Semi OT- comparing woodworking machines to metal working

Steve@Reliance · Nov 4, 2007

Next door a freind of mine has a cabinet shop. My dad used to own a business that made several wood products. I have known many woodworking shop owners as well. Since I have been around machines I have wondered why the woodworking machines never have any measurable form of adjustment. For instance, if I walk over to a bridgeport and turn a handle I can control how far I move the table by counting the number of graduations or looking at a readout. With the exception of the shops utilizing CNC routers, everybody working with wood is still using tape measures to adjust or set their machines. Now this may be accurate enough for wood, but I can't believe this is the fast way to do things. I watch these guys make a door panel for instance. If the door should be 15x24, it might be 15 1/16"x23 15/16" by the time he's done. The parts all fit together and the door looks fine. But you might not be able to mix the parts with the other doors for that set of cabinets. The guy next door does uppity level stuff and has done it for a long time, but if I suggest he put a readout on the tablesaw fence, he evasively mumbles something about it being to expensive and "it wouldn't work anyway". The methods a lot of woodwokers use to make stuff would make a metalworking guy pull his hair out. I can't understand why none of the machine builders utilize things like lead screws etc. so you would know how big you are making your stuff or how much your changing it. Just to be able to do repeatable setups seems like a no brainer to me????????????

fmari --MariTool- · Nov 4, 2007

In many cases it doesn't matter if the door is 24" wide. Next week when it get humid the door may be 24-1/32 wide.

Also unless you have a really strong vacuum system wood dust gets everywhere, much much worse that any metal shavings. Unless the readout scales have a positive pressure air feed I dont think they will be very reliable.

johnoder · Nov 4, 2007

As with any number of technologies, they are stuck in a time warp. Some even think it should be mentioned in sales blurbs, as if the "old way" was somehow better.

You can be sure those plants making millions of quarter sawn oak telephone cabinets 100 years ago wished there was a better way.

John

Racer Al · Nov 4, 2007

Another issue is that saw blades from different MFGs rarely have the same kerf thickness, and different types of blades - ripper, plywood, etc. - have different thicknesses.

Production cabinetry companies -- think Merilat or Woodcraft -- have CNC routers that do all the panel cutting.

John Madarasz · Nov 4, 2007

Plenty of CNC technology in woodworking...I know a guy who uses a five axis cnc machine to cut timber frame structures.

My main cabinet shop guy uses dial indicators to set up his cutters all the time, references and dials in knives that he grinds on a surface plate and uses 4R grad steel rules as standard equip.

Good machines with quality fence setups easily dial in to .03125...then it's just a matter of a quick test cut from something in the scrap bin to tune...quick and easy. Good cabinet work has to allow for movement after assembly, crush factors during assembly. With the exception of inlay work toletances are generally 1/32"...which is a mile in a machine shop

bryan_machine · Nov 4, 2007

Lots of rapid adjustment devices have come on the market, some are succeeding. Look at all the dials and gauges on a Festool Domino Jointer.

But such things are of finite value because wood is vastly more variable than metal. So often one is deliberately fiddling with the cut/grind/scrape to maximize or minimize grain, swirls, knots, etc.

And of course, all wood structures must be designed and built to deal with changes due to moisture load.

In cases like the saw mill, they'll measure the moisture of the wood at that time, and adjust for it knowing how to be in spec when they're done.
Also, there are modern saws that can follow curves (a bit), so that warped/bent/checked logs can still make good lumber.

Steve@Reliance · Nov 4, 2007

I understand most of these issues, but I have arguments for most of them. And of course the larger shops take advantage of the technology and they see it's benefit. It just seems the smaller outfits have a "we have always done it this way" attiude, and to be honest would have to make a fundamental shift in production techniques to realize the advantage of some new technology.

RickWGMkII · Nov 4, 2007

Some metal workers are the same way. Local community college welding dept somehow managed to spend $20,000 on a $10,000 PlasmaCam set up. So far they have made a total of 3 signs in the 11 months they have owned it.
The guy who "knows everything" didn't bother to read the instruction book that it came with & now can't operate it correctly because it's hooked up to the wrong kind of computer... Meanwhile half the welders don't work because they can't afford the parts to keep them working & the *know everything* guy doesn't know how to maintain em...

He has a real nice $6,666 sign on his truck tho...

When I enquired about using the machine I was told I didn't know how to use it, so I then asked about classes & was told they won't be offering any....
Turns out he heard a rumor they may close the welding dept to start up machine shop classes....

Ries · Nov 4, 2007

While home shop guys use woodworking tools that are indistiguishable from those in the 30's, many of the pro cabinet shops, at least where I live, have been using tools with readouts, measurable adjustments, and so on, for many years.
The Biesemeyer saw fence system, for both table saws and chop saws, dates back at least to the late 70's, and makes for quick, easy measuring and setting fences to the 32nd of an inch.
Many of the newer cabinet shops use the european 50mm system, with cnc routers, multihead drills, and other tools.
CNC panel saws have been widely in use for years- I worked at a place in 78 that had one.
Most widebelt sanders have micrometer, or, more recently, digital readout adjustments for thickness.

So the equipment exists, and, in most cases, has for 30 years or more. And smart, profitable shops use it.

Close Work · Nov 4, 2007

Pattern makers use metal working tools to make wooden patterns. Specialized wood working equipment with lead screws has been around for a long time in pattern shops. A high school shop teacher who taught an adult education woodworking class at night once told me he always had a problem with people familiar with metal working techniques because they were always wrapped around the axle trying to measure wood to 0.001" and never got anything done. A professional cabinet maker that does it for a living gets things done fast. The good designs allow for a loose tolerance. The real reason for strips of molding on furniture is to cover the gaps at the joints. The gaps allow for movement due to humidity and the for an increase in speed of construction with limited tools and machinery. A wooden table built by a tool and die maker would cost 10X what the market will bear. CNC, laser lines, digital readouts and nail guns are in use in any profitable wood working operation these days. Not the goofy people fixed on using only hand tools etc.

chrisfournier · Nov 4, 2007

Striving after tolerances costs money. In most cases when it comes to woodworking, the tolerances can be pretty sloppy because everything is hand fit in the small shop.

