Time Needed to Produce Cabinets with a CNC Router

Cabinetmakers compare notes on the machine time and assembly time to make cabinets with a CNC, as opposed to working with a beam saw and line boring machine.May 27, 2014

Looking for a little insight from those of you that have made the step up from a panel saw/boring machine to a nested CNC.

We currently draw a job in KCD, export the cutlist to Cutlist Plus, cut/label parts on a slider, bore on a single row machine, and assemble with staples and screws. My thought is to have parts cut and bored on a CNC for blind dado construction. I have a very good grasp of the times it takes me to currently process my cabinets, but I have no idea how long this takes on a CNC.

A typical kitchen with about 16 cabinets and 20 sheets will take us about 1 hour in the office prepping the cutlist, 4 hours on the saw, and 1 hour on the boring machine. So we are about 6 hours total to have all parts ready for assembly (I am leaving out edgebanding, as this is a constant regardless of a CNC or not). We will then assemble those 16 cabinets with staples and screws in about 8 hours.

With a CNC, how much time can I expect up front in the office prepping the files from KCD, how much time to process the sheets on the CNC? I'm looking for a realistic time, not this 4 minutes per sheet stuff that excludes all the material handling of the parts/sheets. How many actual man hours to run 20 sheets through the machine?

With blind dado construction, can I expect a faster assembly, slower assembly, or similar to existing? Just looking for a real world idea from those of you that have done both.

So now with the obvious use of the machine out of the way (processing sheets into cabinet parts), what else can we do with this machine to generate income, or save us money on outsourced items? We currently outsource all drawers and doors.

One thought was to start pushing a 1 piece MDF door on our customers instead of a 5 piece. We do a lot of paint grade and almost always do it on a 5 piece door. Beyond processing cabinet parts and MDF doors, we are lost on ideas. Another option is to push our services on other local shops. Really just looking for other ideas and things some of you have done to use the CNC to generate additional income.

Forum Responses
(Cabinetmaking Forum)
From contributor J:
We would go from sending the gcode to the CNC from KCDW with the one button machining in about 10 minutes. It would take approximately 2.5 hours to run the 20 sheets, based on standard mix of base/wall cabs. We staple/screw, so no dadoes being milled. This is all processing needed on parts, full line bore, leg leveler socket holes, and the CNC labels the parts. This includes loading the sheets, pulling off parts and the junk frames and cleaning the table of dust.

From contributor D:
I don't like blind dadoes with melamine - the edges tend to break off. I've tried just about every assembly method and have settled on confirmats. Fast, no clamping, the cabinet can be modified if needed.

As far as time goes, I budget 20 minutes per sheet. In addition to all the shelf, slide and hinge holes, I drill 1/8 holes in the backs (plant on backs) rather than hand drill them on the bench. It takes time but every hole is centered and the screw is lined up by the time it hits the opposing panel. If you weren't using confirmats, you could pre-drill for #8 screws.

After edgebanding, it takes my assembler 8 to 10 minutes for final assembly. More if we're installing slides and drawers. I could run the CNC faster if I wanted but that would only create a big pile of parts waiting to be edgebanded and assembled.

From contributor K:
I am a small one man shop with a small iron CNC. It cuts one sheet while I am assembling the previous one. It doubles my productivity. For a mid-size shop, the way you are doing it is faster. For a large shop with a big iron CNC, it is very fast and efficient.

When you use a cabinet program, you have very few wrong parts. It goes together like a jigsaw puzzle once you dial everything in. For a one off custom thing, it's faster on sliders and boring machines. For everyday box building, CNC with a good program will pay for itself even for a little guy like me.

From contributor R:
I'm a small shop that just purchased my first CNC and love it. Parts library took several hours to create, but now I spend about 15 minutes in the office and about 2.5 to 3 hours on the CNC. I get about 6 minutes per sheet of time to do other things like edge banding or assembly. I thought I was good at utilizing material, but the computer is a lot better, very little waste. As for assembly, I prefer dowels.

From contributor K:
Our home office and garage cabinets utilize a blind dado/mortise and tenon assembly method. Unfinished ends use predrilled 3mm holes in the sides and no predrilling on the shelves. Finished ends use a rafix connector. We run backs and drawer boxes in matching 3/4 material. Run time is 5-8 minutes per sheet plus 2-4 minutes to unload and load new sheet. No secondary machining. Edge banding happens while next sheet is running. Cabinets assemble very quickly with no clamps.

There are other threads I have commented on software and I have a Youtube video of generating code to the machine in Cabvision in about 6 minutes. Software set up is the most important part to maximize output.

I do the same volume with 1 guy that used to take 2 1/2 guys with beam saw and ptp.

From contributor L:
We are a commercial only shop but run break room cabinets that are basically a kitchen. You can get savings in office time with good software, router would take 2 1/2 hours for 20 sheets. Blind dado isn't an option for us because it will not meet AWI standards. We dowel and case clamp. You could use a method that combines the blind dado with Rafix so you could have finished ends, no case clamp required.