How do furniture companies square up stock?

[Stephen Tashiro]

How do the large furniture manufacturers prepare stock? Given how much time and skill it takes to use a jointer/planer to square-up stock, I can't imagine that they have boards squared up that way. What kind of assembly line apparatus can do the job?

[Matt Day]

I think everything is just bigger and more automated. In other words, put in a rough cout board and it's taken away by a feeder, it's jointed in one pass and continues to the planer for the other side, and out comes a squared up board. I'm sure others will comment more.

[whit richardson]

Have you looked at how most "furniture" is made these days? :eek:

[Jason Beam]

There's a machine out there that cuts on all 4 sides, yielding a square board. You gotta start with something reasonably the right size (like, say ... a rough sawn 2x4). The stick goes in one end rough and comes out the other end square.

As for straightening and flattening, the above process usually yields something straight/flat enough because of the mechanism that does the feeding - it's unlike a planer that presses down, on these they just feed the stock through in a straight line; letting the blades do the straightening, basically. You gotta start with reasonably straight stock to begin with, of course.

Though, I think the more common way is to let the lumber yard do it. You develop a relationship with a yard and buy skids of wood that they let you pick through and return the boards you don't like. This stock is nearly always S2S or S3S - from that, your parts get built. Those machines work a lot like the 4-side cutting machines except they usually just do two side and then straight-line rip the other. If it ain't straight enough, the furniture maker rejects it and the yard gives 'em a refund.

Our local lumber yard does this so much that they hold an annual BBQ for our woodworking club to pick through the rejects for a discounted price. You don't get FAS lumber, but you do get workable stock for a decent price. As hobbyists, we have more time to devote to working around a given board's flaws.

[Brian Kerley]

I know one of the lumberyards I used to go to had a 12" planer that would surface 2 sides at once. Basically it fed it in, jointed the bottom, then there was a small flat plate to register against, and the top got taken off. Like it was said, you need reasonably straight stuff to begin with, but it worked pretty well.

[Rod Sheridan]

Stephen, a sticker can surface all four faces in one pass, if the material is small enough.

For large items, a large jointer with a feeder can be used.

Regards, Rod.

[Stephen Tashiro]

What I can't visualize about this industrial machinery is the feed mechanisms. One thought is that you could have powerful clamps that grabbed the board from the sides and held it on a sliding bed. The clamps wouldn't extend to the upper surface, so you could plane it off as bed slid. You could have a similar arragement where the bed stayed still and a plane moved over it. (I think I saw a picture of a type of wood shaper that worked like this in an old shop book.) But I suppose if there are two spinning circular saw blades side by side (a "double table saw"?) then the blades will both cut and guide the board. All you need to do to feed the board is to push it. That's the way I visualize what some of the previous posts describe.

[Rod Sheridan]

Stephen, imagine a jointer with a power feeder mounted on the outfeed table, that's the first face done.

Now imagine a second cutterhead at 90 degrees to the previous one, that's the jointing completed as you've done two adjacent faces.

Now imagine two more heads parallel to the first two, that plane the next two faces.

Out the end of the sticker comes stock that's prepped on all four sides.

Regards, Rod.

P.S. You feed the sticker with the output of a gang rip saw, it has multiple blades spaced at whatever width you want your rough pieces.

It has a tractor feed that dips below the saws, so the wood is trapped and has to go through in a straight line. Out comes parallel strips of wood, ready to go to the sticker.

The other machine that could be used is a straight line rip, it rips one edge straight.

[Chris Tsutsui]

As far as mass production goes, check out this Milling warehouse in Saigon.

The furniture goes on pallets that are on tracks.

http://www.westwoodbaby.com/2008_07_01_archive.html

I think that the power feeders for production machines will be those triple rubber roller types.

[harry strasil]

The sawmills around here used to cut DEALS (5 by 9) rough cut stock anywhere from 5 to 10 foot long out of oak and cottonwood for specific furniture Manufactures and bundle them and strap them.

[Cliff Furman]

http://i119.photobucket.com/albums/o135/SVLightnin/CCF07292009_00002.jpg
Here's one way.

[Tom Hargrove]

I worked for a small furniture company in the late 1970's. We started by cutting rough lumber to length, which was somewhat longer than the finished size. We then used an inline rip saw to develop rough width, generally 1/16" to 3/32" oversized. From there the stock went to a jointer with an overhead feeder to receive one flat face. We then used a planer to get two parallel faces. All pieces were approximately 1/16" oversized at this point.

We then used a large shaper with staight cutter head and a big feeder to machine one edge that was perpendicular to the two faces. The wood went through in a "climb cut" fashion, with the fence on one side, the shaper head on the other, and the wood passing between the two. The feeder kept the parts from flying away - most of the time. This is not something you can do by hand, so don't try this unless you have the right equipment and hands on training. If the fence and feeder are not set up just right, horrible sounds come from the machinery, and big chunks of wood fly all over the shop. Pieces of steel can also become airborne, and people get hurt.

