2D Contour Heights - Replacing Plunge Moves with Z Rapid

[jonathanBUCVS]

I am trying to come up with a good default method to reduce plunge moves in mill programs. I would much rather change those moves to Z rapids, as when I am first setting up and proving a program, I can turn down the rapids, but I rarely turn down the feedrate, so lines of code to bring an profile finishing endmill below the top surface of a part like this are quite unwanted, and in my case, much less safe than a rapid move:

G0 Z0

G1 Z-1. F600.

I never use the plunge feedrate for plunging into the work (always predrill, ramp or helix). I could turn it down, but then I am wasting time when the job is setup and running at 100% rapids.

I tried playing around with the heights planes. I could set the TOP and FEED heights equal to the BOTTOM height, and set the SAFE DISTANCE to 0 so there are no warnings on the toolpath. For the example pictured here, it would work, would that be safe practice overall? I am not too familiar with the SAFE DISTANCE feature.

What is your default method?

[daniel_lyall]

For me, it depends on how much is being removed during the facing op and first roughing toolpath its always stock top model bottom for a start then if a lot has been removed and it will not crash I change the top height to the model top and/or add an -offset and all other hights other than clearances are a mm above the top hight with the safe hight as 1.

[jonathanBUCVS]

So you do have a plunge move in Z (off the stock)? Or did I misunderstand the order of the height planes. 

[DarthBane55 · Accepted solution]

You can set the feed height to "disabled".  Then set the safe distance to zero (but this gives a warning). If you don't wat the warning, set the safe distance to 0.005" or something small, it wont cost any time.

[jonathanBUCVS]

I didnt even notice that in the dropdown! I think that should work. Thanks! 

There is still no way to set defaults for the height plane dropdown selections, right? I can only right click on the numerical values. 

Is the Safe Distance just for the distance of the lead-in in Z? 

[DarthBane55]

For the default of the dropdowns, I think if you right click in a field and set "make all defaults" it keeps the dropdown option too... not 100% sure tho, but 90% sure lol.  Mine is always by default set to disabled, and for example retract height is set to "model top"... actually ya, 100% sure now, I changed all these and they are default now.  Just make sure you choose "make all default", so set all of the fields of that tab to what you like the most often, then set it.

The safe distance is a little feed move before the lead-in, and that move is done with the normal feed rate, not the plunge feed rate, keep that in mind. I wish it was the plunge feed rate, but in some operations, it adds a distance in X-Y too I noticed, if you are too close.  Can't remember in which operations it does that tho.

[jonathanBUCVS]

I dont have "Make All Default" in my right click menu.  I have Save as User Default (just for the one numerical value), Reset to User Default, Reset to Sys Default, Edit Expression, Copy Parameter Name. It saves the numerical value, but not the dropdown selection. I feel like I am missing something obvious.

Gotcha on the Safe Distance. That makes sense. 

[DarthBane55]

Dang, you are right, they changed this!  There use to be a "make all default" before, but it is gone!!  That sucks!  Then I don't know how to save the dropdown anymore, if you say the "save as user default" doesn't save the dropdown, that is a bad "upgrade"!

[daniel_lyall]

Save as User Default is the new name it is what you want.

@jonathanBUCVS I don't plunge as the tool is just above the part inside the stock, what I was cutting the tool was moving above the model's surfaces what was below the top of the stock by 4mm then later on it was closer to 6mm below the stock surfaces, I can do this quite safely by making sure the Faces and first rough use tool outside boundary then the next one has tool center on boundry then tool inside boundary if it is going to be finished by a small tool otherwise it is center on boundary then inside boundary this allows me to keep the tool below the stock surfaces as I know there is room for it and all toolpaths are inside the toolpath other than the first two.

The white line is the top of the stock as you can see there is only one move above the stock what is the clearences hight, it saved just over 30 mins doing this on the toolpath above.

[jonathanBUCVS]

@daniel_lyallUnfortunately, Save as User Default does not safe the dropdown choices for me, only the numerical values.

Wow, a 30min savings is pretty good!