Nesting!! Can we do something about it?

[Thomas_L]

Hi everyone

I`m a cabinet maker working with Cut2D Pro in conjunction with Cabinet Sense. I really do like Vectrics except its nesting function.
As to 90% of my jobs which are usually in the size from 15-40 sheet. I found I have to rearrange parts quite a lot. This way I`m usually able to save one or two sheets each time.

Now I`m asking:
-What is the cause of this problem? We have a quite inexpensive nesting software which we use for manual cutting on the table saw. This software works really great. Why is the Vectric nesting function so inefficient?
- Is there a way to have this improved?
- Or can there be a workaround? like a gadget?
- Does anyone already discuss this with Vectrics?
- How are you dealing with this?

I write this not to complain put to find a solution. Because it takes me 15-30min per job to manipulate my nesting.
And also I find this problem creates a lot of waist throughout all the vectrics users.

I`m happy for any impute on this matter.

Regards
Thomas

[Adrian]

The nesting in Vectric is "true shape" nesting which means it works very well with the sort of shapes that humans would take a while to do by hand. Things with very different sizes and shapes such as different size letters, geometric shapes, swoopy curves etc etc.

As you've seen it can leave you scratching your head a bit with the placement of groups of very similar but not identical shapes.

A lot depends on your rotation settings. For example if I'm nesting cabinet parts I always use 90 degrees and nothing else. When nesting very different shapes I use 3 degrees.

I tend to do very little cabinet stuff these days but when I did I often just used the array functions rather than nesting.

[sharkcutup]

+1 to the Array Copy of Cabinet Parts being a better option

I find that the Nesting is a Great Feature for parts of geometric shapes which by hand/manual process would be tedious and very time consuming.

Sharkcutup

[dealguy11]

I suppose it's a tradeoff between your time and the amount of material you will save. Personally I don't mess with the nests very often unless there is something really egregious. I'm doing cabinet doors which is the ultimate in "very similar but not identical" shapes. Nesting 60 doors by hand doesn't justify the time versus the material that might be saved.

I do set my Border Gap for the nest to 0, and I try to keep Clearance to a minimum, generally not more than 1/8".

[Thomas_L]

Thanks for your replies.
The Arey function is not working for me as I have rectangular shapes with lots of different sizes. For example the stretcher of my cabinets are much smaller than the sides. Therefore I must rely on the nesting function.
As of the rentability of rearranging. In most of my projects it is rentable. As the nesting is very badly. And It takes me around 15-20min each time.

Thanks
Thomas

[Adrian]

Have you got an example file you can share? As I said in my post settings other than 90 degrees can cause some weird nesting with rectangular shapes but I've only ever been able to occasionally save a bit of material doing it manually not the multiple sheets you're talking about.

I've attached a screenshot of a nest done with 3 degrees and one with 90 degrees with rectangular parts as an example.

[adze_cnc]

Right now, we only have vague textual descriptions that basically boil down to:

• I have a problem
• Cut2D's nesting is inefficient
• I need to spend time fixing those inefficiencies

What I'd like to see right now are the following images of a nesting run:

1. your nesting settings (see sample image below)
2. an image of a sheet that you think Cut2D did well in nesting
3. an image of a sheet that you think you need to re-nest manually

 

[TReischl]

I am going to throw my two cents worth in here since I have some extended experience with nesting software, or should I say nesting engines?

It is highly unlikely that Vectric writes their own nesting routines. Nesting is a highly specialized area that has been addressed by several companies that specialize in nesting. Geometric (NestLab) and SigmaNest come to mind, and there are a few others. I used Geometric when I was writing CAM software in my other life.

Things to know about nesting sofware (engines) are:

1. The combination of part locations is logarithmic. Simple terms, HUGE. Increase the angle rotation for example from 90 degrees to 3 degrees and the results are now multiplied by 30. More parts being input also increases the complexity.

2. Understanding item 1 is important because all nesting engines work on one of two principles, best solution in a fixed amount of time, or a fixed amount of attempts. Nesting engines do NOT run until they get the BEST result. That is why the results are often less than optimum. The complexity is so enormous that normal computers would probably turn to dust from old age before completing all possible tries.

