Several Sheet Sizes for Nested Parts

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Nat Wheatley
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Several Sheet Sizes for Nested Parts

Post by Nat Wheatley »

Is there a way to enter several different sheet sizes for a multi-sheet nest?

On a typical job, we would enter the size of several off cuts from past jobs, the parts would be nested on these first, then the remainder of the parts would be nested on full sheets.

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Adrian
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Re: Several Sheet Sizes for Nested Parts

Post by Adrian »

Not as such. You can create a sheet as an offcut one by using the vector boundary option on the nesting form. That will nest everything onto sheets with the same boundary though.

In my shop I have the offcut sheet from the last job which I nest everything onto. I then cut that first sheet and then cut/paste the remaining parts (which were nested automatically onto several full size sheets but within the offcut boundary) on the other sheets onto the default sheet and re-nest.

Nat Wheatley
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Re: Several Sheet Sizes for Nested Parts

Post by Nat Wheatley »

Thank you

Nat Wheatley
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Re: Several Sheet Sizes for Nested Parts

Post by Nat Wheatley »

I can't figure out how to do this with multiple sheets of parts. When I try to nest with 'last vector as nest boundry selected' checked, I get the error 'only vectors on the default sheet can be nested'...

ckurak
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Re: Several Sheet Sizes for Nested Parts

Post by ckurak »

Nat,

That is why Adrian was doing the "cut-and-paste" part. The software will only nest the parts that exist on the "Default Sheet" when you click on "Nesting."

The only problem I would have with this is if the parts being cut-and-pasted are made up of different layers. They would all paste to the same layer. For me, this would be a major problem.

One way around this is to Group the parts, then cut-and-paste, then UnGroup back to the original layers.

I do a variation of using the scrap piece from a previous job. First, I do the same as Adrian in that I nest the parts to the left-over piece. BUT, then I save that to a new file. After cutting those parts (the ones that fit on the scrap), I take note of what parts were cut, head back to the original, not-nested file, delete the parts already cut, then nest the remaining parts onto full-size sheets. This prevents the layer issue from being a problem.

By the way, I may have anywhere from 1-20+ layers on a job. So layers are very important. Some are for drilling various size holes. Some are for drilling at various depths. Some are for pocketing at various depths. Some are simply visual guidelines that are for the CNC operator and do not get cut. Some are for dadoes. Some are for profiles. The software that generates my DXF files includes the layer information in its output.

I also find that sometimes it is not worth the trouble to try to use the scrap piece from the last project. Very often nesting the smaller parts into the scrap means I will be creating another piece of similar scrap for the current project. And, in business time is money. I usually prepare the CNC (.sbp) files a few days ahead of the actual cutting so the crew has the files ready when it is time to process the project on the CNC. However, we do save some of the scrap and have found it to be occasionally useful for parts that are miscut, or have internal voids in the plywood that make the part undesirable, etc.

Hope that helps...
Charles
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Nat Wheatley
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Re: Several Sheet Sizes for Nested Parts

Post by Nat Wheatley »

Trying to figure this out... Say for example I have 1 1/2 sheets of parts. I nest the parts and they lay out onto sheets 1 and 2. I draw a rectangle, to be used as the nest boundary, on the unused section of sheet 2

Do I then need to drag this onto the default sheet, to us it as the nest boundry?

Do I then need to select all parts, then the nest boundry? If so, not sure how to do this, as I can only seem to select parts on one sheet at a time, and how do I select the nest boundary last?

Sorry for the naive questions, just stuck on this one, for some reason.

ckurak
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Re: Several Sheet Sizes for Nested Parts

Post by ckurak »

Let me try. Here is one way to do it.

First job: The parts nest onto 2 sheets. Cut the parts.

Now...

1) Make the Default Sheet the active sheet.

2) Import the parts for the Second job. They will appear on the default sheet. Some of them may be outside the boundary of the sheet. This is the same procedure as when you loaded the first job above.

3) Select ALL of the parts on the Default Sheet, the MOVE them off of the sheet to one side.

4) Make Sheet 2 the active sheet.

5) Draw a rectangle (or polygon) on Sheet 2 for the unused area.

6) Sheet 2 is still active. Select the rectangle representing the unused area. Copy (Ctl-C) that rectangle into memory.

