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dave5605
01-07-2010, 04:46 PM
I call these pseudo cubes because they are still attached to each other and not loose.

I need more practice to try and do a loose one. Maybe in the next couple of months. Bought some Acetal/Delrin chunks on ebay to try.

I'm basically new to this metal working thing with about 20-30 hours mill time with a benchtop mill and probably 15 hours 'hacker' lathe time on a old Takisawa 14x40.

Anyway, cubes, 6061 aluminum
1/2", 3/4" and 1-1/4" I have made several of each. All but two have some kind of screwup (too deep, off center). Even with a DRO setup on the mill I can screw it up (not paying attention).

The two smaller ones made on the mill with a 5c square collet setup. The 1-1/4 one was on the lathe with a modified W&S (I think that is who made them) 3 piece collet really made for some kind of automated setup (got them real cheap on ebay).

Trying to keep track of the dang dials on the lathe is a challenge for this newbie. I did manage to set up a carriage stop for the depth but reading the dial wrong on it didn't help. :mad:

Formula for the bores is 85% of the length of a cube side for the bore diameter and 15% for the depth.

Doing the one on the lathe took probably 3+ hours. No I won't be hiring in to any commercial shops any time soon.:p

The ones on the mill were a lot simpler. Hardest part was getting the no name collet holder centered within a thou (or so). Once set up took about 45 minutes to make a 1/2" cube.

On the ones I did on the mill I just bought mills the right diameter (within reason) so basically it was a plunge to depth operation.

1/2" cube...
1st bore---.425 dia, .075 deep (used 11MM mill (.4331))
2nd bore---.298 dia., .053 deep (used 19/64 mill (.2969))
3rd bore---.208 dia., .037 deep (used 13/64 mill (..2031))
Final hole drilled with a #40 drill bit (had to center drill first though or the bit wandered).

3/4" cube used 7/32, 9/32 and 7/16 mills

Last thing was to buy a vibrating tumbler ($50) to tumble the cubes to try to shine them up. Worked well using walnut shells mixed with a little white polish powder. Tried red rouge powder too but the white seemed to work better. 72 hours of tumbling.

I'm going to make a set of dangling ear rings for my daughter out of the two 1/2" cubes I didn't screw up. When she saw the 1-1/4" cube (1st one I ever made) she said make her a set of ear rings except smaller. Until that moment I never thought of making one smaller than the 1-1/4" one.

Found out you can snap small drill bits (when drilling through previously drilled hole if the setup is off .010 because of bit wander (hence the center drilling step). :)

Oh yeah, did a 3/4" out of 303 SS too. Those EBAY metal guys must love me.
http://i180.photobucket.com/albums/x168/DJDphotos/IMG_1587a.jpg

deltaenterprizes
01-07-2010, 05:05 PM
Don't sell yourself short, those look great! Keep trying till you get it right, the more you practice the better you will get. I have been thinking about trying some of those myself.

Black_Moons
01-07-2010, 05:37 PM
Awsome results, and remember, even if its just pratice parts, your learning valueable skills of.. not messing up the dials :) And doing that on small parts made of cheap material will save highly valueable time and material later on :)

mototed
01-07-2010, 05:52 PM
Those look great. I've made one out of 1" steel, and the smallest cube fell out when I was touching up a burr with tiny file. Urghh.:mad: I still don't know how to cut them so the cubes don't fall out. The earring ones are pretty darn neat. Might have to steal that ideal for the wife or granddaughter.
Ted

jimsehr
01-07-2010, 06:09 PM
1 inch ball with ball inside.

bottom 1 inch cube with 7/8 ball inside with a second 5/8 ball inside that.
Jim





http://i86.photobucket.com/albums/k106/jims_03/IMG_0004-11.jpg

mototed
01-07-2010, 06:26 PM
So jimsehr. You won't give up any tips on how to make one! :) I know, my newbee self is going to have to waste a lot of valuable metal to learn.

jimsehr
01-07-2010, 07:53 PM
mototed
You can look at some of my pics on photobucket and see the fixture I made and used to hold the cube. And you can see how I hand ground the radius
tools out of HSS and hand lapped them . Then set the radius to the end of a piece of bar stock before using them inside the cube. I made the fixture so I 5c collet it then take fixture in and out of lathe so it repeats. Made lapping compound out of grinding dust from my carbide grinder mixed with oil.Email if you have any questions. Plus I have more pics of other stuff I have made like ball turner ect.


Jim

search photobucket for jims_03

KIMFAB
01-07-2010, 09:23 PM
Made a batch of these last year for Christmas. http://www.kimfab.com/pictures/turncube.jpg
Here is a good link on how to make them.http://www.cnccookbook.com/CCTurnersCube.html