POLL: Mach3 Lathe and G70/G71/G72 roughing, facing, finishing

[DAlgie]

Ahh yes Mr Melee, you have fixed it again, thanks. As a side note, I haven't tried a boring cycle with M71, only difference would be a reversal of all it does in OD roughing, do you think it would work, or have you tried it to see? I should be able to try it tonight if I get back to it so if I do I'll let you know. Thanks,
     DaveA.

[DAlgie]

Well, the boring cycle with M71 doesen't work, it roughs from the outside as it does on an OD turning cycle. Now I know.

[DAlgie]

Thanks Mr Melee, I'll test it out tomorrow and give you feedback. Hope your window replacement went well.
DaveA.

[DAlgie]

The G77 works perfectly Mr Melee, thanks for doing that. In it's use, you have to be careful about retraction room when boring a hole with close clearances to start with in regards to the boring bar. Best method I think is to use the mach3 wizards and use the boring one; it's retraction is configurable. Then, when you have the bore close to your contour, go with the G77 for roughing and finishing out the profile.

[DAlgie]

I'd have to agree, that it is a pain to get an accurate size on the first try. Now, if you are using the same material, same distance from the chuck, etc, you can hit it very close first time, but, as you say, I like to get a diameter manually if I have to do it one time, and really don't want to scrap an expensive piece of material. However, seeing that my CNC lathe is my ONLY lathe, I have to try it, and sometimes make trial cuts on same size pieces of scrap, etc, just to really tune the tool. I always use the same depth of cut for the finish cut as well, this is important. Also, of extreme importance is a metal sensing proximity sensor for the home switch on the X axis, or your tool set sizes are never the same when you boot up each time. Z axis, doesen't matter much as you set your Z zero on the end of the material each time anyway.

I don't use this lathe for the sake of it, but instead find that I am able to machine exactly what I want, odd contours, impossible to machine parts on a manual lathe, etc, and can save a lot of weight on my parts and have constant wall thicknesses and correct stress loadings through complex contouring, now thanks to you it is possible!

Back to your idea of a M75. I guess that the M71 is fine for this use, so don't really see a need for it unless it was more efficent, then it might be nice to have.
   DaveA.

[DAlgie]

Mr Melee, I had an idea this morning. It might be impossible, but I have no idea so I thought I'd ask you about it. Would it be possible to put a parameter in your M71/77 macros that sets a "no go" line? For example, instead of the B parameter being for billet diameter, could it be the limit of travel for the toolpath? So, it would work as a dimension that when the macro came to that point it would call for a return to the start of the profile, but M71 would rapid the Z axis first. As you can imagine, this would make the macro very efficient without cutting air much, and would in effect make it a hybrid of the Fanuc G71 roughing and G73 reentrant programs. It would also deal with the issue I was talking about in regards to the M77 and boring bar clearance issue. Possible?
DaveA.