Keeping Up with the CNC

A cabinetmaker's new CNC will speed up only one part of his operation. Here, he gets advice on how to streamline the rest of the tasks in his process. May 6, 2007

We've just gotten a CNC router that we'll use to do cabinets and millwork, which is about 50/50 in our 5 man shop. We know it will speed up the millwork side tremendously. We also know it will speed up the cutting of cabinet box parts to a degree. But this really isn't what slows us down. Because after the parts are cut, we'll still have face frames to cut and assemble and place on boxes. About 95% of our cabinets are face frame, and we pocket screw, drawers to cut and assemble (which we butt joint), doors to cut and assemble, and of course adding all the hardware. So I'm thinking on an average job, we can save maybe a couple of hours at the most by using the CNC. So since the CNC doesn't seem to be our bottleneck, what ways have you guys found to either utilize the CNC better, or to speed up the other processes to match the speed of the CNC?

Forum Responses
(Cabinetmaking Forum)
From contributor A:
You won't ever match the speed of your CNC router with manual operations. What you will have to do though is change the triggers. What I mean by that is what processes are done first. For instance, making doors is a time consuming process. If you want to make your own in house, then you will need to start those first or you can always order them from a door maker. As for face frames and end panels, make them first or at the same time you are cutting the boxes on the router. If all of your material hits the assembly area at about the same time, then your cabinetmakers can put the cabinets together quickly. In most shops with routers, the bottle necks are all pretty much the same and all seem to gravitate towards the same cause - lack of material to assemble. If you build your boxes first, then you have to build your end panels and face frames and doors and then you have to assemble same. The only way I know of to speed this up is to build all of the parts at the same time or order out. I know this doesn't give you the answers you want, but I hope it helps you see that all a CNC router does is speed up certain aspects of the job and allow you to create things you may not have had the skill to create before. Face frames, doors, end panels (5 piece) still have to be milled separately and assembled. So think of changing the order of construction and/or outsourcing.

From contributor B:
For my frames I have a whirlwind upcut with a Tiger stop and their optimization program with a printer. The same software you use to output the code for your cnc should be able to output code to a tiger stop. Not only does this save a lot of time cutting frame and door parts - it also saves material.

I use grass Zargen drawers - that way the CNC cuts the parts and all I have to do is band and press together. If you are butt jointing your drawers, why then are you not cutting them on the CNC? The quickest way to speed things up is to use that CNC for anything and everything you can think of. You will never be able to keep up with the CNC in the rest of the shop.

From contributor C:
We cut a big stack of base panels at once for kitchen and bath. This allows me to quickly assemble a bath vanity or a small kitchen run even if we're in the middle of something else. For instance, we're working on a fairly large houseful of cabinets right now. I had a couple of small jobs come in, a bath vanity and an eight foot run of bases for a kitchen update. I'm able to just go over to the stack of panels, grab a couple out and put those boxes together right in the middle of the big job. I have a small shop, so this ability means quite a bit of money for me. I also precut the parts for drawer sides and frames, not the lengths, but the widths. Then I can just take the long boards over to the miter saw and chop them to length.

From contributor D:
Buy a bander and do frameless cabinets. If you really want to speed things up, order your doors. Without knowing the intimate details of your day to day operation I really don't think we could tell you what your bottlenecks are. I do know that switching to frameless will really, really make things go faster.

From contributor E:
Shoving boxes around has never been a real problem for us. It's probably the easiest part of everything we do. We build a euro box and plant it behind the face frame. Sometimes the PVC shows and sometimes it doesn't. We can cut-out, drill and assemble any box we sell in under a half-hour per box. We are working on some systems which will cut that time in half. Like you, the majority of our work is face frame. Almost all of it is flush inset and half of it is fully mortised butt hinges. Just because we build a "Geppetto" type product does not mean we can't standardize our systems of production.

What you are trying to do is balance the use of your resources so that you have everything that you need when you need it. It sounds like you have boxes under control. I would start next with a list of everything else you make.

You build face frames. Face frames consist of stiles, rails, mullions and muntins. Each one of these parts requires a separate set of operations. To build a face frame you have to:
Allocate sticks
S4S sticks
Chop to size
Pocket drill
Detail Sand

Each of these operations occur somewhere in your building. Depending on who performs the operation you probably have several methods at your disposal. Of all the possible methods, one of them is probably better than the rest. You should figure out which one it is and make that your standard method.

Where an operation occurs is probably linked to when it occurs. If the big guy is impatient to get the face frames hung then his helper has to do the detail sanding when the face frames are on the box. If this process happened earlier in the pipeline, the face frame could be sanded under better lighting conditions, quicker and probably with better results. The apprentice would be a lot happier, because nobody likes to sand and the company would be better off because this guy is now freed up to learn something new.

Where you do it, when you do it, how you do it and how you train people to do it will make a bigger impact on your company's success than any technology you can buy. Writing all this stuff down is a real chore but if you can't write it down you can't measure it. If you can't measure it you can't improve it. If you can't document it you can't train it.You also need a 4 sided planer. There's a million ways to cut out a box but there is only two ways to surface lumber on 4 sides.Tim