turner because it need to be cantilevered to avoid contact with the stock.
Here is what I came up with:










As you can see, it works on smaller stock. I have to admit I was a little unclear on how to do the bearing. I have a large bearing face with the tool carrier disc resting on the cantilever. I used a 1/2" center hole with a brass bushing threaded 1/4 x 20 in the center. A 1/4 x 20 screw goes in from the bottom and nylock nut and washer hold the tool carrier down. There is a small amount of slop. Any better ideas?
The arm is a little flimsy and I may need to upgrade to 3/8".
More details when I get in some 4" round stock. The hemisphere will be just about 2.25"
R

 

[derf]

The first thing that struck me......I would cut worm gear teeth on the o.d. of your tool holder disc and add a screw and crank. By eliminating the handle, you could add a disc support over the rear of the disc.

 

[rwm]

Ahhh. A mini rotary table per se. Interesting idea. May be overkill though.
R

 

[rwm]

 

[rwm]

I love it when a plan comes together.
Robert

 

[strantor]

That's awesome! I want to make one now. It's on the list.

 

[MozamPete]

I'd say that worked perfectly. Looks like a great surface finish too.

 

[rwm]

Thanks guys. Surface finish is good.


Next drilling long holes.....

R

 

[TOOLMASTER]

how about indexing them

 

[rwm]

All done except cleaning up a bit.
I drilled starter holes for the guides on a rotary table on the mill so they are dead on. I had to finish the 4" long holes with a hand drill but that worked great.




Very smooth action.





I will make a few with boiled water and see if I can get some perfectly round clear ones. This works very well. Makes an ice sphere in about 60 sec. Its amazing how fast it works. I used a pretty large mass of aluminum.
This one gets shipped out to a friend in Dallas but serial number 0002 is in process.
R