7) Make the Default Sheet the active sheet.

8 ) Paste (Ctl-V) the rectangle on the Default sheet.

9) Select NESTING.

10) Select the rectangle FIRST. Then, keeping the SHIFT KEY depressed, select all of the other parts for the second job.

11) Check the box that says "First vector is nest boundary"

12) Nest the parts. You will get a message in a pop-up box that says "Existing Data on Sheets Will Be Lost... If you nest new data, any existing nested data on sheets will be lost. Do you want to continue?"

13) Select "Yes" to continue. The parts from the first job that were still on Sheets 1 and 2 will be purged. The parts on the Default Sheet will be nested into rectangles that are the same size as the rectangle you drew by hand in Step 5.


Now you can cut the parts that fit in the scrap piece. You will then need to figure out which parts you cut and which still need to be nested onto new sheets of material. I explain how I do that in my previous post above. You could add a procedure above between Steps 2 and 3 to save the file. Then, save it again with a new name before nesting. Then, after Step 13, open the first file, delete the parts already cut from the scrap, then nest onto full sheets.

I hope this makes sense.

There are probably a lot of variations of this that will work. I would suggest that you write down the sequence of steps that you take. If you get the correct results, save that sequence! :D
Charles
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Nat Wheatley
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Re: Several Sheet Sizes for Nested Parts

Post by Nat Wheatley »

Thanks very much Charles. On step 11 I see an option for 'last' vector is nest boundary, but don't see one for 'first' vector is nest boundary?

ckurak
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Re: Several Sheet Sizes for Nested Parts

Post by ckurak »

OK. I have an older version of the software. Mine has the option for "First vector..."


Now you have me wondering... I just downloaded the latest Aspire Trial Edition. (I have an older version of VCarve.)

The checkbox does say "Last vector..."

So, modify the nesting steps to select the parts you want to cut first, then select the scrap rectangle last. That should do it.

By the way, when using a left-over sheet from a previous project, I either a) leave the sheet on the CNC table between projects, or b) label the partial sheet with the filename of the first project so I can identify it later, then put the sheet back on the CNC table in the same exact spot. I align (register) all of my 4x8 sheets from the same places every time, so this is simple and quite accurate.

I have also been known to make a copy of the last sheet processed from the previous job, place it on the default sheet, then hand-nest some of the parts onto the unused areas. It is not as high-tech, but it works. There are times when the scrap area is not a nice, clean rectangle. Drawing a polygon with lots and lots of vertices can be time consuming. Sometimes I find it faster to just "grab" a part or two from the next job to place in the unused areas by hand (digital hand, of course).

Let's try again. I hope this helps.

By the way, did you take a look at the nesting tutorial on vectric.com? They may explain the process in a different way that may be helpful. I don't think they address the scrap piece specifically, but there may be something there to learn.
Charles
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ShopBot PRT12060, PartWorks, PartWorks3D

Nat Wheatley
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Re: Several Sheet Sizes for Nested Parts

Post by Nat Wheatley »

Got it working, but only if all pieces are smaller than the offcut. If any of the pieces are larger than the offcut, it shows an error message for each of these parts, then proceeds to nest none of the parts...

Thanks very much for the help, and sorry to be a nuisance. Thinking I may need to contact support re: this last hurdle.

ckurak
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Re: Several Sheet Sizes for Nested Parts

Post by ckurak »

Yup. That sounds right. If it cannot nest all of the parts, you get an error message.

What I then do is to NOT select the larger parts during the nesting process. Moving them over to one side helps me visualize this and keep things organized. Then, I try nesting the smaller parts onto the scrap.

As I mentioned previously, sometimes it is faster to hand-nest some parts onto the scrap, cut them, then nest the remaining parts onto full sheets. This may not be as efficient in using the material, but time is money. A bit of non-used material is a lot less expensive than an hour of shop-time. Keep in mind, I do this to provide an income. Every minute I spend fiddling around with something unnecessarily is one less minute I have to make a living. Those minutes add up real fast.
Charles
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ShopBot PRT12060, PartWorks, PartWorks3D

Nat Wheatley
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Re: Several Sheet Sizes for Nested Parts

Post by Nat Wheatley »

Couldn't agree more, thanks for all the help.

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