First Cuts, Not Bad But Not Great.......

Crow Horse

Crow Horse

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I finally got everything together to take a shot at doing some practice turning. I knew from the get go that there will be a learning curve as with any skill.

I had difficulty to get the 1" 6061 to run true in the jaws. I did disassemble the jaw to verify that I had put it together correctly. One caveat is that the jaw I have doesn't have an ABC, only a "dot". I assumed that this is the starting point and worked from there. The jaws all meet when closed so I'll assume that isn't an issue.

I took quite a few conservative passes and the aluminum peeled off in long strands. Speed without a tach is guesswork at this point and I probably had it spinning slower than what it should spin. I used WD40 as a coolant and will look to different products if that is required.

I tried and failed at using the rear mount parting tool. I slowed the speed and fed very slowly but it jammed several times. Not wanting to do any damage or cause injury I stopped. Back to the books to see where I went wrong.

The pic makes it look worse than it is but the finish is far from what I think it should be. Any input will be appreciated.IMG_4417.JPG
 
That doesn't look bad- your tool bit is probably responsible for the roughness
Remember you can only hang workpieces out so far without support- about 3 or 4 times the diameter in your case
Parting tools are a study in themselves. They need to be sharp and on center, and tucked in close to the chuck
Some lathes hate parting, some are a dream.
-Mark
 
For turning something sticking out that far, you will need to use your tailstock to maintain rigidity. Reduce stick out by about 1/2 of what you have there and you won't need the tailstock.
For parting, make sure that only the leading edge is contacting your workpiece, all other surfaces should have relief. A slightly angled cutting edge can be helpful, and it will usually leave the nub on the stock and not the part. Most importantly the parting tool needs to be almost perfectly on center.
Sometimes your round stock isn't perfectly round. You could chase it all day and never get it perfect.
 
rounded or radius tipped tooling produce the best surfaces finishes
aluminum can be turned at high speeds with generous DOC's.
tools with high relief angles can be used to great benefit

don't be too worried about dialing in a workpiece in a 3 jaw chuck, as soon as you take a cut,
the turned section will be true to the axis of the lathe
 
Parting a piece with a hole in the middle is much less problematic.
 
You do not say anything about what sort of cutting tool that you used.
 
Good point. I was using the Sherline 1/4" cutting tools. In the future when budget allows I'll be ordering a set from Z2V.
 
What ulmadoc said above is the gospel for aluminum, lots of side rake sharp cutting edges and a radius nose is the order of the day, whether carbide or HSS.
 
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