We have a 5x12 CNC Router and it starting to become the weakest link in the chain. It is taking too long to process parts due to the way we program, load and unload. We are a commercial casework shop that does almost exclusively plastic laminate cabinets. 70% of our sheets are 5'x8' everything else is 4'x8' with the occasional 12' sheet for countertops. We currently use the default optimizer that comes with Microvellum. I have a few questions for you.

1, How do you load and unload sheets on and off of your routers?
2, What is your average changeover time between sheets?
3, What optimizing software are you using? Aftermarket or default included in cabinet software?
4, How often do you surface your spoilboard?

We have a Morbidelli N100 and we chose to get the rake and offloading table. It works well, we load a new sheet before we go to the offloading table and unload the parts. If you have space the loader is nice but you gain the most from the rake and offloading table.

Load: park a unit of Melamine at the foot of the router, outside the safety-zone, but close enough to slide a sheet off the end of the unit onto the table.
Unload: We don't label parts, so its a manual unload and stack parts on a cart for edgbanding. The carts are stacked according to part type and edgeband color, then sorted as they're built at the bench. Most sheets of cab parts are about 60 seconds to unload and clean table of dust w/compressed air. Drawer parts or smalls take longer because there are simply more parts to grab and stack.
Average changover is likely around 2 minutes. An operator 8 hour shift can usually process an unit of board +/-.
We use the nesting software that Thermwood has native to their control. It is alright, there are many ways to nest, but the Control Nesting has some options for priority, additional collar, nest to edge of sheet, etc. I've personally never found it wanting. The off-fall calculator seems to miss some areas for an unknown reason, but it is nearly always less than a square foot of material and likely is legitimate waste anyhow.
I surface the spoilboard about once a week, more in the summer, less in the winter. Having an insert spoilboard cutter means always having a fresh edge and accurate Zs. If I have a critical part, I might fly the spoil before running it. If your cut-through is set up properly (about 0.002) the spoil sheet lasts quite some time.
FWIW, we cut about 2-3 units of 4x8 commodity melamine a week, + ply and prelams, solid surface and flake.

Stuart, thanks for the info. I would guess we are doing roughly the same volume as you are. I have a few questions regarding your spoilboard. I am cutting my spoilboard down with the fly cutter 2-3 times a day. That is mostly due to the amount our bits are penetrating the spoilboard. I have found I change bits less often if I cut that deep. How often are you having to change your compression bit? (I'm assuming you're cutting with a compression bit) I would love to be able to cut the spoilbord down once a week even if it is at the expense of using more tooling.

When you say unload how do you do it? Are you unloading on the machine bed itself? Or are you pulling the parts off of the machine?
Thanks in advance.

I run the compression bits (outline mostly) about 2-3hrs each. Our control has a countdown timer and Its set to two hours. I usually check the flute tips by eye and by feel at that point and see if I can continue cutting. Usually I can run another hour or so, but its discretionary. I'm looking for wear at the flute tips, and the spot 3/4" up where the other melamine edge is. I know there is a tolerance that Vortex (for resharpening) uses to put the factory grinds back on. If I run a bit too long, that wear spot @ 3/4" wont have enough carbide to resharpen. I use a mortise compression for doing 1/2" drawer parts and that bit gets a substantial amount of wear at the tip from making the second pass thru an onion skin. That bit can also usually run past two hours cut life.
Our unload protocol goes like this: release vacuum, remove parts to cart, flipping each one over for edgebanding (flipping each part ensures the end cutters on our bander doesn't blow the face off of parts that had a double pass and leave the micro-lip). You should be able to manually set a machine variable (tableboard thickness, or spoilboard thickness) to incrementally step the Z reference untill you are JUST barely cutting past the part/spoilboard interface. Using an insert cutter for flying, I might adjust 2-3 thousandths if I use an insert pair for more than 3 flys. Often it is spot on. I DRAG most of the dust off the table towards my feet with the parts to minimize the cloud produced when puffing off the table to prepare for the next sheet.

