mastercam vs Unigraphics with inconel

[Bill Z]

which CAM system process better tool paths for machining inconel? Anyone have experience machining large inconel parts with both systems?

[Guest]

The one that has the best mouse jockey.

 

They will BOTH give you good path if you know what you're doing.

 

That's really an open ended question.

[Bill Z]

sorry. It's open ended cause I don't know what I'm doing...

I've never machined inconel before. This is for on a large VBM machine. I'm being told that you can't just program straight roughing cuts. For example you have to ramp the tool so that the depth of cut varies so you don't get notching on the insert. Also it is important to lead in to the part a certain way.

[Nick Eaton]

Depth of cut notching can be a problem in difficult to machine heat resistant materials such as Titanium and Inconel.

I have used ramping to control notching mainly in Titanium. Inconel is an even "tougher" material than Ti and is more abrasive due to high nickel content and so will resist ramping even more.

Inserts are not sharp and have rounded "nose" and ramping is kind of like a conventional cut.

The best analogy I have heard is that it is like trying to pierce the surface of the material with a ball bearing at an angle, the cutting edge is always trying to "push off" the surface.

This is why you must climb cut with inserts in these materials. I have conventional cut with solid carbide but its usually fairly ugly and I only do it when I am forced. HSS cutter are OK because they are ground sharper.

I would set up the job normally and see if depth of cut notching is a problem before doing something about it.

There is no Mastercam toolpath that I am aware of that automatically gives you the kind of ramping you need, you really want to ramp up and down so you are moving the cut line back and forth over a range of cut depth. You would have to create geometry to drive the cutter. Don't know about UG. I used to do mine in APT, which was fairly straight forward.....for APT!!

The size of your part (larger parts are easier to use ramping), horsepower of the machine (the higher the better), rigidity of the overall system (remember the cutter is trying to "push off" and not take a chip) and the type of cutter (free cutting tools such as 45 degree facemills are preferable) you use will all impact your ability to use ramping to reduce notching....and you will never illiminate it.

Not a material for the feint hearted. You can't just stop in a cut as with Al. So do your homework , can't stress this enough....maybe some test cutting if you have never machined Inconel before, and try and find someone who has done something similar with a similar machine/setup to get you in the "ballpark".

Your optimal parameter range will probably only be +/- a couple of percent.

Good luck

Nick

[GoetzInd]

quote:

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There is no Mastercam toolpath that I am aware of that automatically gives you the kind of ramping you need, you really want to ramp up and down so you are moving the cut line back and forth over a range of cut depth.

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Contour oscillate toolpath should do the trick.

 

Mike

[Bill Z]

are you talking about a mill toolpath? What about a lathe toolpath where you start at .1 depth of cut and end at 0. Then the next path is straight across. and you keep doing that til the part is roughed.

[GoetzInd]

Yes I am talking about a mill toolpath. Do a regular contour and under contour type, select ocillate.

 

Mike

[RandleXX]

Ocillate is nice, but it doesnt let you use depth cuts.

 

Variable depth cuts would be a nice feature in MC, right now I have to use multiple ops to get different depth cuts. NX lets you do it all within one operation.

[Nick Eaton]

Forgot about that new oscillating option...Thanks Mike!!

You only need about .005 - .02 ramp per foot of material.

I have only done this on a mill, but I would imagine the same theory applies on a lathe.

If you don't have much straight line ramping distance you will probably be better off just varying your cut depth.

Nick

[Matthew Hajicek - Singularity]

You can also use ramp-contour, and as stated before you can do a 3D contour off of manually generated geometry if you really want full control.