Turning a Small Dia

[carryinwood]

Hi

How would you go about turning a small dia.  .125 X 1.25 long  I tried turning the whole length at .125 dia. and of course after a few passes in bent.  Is it possible to do it in steps?  Stock is starting at .5 dia.  

 

Thanks for any ideas.

[gcode]

Do your roughing passes at 45 degrees

 

[JParis]

Another thing to try is turn is back in steps....

Z0 - Z-,25

Z-.250 - Z-,50

Z-.50 - Z-,75

Z-.75 - Z-1,00

Z-1.00 - Z-1,25

A center can help but the pressure will have to be exceedingly light

[carryinwood]

Thanks..Ill give both a try

[Guest]

10 hours ago, carryinwood said:

Hi

How would you go about turning a small dia.  .125 X 1.25 long  I tried turning the whole length at .125 dia. and of course after a few passes in bent.  Is it possible to do it in steps?  Stock is starting at .5 dia.  

 

Thanks for any ideas.

Moving the cutter along the z axis in reverse in a "rake" motion should work . What insert type are you using? CNMG is not good for that situation.

Machining to final/near final dimension in .50 to .100 thou steps can also help. Since the stock deformation happens as you cut the shaft thinner amd thinner.

Do it in steps instead.

Posting a mastercam file is always a great help as well..

[crazy^millman]

Do in a Swiss and call it a day. Other choice is to make a false center stock to remove later. On other options is to buy the .125 drill rod already TGP of the Material you need and run it through a collet and then you can do your end work. 

[JoshC]

There is also a setting in the lathe rough toolpath called Section Turning that works great for long small dia parts. You can simply activate section turning, set it to a certain number of sections, and then instead of turning the entire dia. down it will turn the part down in sections to maintain rigidity. Its similar to how Swiss or screw machine parts get cut into sections to maintain rigidity. Works great from my experience

[heavychevy2155]

I used Section turning all the time, a great tool that is really flexible. You can also turn on semi finish and put stock to leave to 0.0 and add number of semi finish cuts to 2-3 and really dial stuff in. 

[ostie01]

Depend on what material, but you could try in one pass.

 

[Elmer Fudd]

23 hours ago, crazy^millman said:

Do in a Swiss and call it a day. Other choice is to make a false center stock to remove later. On other options is to buy the .125 drill rod already TGP of the Material you need and run it through a collet and then you can do your end work. 

Cause everybody has a Swiss laying around. I think I will call it a day.

[crazy^millman]

50 minutes ago, Elmer Fudd said:

Cause everybody has a Swiss laying around. I think I will call it a day.

Wow aren't we sensitive it was a joke.

[Elmer Fudd]

42 minutes ago, crazy^millman said:

Wow aren't we sensitive it was a joke.

I was joking also.

[carryinwood]

Thanks for Ideas Guys..Great Site ya Have,   I used the section Turning method..Turned .25 per section. up to 1.25 length i needed.  

Thanks Again!

[Jespertech]

Section turning is definitely the way to go here, its worked wonders for a bunch of jobs at my shop. It's also important to use the right tool, a neutral rake holder with a positive rake insert like a VCGX style made a huge difference for me. You can also create  geometry off the tool path in back plot and make modifications If you want to have more control over the overlap and lead in/ lead out of the tool. I had an issue with the tool leaving small ribs on a .078 dia mixer impeller so I added radiuses to the beginning of the overlap and it took care of that. Best of luck