Un-machined material aware Finishing Pass

[IMK]

I have managed to install and get running together Alibre Design Xpress and Alibre CAM Xpress… However CAM Xpress seems to only do a Finishing Pass so I can’t really evaluate it.

So my question is this for purchased version of Alibre CAM:

If I have a pocket that I rough out with a large diameter tool (say 20mm) it would leave a chuck of un-machined material in a rectangular corner. Now if I do the finishing cut with a small diameter tool (say 2mm) would the finishing cut mill the corner in steps or attempt to mill to full depth in one go?.

I ask because I recently reviewed a CAM package and tested it as above and now have half of the 2mm tool stuck in the work as the finishing cut simply had no idea that there was a large chunk of un-machined material there.

Many thanks IK

 

[wathavy4]

Can you upload the part you created?
Someone (inclusive of myself) could show you how the CAM work, I bet.

 

[IMK]

Can you upload the part you created?
Someone (inclusive of myself) could show you how the CAM work, I bet.

Hello,
And many thanks for your reply.
The part in the photo was very similar to the attached.
Many tahnks IK

 

[DavidJ]

This can be done with CAMXpress using horizontal roughing, followed by 2 1/2 axis profiling - you may have to edit the entry/exit conditions and roughing/finishing ratio on Parameters prior to generating the toolpath to ensure that the tool doesn't dig in. Unfortunately the entry exit point is determined from the original sketch and I can't see a way to change it. See below.

 

[wathavy4]

I haven't even tried before, but I could do a simulation.
This is 30 days free trial version. You can do this for only 30 days after the first installation.
Then it truncate into demo version.

I don't think you can generate G code while you are in trial.( But I'm not sure.)

If you're serious, you could ask Alibre or the CAM supplier for the 30 days trial, I bet.
(Or you already acquired..?)

Anyway, my trial is this much, since I am not the one who is CAM guru. ( Tim is. :mrgreen: ).

Cheers.

 

[danbrinkman89]

As a work around I think you could create another sketch for the finishing tool to take out the material in that corner and also program to cut at as many z depths as youn want.

 

[MikeH]

I have managed to install and get running together Alibre Design Xpress and Alibre CAM Xpress… However CAM Xpress seems to only do a Finishing Pass so I can’t really evaluate it.

So my question is this for purchased version of Alibre CAM:

If I have a pocket that I rough out with a large diameter tool (say 20mm) it would leave a chuck of un-machined material in a rectangular corner. Now if I do the finishing cut with a small diameter tool (say 2mm) would the finishing cut mill the corner in steps or attempt to mill to full depth in one go?.

I ask because I recently reviewed a CAM package and tested it as above and now have half of the 2mm tool stuck in the work as the finishing cut simply had no idea that there was a large chunk of un-machined material there.

Many thanks IK

You asked about a purchased version...

We have the full version Expert that has many options. I must first apologize for not knowing everything about xpress since we went with CAD Prof and CAM Expert. I do a lot of "play" on stuff that doesn't matter to learn and being able to simulate over and over using different techniques including re-roughing with the same tool or a smaller rougher is the best way I know at the moment. It has knowledge of previously machined areas. You could cut down the area while still having plenty of stock left (you control everything). If you pay attention to the simulation (in Expert) you can catch subtle mistakes that you would think you caught as you get confident (cocky). At one point on an actual job I caught a real small error that would have ruined a good junk of aluminum (12"x12"x2"). The tool would retract to the clearance plane and ramp down to the next pass but on its way the mill would catch a corner of the part in the simulation. Of course the fault was mine and adjusting the parameters solved the issue. The simulation also turns red in areas that the tool holder hits. This is a real program not some cheesy attempt at CAM.

I can post some simulation pics of a subwoofer beveled face if you are interested? Its one of my practice pieces. At work we take either our own creations or STEP files generated from a customers Solidworks 2008 (or an ALibre converted Solidworks part file).

 

[IMK]

Hello MikeH,
Well thank you very much for letting me know about the capability of Alibre CAM re the un worked material when pocket issue and a re roughing cut I guess is the way to tackle it. So I have another question if you don't mind please. Can the re roughing pass be done with the finishing tool so I only have to change tools once? Also is the re roughing a completed different pass or is it like a Smart finishing pass?

And what you say about pretend CAM packages on the market well I guess you get what you pay for and my venture although has not cost a lot in tools or material it did in time and rocked my faith in CAM.

Again thank you for the reply IMK

 

[indesign]

Remember that CAM is like many things. It takes experience to get it right. Not too many students straight out of school could step into a job, even if they have a masters, and could do it without some first hand experience. (good thing those doctors must do a residency)

CAM is almost as much about how to machine as it is how to make the software work. Without experience in either area it takes time (and patience) to get it right. And even then when moving from one system to another (CAM or machine) there are typically some learning curves. CAM is a very good tool but it can also be frustrating if it is not setup to fit the current need. Not all software is easy. Not all software is good. No software is perfect. No person is perfect. So when combined you get problems. CAM software varies as greatly as the need. So not every CAM package will meet every persons needs.

 

[MikeH]

Remember that CAM is like many things. It takes experience to get it right. Not too many students straight out of school could step into a job, even if they have a masters, and could do it without some first hand experience. (good thing those doctors must do a residency)

Wow, you nailed that on the head! However I don't want to wander from the topic which I could easily do...

I agree entirely and that is why I practice on other stuff. "play" as I call it. At least this is not a big $$ investment only to be a mistake.

Anyway, you can make as many separate passes using any tool you wish leaving as much stock or as little as you wish. You will find that you will want to tweak things as you learn.

Here is a picture of that large bevel being remachined after two roughing passes with a roughing tooling spiraling outward. I use a new tool, ball mill, to start finishing the bevel. The picture shows two passes, one with more material being left behind. So in theory and practice this is using a finishing pass as a prefinish or a third re-rough. All these choices are up to you and the ability to simulate really makes a big difference. Of course, you can use the same tool which I have done in some of our aluminum production parts. The best part is that I can do this at home on a DELL M4300 Laptop, tweak all weekend, and post Monday morning.

I learn something everyday and the day you think you know it all is not going to be a good day...