I thought I would write a program that creates cut diagrams similar to
the free & commercial products out there as a side project, and I'm
trying to figure out a set of common rules to use when laying out the
parts.
If you were to create a cut diagram on paper, how would you go about
finding the optimal layout on the boards without using a software
program. Do you have a systematic way of figuring out the best way to
cut the boards to minimize waste?
Thanks!
Chris
Chris wrote:
>If you were to create a cut diagram on paper, how would you go about
>finding the optimal layout on the boards without using a software
>program.
It's called "paper doll" time.
I use 8x8 grid paper.
Make cut outs for each piece or group of same size pieces.
Layout a full sheet on a sheet of 8x8 grid, then arrange cutouts on
that sheet.
Before puters, industrial engineers did plant layouts this way.
Lew
On Tue, 23 Jun 2009 17:57:25 -0500, Larry Blanchard
<[email protected]> wrote:
>On Tue, 23 Jun 2009 14:21:49 -0400, Tom Watson wrote:
>
>> It's a fun problem but its been done to death.
>
>Back in the '60s I worked for Calcomp. One of the projects was to do a
>cutlist program for the garment industry such that the cloth could be cut
>on a modified flatbed plotter.
>
>After a lot of gnashing of teeth, the program worked. It even allowed
>for "grain" orientation. But it still couldn't do any better than a
>skilled cutter with many years experience :-).
I entirely agree.
I wrote a program in VB5 for kicks.
I actually did my work by taking the selection rectangle and applying
it to a pre-drawn 4x8.
Regards,
Tom Watson
http://home.comcast.net/~tjwatson1/
On Tue, 23 Jun 2009 09:51:08 -0700 (PDT), Chris
<[email protected]> wrote:
>I thought I would write a program that creates cut diagrams similar to
>the free & commercial products out there as a side project, and I'm
>trying to figure out a set of common rules to use when laying out the
>parts.
>
>If you were to create a cut diagram on paper, how would you go about
>finding the optimal layout on the boards without using a software
>program. Do you have a systematic way of figuring out the best way to
>cut the boards to minimize waste?
>
>Thanks!
>
>Chris
Are you going to optimize for yield, or for time?
Is the material consistent, as is MDF, Plam, etc., or are there
directional, or visually based decisions to be made, as in cutting
figured ply, hardwood, etc.?
A nesting program for a CNC router is going to be different than that
for a hand fed tablesaw.
It is fairly simple to cobble up a tablesaw cutlist and layout for
something like MDF. You can use an Excel sheet as a table for
parametrics that can drive a drawing layout. Excel will sort for you
based first on width, then on length. You will rip all pieces of a
given width until you have the lengths you need, then you rip the next
smaller width, etc. until finished. Then you will cut to length and
will probably have to re-rip some pieces to fully optimize for yield.
This, of course takes time and you can build in a calculation that
runs value of time against value of material to see if it is worth it.
It's a fun problem but its been done to death.
Regards,
Tom Watson
http://home.comcast.net/~tjwatson1/
The answer is... Cutlist Pro
Honestly though, this is a very well studied problem with lots
published.
Google "Nesting Algorithms"
It is a recursive sorting problem that goes something like biggest
pieces first, next size next, recheck leftovers to see is
rearrangement reduces waste.
On Jun 23, 9:51=A0am, Chris <[email protected]> wrote:
> I thought I would write a program that creates cut diagrams similar to
> the free & commercial products out there as a side project, and I'm
> trying to figure out a set of common rules to use when laying out the
> parts.
>
> If you were to create a cut diagram on paper, how would you go about
> finding the optimal layout on the boards =A0without using a software
> program. Do you have a systematic way of figuring out the best way to
> cut the boards to minimize waste?
>
> Thanks!
>
> Chris
Chris wrote:
> I thought I would write a program that creates cut diagrams similar to
> the free & commercial products out there as a side project, and I'm
> trying to figure out a set of common rules to use when laying out the
> parts.
