laser layout optimumization

========= The first step is to compile accurate records, which may already exist, showing the work flows to/from the machines. The Pareto principal of the vital few but the trivial many is probably active here.

It may be possible to optimize the part to input [area] yield, but this may impact other areas such as requiring sorting after production into different customer piles and increased programming to nest small parts around the big parts and in the cutouts. This may not be cost effective with small runs and frequent changes.

You may pick up some incremental improvement if your programs load quickly by having a small parts program to use up tag ends of larger runs or larger parts where you can't get a full row out of the remaining material.

A frequently overlooked factor is the actual machine on time. Most equipment of this type will have hour meters, so it can be useful to have each shift record the start and end readings.

If the readings seem low, the causes should be investigated as these can range from excessive set-ups [institute short run set-up charges], material change overs [try to consolidate all the orders using the same type of material to run one after the other], and excessive time for first part approval by QC, e.g. QC tech going on break just as the first part comes off the machine. In some instances excessive or poorly scheduled [all the operators go at the same time shutting down the department] break times may be impacting production.

Remember that the objective is to minimize the total "out-the-door" piece part cost, not optimize a particular facet of the process [such as material utilization]. This is where many efficiency/economy efforts have failed in the past.

Unka' George [George McDuffee]

------------------------------------------- He that will not apply new remedies, must expect new evils: for Time is the greatest innovator: and if Time, of course, alter things to the worse, and wisdom and counsel shall not alter them to the better, what shall be the end?

Francis Bacon (1561-1626), English philosopher, essayist, statesman. Essays, "Of Innovations" (1597-1625).

...

You must be a consultant

Keep in mind "the Kid" is not management. He can only look to make an impact under his sphere of influence. He is responsible for the programs that get run, most of them 1000s of times. And the special order programs.

He made the statement "the waste is terrible". I'm just trying to find a few ideas for him.

karl

-------- No, but I used to play one when I wore suits and pointy toed shoes that hurt my feet.....

Unka' George [George McDuffee]

------------------------------------------- He that will not apply new remedies, must expect new evils: for Time is the greatest innovator: and if Time, of course, alter things to the worse, and wisdom and counsel shall not alter them to the better, what shall be the end?

Francis Bacon (1561-1626), English philosopher, essayist, statesman. Essays, "Of Innovations" (1597-1625).

Karl,

Methinks there was deep discussion on this very topic in this forum within the last couple of years. Try a search and see what you find.

In the stone age, when material usage was expensive such as silver or beryllium copper alloys we used to cut out parts by hand and play "kindergarten" and shuffle the pieces around to optimize the scrap strip layout. It worked remarkably well. Another way is to nest different parts from different customers but then storage needs to be allowed for.

George, I think you hit the nail on the head; but if the brass doesn't care one can only control one's sphere of influence.

Wolfgang

On Sun, 14 Sep 2008 10:57:48 -0500, Karl Townsend wrote: [...]

[...]

A number of companies sell stock-cutting planning programs -- I imagine they already are using some such program where your son works. But note that stock-cutting planning is NP-hard.[1] At present a company could devote a bank of supercomputers to solving packing and cutting problems and still not find optimal[3] solutions in reasonable amounts of time.

Aside from the operational ideas that George and Wolfgang mentioned, it might make sense to have someone glance at bad layouts -- ie, when a layout uses less than say 50%, have someone look at it and fill up the holes with little parts, or even just cut the unused stock into standard-size rectangles or washers that could be sold at a higher price than scrap. If the CNC lasers are booked up (as you imply) maybe they could buy some old shear or stamping equipment to make such items.

-jiw

[1] For precise definition see the general idea is that no method is known for efficiently and definitively solving such problems.[2] [2] More than 800 academic papers about packing & cutting problems have been published, per still, nobody knows if an efficient definitive method exists, much less what that method might be. If you can show a method exists, even if you don't know what it is, you can win a Clay Institute Prize and put $1000000 in your pocket - see eg [3] Optimal = definitive best; optimization = looking for optimal solutions, and in the process, hopefully, finding some feasible near-optimal solutions.

Probably the best in the world. They used to have an office in Houston.

What the others said about software. If you have good software, it will dramatically reduce the waste

One thing that most shops don't do is mix orders from multiple customers on the same cut list. When you have an order for 100 assemblies that use

6 of A, 4 of B, and 2 of C per each, you have a fixed order. But if a different customer has a stand> I just got off the phone with "the kid". He's moved jobs again. he's now

I program 2 Mitsubishi and 2 Mazak LASERS for the LASER Shop in Germantown, Wi. We use Sigmanest for nesting parts on sheets or plate up to 5' x 10'. We also use it to develop nested part DXF files for programming our waterjet. They also have modules(which we didn't buy) that can control and track the order and material from in the door to shipped out. Mixing customers orders on the same sheet is no problem.

David

I have several inputs.

1. If you have a customer that asks for part xxx in various volume and is somewhat reliable in asking for some - cut some of those as well. Building a small part count from the scrap steel that might make money is just keeping the same steel from the junk man. More money from customer. Failsafe : sell them to the metal junk man for scrap. Weighs the same. it was just a bet on the laser and table use.

What is the issue with time - is there time for these or is there to much work ?

1. See if you can make standard straps and angles and Y's and such for fence beam work. [ Rationale - my steel company saves strips and squares from their sheets when cutting out for customers. They sell strips and squares on their web page. Circles of various pipe size for end capping can save a welder from flame cutting one.

Really depends on the local and what is used.

