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Lumber cut-list, aka materials needs list...


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Hello All,

I'd like to be able to have a "cut list" be generated automatically from my extruded polygon items.

I create construction drawings for stage scenery in 3D. A flat (fake wall used on stage) consists of 1'x3' lumber framed and covered with either cloth or plywood. Each 3D object has an X, Y and Extr value. How do I get VW to compile a list of all my (selected) items and these values?

The attached file is a construction drawing I send to my scenery shop for building. Each piece of lumber has the sizes shown. But, it would be dandy to generate a spreadsheet list to place on the sheet. Furthermore, it would be helpful to compile a wood order for the lumber yard.

These fake walls come in all sorts of shapes and sizes, so the wall tool doesn't really serve with ease.

Thanks, Scott

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I'd like some Kool-a ... ah...no not really.

As far as I know there's no simple way to get the extrude value. X and Y values (height and width) are quite easy but are view dependent, so you need some way to transpose the X value of a horizontal to length. Enter vectorscript and classing of your pieces.

You could attach a record to each and manually fill in a length field. Not that much work really.

But anybody qualified to build these should be able to do a take-off and part list in about as much time as it'd take you to fill in the records.

Good reliable part listing software is expensive.

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I think Kool Aid's proposal is interesting - but doesn't account for the angle cuts. You could class each item by section type and find the max length.

Probably by comparing max and min lengths you could infer the angle cuts on both ends.

Edited by bcd
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Unfortunately, even that would not actually do the job to the level of accuracy that would generate a true cutting list: some members may be of parallelogram -type of geometry.

To get that accuracy, members should be extruded in elevation projections. Then a script could go ?into? them and calculate the gross length and also angle settings for cutting.

Gross lengths would then be listed. Now, at the timber yard they have certain standard lenghts. Some members may ?take? an entire length, but more than one shorter ones will be cut from one length. Enter optimisation?

Let's assume all this can be done. Now, at the shop, each member becomes a Part with a designated location and it is cut from a specific length of material. After selecting the correct length from the pile of planks supplied and cutting, the saw operator has to write the part number on the piece of timber; the chippie has to find the parts from another pile of planks and assemble them by the numbers.

It just gets very, very complicated! Of course this is, by and large, how timber element factories operate, but the scale is somewhat different from a scenery shop.

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Length cutting optimization in a nut-shell:

- get a list from somewhere

- sort it from longest to shortest

- get the first part length

- look in the scrap bin for the shortest piece that'll do the job

- cut the piece of scrap if you find one, else cut a piece of stock

- if a length of stock is used then up the tally of lengths required

- put the cut-off in the scrap bin

- get the next length needed from the cut-list

- repeat the above 5 steps until list is finished

It's really just a game of simple math, shuffling numbers and sorting.

It took me who knows how long and about 300 lines of vectorscript, not including the data input part. The list comes from a rather huge dialog in one tool, and a chunk of script in another which runs thru objects in the drawing to build the list.

I learned a lot. One thing I learned is just how valuable a good tradesperson is.

(Just thought I'd share my experience with this whole thing)

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I learned a lot. One thing I learned is just how valuable a good tradesperson is.

Couldn't agree more. Even when I was young, I never hired a tradesperson under 50?

Now, with our Case, 1"x3", the commercial reality may well be that, by default, every piece is cut from whatever pile of timber. Going through the scrap bin may not be economically-rationally justifiable.

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This doesn't exactly answer the question, but since a flat is almost two dimensional and all your framing members are the same width and thickness and in the same plane, (with the exception of the corner blocks) perhaps you could lay out the framing members in 2d (using rectangles) and have the worksheet report height and width of each.

Since this type of lumber is typically sold by the linear foot not the board foot, you don't really need to calculate the volume.

If you need to have the flat be 3d in order to place it on the model of the set, you could create a duplicate of your original layout on a separate layer and extrude all the elements to 3/4" to create the model.

Hope this helps.

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the commercial reality may well be that, by default, every piece is cut from whatever pile of timber. Going through the scrap bin may not be economically-rationally justifiable.

But that right there is cut-list optimization! If you work from longest to shortest, and use the shortest piece in the shop that'll do the job you get the best possible yield.

What I posted is just the algorithm (if I may be so bold as to call it that) for the script.

The scrap-bin is the array that stores the cut-off lengths. The key is keeping it properly sorted and this is true for both the software and the shop.

