Nesting Spacing Problems w/ 7.5

[Customizeddesigns]

I recently noticed I had way more space between my parts than did previously and sure enough, Vcarve is adding additional space between my vectors for some unknown reason. As you can see from the attached picture the spacing should only be .25 but is .6.
I uninstalled 7.5 and reinstalled 7 and fixed the problem. As soon as I updated to 7.5 the problem came back.

Is this a known issue? Anyone know the cause? The fix?

Until I can fix the problem 7.5 is essentially unusable.

[scottp55]

Just tried 3 times with my version of 7.51, and after linear arraying at different offsets and gaps, nesting always rearranged them to the bit size clearance so long as Clearance(C) was set at 0. Only tried on 2" cubes though. .6" does seem to be some kind of default with the .25" bit as that was what showed in clearance when I opened up nesting.

[Customizeddesigns]

I've tried with 3/8, 1/2" bits and the spacing was still .6. When I wen't up to 3/4" the spacing jumped to 1".

What gives?

[Customizeddesigns]

The nesting spacing is completely unpredictable. It varies between parts and there is no logic to it. Take a look at the attached image. With those settings there is literally no explanation as to the added space.

[Customizeddesigns]

And now I'm totally screwed because all my files have been modified in 7.5 and I can't use 7.0 to work on them now.

[Mark]

Hello Brian,

As we mention in the Help file and reference manual, the True Shape nesting tool is principally designed to nest complex shapes.

The Nest Vectors function excels when the parts are relatively small compared to the nesting area and there are a large number of parts to nest.
If you have a relatively small number of shapes to nest or you plan to cut the same set of parts many times then it may be better to take the time
to manually nest your vectors. When you use the Nest Vectors function and see some obvious.
The nesting tool is not designed to create an accurate array of regular shaped objects.
The Array Copy tool, is the correct tool for this job.

The only thing that use of the true shape nesting tool will guarantee, is that the gap between the objects will be at least
the sum of the tool diameter and the clearance, but it is rarely exactly this gap, it is usually more (in both version 7.0 and version 7.5).

I hope that this helps to explain the use of the tool.

Cheers,

mark.

[Customizeddesigns]

Hey Mark,
I appreciate your response however, your explanation doesn't explain why the nesting feature functions differently in 7.5 than it has in every previous version.

See the first two attached images. This is the same part with identical nesting settings. One was done on our CNC computer that is running 7.5 and the other was done on my office computer which is still running 7.0. As you can see there is a significant difference in the way it is nested. In this specific case I was able to fit 36 parts with 7.0 and only 35 running 7.5. While there isn't a huge difference with this file, some of my other files is the difference of 15 or 20 parts.

To further illustrate the bizarre nesting problems in 7.5 see the last two attached images. A simple E in bank gothic font. In 7.0 it nested 388 per sheet but when I did the exact same thing in 7.5 the result isn't even remotely the same.

Additionally, this is not isolated to one computer. When I updated my office computer to 7.5 it produced the exact same results which leads me to believe it is the software itself, not a problem with our computers.

There is definitely an issue with 7.5's nesting and it looks like it isn't something that can be resolved from a user's standpoint.

[darde]

Is there a grain direction in the material setup that would not allow it to rotate or mirror one

[Customizeddesigns]

Anything on this?

[IslaWW]

Brian...
I am not sure of this, but there are often minor changes to features with each version. My guess is that was a small tweak or two in the nesting algorithm to allow it to accomplish its designed task better in v7.5. You may have missed where Mark explains that: "The nesting tool is not designed to create an accurate array of regular shaped objects. The Array Copy tool, is the correct tool for this job." In this case, if it is the case, those tweaks will help nest irregular geometries better, but as it appears, at the cost of different or lesser efficient nests on your specific geometries.

There will be few cases where a human cannot come up with a better nest AFTER seeing an automated one. The nesting algorithms in VCPro are no different. They are good, but not infallible to the human eye. Give the array copy a try, it only takes a couple minutes, as your parts are very uniform and predictable. Much different than say, nesting two copies 9" and 5" high of the alphabet. Which, by the way, is what Vectric's nesting is designed for.

[Customizeddesigns]

Hey Gary,
Everything I've tested, whether it be a square, circle, letter or complex shape is nested much more efficiently in 7.0 than 7.5. If the goal is to "tweak" it's functionality to work better then the didn't achieve their goal.

As if I didn't make my point well enough in my last posts, see the attached images. Are those shapes complex enough to make 7.5 work better than 7.0? Apparently not because the spacing is far more efficient in 7.0 allowing me to fit an additional 15 stars.

I'm not sure how anyone can defend the changes made to nesting in 7.5 after all the examples I've provided. Before the patch if I told it to nest squares with a .25" bit and a .01 spacing it nested them at .26. Now it nests them at .6. Am I the only person who sees this as a problem?

[Customizeddesigns]

Not sure how many different examples I need to post before this issue is addressed.

[IslaWW]

Brian...
I would imagine that you can post as many as you wish, but you are missing the point. The point is that the nesting feature is NOT intended for regular, especially regular identical shapes. That includes circles, squares, stars, and yes, even the letter "A". They are all regular AND IDENTICAL SHAPES. As stated twice before: use the array copy for this function. You will have precise control over all vector spacing.

You also misinterpreted my "alphabet" response. The alphabet is 26 letters, 2 copies and 2 sizes. I have included an example of alphabet letters.

FYI... nesting parameters are usually set as minimums. Other parameters are set as maximums. Very few parametric setting return "exact", or even expected results. What they do accomplish is a few second solution to a long drawn out manual process. The savings should be in time, seldom materials. For my money, I would select the nests that you show returned by 7.5 in most every case. The ones you show from 7.0 actually have the parts placed so close together that they would be difficult to hold down, and possibly even more difficult to remove from the table. If you require precise control over your nest spacing, use the array copy feature.

I am sorry this is not the answer that you are looking for, but personally, I see no problem, nor would I cut product nested with the close proximity that you desire. I am not sure, but lack of response may mean your perception of a problem places you in a minority.

[Customizeddesigns]

No, it's you who are missing the point. I have a $15,000 vacuum specifically so I can nest my pieces this close together and even if I didn't, it's not up to Vcarve to decide how much spacing I "really" need between my parts which is the entire purpose of the Clearance setting in the first place.

Is the goal in fabrication and manufacturing to get the best yields out of a piece of material? Yes
Is the main role of nesting functions in CNC software to obtain the highest material yields with the given shapes using complex algorithms humans cannot achieve? Yes

Then please, PLEASE explain the two images below. Full alphabet, two different size, two copies each.

How is this better?

"The savings should be in time, seldom materials. For my money, I would select the nests that you show returned by 7.5 in most every case."

Why? Perhaps if you were cutting $900 sheets of 3form your opinion would be different.

I may be in the minority but that doesn't change the fact that I'm right and that there is no reasoning for the changes to the nesting in 7.5 other than the increased processing speed and the lack of legitimate response, even after I've emailed Vectric support asking for one, has really changed my opinion of the company as a whole after 5 years of nothing but satisfied use of their software.

[Adrian]

I do several nests a day and it works fine for me but then I'm metric. The nesting module isn't developed by Vectric, it's a 3rd party library.