Mart> I just got off the phone with "the kid". He's moved jobs again. he's now

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That's close enough for a road trip. Your company allow visitors?

Karl

That was my thought: Customer X orders 1,000 to 1,200 brackets every other month, without fail. You can cut those brackets out of the scrap from Customer Y's production orders, and make them up as Customer Y scrap becomes available. (And vice-versa, get ahead on Customer Z and AA and BB when running Customer Y parts.)

Then do the bend and prep when machine time becomes available, fill that last half-hour before Lunch with a short run.

Customer X calls up to make their regular order of brackets, expecting them in a week - Or worse, they get an unusual order for their end widgets and run out of brackets, and call in a panic going "Help, I need at least part of the order fast!"

You say "I have 200 boxed and ready to ship, the other 1,000 we can have in 3 days - 500 are blanked but not formed yet." Shock the heck out of them, but in a good way.

And it turns scrap into useful things. Even weld practice coupons are more useful than the scrap bins, sell them to schools.

I've been looking for a source for the brackets and bobs for truck racks, since I have to modify mine to have swing-away crossarms (with the rear one able to accept a "Traffic Director" light bar and still fold away for bed access) and side tabs for other warning lights, add conduit carriers and tie-down anchor tabs, etc. And I don't relish the thought of hand-working every little piece.

A shop that CNC Cuts and CNC Bends and Punches brackets like that would be perfect, since it minimizes labor costs - let the customers help design your products with the understanding that it's a 'Creative Commons License' of sorts (like Linux), and write the blurb for what to do with that little bracket or tab so others can make use of it. Make it a Win-Win.

("C bracket for pivoting 1-1/2" square tube crossarms, drilled for

3/8 clevis pin hinge. 1/4" Hole on rear face for attaching an optional hex nut for a 'Slop Bolt' nylon-tipped locking knob-head screw, clamp the bar against the clevis pin to prevent rattling.)

Then all you have to do is let the laser cut the standard sized blanks for the brackets and practice coupons after the primary parts get cut out. Then divert the precut drops into a few holding bins.

Do the forming of the findings "after hours" - and they might be able to get more machinery out of the deal, since production goes up. And a few Wives and Kids can get hired to run the Mail Order Division.

And it develops a 'retail' customer base and spreads the workload to more baskets, so loss of one large client isn't a disaster. Witness some companies that ramp up on facilities and equipment to supply a single huge customer - and then get killed when the big customer takes the design to Asia and leaves a very expensive plant idle.

-->--

========= You say, "we can squeeze you in, but there will be a special short-run set-up charge for a 200 part emergency order to get you out of immediate trouble, and there is a standard small run expedite charge for the next 1,000 you need."

Don't worry about the good will as the people you are dealing with won't be there in a month, and they are going to send the job to China or Vietnam in a few months anyhow. If they complain, tell them to take it out of all the money they saved by going to JIT inventory scheduling.

Unka' George [George McDuffee]

------------------------------------------- He that will not apply new remedies, must expect new evils: for Time is the greatest innovator: and if Time, of course, alter things to the worse, and wisdom and counsel shall not alter them to the better, what shall be the end?

Francis Bacon (1561-1626), English philosopher, essayist, statesman. Essays, "Of Innovations" (1597-1625).

I work in the engineering department of a sheet metal fab company as a planner/quoter. If we get less than 80% sheet utilization, the shit hits the fan. 90% is more the norm. That said, it depends on what you are cutting! To get high sheet utilization requires nesting small parts with big ones. If all your parts are big, you better have quoted right! All the parts we quote are for single usage of the sheet. The nesting saving is an "undocumented profit center". Another way to save (for us) is to consolidate parts from small orders into larger production jobs. A customer will order 2 or 5 of something every few days or weeks. A good part of the cost is setup time. By consolidating these into larger job runs, we can save money. Our programmers use nesting software, and are in the process of evaluating newer, high dollar software just for that purpose. We only have one laser, but we also have two CNC turret punches. A laser can only emboss once and it is pretty expensive. IIIRC, the software is SMP and Computes.

Not generally, unless they're customers or prospects. A lot of the problem is that we are just too BUSY! We just installed the second Mazak and I have never seen a machine go from boxes of parts to cutting production so fast. The only reason we're not 24/7 is that we can't find enough operators or train them fast enough.

David

You mean the economy ISNT in the toilet?

Gunner, installing 3 new mills Wed.

"Obama, raises taxes and kills babies. Sarah Palin - raises babies and kills taxes." Pyotr Flipivich

George, I have told 3 customers that exact same thing over the years. One customer of 32 yrs sent a lot of my jobs to china/India but when the boat is late they call & my original price X3 is what they get. With 2 day shipping (I have stock on all their jobs). That JIT bites them hard when their lines are shut down for lack of parts.

I missed the Staff meeting, but the Memos showed that Gunner Asch wrote on Mon, 15 Sep 2008 20:42:21 -0700 in rec.crafts.metalworking :

Took me 13 days from firing to hiring. Took so long because I forgot to sign one of the forms and they had to call me back. Dang, if it had happened after the closing, I'd have taken the week off to move, then gone job hunting. Oh, well, I'll just have to settle for ten cent raise and a little bit of madness while I move into my first house.

Good on you.

Good news here in the Pacific Northwest. Summer came late, but I can enjoy it, cause I'm on day shift for a change.

-- pyotr filipivich "I had just been through hell and must have looked like death warmed over walking into the saloon, because when I asked the bartender whether they served zombies he said, ?Sure, what'll you have?'" from I Hear America Swinging by Peter DeVries