Need formula to cut and weld steel pipe with minimal waste.

Thank you so much! However, the project took a turn for the larger. What we need are 10 pieces @ 30', 7 pieces @ 45', 5 pieces @ 50', 2 pieces @ 35', and 1 @ 20'. The lengths that we have to do this are: 19.5,47.7,34.9,39.4,47.5,41.5,41.5,41.5,42.8,32.5,35.8,35.3,31.7,49.1,44.8,25.7,31.7,20.8,21.7,18,39.9,17.8,27.2,35.5,37.2,25.1,22.7, and 41.7. And to answer the question before, we only want 1 mid weld if possible on each pipe and we would prefer it to be at least 3.3 feet from the end of the pipe. I know I'm asking a lot but this would be a big help to us as we normally turn down jobs that require this kind of constant cutting and welding, since we have other projects we are working on as well. But what you made so far was great and thank you so much!

Here you go. Thanks so much!

I also wanted to say that I appreciate your patience with me and I really appreciate the help. That being said, (I know, I know what now?) on the new workbook can you write in there how I can use that for future projects? Thanks so much!

Correct, I listed every length. If there are duplicates then they are listed. Thanks!

Checking the values in the uploaded file (lenghts.xlsx) I find that the sum of "original lenghts" adds up to 950.5 but the sum of "lenghts needed" is 955.

What am I missing?

Alf

Hi Jacc!

I liked your mix of solver with the vlookup function and rounding it up by using "Evolutionary" solver.

Is this possible to solve with Solver?

I have no idea i.e. I've been trying to see if I could find a solver setup that makes sense but so far no luck. Let's hope that forum guru shg takes an interest in this thread. If anybody could solve this he is the one!

I find that as a solver problem this is quite fascinating so I have not given up yet, I'm still tinkering with it.

As the OP uses Excel 2010 he could perhaps try to contact the support department at http://www.solver.com/

they may be able to help him.

Alf

Hi Jacc!

The cutting stock problem is similar but less complex I believe.

Oh yes certainly as you have a standard stock length and you are cutting a number of different lengths from it. So you set up umpteen cutting pattern and every pattern is set so that the leftover from each pattern cut is less than the smallest piece you can use.

Quite some time ago I tried to set up a model for that. I think I got all the possible combinations, then I trimmed it down to a smaller model. In reality both results should be the same but they are not. Must try some day to analyze and see why the result differ and if you like to have a go at it be my guest.

The poor OP here we are spending time on idle pleasures when we should be concentrating on his problem.

Alf

Thanks shg!! You are the man! Now I'll probably spend most of Christmas trying to understand the workings behind both you your solutions. But with two serious handicaps one being a Norwegian (not known as the great minds of Scandinavia) and the second having passed the "three score and ten" age of man I'm rather doubtful if I'll succeed.

Alf

Ps Do you know why Norwegian brain surgeons have a year longer education than the other Scandinavians? It's because it contains a one year course in wood carving as well.

Impressive, waste went down from 45.5 to 25.5 in the "improved" version!

Alf

Thanks so much to everyone jumping on this thread and trying to help! You guys are awesome!
@shg
I looked at your attempt and noticed that you only have 41.5 listed once when there are 3 at that length.