Machinist Puzzles?

Home Model Engine Machinist Forum

Help Support Home Model Engine Machinist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Powder keg

Well-Known Member
Joined
Oct 10, 2007
Messages
1,091
Reaction score
3
I started getting a new Mag called The Digital Machinist. It caters to home shop CNC users. I don't have a CNC at home yet, but they just got one at work that I'm learning how to run. I thought the practice would do me good.

Anyway, in one of the issues there is a cube with 4 cubes machined inside it. I'm going to attempt to make one. Does anyone have any pictures of similar items? They were used in days past to test or show off ones skills. Here is another example that A guy I went to school with made.

knight02.jpg


Knight01.jpg



Later, Wes
 
Hi Wes,
In the mid 80's I did a specialist course in precision machining and one of the tasks was to make the cube within a cube on the miller. It is too far back to remember the whole procedure, but basically you started with a round billet of ali, which you milled into a precision cube, then it was boring four different sized holes on each of the faces of the cube, you machined into five of the faces to release five of the sides of each cube, then on the final face you released each in turn starting with the smallest. The very hard part was deburring it afterwards. We actually surprised the instructors when two of us did the same thing on the lathe, as it is inherently more difficult on a lathe because it was all four jaw work, whereas on the miller, once you had your backstop and fixed jaw in position it was just a matter of flipping the faces round.
The main problem was that we weren't allowed to keep them as they were classed as test pieces for the exam, but I am sure the instructors had a sideline going to sell them.


John
 
Searching on 'Turner's Cube' on Google and the other forums will find more info as well.
 
To bad you didn't get to keep it John. Thats one of the hard parts about being a machinist "for me" Is giving up some of the stuff I make. I'll post pictures of my success or failure. I have the metal and am milling the sides down to dimension now.
 
I was once challenged by a friend to make 5 spheres inside a billiard(or pool!) ball, it took about a month thinking about it but managed to do it in the end, on the wood lathe in a four jaw ,it's quite simple really, cross drilling 3 holes and using a left-handed hook tool going in through the holes one by one, I have it somewhere, when I manage to find it I'll post a pic!. I guess the cubes could be done in more or less the same way ,but as John says the de-burring and cleaning up the inside corners is the tricky bit!....Giles
 
Cubes/balls within balls etc, you did mechanically what the Chinese did by hand in Ivory hundreds of years ago, i'm amazed at your, and their ingenuity and patience!
 
I want to see some mathematically inclined machinist do a nested set of the Platonic solids on the lathe.
 
Made some progress:O) The mill at work has been broken for the last couple weeks. But it has been fixed. I started buy squaring up the 2" aluminum shaft and drilling 3/8" holes clear through all sides. Then I loaded the program into the CNC mill at work. It took me a couple hours to get the bugs worked out. Mainly stupid mistakes on my part. But here is where I am. I have the 4 pockets finished on all six sides. Not much aluminum left?
MachinistPuzzle001.jpg


Next I have to deburr the blocks and mill away the corners using a 45 degree cutter.

Wes
 
Powder keg said:
Made some progress:O) The mill at work has been broken for the last couple weeks. But it has been fixed. I started buy squaring up the 2" aluminum shaft and drilling 3/8" holes clear through all sides. Then I loaded the program into the CNC mill at work. It took me a couple hours to get the bugs worked out. Mainly stupid mistakes on my part. But here is where I am. I have the 4 pockets finished on all six sides. Not much aluminum left?
MachinistPuzzle001.jpg


Next I have to deburr the blocks and mill away the corners using a 45 degree cutter.

Wes

What I like about that is I am a lathe man, If I could get away with never milling anyting I would.

My whole machinist careerer I was running 1-5 HP milling machines and 7-50 HP lathes so the lathe was always the machine to do the job the big high speed rip and dig operation in my eyes.

The lathe is #1 to me. Anyone a mill man and dont care fo lathe work?
 
I prefer the mill. The first time I saw one of these cubes, it was referred to as a "turners cube" I was thinking "that would be easy on a mill". I lost interest in making one till I read the article in The Digital Machinist. I'll try to get these done by the end of the week. I'm making 5. I have 5 min. per side into them now. Probably there will be 3-4 more min. Then comes the fun part. De Burring....
 
tattoomike68 said:
What I like about that is I am a lathe man, If I could get away with never milling anyting I would.

My whole machinist careerer I was running 1-5 HP milling machines and 7-50 HP lathes so the lathe was always the machine to do the job the big high speed rip and dig operation in my eyes.

The lathe is #1 to me. Anyone a mill man and dont care fo lathe work?

I have to say that I am more comfortable on the mill than on the lathe, but that is not to say that I dislike using the lathe. For me, it is the level of experience that gives me the comfort factor one over the other. I have more time cranking the handles on the milling machine than I do on the lathe.

The turner's cube project is very interesting. I was going to do one about a year or so ago, but another project interfered and I never made it back to it. That might be a great "quickie" project one of these days!
 
Everyone at work thought I was making Christmas ornaments? I don't know how many people I had to tell they weren't done yet:O) These are all being done on the mill. I'll try and get a video of the next operation.

Wes
 
PK,
Lovely bit of work, but as you most probably know by now, the deburring usually takes longer than the making.
I used a ground up hacksaw blade in mine to gently 'scribe' through the corners ( the smallest one first by the way, otherwise you are in trouble).

John
 
Well, Here it is:O) I'm going to throw it into my polisher for a week or so to see how it looks then.
MachinistPuzzle.jpg

This was a fun project. I have a couple knife projects planned for my CNC future. I'll share them here to if any are interested.
 
Back
Top