Feedrate reduction for last depth pass?

[Leon82]

I'm sure there is a post mod,  but is something like this in the works?

 

Pockets and contours. 

[jlw™]

Do these not work for you?

Contour:

Pocket:

Set it to machine finish passes at final depth only, override feed/speed on finish.

[jlw™]

Wait, nevermind.  It just clicked what you want.  Sorry, I got ahead of myself.

[Leon82]

12 minutes ago, jlw™ said:

Wait, nevermind.  It just clicked what you want.  Sorry, I got ahead of myself.

It's ok.thatsbworks for final finish, but I want to cut the whole floor slower

[Goldorak]

The option to control feed and RPM on the last cut are not available with dept cut, this is a big lack in mastercam 

What I usually do is use 3 different operations one to rough with a pocket toolpath (Opti-rough works like a charm in pockets) ,  finish floor with a pocket toolpath leaving a bit more stock than the rough on walls  then finish wall with a contour toolpath

[jlw™]

My "simple" pockets always have 3 ops as well.  One to rough.  One to finish the floor and one to finish the walls.  I generally use different tools for rough/finish too though so that accounts for 2 ops.

[Newbeeee™]

Have they added finished cut S+F for facemilling yet?

Rough fast - finish cut slow?

Simple things like this are so much more productive and nice to have options.

[BrianP.]

1 hour ago, Newbeeee™ said:

Have they added finished cut S+F for facemilling yet?

Rough fast - finish cut slow?

Simple things like this are so much more productive and nice to have options.

Nope. Such a simple thing yet after 35 years you still either have to manually change it after post or create a 2nd op.

[neurosis]

I was happy when they added zig/zag to  multi-passes.   

[Newbeeee™]

38 minutes ago, BrianP. said:

Nope. Such a simple thing yet after 35 years you still either have to manually change it after post or create a 2nd op.

To quote Foggy :-

"Low hangin fruit..."

 

 

[Colin Gilchrist]

13 hours ago, Leon82 said:

I'm sure there is a post mod,  but is something like this in the works?

 

Pockets and contours. 

The Post Mod is actually more complex than you would think. There isn't really a variable available to tell the Post "hey, this is the final floor cut". That's because there are many combinations of depth cuts, and multi-passes. In addition, there isn't a set "roughing step down value". There is a "maximum" step down value, and a "final step x # of steps".

So, Mastercam starts by calculating the total depth, based on the combination of "abs/Inc" settings in the Linking parameters. It looks at "depth vs. Top of Stock", and this is used to calculate the "total depth" of the Operation. Let's say for sake of argument that our TOS is 2.25" and our Depth is set to -1.5". In this case our total depth for the operation is 3.75" deep.

Once you've got the total depth, then "final Z depth", is offset by the "finish depth cut(s) spacing". So if your final floor pass is .025, but you've also got 2 finish passes enabled, then your final depth is offset by .05. Let's use this value as "Floor Depth". So the Total Depth, minus the Floor Depth is now 3.75 - .05 = 3.700 (Roughing Depth).

Next this Roughing Depth, is divided by the "Max Depth" value. If the total rough depth, divided by the 'max' step is an even number (no remainder), then great. If not, say your rough step was .25, and you've got 3.7 of rough depth stock. 3.7 / .25 = 14.8. Since that isn't an "even number", Mastercam will round up the number of passes, and then divide the rough stock depth by this new number. In this case: 3.7 / 15 = .2466, depth per pass.

So, we'll have 15 rough passes at .2466, then 2 finish floor passes, at .025 each.

Now, that's just counting the Depth Cuts. It gets even more complicated, when you are figuring in "multi-passes"...

That is what makes this such a difficult Post Mod. I have no idea as a Post Developer, how you as a programmer prefer to organize your operation, so coming up with an algorithm that will accurately "track" if you are cutting the floor or not is a pain to say the least...

 

[Colin Gilchrist]

1 hour ago, BrianP. said:

Nope. Such a simple thing yet after 35 years you still either have to manually change it after post or create a 2nd op.

Yes, it seems like a simple thing. For the guys designing the software, they should be able to do this fairly easily.

The only other "solution" would be to use the Toolpath Editor, to change the federate manually on the last pass of the floor. At least this would prevent a "hand-edit" of the G-code program, and technically you could use a Manual Entry Path (turn off Posting), to alert your coworkers what that "edit" was...

[Leon82]

I haven't used the Toolpath editor, I'll have to give it a shot

[Newbeeee™]

42 minutes ago, Leon82 said:

I haven't used the Toolpath editor, I'll have to give it a shot

To me it is very "clunky". But I've only dabbled  or times with it.

I found it easier to edit the code in NCPlot.

Go on, line up and stone me...  

[Colin Gilchrist]

45 minutes ago, Leon82 said:

I haven't used the Toolpath editor, I'll have to give it a shot

The tricky part is that you have a dialog box with "passes", and "points", in the toolpath. You have to click through each point in path, until it highlights the "move" that you want to edit. Now, when you click on the "line or arc" that is being edited, you must click "near the far endpoint", of the move you want to edit. If you click on the near side of the mid-point, it will apply the change to the move "before" the move you really want to edit.

[Mark VIII]

23 hours ago, Leon82 said:

I'm sure there is a post mod,  but is something like this in the works?

 

Pockets and contours. 

 

You can always you toolpath editor. That's how I like to get my jollies.

[huskermcdoogle]

11 hours ago, Leon82 said:

I haven't used the Toolpath editor, I'll have to give it a shot

Toolpath editor is very handy.  You will use it more once you get a feel for how to use it.  It is absolutely necessary from time to time to get a good output in the multiaxis world.

Another deficiency that I have begun to hate is the lack of ability to combine the last finish multipass with the depth cut finish pass.  Not really an issue I ever noticed cutting metal,  but cutting wood it is just a pain in the but to have to create another op for the wall, and final floor finish.  I have started just deleting the unneeded pass using toolpath editor.

[Leon82]

I'll give it a shot. Hopefully it gets translated into camplete ok. 

[Mark VIII]

20 hours ago, Leon82 said:

I haven't used the Toolpath editor, I'll have to give it a shot

 

Just remember. ANY change you make that requires regeneration means that you lose all of your toolpath editor changes. This becomes a nightmare in lathe because ANY minor changes to prior ops means you have to regenerate all following ops. 

[crazy^millman]

53 minutes ago, Mark VIII said:

 

Just remember. ANY change you make that requires regeneration means that you lose all of your toolpath editor changes. This becomes a nightmare in lathe because ANY minor changes to prior ops means you have to regenerate all following ops. 

Unless you uncheck update stock.

[Mark VIII]

12 minutes ago, 5th Axis CGI said:

Unless you uncheck update stock.

 

That would cause many more problems

[crazy^millman]

38 minutes ago, Mark VIII said:

 

That would cause many more problems

Depends on how you approach it.

[Mark VIII]

19 minutes ago, 5th Axis CGI said:

Depends on how you approach it.

The way I approach it is from a shop that cannot order the same size material for the same part twice.

[crazy^millman]

1 minute ago, Mark VIII said:

The way I approach it is from a shop that cannot order the same size material for the same part twice.

Like everyone else.

[Mark VIII]

So, now you know why stock update is important. Kinda like answering your own question.