My first turners cube project

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skiprat

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I decided that I'd had enough practice on my metal lathe to attempt a turners cube. Supposedly, it's a right of passage challenge given to old school machinists to show they can set up and use a lathe properly. The end result can look pretty cool if done well. This is probably the most simple version and if you look on-line there are many seriously complex versions.

Anyway....I could have made a clamping fixture to hold it in my 3 jaw chuck, but decided to fit my 4 jaw self centering chuck. Unfortunately it was about 0.5mm out of true, so I had to endure the pucker factor of taking my machine up to warp factor 6 and grind the jaw faces with my dremel. I'm pleased to say it is now about only 0.03mm out at about 150mm from the chuck. :biggrin:
I simply marked each face with a black marker and took dozens and dozens of extremely light passes till they were all clean of the marker.:wink:

The cube is about 35mm square which I hacksawed from a big chunk. It was squared and bored completely on the lathe.
I think this may be my new Posh Pen Pic Prop....:biggrin:

A great fun little project !! Has anyone else with a metal lathe had a go making one yet?

I don't have DRO on any part of my lathe ( except revs ) so I had to fully trust in the dials. :eek: A great exercise. :biggrin:
 

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Curly

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Nice work. I think I'll be putting one of those way down at the end of the list of things to make. :smile:

How did you preload the jaws to grind them? It's my understanding that one is supposed to clamp the jaws on a ring or holder of some kind when grinding a chuck so they are centred when in normal use. Simplest one I've seen posted is a length of tube/pipe with a slot for each jaw to seat milled in it. The slot is wide enough to let the jaw protrude enough to be touched with the grinder.

Chuck Jaw Truing Fixture

http://cvbt-web.org/uploads/Equip/AtlasLathe/chuck truing scan.pdf
 

skiprat

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Pete, I also knew about preloading the jaws, but I decided not to.
I stripped the chuck down and thoroughly cleaned it of all grease ang muck. Then I set the lathe at full tilt..2400rpm. I figured the centrifugal force would spread the jaws almost as good as preloading them.

I couldn't get my head around that preloading with a ring, would still leave a jaw not as tight as the other three. But the result is good and I'm happy:biggrin:
 

skiprat

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Go for it Mark. :biggrin:

If anyone wants to see one being made then check out my favourite Russian basement machinist on YouTube. BrunS. He did a great video.
I think his videos are all great. Watch his buddy steal his stuff while he made him a really cool tobacco pipe. Or his wife that treats him worse than we treat Chuck...:biggrin:
 

Terredax

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I've seen a couple of variations for the machinist cube and I've considered making an attempt. I wasn't going to use metal though. It's on my list to try someday.
 

RegisG

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Nice work, especially without DRO help. You have great patience.

I just put my 4 jaw on for the 1st time Friday to round the ends of some square rod. Swapped from my 3 jaw to 4 jaw and was happy to keep my fingers. But, it will be more hazardous pulling that 4 jaw off...LOL.

Regis
 

Curly

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Put a 1' or 2' dowel or pipe in the chuck and beyond into the spindle and tighten the jaws on to it. When you loosen the chuck it won't drop to the bed and you can be ready to remove it with out straining. As you slide it away from the headstock you can get your left hand behind the chuck. Goes back on in the same way.
 

skiprat

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Make a wooden cradle for yor heavy chucks. Another Youtube channel I follow is Texan Joe Pieczynski. In one of his videos he showed a simple but clever wooden cradle. :wink:
 

More4dan

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Having just purchased a 4 jaw chuck, It looks like pens are getting set aside for a bit to give this a go.

Very cool! I like that you didn't separate the cubes by undercutting.

I'm thinking of a version with the first shape a cylinder with the cubes nested inside. I may even try to make the hole in the last cube a receptacle to use as a desk pen stand. Time to make some chips!
 
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