Only a fool would buy state of the art digital/robotic equipment to do a job that simply won't bear that kind of capital investment.

I would argue that being out a 1/16" is not the best work in the world of woodworking but this kind of variance from a spec will rarely cause a product failure,be detectable in use or recognized by the human eye.

Tolerances must be put within context to mean anything.

How much satisfaction would you really get from knowing that your dining table is within .005 per foot in all dimensions?

railfancwb · Nov 4, 2007

Grizzly Industrial sells a combination metalworking/woodworking mill -- http://www.grizzly.com/products/G9959

It has a larger table and faster spindle speeds than a metal-only mill of otherwise similar size would have.

bryan_machine · Nov 4, 2007

There's also a real cost issue. You can get "basic" import wood working stuff (which is a literal copy of stuff from the '30s...) for not very much money.

Felders and Altendorfs cost a lot of money by comparison (5x to 25x or so.)

tnmgcarbide · Nov 4, 2007

metalcutting machines are generally much safer
to operate .

feeds and speeds for woodcutting , when combined
with the minimal fixturing (a pair of human hands)
equals high risk of disaster in the blink of an eye.

with the exception of pedestal grinders , contour
bandsaws .... metal fixturing is much more positive
and safe.

the radial arm saw + the tablesaw are among the
most dangerous tools known to man. (sure, there's
the new $3k "sawstop"...but who has one in their
shop?)

a vertical bandsaw traveling at 150sfm , w/ a
10 tpi blade will gash a knuckle , or tear off
a fingernail if i slip cutting steel.

change that scenario to wood ...4 tpi , 3000 sfm
and i've lost at least 1 finger and a pint of blood.

Petersontools · Nov 4, 2007

Well, while I certainly use tailed apprentices in my woodworking, when I am making a special tool, for example, I use hand tools. And h*ll no, I am not 'goofy.' Peculiar maybe

Production woodworking, i.e., cabinetmaking is not the same as furniture making (joiners) or woodworking tool making. Sure, I'll use my table saw to resize my stock...but sometimes, I'll pick up a Disston D-42 Victory 12 ppi finish crosscut or 5.5 ppi rip and resize that way. Takes a bit longer.

Some of us like to use older technology--

Joe

dharnell · Nov 4, 2007

I work for a large European manufacturer of woodworking tooling. They have come a long way, carbide knife inserts,multi insert heads, PCD(poly crystalline diamond coatings), insert planer heads. If you want to spend the money it is easy to obtain 0.010" tolerances in woodworking.

Dave

matt_isserstedt · Nov 4, 2007

Just a couple of thoughts...

1. use of leadscrews relys on having precision "guides" in the case of metalworking, the typical dovetailed slide on a milling machine so the screws don't get racked into a bind. This would add some cost over the Biesemeyer system.

2. speed, cranking a .100" per rev leadscrew for 24"+ regularly would get many to cussing!

Interestingly, along the same lines, if a milling machine came standard with a DRO, the leadscrews there could be reduced to Home Depot threaded rod (joking of course, but the concept is that the DRO measures actual table position rather than relying on the precision "lead" of the screw).

Greg Quenneville · Nov 4, 2007

There are plenty of good quality European machines that allow walk-up 'n' cut accuracy to 0.004". And I'm talking about hobbyist machines, too. The entry level panel saws will all do this-the better ones will have DRO's on the fences as well as automatic positioning of fences and planer tables.

Anyone still using a Unisaw or R.A. saw in a commercial setting is losing money. Especially if there are employees involved.

BTW, the accuracy my machines deliver allow me to make some much better things than I could otherwise; better machines make up for lesser raw ability, same in any trade.

JST · Nov 4, 2007

Woodworking folks are (or were) set in their ways.

The shop at my old work got a CNC router. We then designed speaker cabinets that needed the accuracy of the machine, because we had to in order to stay competitive.

So what did the woodshop bozo in charge do?

He kept the machine busy cutting full sheets of one part, and complained that the shop was too stacked with parts when they ran our cabinets, because they had a lot of different parts.....

Mind, we had set up the cabinet design so you could get two out of a full sheet, or three out of two sheets, cut identically..... Easy as anything, every few minutes you got parts for another couple cabinets, which was as fast or faster than you could assemble them.

MUCH better than having carts loaded each with a full run worth of each part, and waiting days before getting any out. Plus, the rest of the shop could still run the other cabinets, that still used the tenoner, etc.

The shop boss WOULD NOT program the parts to get a cabinet per sheet..... which would have resulted in a HUGE savings of labor and effort. And our plant manager backed the shop guy to the hilt and told us we knew NOTHING and shouldn't design that way any more because it "didn't work".

The WORKERS and FLOOR SUPERVISORS really WANTED to run the parts that way, but the old guy in charge said it wouldn't work, wouldn't allow it, and that was the end of it...... He had been in the wood business for 40 years and was "the expert" for everything wood.

Chet Spencer · Nov 5, 2007

Our woodworking shop has:
DRO on our 24" Buss planer
Tiger stops on 3 table saws and a Crosscut.
DRO on wide belt sander
DRO's on vertical saw adjustments
Dial ind on shaper spindle housing.
and a laser on our straight line ripsaw

Semi OT- comparing woodworking machines to metal working

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