Tailstock Haas Sl-30

[dlall]

Hi there,

I have a problem whereby I'm trying to turn the OD from 28mm to 10mm on a part 180mm long.

The problem I am having is that during each depth of cut, e.g. when the tool has finished moving 180mm in length, you can see a step type pattern on the face at the end which means that the 180mm cut is not consistent during each roughing pass.

I created a stop so that the stock material jams securely in the chuck, so I am sure its not moving on that end.

The only other thing that I could think of is the centre in the tailstock.
Which gets slack after machining the first pass.

Are there any special types of centres I'm supposed to use for CNC turning, right now I'm using a brand new revolving centre ?

Your help will be greatly appreciated.

[Donkey Hotey]

Something else sounds wrong. The tailstock is hydraulically clamped, isn't it? The pressure should take up any slack during the machining.

Is this the first time you've used this machine or is this a new problem to a machine you've run for many hours?

[dlall]

Thanks for your reply Donkey Hotey,

Its the first time I'm using the tailstock and after doing some more research after submitting my post I realised I was using the tailstock wrongly.

I was manually advancing the tailstock until it came into contact with the job then starting my program. I didn't know that this doesn't apply a pressure to the job and the tailstock can still 'creep'

This link spells out my problem exactly together with the solution:

http://www.haascnc.com/cncmag/articl...&ArticleID=440