# How much precision do we need in woodworking?



## b2rtch (Jan 20, 2010)

I have posted again and again about my Powermatic 60 jointer.
Now I am still wanting to adjust the tables.
For that I need a good straigth edge, I have been borrowing a Starret from work but it is only 36". 
I would like 72 or 96" so that I can use it for other things but really good straigth edges are extremely expensive. 
So, like may other people, I was thinking about buying a steel ruler or may be a carpenter level (I need a new one anyway).
Many time I have been wondering if we demand too much precision when doing wood working.
Do we really need to adjust a TS or jointer within a few thousand when we are working wood, a living materiel which will move again any way?

I understand why I need my jointer tables need to be co-planar and flat and so on but when do we become obsessive/compulsive about it?

What is acceptable and what is excessive and our quest for precision and accuracy?

(by the way, I work in the pharmaceutical industry and I daily check our equipment with an accuracy with a few 1/10 of a thousand of an inch and/or a few tens of a thousand of gram)


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## BrentNichols (Apr 30, 2010)

Bert, 
My experience from this is that it does not need to be perfect. However it may seem that you are a little like me and we are perfectionists to a small degree. I do too put a dial indicator on my jointer blades when changing to get them within .001 of an inch, as i also do this to the tables. I also use this method align my tablesaw fence and miter track to the blade. My other friends tell me that i am way to picky when setting things up like this and as long as its close it will work fine. It would be perfectly fine without the precision we use but it would be the idea of knowing it was not close to perfect that would bug me to fix it. I hope this hepls a little.


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## b2rtch (Jan 20, 2010)

BrentNichols, I believe that this is a good explanation.


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## CplSteel (Jun 22, 2012)

I like it when things fit together well however, If you are asking if we need our tools dialed in percicesly the answer is no, precision can be had easily without exact error free tools. There are two different ways of working, machine precision and cutting to fit. Neither is right or wrong and they have different advantages. If you want every leg of a table the same length, you can dial in a saw to 1/100" a, measure, and cut each leg. Or you can cut one leg and use that to measure the others. In the first example, if your measurement is off between one leg and another, the variance is small, in the second because you are referencing off the piece, if you are off the variance is small. You can always go back and true them together, all four at the same time to ensure they are exactly the same length.

If you watch Roy under hill, he may measure a piece at 6" and cut it, but when he goes to drill the center of it he doesn't measure in 3", he uses dividers. That way even if 6" is 6 1/8", center is still center.

Another example is door fronts. If you batch them out ahead of time then your measurements, on all the cuts, not just the drawer fronts, need to be percise because a 1/8" gap stands out. However, if you cut to the size you need, not the size you planned to need, the left drawer may be 1/8" wider than the right, but because you can cut it that way the gap between them will be uniform and unoticable.

Obviously if you are making many identical cuts in a production shop and you are using very stable material, like mdf, then taking the tIme and expense to dual in your tools will be money well spent. A home hobbiest working with real wood can just work a bit differently. After all do you need 4 legs all exactly 23" long or do you need four legs about 23" long and exactly all the same length. The latter is far easier to achieve than the former.

Most importantly is to work the way you enjoy. I am lucky enough not to own any machines made well enough to be dialed in with that kind of precision. When I do, I will probably try to get them exact as well.


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## b2rtch (Jan 20, 2010)

CplStee, thank you for your very good answer, I truly like the way you explain the way you achieve what you want to achieve.
This makes a lot of sense to me but my sequestration is more oriented toward how much precision do ewe need while adjusting our power tools.
I read review and read about people using, say, Incra miter gauge that they can dial in within 1/10 of degree or so, is this really necessary?


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## LeeBarker (Aug 6, 2010)

To find what is acceptable for you in terms of accuracy, improve things until you aren't apologizing for your work.

Kindly,

Lee


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## EPJartisan (Nov 4, 2009)

With an Industrial Design background.. I was taught to do the best you can at every stage of the process, because you can not be perfect and all those small imperfections add up at the end… BUT that was for manufacturing mass producible items.