After all the pieces were milled, we adjusted the shaper fence, and ran the other edge by the head to obtain the desired width. At this point all four sides were perpendicular.

After additional machining, (routing, shaping, boring, etc.) almost all parts went through a large two head wide belt sander to reach final thickness. The first head used a coarse grit to remove as much as 1/32" from one side, and the second belt/head had a finer grit to do the final finish sanding. The parts were then flipped, and after the machine was adjusted to final thickness, the parts were run through again to reach final thickness.

We could also feed finished assemblies (i.e. assembled table tops) though the sander, but it only to do final sanding.

[Michael Conner]

Here is a link to a 4-sided planer molder. Rough cut goes in one side and dimensioned material comes out the other. The description above regarding cutters doing all of the flattening/straightening is dead-on.

http://www.baileysonline.com/itemdetail.asp?item=PH1+260&catID=

[Cliff Furman]

770 #'s A light weight.
The the motors in the previous post most likly weigh that much!

[Howard Acheson]

The factories I have been in all use combination, automatic feed tools. Rough cut wide boards are fed in and cut into multiple boards. These boards are then automatically fed into a jointer, planer and edger machine. The come out surfaced all four surfaces. Takes maybe 30 seconds to a minute per initial board.

Smaller factories may have smaller equipment where a person will feed the boards into the machines.

[Brad Shipton]

Here is a link to a modern Weinig Moulder. A big boy toy for sure that'll set you back around $300k+. It needs great amounts of power and a huge DC machine to pick up the chips. This plus a 25hp gang rip saw and you will be firing out so much wood every hour you will not know what to do with it all.

http://www.weinigusa.com/products/moulders/powermat/p1000/main.htm

Brad

[Paul Ryan]

The sawmills around here used to cut DEALS (5 by 9) rough cut stock anywhere from 5 to 10 foot long out of oak and cottonwood for specific furniture Manufactures and bundle them and strap them.

The mill I buy most of my wood from is one of these mills. Most of the stock they sell goes over seas. It is nice and flat, usually doesn't need to be jointed, just planed and straight lined.

[Peter Quinn]

We have a Weinig and several Wadkin through molders in the flooring department of the shop I work in. They do 'surface' all four sides of the stock, and they do flatten lumber to some extent, buy they don't flatten stock to the extent you might want for custom making furniture. All the material fed into them has been planed "hit and miss" to a consistent thickness, and has been gang ripped to a specific width with parallel edges. Mice machines, but they don't flatten wood.

I think there are S4S machines that do flatten wood fairly well, but I have not used one of these.

If you look at much of the 'factory made' furniture, it has the tell tale signs of mass production design. There are almost NO flush faces at any intersection, and those that do exist have a chamfer on the rail portion of any rail stile intersection. They may not be using or counting on truly flat stock. You also won't find many doors with tight reveals, or drawers riding in a system of kickers and doublers with tight tolerances. Computers have often chosen the grain match, and stains/dyes have served to 'match' the color and grain. That "mocha mahogany" look is quite popular in part I think because it allows manufacturers to cover up almost any grain but still have a wood like look.

In short, how do they flatten wood? I think they don't, they work within "flatish" tolerances.

[Frank Drew]

I think the Oliver Strait-O-Plane that Cliff pictures face joints and surface planes in one pass, yielding flat stuff; I'm not sure if it also does the edges.

[Rich Engelhardt]

Hello,
Krapmaid has this blind guy with a chainsaw,,,,

[Stephen Tashiro]

All this industrial machinery is impressive. It is also interesting to know how designers avoid designs where absolutely true stock is required.

The way that I visualize a jointer flattening a board with one pass is that it would have to have a depth of cut that was about half an inch -no gradual shaving off of a few 64ths. I see why it would have to use a power feed

[Rod Sheridan]

All this industrial machinery is impressive. It is also interesting to know how designers avoid designs where absolutely true stock is required.

The way that I visualize a jointer flattening a board with one pass is that it would have to have a depth of cut that was about half an inch -no gradual shaving off of a few 64ths. I see why it would have to use a power feed

Stephen, power feed is also required because a person can't feed fast enough to have the wood cut properly.

The other issue is power, people aren't very strong over the long term, try pushing wood through a saw or jointer for 8 hours, you'll have a very small pile compared to a machine with a feeder.

Regards, Rod.

[J.R. Rutter]

Defect/Crosscut
Gang Rip
(both of these can be fully automated for enough investment)
Glue panels
and
Moulder with hopper feed for individual sticks

[Pete Bradley]

How do the large furniture manufacturers prepare stock?

First, they roll in a pallet of veneered fiberboard...