Fanuc OT-C and G71 Cycle

[rrbmachining]

I have a Colchester Tornado lathe with OT-C control. I need to produce some ball ends for a customer and the book says that you should not programme re-entrant shapes, only continuously ascending contours are allowed. Does anyone know of a way to overcome this ?

Richard
RRb Machining Services
Southend on Sea
United Kingdom

[timlkallam]

I have Colchester Storm lathe with a 21T control and my g71 cycle is the same as yours asending or desending contors only.

If you post a print , type of inserts your using type of tool holders your using and materal.
I would be happy to write you a program for you.

[rrbmachining]

can you let me have your email address

[gbowne1]

I have a machine with a 0T-C and would love to see a sample contouring (either ASCD or DEC program).

[sinha_nsit]

Can use G71 type II, which allows both increasing and diameters on the profile.

But, you have to take care of interference between the tool and the part. In some cases, you would need to use two different tools: one right-hand and the other left-hand, and two different G71 would need to be programmed.

[gbowne1]

I use a L and R hand diamond shaped insert on a part program that is part of a valve assembly.

So the G71 could be more effective on the program.

Greg

[rrbmachining]

I dont think this version of control will support G71 type 2

[sinha_nsit]

If two tools are being used, there is no need for G71 type II.
Machine from right-to-left upto the topmost point, and then use the other tool to machine from left-to-right upto the topmost point. The X-offset for both the tools must be accurate; otherwise a kink would be observed at the topmost point. Add a small linear segment (1-2 mm), parallel to Z-axis, at the end of the profile (at topmost point).