To me, wood working is more like sculpture. I love being perfect, but i never let the tool determine the process nor the result. I gave up "perfection" a while ago, my tools move each season, blades go dull in the middle of a process… the wood a living material and if you don't work with it… it will work against you. yet I work that there are places people see and feel and those places I make perfect, but the rest I just don't stress about, so I say always do your best, and only focus on perfection for those few areas: joints and visible places. Thus I focus on beauty,, not perfection. Just take a serious look at Japanese cabinet makers… little spaces, uneven areas, plane marks.. they are about the beauty and efficiency… the perfection comes from the passion and repetition.

The other thing is.. people are far more amazed YOU actually made something from scratch.. people are kinda blind to the imperfections we beat ourselves up for.. and I only fear other woodworkers scrutiny.. LOL. There is a book titled, the structural properties of materials.. and they have a chart that explains how much you can be off before it is a) actually visible to the client… b) or will fail from stresses. and you know.. we get a lot of wiggle room.


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## b2rtch (Jan 20, 2010)

Lee and Eric, I truly appreciate what you write, I believe that these are good lessons.


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## jdmaher (May 4, 2011)

As CplSteel said, fit is easier to achieve. And remember, you ain't gonna hit spec anyway.

I'm not doing production work with metal. I'm doing hobby work with wood. I thickness the boards to 3/4" - on an August day that's 98 degrees and 87% humidity. Then I have to work for a living; and my wife insists on visting people and having guests over and taking a trip and replantting the gardens; and I have to work for a living. When I finally get to cutting the tenons on the end of those boards, it's almost Halloween and 45 degrees with 45% humidity - and I mis-measured when I thicknessed anyway - so damned if those boards aren't 11/16ths thick!

I try to keep my focus on making something that looks good and fits, not something that measures out exact.


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## EPJartisan (Nov 4, 2009)

For my empathy.. I purchased a jet 6" jointer about 6 years ago. It was on sale and Rockler only had the floor model left. needless to say.. I will never buy the floor model again. The beds are not parallel, infact one has a slight bend to the bed as if it was dropped at some point. I was a naive to the tool at the time, but now I know more than I have ever wanted.. it is a great tool to have on hand.. but a total PITA to maintain and adjust. I moved on to make sleds for my table saw, but I still use it for pieces under 20".. yet I still get angry at it and try to adjust it, shim it.. take it apart.. then give up! I only use it the best I can and move on with the desire to trash it and get a 8" grizzly or something.


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## WrathOfSocrus (Sep 8, 2011)

I agree that changes in moisture can negate accuracy, particularly in humid climates like where I live. I also agree that woodworkers beat themselves up more than non woodworkers would care or notice in your projects.

One thing I would say is that I don't think it matters to have that level of accuracy over 6 feet or more. The weight of the wood would lay itself down if the ends of your infeed and outfeed are off a few thousandths. I'm sure if you planed a piece of wood (say 4 feet long or more) perfectly flat and uniform in thickness, then clamp one end to a bench and let it hang off, it would sag more than just a few thousandths. If you can get the 18" - 24" on either side of the cutting head to a flatness you find acceptable, then you should be able to produce stock reliably within your tolerances. If the machine has long feed tables then I would just check each for flatness and then flatness and accuracy between tables at the cutter head. If you use add-on feed extensions I would just get it close without going crazy. If you are spending more time lining up extensions than u did building them then it probably isn't worth the time.


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## dbhost (Jul 20, 2009)

If we were working with highly refined alloyed metals with controlled expansion / contraction rates, and building components intended for high speed operation I could see tolerances in the thousandths or ten thousandths being the range we want to work in, but we aren't, we are working with wood, a media that moves and flows on its own. While I don't encourage anyone to be sloppy in their work, I don't see the point in going to extremes for accuracy when there is no real benefit. If for example a piece of steel stock used as a straight edge is within .001" in an 8' run, to consider that not straight for woodworking purposes is for all intents and purposes over concern with accuracy. I would however be concerned if there was variation at the .1" per 8' level…

You say you have a 36" straight edge that is known good. You can check an 8 footer with your 3 footer. If 3 feet are good, then move down 2 feet so you are checking against a known good foot, and check, repeat until done…


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## ssnvet (Jan 10, 2012)

I'll add a couple thoughts….

In general, I think chasing thousandths in a woodshop can be misplaced effort. Because wood can be porous and has grain, variations of a few thou. are inherant to the material. Also, because wood "moves" a part that is spot on today, may not be tomorrow.

But the human eye and sense of touch can detect differences as subtle as .005" quite easilly… so you want to have "perfectly" matching surfaces…. but how you get there with wood is a different approach… one that reflects more "craft" than it does "math". So little things like the sequence in which you cut… making the final pass for all your table top boards through the planer at the same time, without and changes to the settings (so the part to part variation is effectively zero) is more important than the ability to dial in 1.000 on a Wixley.

Woodworking craftsmenship has to take into account shrinking and swelling as well. So the better mortice and tennon joint isn't necesarilly a 1.000" tennon in a 1.000" mortice. But rather, a slight interference fit achieved by lightly sanding a tennon that is intentionally cut slightly oversized untill it can be driven into the mortice, with relief cuts around the shoulder may yeild superior results.

I certainly like precision… but I'm finding that the absolute measurements are of lesser importance than the relative measurements between mating parts..


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## Loren (May 30, 2008)

I think there is too much emphasis on making wood objects perfectly
right off the machine. Even if you square plywood good panels very
square, there will still often be a little twist in a plywood cabinet
due to distortion in the material. You can learn to make things
look good and function well anyway. Perfection of the geometry
of the box is not essential to its function and good appearance.

I know from experience my jointer doesn't have to be perfect to
be mostly effective (I had a 12" machine with funky tables
and worked around it). Wood always moves and the process
of jointing and then flipping the board over and planing the other
side to thickness always results in the balance of tension in the
board changing. I check long boards with a 78" level and 
winding sticks (though my eyes alone have got pretty good). 
Corrections are done with hand planes. Sometimes the smart
thing is to take the tool to the work.

A reliable thickness planer is more of an asset to me than a 
large jointer. Thickness consistency from part to part is
important to me… more important than surface finish off
the tool. This is why I use a Belsaw.

I recommend a 78" level as a most useful device for making
good boards. In millwork, the long level is essential to
the way I work.

A black lumber crayon and a white piece of chalk or grease
crayon are also very useful to mark flaws in board faces
and help keep track of which side was planed last.


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## DanKrager (Apr 13, 2012)

I have learned that as you gain experience, there are many times you don't want a board to be perfectly straight. For example, gluing up a panel with tension in it will help it last for lifetimes without splitting. A jointer set to get a perfectly straight edge most likely will not do it on a regular basis and the board will more likely than not have a convex curve in it. I used to adjust mine so a very slight concave curve resulted. Another example, A bit of curve on a hand plane blade is useful to speed removal of rough surfaces and slight (<.002> concave edge for edge gluing. 
Agree with those above. Perfection is not needed everywhere, just in the critical areas. Like finishing a house…the only two places perfection is needed is in front of the toilet and around the front door!

BTW I'm happy if a 10" blade wobbles less than .005.
Dan


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## PurpLev (May 30, 2008)

I think people try to be too precise when it comes to woodworking many times when it comes to perfect joints and what not, but when it comes to straight/square cuts - small differences do show up in the finished product and yes, it does make a difference. to a few thou in the finished cut? definitely not, but definitely to 1/64th.

thats as far as cuts go, but when we discuss setting up machinery there is another aspect to it - safety.
setting up the blade parallel to the miter slot with too much variation can lead to pinching of the wood between blade and fence and can lead to kick back for example (there are more cases of course, but this is the most obvious). so when setting up machines - I would indeed use the 1/1000 scale

bear in mind - setting up machinery with precision is greatly different than using that machinery to cut wood precisely…. 2 different scales being used there.


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## knotscott (Feb 27, 2009)

Good nuff to fit well and be appropriate for the project. A 1/16" gap can look pretty darn big on a jewely box….not so much on a swing set.


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## Smile_n_Nod (Jan 20, 2011)

Bert, instead of buying a long straightedge, you can make your own "straightness gauge" out of three boards and some screws.

Obtain three long boards that are not warped. Drive three (or more) screws into one side of each board (the screws must be equally spaced and in a straight line with each other).

Next, lay two boards on their sides so the screw heads are facing each other. If the tops of each pair of screw head are not touching, adjust the depth of one or both screws until they are touching.

Now, replace one of these boards with the third board. