Question
If I were to transition to confirmat screws for carcass construction, what would I need to drill the pilot holes? I read that it takes a special step drill. Anything else to watch out for? I will be starting my first Euro style project and would like to use butt joints and confirmats. Any advice concerning assembly using butt joints? (We normally build ff cabs, using dados, glue and screws.)
Forum Responses
From contributor L:
If you want to get the benefits of systemic manufacturing at a basic level, take it off the bench and put the critical work onto equipment. Consistency and reliability come from holding tolerance, and tolerance comes from properly machined parts.
At your transistional phase, I'd suggest you purchase a "mini-fix" jig. Bush it to suit the diameter of the confirmat specification, and bore your horizontal members accordingly. Use either a drill press or your line borer (you can hand drill) to bore the vertical members. Although I prefer the larger diameter confirmats, you can use the ones with a 5mm shank. You can then use your line borer to drill through the vertical member at the desired location.
Tip for dual purpose line borers: Use 70mm length drills in the construction spindles to avoid removing all the other drills.
So the perfect bit would have a 6mm spearpoint section 40mm long, a 7mm section that was 20mm long (we bore mainly 18mm stuff) and, of course, a 10mm countersink with a 10mm shaft.
I made some comparison tests with confirmat vs Titus--make a joint and then break it. Both worked fine. The particleboard is the weak link with either screw. I like the Titus because the drill setup is simple and cheap. Five Bessey corner clamps, an electric drill and driver and away you go.
Another consideration? The smaller diameter can function like the sharp edge of a blade to shear through the panel. Which edge cuts quicker, the sharp face or back of the head on the ax?
Confirmats are a substitute for the case clamp and adhesive. Confirmats function as dowels to reference and locate the parts with consistent accuracy.
Thus the Euro hinge is inserted using plastic dowels. Most shops are now equipped with a hinge machine for the purpose. The Euro slide can be inserted using plastic dowels and cases are assembled using inserted wood or plastic dowels. Drawer boxes are doweled and even 45° plastic dowels are available for mitered corners.
The assembly screw is a very good and viable assembly method, but really it's a bridge from manual to machine assembly. As stated above, while assembling a cabinet, you're not turning an assembly screw, you're hanging doors. That is a simple explanation of "production" or efficiency.
Many times, cases are clamped for long periods in an attempt to overcome the hydraulic effect of high viscosity adhesive, overlength dowels or improperly machined components.
You didn't mention the type of dowel insertion you will use, but I think you'll rest easier with a "glue as you go" process in tandem with a true furniture cleat block. I wouldn't rely on dowels alone to build this type of case.
You don't need the headaches associated with adhesive in the butts, besides the finish prevents it from attaching itself to the wood.
I wouldn't rely on a back panel to "hold" the case square. In high-end audio, an easily removed back is a sales benefit. PE the case to include vertical members tied to horizontals to achieve a square case. Think of the keel on a sailboat.
Do it right the first time, overbuild your mockups, and "backup" from there. There's no reason to cut a corner in construction, especially when dealing with this type of product.
On the very cheap end you're going to have 85-90K in a small P2P, another 50K in a saw, 6-7K in a dowel gun, 5-8K in a clamp. You will also easily spend 30K on software. You guys know as well as I do that the machines I'm talking about here are not able to produce the volume you're talking about, but it does give us a reference for the sake of argument--say 180K for an entry level doweling setup.
The other side of this: with a couple of 12K boring machines you will have a nice setup for using confirmats/European assembly screws. You can get in a decent slider for 30K, so for 54K you can have a good setup for doing smaller volumes.
My point here is if you're making a buck turning screws, what enticement is there to go into business with your local banker? Higher volume? Does higher volume really translate to more profits in this industry? Especially in a small shop, which is how I'm looking at this. I ain't even going to go into how I fit the saw, P2P, clamp, dowel inserter into my 24'x24' garage:)
The key to the strength IS in the design using vertical pieces as stiffeners. I want to get the best glue joint possible using dowels and was wondering if using pre-glued dowels has any advantages or disadvantages over glue capsules. I do not have a dowel inserter but I think it may be a wise investment.
Growth requiring semi or unskilled labor could be time to re-examine the dowel issue. At this point, a fully doweled case can begin to make sense.
One of the reasons I am high on confirmat construction is the changeover to fully doweled cases is so simple. It is simple because the cases are constructed just like I would with a fully doweled case.
In confirmat or mini-fix cases, I use dowels, typically glued, in my rails, rather than two confirmats. On runs of a hundred or so, I'll usually pop a couple of dry dowels into the full depth horizontal members to aid the assembler in alignment.
Increase the numbers, and I'll replace the confirmats with glued dowels. I liken this to planned growth instead of being pushed into reinvention in the heat of battle.
For equipment, the semi-automatics can deliver a large quantity of high quality components. The P2P can quickly hit its peak. Can't a dedicated horizontal borer/doweler, a double line borer and a construction borer be had for about the price of a P2P? And these machines are always "in demand" in a growing operation.
We don't need to always optimize our speed of operation, since we only make money on the performance of the total operation.
I know this sounds confusing, but here's an example. While cabinet parts requiring finish are in the spray room and drying, you could be working on drilling pre-finished doors or putting tracks onto pre-finished and pre-assembled drawer boxes.
Another example: use the point to point only for the cabinet sides (if you don't use partitions), keep your existing horizontal boring machine set up only for end drilling on floors, tops, stretchers, and kicks. As was said, you could actually upgrade from your horizontal borer to a borer/inserter for about 20,000 more. You can do 1 side every 30-45 seconds on a point to point, but you can do two horizontal rails drilled and inserted if upgraded to this machine in 1/3 the time. In fact, a point to point is a real bottleneck maker if you decide to use it for every part. This assembly speed is only attainable with a dowel method, not staples and screws or blind dados. It's a constraint of the machinery available to process parts at this speed. They simply want to drill and shoot dowels, not confirmats or staples and screws.
This is expensive stuff, and it's true that you wouldn't be able to produce hundreds per day with a point to point. The method you choose must relate to your entire mode of doing business--that means gross, personnel, budget, machinery and communications.
The point to point has made a significant positive difference in our casework production, (partly because it simply helps to force a new level of rationality on the process). But the point to point has truly revolutionized production of most of the other things we make besides boxes, and that is where it is really earning its keep. It is also bringing in a steady flow of highly profitable piecework from other businesses who haven't made the technological commitment but who need the results.
In our FF shop, we had 10 people running the finish department in two shifts. I nearly ended up in the hospital with stress fatigue, and we were loosing money hand over fist. There were several factors working in that situation, but I can now do with 1.5 people nearly what I was doing with 10, we make a profit, and my stress level is nearly 0.
My point is that I am making money at what I'm doing, so why should I want to add the complexities of doweling into the mix? I don't want 15 people in my shop. I only need to depend on 2 guys to show up for work. I just don't care to be big for the sake of being big. I see the headaches my brother goes through trying to get and keep employees in his shop and I don't need it.
To contributor R: is your entire system up and running yet? Are you labeling at the saw, and using barcodes at the P2P and Hdrill/inserter? How long to get this thing going and all the associated hiccups ironed out? What has happened to the bottom line? How long to learn, set up, and implement the software?
It's too soon to say how the bottom line is affected, but throughput is already improved. Our worst bottleneck has been in the office, getting work from the returned submittal stage out to the shop to start processing, and Microvellum is already cutting this time radically. Fold in the accuracy of cutting lists, the ease and efficiency of cutting well-optimized parts and the speed of barcoding at the p2p and I think it will pay off very quickly. I couldn't say how life would be if we had never started with dowel construction back then, but our evolution from manual to automated has been a success. I think that with the right tools, doweling actually simplifies things, but the cost of the tools is prodigious. The shop almost looks like my vision of what I wanted when I started- quick, clean, quality. Now we've just got to learn to relax!
I may be a very lucky businessman but I have a payroll of 34 and no current employee headaches. When I bought the business all the problem people quickly left (10 of them are currently working for one of my competitors!) and the remaining group is dependable and working hard. I am trying to create some common goals, both financial and otherwise, and we are working together as a group for the first time in 10 years. An intangible benefit of the technology move has been the change of work and attendant excitement for at least 5 of my employees who might have otherwise been deadening in their careers--these guys are supercharged right now and carrying others with their energy. Learning new things is a great motivator.
I don't have any interest in being big for the sake of being big, either. We were the biggest in our state for several years and the bigger we got, the less money we made, to the point of near collapse. I like the size we are because it enables us to take on the projects that no one else can. I'd really like to shrink a bit because I feel exposed to a downturn in the economy, and I don't especially like to work as hard as we do currently. But I really enjoy the challenges we face and I am gratified that realizing my personal set of goals is also providing a good and rewarding living for a whole lot of other people and their families. If I stop liking my employees, I guess I'll stop liking the business and stop wanting to enable them to get where they want to go. So far I'm getting what I want out of the whole thing.
