Approach feedrate 2

[kukelyk]

In the engage moves in Cavity mill, we use arc. There are parameters like arc radius, arc angle height, minimum clearance. We set the height 0, because the engage feedrate is 100% of Cut feedrate. When the feedrate is 21000mm/min, it would be great to define a lot smaller feedrate for this axial engage move. If I set the 'approach move feedrate' to ie. 2000mm/min, then the tool comes from the clearance plane verry slow.
Can we somehow implement it?

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kukelyk

 

[diamond3210]

Not sure if I'm understanding what you are after, but the axial engage move is the Approach, we set the Approach to a feedrate near the rate that the machine rapids at, so that the program posts with a G1 and feedrate but still travels at a rapid feed, then the Engage is set to the same as the Cut feedrate, that way it travels fast to the cut plane then feeds into the part with the cut feedrate. If your path is showing the engage move starting as part of the Approach you can go into Non-Cutting Moves under the More tab and turn off the Collision Check toggle, that will get rid of the axial part of the engage.

 

[kukelyk]

Thank for your answer, now there is an attached image, where I try to show, what I need.
In the top of the image, there can be collision, the high engage feedrate in axial move can damage the tool in ie. an island contouring.
In the second case, the tool comes from the clearance very slow.
In the third case, what I would like to get, a high speed or rapid axial approach near the part, then a slow axial infeed move, then the normal to tool-axis arc with cutting feedrate.

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kukelyk

 

[diamond3210]

Okay try turning on the Collision Check toggle that I described in my previous post, that will give you the yellow engage color on the axial move like in your first picture, then set your Approach feed to zero which should cause it to be output as a rapid move, then set your engage to your desired cutting feed. Doing this should rapid down to the start of the yellow axial move then it will use the engage feed rate to finish the axial move then move into the cut.

 

[kukelyk]

Thanks for Your attention, but I show You an other sample:
Collision checking is on, approach is rapid, engage feedrate is equal to cutting feedrate (ie.8000mmpm)
When the tool engages outside the part, the engage move is a simple arc. Correct.

When the toll engages the finish pass, there are in the attached picture two different cases.
The first, when there is a rapid approach till the part face. I say nothing..
The second, when there is a small axial engage, but there it should be reach the surface much slower then the above engage feedrate (ie. 500mmpm).
I cannot separate them, thats my pain.

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kukelyk

 

[diamond3210]

One last thing, in Cutting Parameters, under the Connections tab is Feed on Short Moves toggled on, you can adjust the Max. Distance to try to get rid of those engages altogether so that it does the finish pass while it is already there instead of coming back to it. If this doesn't help then I think you are left with manually inputting the feedrate that you want when you post the code.

 

[capnhook]

JEEBUS!! All this dicking around to get cavity mill to operate PROPERLY, like just about every other CAM milling product on the market does.

It is 2013..........I expect more out of NX than what it is giving me.


Thanks for your hard work. diamond3210 and kukelyk, but this is getting ridiculous.

Proud Member of the Reality-Based Community..

[green]To the Toolmaker, your nice little cartoon drawing of your glass looks cool, but your solid model sucks. Do you want me to fix it, or are you going to take all week to get it back to me so I can get some work done?[/green]

 

[diamond3210]

I think I have found a way you can get what you want. After generating the path you can right-click the operation and under Tool Path choose Edit, then you can go thru and change anything you want line by line, just double-click on the line in the Name section that you want, in the Motion section you can change Feed Rate Type to Custom and change the feed rate line by line if you so choose. The only thing is if you regenerate the op. it will undo the edits, so make sure the path is good before editing.

 

[kukelyk]

I know this way, but my paths are so looong, there are so many engage moves, now I have to edit the 20 percent of my paths because the incorrect engage moves. It takes already too much time for me.

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kukelyk

 

[wmalan]

I do this all the time for getting long cutters into deep pockets safely. Use a couple goto points to get near the engage. You then set rapids or feeds to those prior to the engage. You can then set Clearance down in the pocket for multiple passes. Hopefully that makes sense.

Bill

 

[capnhook]

Hand-editing is the primary cause of machine crashes. There may be hundreds of lines of NC code to edit in a cavity mill operation.

Goto points and fake feeds are the only way to do what you need to do now.

We have neen kludging this weak cavity mill function for many YEARS......when is some maintenance $$ going to be put into fixing Cavity Mill?

Proud Member of the Reality-Based Community..

[green]To the Toolmaker, your nice little cartoon drawing of your glass looks cool, but your solid model sucks. Do you want me to fix it, or are you going to take all week to get it back to me so I can get some work done?[/green]

 

[wmalan]

Assigning a feed to a goto within the operation is by no means "fake". It remains intact when regenerated. Plus, if you create hard points to drive, the next programmer who looks at the file will see the logic.

Bill

 

[capnhook]

Well, oh now, I have been properly convinced........please don't change a thing to cavity mill.....sheesh, thanks...nothing to see here........move along

Proud Member of the Reality-Based Community..

[green]To the Toolmaker, your nice little cartoon drawing of your glass looks cool, but your solid model sucks. Do you want me to fix it, or are you going to take all week to get it back to me so I can get some work done?[/green]

 

[kukelyk]

Bill, could You please show a sample about goto points? I have never used it, and do not know how to use. Thanks in advance.

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kukelyk

 

[wmalan]

Within the operation under Machine Control are Start of Path and End of Path Event. Within there is Goto event. Select it and pick your point (I usually create some hard points first). You can then apply a feed to those points. You create them at the End of Path Event as well. I put one at the top, one near the Engage location, etc. You can then use the Clearance Plane down in the pocket with the Goto point up clear in the End of Path Event.

Btw, we are not allowed internet access from work (don't ask...) so I have to use my phone for this stuff during the day. Hard to show you examples Maybe attach a phone screen shot if you still need help.

Hope this helps.

Bill