>
> If you were to create a cut diagram on paper, how would you go about
> finding the optimal layout on the boards without using a software
> program. Do you have a systematic way of figuring out the best way to
> cut the boards to minimize waste?
>
A few years ago, the Wall Street Journal ran a story about a chap that owned
a company that made institutional underwear ("Southern Bloomers"). His
biggest customer was the federal prison system (before you ask, the largest
bra he constructed was a 55DDD). Anyway, he paid big bucks for a
laser-guided cutting system to get the most useful parts from his bolts of
high-quality linen. In spite of the best program in the business, he still
ended up with about 30% waste which he sold to rag dealers for about
$3.00/hundreweight.
Shift gears.
One day his nephew invites this chap to go duck hunting. After the hunting
foray, he and his nephew are sitting around, drinking beer, and cleaning
their shotguns. The nephew keeps going on and on about the crappy cleaning
patches leaving lint, not big enough, etc.
Light goes on.
Guy goes back to his shop, re-programs his cutting software to squirt out a
bunch of 2" patches from the otherwise almost worthless waste. He puts 500
of them in a ZipLock bag and takes the bag to Bentonville. He figures if he
can get 80¢ per bag from Walmart, he'll make out like a bandit!
The buyer looks at his stuff and compares it to Walmart's current product
line, and says "We can give you $1.75 per unit."
Every time I clean my guns, I wonder that this little patch came THIS CLOSE
to being a 55DDD!
P.S.
The new product line found other buyers. Today, Southern Bloomers provides
patches to over 7,000 law enforcement agencies.
"On behalf of the U.S. 10th Special Forces Group (Airborne), I would like to
extend our thanks for your assistance in deriving high-quality equipment for
our precision weapons system."
Sales of gun patches now out sell underwear 4-1 and the company produces
about three TONS of patches per week.
On Tue, 23 Jun 2009 15:13:38 -0500, "Upscale" <[email protected]>
wrote:
>Only difference with sheet
>goods is that you want as many pieces inline as possible so you can rip
>lengths.
Or line 'em up to make the crosscuts first if you're using a panel saw
(in crosscut mode) to break down the sheet. But for sure, the program
must align the parts to allow at least one full length rip or
crosscut. Just one more option to go on the list.
Once upon a time I did application programming - mostly relational
database front ends - but, considering the costs involved, IMO it
wouldn't be worth the time to develop my own nesting program unless
there was a good chance of selling it (which brings up its own bucket
of worms). But if the OP is looking at it as a "fun" project for
personal use, then more power to him.
Tom Veatch
Wichita, KS
USA
"HeyBub" wrote:
> Anyway, he paid big bucks for a laser-guided cutting system to get
> the most useful parts from his bolts of high-quality linen.
Used to get my suits custom made at Richman Brothers in Cleveland,
home of the "plain pipe rack" suit stores.
Back then, a standard suit was $80-$90.
A custom suit was a $10 premium over a standard suit in those days
which was a heck of a deal.
Was given a tour of the factory where several laser cut machines were
cutting out pieces for suits from bolts of cloth.
Was told the machines had been developed by Hughes Aircraft and
adapted to the "rag trades" by Hughes.
Lew
On Tue, 23 Jun 2009 14:21:49 -0400, Tom Watson wrote:
> It's a fun problem but its been done to death.
Back in the '60s I worked for Calcomp. One of the projects was to do a
cutlist program for the garment industry such that the cloth could be cut
on a modified flatbed plotter.
After a lot of gnashing of teeth, the program worked. It even allowed
for "grain" orientation. But it still couldn't do any better than a
skilled cutter with many years experience :-).
--
Intelligence is an experiment that failed - G. B. Shaw
"Larry Blanchard" wrote:
> Back in the '60s I worked for Calcomp. One of the projects was to
> do a
> cutlist program for the garment industry such that the cloth could
> be cut
> on a modified flatbed plotter.
>
> After a lot of gnashing of teeth, the program worked. It even
> allowed
> for "grain" orientation. But it still couldn't do any better than a
> skilled cutter with many years experience :-).
That makes more sense than Hughes Aircraft being involved as I was
told.
