Material Utilization

05/12/2014


From original questioner:

Hi, I would like to know how other shops are utilizing their material(sheet goods) that come off the cnc. We use cabinet vision software and and know there is an off cut manager tool that we could use to help us in trying to eliminate waste. We have 3 draftsmen that draw and generate code to the cnc. The problem we're having is the jobs we generate to the cnc do not always get cut out in that specific order. This would basically make the off cut manager tool irrelevant, right? We would like to utilize all that is possible. Let me know how the rest of you guys operate or any tips on how to use up left over scrap coming off the cnc. Thanks

From contributor Dr


I have this nightmare that the off cuts that I use for the next job are replaced by identical off cuts.

From contributor Le


Just a couple of common-sense thoughts - can you feed your off-cuts to a single draftsman and when he uses those materials in a job, put it at the front of the queue? Or, depending on what you make, use the off-cut material for shelves, backs, and other parts that can be cut on a saw and use up the material that way. Will the time and energy you spend managing the off-cut material really pay in savings if it interrupts job flow, etc.? Or try a different optimizer?

From contributor De


This is a tough one that we struggle with as well. I only have one guy generating code and we have an off cut rack we keep larger pieces in and we use them in the next job when we can. Sometimes we spend more time than its worth on it though.
my one thought on your process , would it be possible to have your drafters complete the job but have 1 person generate the code so that person can be on top of the off cuts

From contributor ca


we run what we can looking for best yield. Sometimes guys stand at the saw and cut up nailers and ladder base parts out of the off-fall and stock it in parts bins. Saves a lot of time, this is for the short nests that require say 1/2 sheet for nailers and such. The cut list goes to a sawyer and pulls from the bin for nailers and cuts backs while the machine is nesting doors and case goods.

From contributor Jo


Thanks for the responses everyone. We have heard that other shops sometimes use only one guy to generate code to the cnc, this would let this one guy manage the off cuts but I'm not so sure this is the correct way. Like I said we have 3 draftsmen/project mngrs. that are responsible for the jobs they take on. This could mean from working with customer, to field measuring, proofing the drawings, running the jobs to the cnc, and then answering any questions from shop employees. I just think it would make more sense to have drftsmn./pr. mngr. be in charge of everything that way there is no finger pointing when the job is going through the shop. I think the key would be to have the cnc operator manage the off cuts and keep certain size off cuts labeled and organized in a bin that are easily accessible. Scrap is not always a bad thing as you need nailers, counter top doubler, etc.

From contributor Pd


We use CV also and the offcut manager is great until a guy in the shop uses one of the scraps and you don't know it. So, I make a list of the materials right before I optimize and have a guy in the shop write down all the scrap sizes we have (alternatively, you could print out the offcuts in the manager and have him check those off). Then I put those in the O.C. manager and optimize right away.

From contributor Le


The key point is the tradeoff between the cost to manage the offcut inventory and the cost of those materials. You can't utilize material that doesn't exist, so if someone uses materials that you think are in inventory, you're going back to the office to re-optimize the job. Perhaps you start by separating materials by cost - it pays to track expensive sheet goods, but do you want to put the same effort into MDF, particle board, and melamine? Size also matters - large sheets are easier to earmark for future machining and to utilize than small pieces. Ultimately it's all about the return for the effort invested.