In the real world the guy looks at what's left over and either throws it in the trash, or puts it aside to use for one of the shorter lengths in the list. If he's working with 8' stock and the list asks for 4 pieces 59", and 4 pieces 36" he knows he can get it all from 4 lengths.

If he doesn't know what he's doing he might cut all the 3' pieces first and end up using 6 lengths and leaving a lot of fairly useless clutter. Of course 1x3 is so cheap compared to labour that it doesn't matter much how it gets done, so you're right about the trade-off between labor and yield. With some other materials and a longer list you do it right or lose the shop.

Boxjoint:

That right there is why I'm still working in 2d. One day we'll buy Interiorcad and I'll let my quirky system of worksheets and scripts fade to obscurity on some obsolete storage disc. I'll be sad to see it go though. It has served us well.

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Charles,

Sadly, I agree with you.

On the surface, it doesn't seem to be much to ask that an object that is one inch by three inches and extruded to twenty inches should be able to transfer it's dimensions to a spreadsheet. But, I am not a computer wizard and so there must be reasons for why it cannot.

I realized after posting my suggestion that it would not work so well with the diagonal members of the flat, since the bounding box becomes the "object" rather than the actual diagonal object. Again, I find it difficult to imagine that I can see this diagonal object on my screen, yet the program is unable to tell me it's dimensions.

Have you found a way to overcome this obstacle?

boxjoint

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Back in the day I used to use EAPs because it was easy to get the length on a worksheet, add the lengths, count the pieces, etc.

But Petri's comment about using volume and dividing by the surface area of the cross section made me rethink things.

Attached is a very simple example that will generate a cut list for each unit and estimate a materials order (+10%) based on the length of the stock (ie how many 12' 2x4s vs 16' 2x4s) ordered for each unit and a total for the drawing.

It uses simple extrudes and extrude along paths. Most of the extrudes are generated from blue symbols and then stretched to length. Not necessary, but it made the process of "tracing over" an elevation or ground plan very fast.

Still doesn't account for angled cuts. But I'm not sure how the cuts could be reported on a list in a meaningful manner even if it could be figured out...

michaelk

Edited by michaelk
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  • 2 years later...
  • 5 years later...

Hi All,

I'm new to the forum, so please excuse any breaches in etiquette.  I was wondering if there is a designated function for the area of the cross section, or if folks are figuring that out from height and width?  I, too, am trying to create cut lists from 3D models and am trying to figure out a workflow.  The information here has been really helpful.

Thanks,
Catie

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Catie

 

Welcome to the forum.  Depends on what kind of model.  If you are using the Framing command for walls, for example, there is an option to create a cut list.

 

If you are rolling your own, then you are correct.  I usually class each material type, i.e. 2x6 lumber or 1x2 box tube steel and divide the volume of the object by the area of the cross section to get the length.  It all get's a little wonky if the end of the stock is mitered or has holes in it, but it works well enough for cut lists for simple items and approximations for budgeting larger ones.

 

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Hi Michael,

Thank you for the reply! I am trying to figure out a system that would work with extrudes and EAPS. Do I have to figure out the surface area of the cross section separately, or is there an area function that will return this value regardless of the view in the drawing? Lent, width, and height all seem to be view dependent.

All the best,

Catie

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When I last looked into this, you couldn't always count on which dimension of an extrude is the length and which is the width.  For short pieces of 2x6 it could easily return a =Length of 1.5 or 5.5.

 

If I remember correctly.  :-)

 

I'm on the road at the moment, but I think I have an example file that does this on this computer.  I'll hunt it down and post it.

 

 

mk

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OK, I found this and cleaned up the extraneous junk.

 

It uses classes to separate each kind of stock.  And it has fields in the worksheet for actual dimensions of lumber and a waste factor for calculating a quick shop order.

 

It's great at getting lengths of stock as long as the ends aren't mitered and there are no holes.

 

It can count the number of sheets of various sheet goods needed, but the sheet good dimensions are dependent on what view the drawing is in when the worksheet is recalculated. i.e., there is one sheet of 1/4 Luan that is bigger than one sheet and is correctly counted as 1.03125 sheets no matter what the view, but the sheet is vertical and it's dimensions show up in top plan as 8'0" by 1/4".  Actually it's 1/4" thick and it's 8'0" x 4'1.5".  In an isometric view it's just nonsense dimensions.  But the sheet count is correct.  It's close enough for my needs, so I've never bothered to fix it.

 

The fields for actual dimensions and waste factors are used in the calculations.  It's easier to change things there when adding new stock sizes rather than put it directly into the formula.

 

hth

 

 

 

Cut List.vwx

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