Facemilling Enhancements Ziz-zag with tracing

Samarinder Singh

Facemilling Enhancements Ziz-zag with tracing

Hi,

I think it would be a good enhancement for Facemilling where user can trace the tool-motion by reversing it between levels. I made a customized tool-motion using 6-pocketing operation( pretty much one MO for every level including last finishing levels) Please see attached video clip for it.

And another option would be nice where tool goes back to the start point for finishing pass only. I believe APT/NCL folks can do it all day along with no problem. I wonder if any other CAM package does offer this capability.

I can make a powercopy for the cl-curves and drive the tool in one MO only but that would put extra baggage of geometry in NCGeometry.catpart. So it would be a real time saver if this idea is implemented inside Facemilling MO

Regards,
Samarinder
Attachments

  • Facemilling-ZigZag_Tracing1.zip (295.8k)

Bryan Carpio Felsher

Facemilling Enhancements Ziz-zag with tracing
(in response to Samarinder Singh)
The way I have always faced is to stop ON when roughing, and only go PAST on
the finish pass. I just do it with 2 MO's, but it would be nice to be able
to set a different start/stop point for finish passes. It's a waste of
time to come all the way off the part on the rough passes.

I was also taught to face as much as feasible from right to left, so you
throw the chips away from operator and into the chip auger. If it is a
small part and the run-time isn't affected too much, I still try and do
this.

Samarinder Singh

RE: Facemilling Enhancements Ziz-zag with tracing
(in response to Bryan Carpio Felsher)

I am trying to discuss an additional idea/option as a possible enhancement and not how we cut and how chips fly on the floor. By the way I pay attention to my facemilling and keep one-way only when it is required.

Most of times I choose Zig-zag for softer metals the way you saw in the video clip and for hard metals one-way. I never the leave the workpiece while looping(rolling into the cut based upon some formulas in App/Ret macros) at the ends. Again it depends on the shape of the part you are cutting, setup rigidity, if there are going be vibrations, etc... And I am pretty sure every NC-programmer pays the attention while programming the parts.

So there are some factors which dictate what to choose for the given condition. The more options you have better it is. As Dave says,"If this option is available would you use it?"

The place I work makes high quantity of parts. So every minute saved adds up.

This idea came up as I was programming 460-inches long part where time adds up especially most old gantries don't move as fast as smaller machines.

Regards,
Samarinder

Dave Frank

RE: Facemilling Enhancements Ziz-zag with tracing
(in response to Samarinder Singh)

Bryan is always great for proposing real world workarounds to almost any issue.

That said, I am a control FREAK. Ss speaks of old machines....well........I have a bunch of brandy new 12,000 RPM 5-axis ATC machines that are fully enclosed........so chip direction is not an issue.  Now I do it exacty the way Bryan mentioned...if the operator is in danger of getting sprayed wiith a curtain if Ti, or other.  I have scars from blue swarf chips.

I have also drove 45 deg x 3 in chamfurs in corners...to keep constant load on the cutter to keep the part down. It was a thin part. I say keep the ideas rooling in......some day  DS will catch up...and this kind of stuff will help  "Those that need it"

Dave

Bryan Carpio Felsher

RE: Facemilling Enhancements Ziz-zag with tracing
(in response to Dave Frank)

I pretty much have been able to get this path using Pocketing which is usually how I face parts.  No formula's, no nothing- just playing with soft and hard boundaries, HSM, approach/retract macro's, using back and forth, and playing with the values, you can get the toolpath you show in the video.  Anyhow, I have it saved in my MP catalog so I don't have to figure it out every time.

See the screenshot.  3 depths of cut with final pass .050 and coming off the part.  As you see, only one approach and retract.

In titanium, I get rid of the HSM, because it's faster without it, and machine is moving so slow, it's unneccesary.

I still have to use 2 MO's, so ONLY the final pass completely comes off the part for good finish. No big deal. I just change the offset on the soft boundary on the final pass.   I state this, because unless this is also possible with your idea of an enhancement, then I would STILL have to use more than one MO to get a good toolpath. When you're working on aluminum, you might not save much time, but when you're machining titanium, it saves a heck of a lot of time.

Attachments

  • ScreenShot001.jpg (371.3k)

Samarinder Singh

RE: Facemilling Enhancements Ziz-zag with tracing
(in response to Bryan Carpio Felsher)

The main idea is to trace the tool-path back and forth between levels. And Catia has already similar algorithms implemented for the surface machining tool-paths. For example "Reverse tool path" in Sweeping and Contour-Driven MOs.

And this algorithm can be utilized between levels for Facing/Pocketing MOs. So the user doesn't have to create multiple MOs or an extra NCGeometry cl-curves for the desired toolpath.

I use formulas only for HSM radius and for controlling the App/Ret macros (initial and final using this workaround because of one level with one MO). I used 6 levels in this video-clip because customer had left too much extra material. All you need is maximum 3 levels for almost any job. But mostly 2 levels are sufficient. So I don't mind creating multiple MOs for facemilling.

I always use this type of motion using HSM. But this time I was facemilling on a 3spindle 5 axis machine and there I had to go back to safety plane each time for the next level or I had to use the local feedrate and stay close above the part surface. These gantries take more time in either method so I came up with this idea of using multiple MOs for each level and reversing the tool-path between levels.

All DS has to do is provide this capability in Facing/Pocketing MOs and the Facing MO needs a few more settings/options

1. Prismatic Machining Area to be used with MP (By using "Prismatic Slab" feature for facemilling)
2. An option to go around the check/trimming boundaries( fixtures, clamps, bolts, etc..) using "Limit machining area with fixture".
3. Some settings similar to "Soft and Hard boundaries" or "Islands" to control the tool-motion around large cut-outs in the part surface. This will more trickier because it will generate linking macros and tool-motion will be broken. User has to spend more time with adjusting offsets on such Islands for cut-outs.

4. HSM option to create smooth motion at the ends. It is only required when machining softer metals or when machining with much higher feedrates.

As of now you have to analyze the geometry/shape and make cl-curves and drive them in a old-fashioned way. Or just ignore everything and use the MO as it is. It all depends on the customer. Personally I prefer using a cleaner, smoother tool-motion.

Regards,
Samarinder