we sell cnc in Israel
we produce it in china but all control system from us(we use mach 4 )and we design it according our need
i can tell you all our clients use load/unload
and auto labeling
so you have only about 1 min between boards(1 min is approximately time to load unload and clean the table)
the nesting software is very important ,its not about save the material,its about optimize the order and the lead in point for each part ,we cut 18 mm plywood laminate 2 side with 6mm diameter tool in one path(no any onion skin)speed about 18m/min
and use 2 water base vacuum pump(10 hp each)
we "eat" 0.2mm from spoil board about every 40-50 sheet
hope its help you

Hi Rob,
I usually do not comment here, I am a machinery salesman.... HAHA
This subject is interesting and could take hours to discuss however I do have a few comments. 1st, does going faster at CNC help down flow process or does it create a bottleneck? 2nd does yield based nesting help or hurt the process? (I.E. you save money on material but spend more getting the savings from what you have to do to make it in labor/hours). 3rd. do you have options with your system to modulate Z height (I assume the laminate is the problem) and can you common line rather than toolpath back through areas you already cut (save tool life by cutting fewer inches).

Chris, let me see if I can answer your questions.

1, The Router is our current bottleneck. I need to get more parts through it daily in order to alleviate the pain created by slow processing.

2, Currently we nest based off of yield. I feel like nesting for the shortest tool path or shortest time would even itself out by having to load more sheets on the router due to a lesser yield.

3, I have the ability to common line nest with Microvellum. I have never tried it. It would definitely reduce machine cycle time, and extend tool life. I would be willing to try as long as both edges acceptable from the common pass. Also, I can manually change the Z offset on the FANUC controller to ensure we are cutting on different parts of the tool.

Thanks for the help.

I think you need to watch your operator and make constant adjustments for them.

Are all the panels prepped ? Are they close to the machine ? Is the paperwork clear ?

Look at your nesting. Are you nesting entire jobs ? Or, are you phasing ? Meaning if a job has 10 exam rooms, are you running them all at once ?

Cutters. I use a coated from cnc-tool 3/8” compression that’s been on the machine for two units of melamine, 40 sheets of Plam, 100 sheets of pb, and it’s still sharp.

Tolerance 2nd sharpening, sometimes I wonder. After a long study, I’m almost about to go with Larry Sweitzers recommendation not to.

Anyway, we ran a 5x12 for a long time no sweep. It was hell. Look at the online photos of cnc’s from Omnitech. Lots of ideas for roller tables to feed or take off. Low cost

BTW. We also cut corian on our machine daily. I feel your pain. We all do.

I would label all parts. Break you jobs down into rooms and nest 2-4 at a time with nothing over 12 or so melamine sheets. Don’t pay to sort. Pay to cut them build with billable product sitting every few hours

Cabinetmaker

I agree that training and fixing broken processes are part of my issue. Those are currently being fixed and addressed with the operator.

Throughout the years we have developed simple yet complete "paperwork"-(its all on a tablet) for the operator to use. All materials are stored within a few footsteps of the router.

A general rule of thumb that I have is to never nest more than 18 cabinets. If we do I will have people downriver standing around waiting on parts.

I use an Onsrud 3/8" compression bit with the marathon coating. I would be open to trying new bits to see if we can extend tool life. I don't sharpen bits as it creates more of a headache.

I have a 5x12 machine and have built my own off-feed table. We have rigged up a "Rake" that attaches to the sheet after it is cut. Then the pulleys and ropes are used to pull it off the bed of the router. We load and run the next sheet before we label part on the off-feed table.

Thanks for your help.

Take time and just watch your operators how they load and unload machine. Make sure they understand the urgency of the CNC. I have an auto load and unload Biesse and we can run 45 seconds between sheets. At times we have struggled with output and I found the machine sitting idle because they were doing other task instead of making sure CNC was running. When we are real busy, we run split lunch’s and breaks, the CNC never stops and we rotate operators.
Before I upgraded to the auto machine, we had run some trials with a 1/4” base spoil board and sliding parts of with a thicker spoil board. Run would end, slide whole spoil board with parts off onto cart and slide new one on with new panel on it. It worked but we already had machine on order so we didn’t implement.
Additionally to speed up unload you could add an additional person to help unload