[SOLVED] Adaptive profiling: the path does not end correctly?

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Giulio Buccini
Posts: 541
Joined: Fri Aug 26, 2016 9:07 pm
Location: Munich - Gemany

[SOLVED] Adaptive profiling: the path does not end correctly?

Post by Giulio Buccini »

Hello,

I'm playing with the Adaptive operation to substitute the usual Profile operation, since the adaptive approach seems to offer a way better chip evacuation.

I created a 120x120 mm square plate to make a test. The adaptive path seems great until... I check what happens at the end of it:
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Selection_8077.jpg
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Are those "streched" and elongated path normal? It seems that I'm going to break my tool with that. :?
I'm setting something wrong? :?

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Word size of FreeCAD: 64-bit
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Python 3.10.6, Qt 5.15.4, Coin 4.0.0, Vtk 9.1.0, OCC 7.6.3
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Giulio Buccini
Posts: 541
Joined: Fri Aug 26, 2016 9:07 pm
Location: Munich - Gemany

Re: Adaptive profiling: the path does not end correctly?

Post by Giulio Buccini »

I have inspected the tool movements ad the very end of the loop around the plate by examinating the gcode.
It seems that I was wrong: the final movements that seems to push the tool straight into the material are actually crossing an almost empty space.

The "arc-like" at the beginning of the operation (around the initial helix), and the last arc made at the end of the loop, have alrfeady removed enough material. So the "trench" around the part is almost finished.

I manually draw some circles of the same size of the tool diameter centered on the path. As I can see the circles on the left and right side are intersecating each other.
So the final straight movements of the tool are just a refinement of the walls. It seems that there is no overloading of the tool.

Shame on me! :D
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MRx
Posts: 319
Joined: Wed Jul 08, 2020 5:59 am
Location: Tainan / Taiwan

Re: [SOLVED] Adaptive profiling: the path does not end correctly?

Post by MRx »

This seems to be a highly inefficient path, you better do some adaptive clearance from outside with a larger endmill - without plunging.
Giulio Buccini
Posts: 541
Joined: Fri Aug 26, 2016 9:07 pm
Location: Munich - Gemany

Re: [SOLVED] Adaptive profiling: the path does not end correctly?

Post by Giulio Buccini »

This was just a test shape.
Anyway, the approach you suggest is useless when you have to cut many exemplars of a shape from a large plate of aluminum.
MRx
Posts: 319
Joined: Wed Jul 08, 2020 5:59 am
Location: Tainan / Taiwan

Re: [SOLVED] Adaptive profiling: the path does not end correctly?

Post by MRx »

You can go to your supplier and ask them to pre-cut the stock (that's how we do that and we do many of them).
Using a small endmill does not only wear up the endmill but also risks to break them easier. Plus it's damn slow and you need to see that you can evacuate the chip properly. Outline profiling with a large endmill won't have that issue you can just let it go.

And guess what? I also started like you did using a small endmill and doing damn slow profiling.
I might still do that for a few single items, but then I'd rather use a straight slot (possibly two slots nearby so there's enough space for evacuating the chips).
Giulio Buccini
Posts: 541
Joined: Fri Aug 26, 2016 9:07 pm
Location: Munich - Gemany

Re: [SOLVED] Adaptive profiling: the path does not end correctly?

Post by Giulio Buccini »

I usually cut 20 or 24 shapes from a single plate of aluminum. If you ask the suplier to cut the plate into small pieces the price skyrocket here in Germany.
Least but not the last: when you have an irregular shape you can save a lot of material by overlapping their "bounding boxex" a little. 8-)

Anyway, I think I will adopt your suggestion to use a bigger end-mill to speed up the operations. Thanks!
Giulio Buccini
Posts: 541
Joined: Fri Aug 26, 2016 9:07 pm
Location: Munich - Gemany

Re: [SOLVED] Adaptive profiling: the path does not end correctly?

Post by Giulio Buccini »

@MRx
Question: is still profitable to make raw profiling with an adaptive path and a larger endmill? By doubling the mill diameter I should double speed...

P.S.
I still think that wearing only the tip of a tool is a waste of money (I'm using quite costly DLC bits...).
For this reason now I try to use the adaptive path as much as I can.
MRx
Posts: 319
Joined: Wed Jul 08, 2020 5:59 am
Location: Tainan / Taiwan

Re: [SOLVED] Adaptive profiling: the path does not end correctly?

Post by MRx »

Giulio Buccini wrote: Mon Nov 28, 2022 8:44 pm @MRx
Question: is still profitable to make raw profiling with an adaptive path and a larger endmill? By doubling the mill diameter I should double speed...

P.S.
I still think that wearing only the tip of a tool is a waste of money (I'm using quite costly DLC bits...).
For this reason now I try to use the adaptive path as much as I can.
they charge per kilogram here (in Taiwan, our supplier nearby), I'm down to a few minutes for the entire profiling (13mm aluminum), before it was also annoying to clear the chips.
I'm using some sharp HSS tool 10mm, not coated (I don't remember how much it cost but I think it was between 10-20$), no visible wear on that for a long time. The tool is made in Taiwan too and we bought it from a local shop nearby.

Nesting doesn't seem to be worth it for our shape.
We recycle the chips and get some money back (not too much but a little bit at least)

I think you should have a look around for different suppliers last time I checked the price difference between Taiwan and Germany wasn't that much, just a few $. We can even buy Aluminum from Germany here.
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