Throughput, cycle time & production

[Jeff Blewitt]

I own a small cabinet shop and am putting together a package for some prospective investors on purchasing a CNC. But I'm having difficulty puting together production numbers to compute a realistic ROI. I realize there are multiple variables that effect cycle time per sheet. But if some of you who already have machines could share with me 3 pieces of information it would be greatly appreciated. What's your primary material, and product (example: Melamine Cabinets)? How many sheets can you cut on the machine in an average 8hr day? And What's the most number of sheets you've done in an 8 hour day?

Thanks for your help!

[Mark Taylor]

Hi Jeff...

We are a small cabinet shop cutting primarily 1/4\" thru 3/4\" plywood. We're not a production shop, so I know there are methods for increasing production over what we produce, but at the moment that's not my primary focus.

We have a single person load, machine, label, sort and stack the parts...don't forget you have time loading the file, loading offcuts (if available), nesting the file, printing the sheets & labels and then finally writing the CNC file before loading the first sheet on the router!

Obviously the number of sheets cut per hour depends on the size and number of parts on each sheet as well as the size of the sheet material itself. For example if you have a job with a huge amount of drawers you can end up with 30 to 50 parts on a single sheet. It not only takes longer to machine because of the number of different type cuts and tool changes, but it takes time to label, sort and stack. You may only get 2 sheets in an hour - however if your running 1/4 plywood backs through you might be getting 2 to 6 parts to a sheet with only an outline cut and producing 6 or 7 sheets an hour.

Our shop will average 3-5 sheets an hour based on an 7-9 hour working day. Which means we can cut an average to larger size kitchen in a single day. We also use prefinished plywood (one side) which means our cabinets are basically ready to assemble once they have come off the router. In addition everything is also labeled and stacked on carts as a unit so we can be fairly productive in the assembly process as well.

As far as the most number of sheets cut in one day - We had a large job (over 60 sheets) that I and a helper cut in a single day...it wasn't an 8 hour day though! I know we can hit somewhere around 30 sheets a day with out too much problem.

Hope that helps...if I can be of any additional assistance you can send me an email and I'll be happy to see if I can be helpful

Mark

mtaylor@handymansolution.com

[Mark Hesketh]

at our shop, we cut mostly 3/4 melamine. depending on the sizes of the cabinets, and how many stretcher rails in each job, we can usually get between 30-40 sheets in a hard-working day. We also have some of our feedrates dialed down a bit so as to almost eliminate any chance of chipout.

as i said, the number of sheets largely depends on the number of rails in the job. i can cut a sheet of base gables or decks in about 5 minutes or less, but a sheet with 60+ rails on it will take closer to 30 minutes (slower feed rate for smaller parts and double pass to minimize parts flying off the table).

the long and short of it is that we generally manage to pump out 3-4 average kitchens in a day.

good luck!

[Mark Hesketh]

btw, forgot to mention, we cut 5' x 9' sheets of white melamine. this really cuts down on waste and offcuts.

remember that your waste percentage usually drops when using a cnc since you get the \"true shape\" nesting.