IIRC, when I was writing this stuff I discovered that limiting the variety of parts helped with results. For instance, if there were 30 distinct shapes of widely varying sizes it was better to place a few large shapes with a few smaller shapes and run that. Rinse and repeat. Also order of input seemed to play a role. In my software input order could be controlled, not sure about Vectric's because I never use it (that is not a shot at Vectric, I just do not nest parts ever).

My point is that anyone who thinks that they should be able to just dump a lot of different parts into a bin and hand it to a nesting engine with great results is deluding themselves. A little pre processing pays big dividends.

[Thomas_L]

Sorry for getting back so late.
Thanks for the great inside on this matter. That is very interesting.
Do you think verctrics could improve its function to ad a nesting option dedicated only for rectangle shapes?
The reason I`m asking this. Is that I was working with other nesting software (non cnc tough) and I never saw any really bad nesting with this. Lets say I could trust the software to do a better job than I could have done.

My nesting in vectrics set either to 0 deg. or 90deg.

Regards

Thomas

[Adrian]

I'd still like to see a file that isn't nesting the way you would want it to. It may well be that there is an issue but it could also be that you're misunderstanding how a setting works or there's a more efficient way to do it.

Having said that a lot of nesting software designed for table saw use is extremely efficient at processing rectangles as that's all it needs to.

[sharkcutup]

Just my two cents worth --- A heck of lot faster cutting rectangles and squares on a Table Saw over a CNC Machine unless of course you have a Production CNC Machine that can cut all in one pass.

Sharkcutup

[Thomas_L]

Just my two cents worth --- A heck of lot faster cutting rectangles and squares on a Table Saw over a CNC Machine unless of course you have a Production CNC Machine that can cut all in one pass.

Sharkcutup

Your right!
But I`m doing cabinetry.
If it would be only rectangles the table saw is faster. But I have lots of holes, line borings, notches, dadoes... which are done on CNC.

[Thomas_L]

Right now, we only have vague textual descriptions that basically boil down to:

• I have a problem
• Cut2D's nesting is inefficient
• I need to spend time fixing those inefficiencies

What I'd like to see right now are the following images of a nesting run:

1. your nesting settings (see sample image below)
2. an image of a sheet that you think Cut2D did well in nesting
3. an image of a sheet that you think you need to re-nest manually

 
nest settings.png

Here is a job I did this week.
It`s not one of my worth examples but still after manipulating the nesting I was able to save the last sheet.
at this sample I had turned off 90deg. rotation as it has a woodgrain and my pieces need to be placed without rotation.

[sharkcutup]

Just my two cents worth --- A heck of lot faster cutting rectangles and squares on a Table Saw over a CNC Machine unless of course you have a Production CNC Machine that can cut all in one pass.

Sharkcutup

Your right!
But I`m doing cabinetry.
If it would be only rectangles the table saw is faster. But I have lots of holes, line borings, notches, dadoes... which are done on CNC.

Oh WOW! Okay! That does tend to make a difference!

Hope you are able to get your issues solved!

I tend to agree with another forum member who has posted earlier (Adrian) on the fact that the Nesting here in V-Carve and Aspire tends to lean more towards parts that are not symmetrical (odd shaped) for getting the most usage out of the material being carved. But as what has already been said too with a little time and patience you probably can eventually come to a satisfactory Nesting Layout. Of course, you can always go search online, and pay a bit more for a Nesting Program Solution but from what my research has shown me that venture can be rather costly!

Sharkcutup

[Thomas_L]

Does anyone think there could be a way for a gagged to link vitric with a third party nesting software?
I do not have enough insight to know how these algorithm work. But knowing there are nesting software's that handle square parts better. Leaves me with the question if this could be somehow implemented in vectric.
I guess how realistic this is, depends on how much it costs and how many people would split the cost of it.
As I`m probably not the only one trying to find a solution.

Regards

Thomas