But heck the guy who told me was a tailor, not the purchasing dept.
Lew
On Tue, 23 Jun 2009 22:11:18 -0400, J. Clarke wrote:
> Lew Hodgett wrote:
>> "Larry Blanchard" wrote:
>>
>>>
>>> After a lot of gnashing of teeth, the program worked. It even allowed
>>> for "grain" orientation. But it still couldn't do any better than a
>>> skilled cutter with many years experience :-).
>>
>> That makes more sense than Hughes Aircraft being involved as I was
>> told.
>>
>> But heck the guy who told me was a tailor, not the purchasing dept.
>
> Maybe he had Hughes confused with Lockheed, which owned Calcomp for a
> while.
This was before Lockheed bought Calcomp. And I also worked at Hughes for
awhile (on the Surveyor program, among others). There was no such effort
at Hughes that I was aware of, but it was a big corporation. And there
may have been one later.
--
Intelligence is an experiment that failed - G. B. Shaw
On Tue, 23 Jun 2009 23:19:29 +0000, Lew Hodgett wrote:
> Was given a tour of the factory where several laser cut machines were
> cutting out pieces for suits from bolts of cloth.
>
> Was told the machines had been developed by Hughes Aircraft and adapted
> to the "rag trades" by Hughes.
Just out of curiosity, do you have an approximate year for that?
--
Intelligence is an experiment that failed - G. B. Shaw
"Upscale" <[email protected]> wrote in message
news:[email protected]...
>
> "Chris" <[email protected]> wrote in message
>> I thought I would write a program that creates cut diagrams similar to
>> the free & commercial products out there as a side project, and I'm
>> trying to figure out a set of common rules to use when laying out the
>> parts.
>
> The same rules as when you're moving and filling up the moving van.
> Largest
> pieces go first and you work your way down to the smallest ones filling in
> little spaces. Same when cutting sheet goods. Only difference with sheet
> goods is that you want as many pieces inline as possible so you can rip
> lengths.
CutList Plus will allow you to choose crosscut, rip, or optimise for best
yield on the first cut, you get many choices so that you can more easily
make the first cuts.
> just a thought, but the free plugin for Sketchup, CutList 4.0,
> is a ruby script that contains the algorithms used to produce the html
> output. It can be read in any ASCII editor (i.e. Notepad). Might be
> able to get some ideas or reverse-engineer the code.
I'll check that out. I also found a Delphi application that I'm trying
to figure out.
Thanks!
"Chris" <[email protected]> wrote in message
> I thought I would write a program that creates cut diagrams similar to
> the free & commercial products out there as a side project, and I'm
> trying to figure out a set of common rules to use when laying out the
> parts.
The same rules as when you're moving and filling up the moving van. Largest
pieces go first and you work your way down to the smallest ones filling in
little spaces. Same when cutting sheet goods. Only difference with sheet
goods is that you want as many pieces inline as possible so you can rip
lengths.
"Leon" <[email protected]> wrote in message
news:[email protected]...
And to add a bit more, I use Cut List plus more often to optimize lumber
than I do for plywood.
"Chris" <[email protected]> wrote in message
news:04ceaab2-da58-4af0-9ba0-f154eff21b0b@y33g2000prg.googlegroups.com...
>I thought I would write a program that creates cut diagrams similar to
> the free & commercial products out there as a side project, and I'm
> trying to figure out a set of common rules to use when laying out the
> parts.
>
> If you were to create a cut diagram on paper, how would you go about
> finding the optimal layout on the boards without using a software
> program. Do you have a systematic way of figuring out the best way to
> cut the boards to minimize waste?
>
> Thanks!
>
> Chris
Chris,
I assume you meet for sheet goods so don't forget that plywood comes in
2'x2', 2'x4', 4'x4' (handy panels or specialty plys) as well as the
usual 4'x8' sheets. Then some suppliers have 4'x9', 4'x10' and 4'x12'
sizes.
The really good cabinet grade stuff typically is found in 5'x5' sheets
and there are metric sizes as well so your options are numerous if you
include all the typical sizes found in both imperial and metric
measurements.
As for how I do layout when working with sheet goods is typically by
using AutoCad and making it fit manually by trial and error and keeping
the grain orientation in the right direction for pieces where it
matters.
Be sure to allow for the kerf sizes for the typical plywood blades,
thin-kerf and full-kerf blades.
I have a feeling you'll be pulling your hair out but should be a great
exercise and learning experience.
Bob S.
Lew Hodgett wrote:
> "Larry Blanchard" wrote:
>
>> Back in the '60s I worked for Calcomp. One of the projects was to
>> do a
>> cutlist program for the garment industry such that the cloth could
>> be cut
>> on a modified flatbed plotter.
>>
>> After a lot of gnashing of teeth, the program worked. It even
>> allowed
>> for "grain" orientation. But it still couldn't do any better than a
>> skilled cutter with many years experience :-).
>
> That makes more sense than Hughes Aircraft being involved as I was
> told.
>
> But heck the guy who told me was a tailor, not the purchasing dept.
Maybe he had Hughes confused with Lockheed, which owned Calcomp for a while.
"Leon" <[email protected]> wrote in message
news:[email protected]...
>
> "BobS" <[email protected]> wrote in message
> news:[email protected]...
>> I assume you meet for sheet goods so don't forget that plywood comes
>> in 2'x2', 2'x4', 4'x4' (handy panels or specialty plys) as well as
>> the usual 4'x8' sheets. Then some suppliers have 4'x9', 4'x10' and
>> 4'x12' sizes.
>
>
> A decent lay out program does not put any restrictions on materials
> size. I have hundreds of sizes in my inventory that are not of
> conventional size and the lay out program takes this into
> consideration.
> If the program is limited to specific sizes it is really of little
> value over what is available now.
>
>
>
>
Leon,
I've never used one of those programs so I don't know what, if any, the
restrictions may be for sizing. I was simply pointing out some points
for him to consider. It makes sense that the program should
accommodate any size sheet - no argument.
Bob S.
"BobS" <[email protected]> wrote in message
news:[email protected]...
> I assume you meet for sheet goods so don't forget that plywood comes in
> 2'x2', 2'x4', 4'x4' (handy panels or specialty plys) as well as the usual
> 4'x8' sheets. Then some suppliers have 4'x9', 4'x10' and 4'x12' sizes.
A decent lay out program does not put any restrictions on materials size. I
have hundreds of sizes in my inventory that are not of conventional size and
the lay out program takes this into consideration.
If the program is limited to specific sizes it is really of little value
over what is available now.
"BobS" <[email protected]> wrote in message
news:[email protected]...
> Leon,
>
> I've never used one of those programs so I don't know what, if any, the
> restrictions may be for sizing. I was simply pointing out some points for
> him to consider. It makes sense that the program should accommodate any
> size sheet - no argument.
>
> Bob S.
AND I did not mean to sound like your suggestion was not valid, just that
What you mentioned should be a very very minimum for his own personal use,
with a common size restriction the program probably would not sell.
On Tue, 23 Jun 2009 09:51:08 -0700 (PDT), Chris
<[email protected]> wrote:
>I thought I would write a program that creates cut diagrams similar to
>the free & commercial products out there as a side project, and I'm
>trying to figure out a set of common rules to use when laying out the
>parts.
Chris, just a thought, but the free plugin for Sketchup, CutList 4.0,
is a ruby script that contains the algorithms used to produce the html
output. It can be read in any ASCII editor (i.e. Notepad). Might be
able to get some ideas or reverse-engineer the code.
Before anyone flames me for encouraging copyright violation, the
following is a quote from the script file:
<quote>
# Copyright 2006-2008 Vendmr
# Based on CutList.rb, Copyright 2005, CptanPanic
#
# Permission to use, copy, modify, and distribute this software for
# any purpose and without fee is hereby granted, provided something
the above
# copyright notice appear in all copies.
</quote>
Google "Cutlist 4.0" for download links.
Tom Veatch
Wichita, KS
USA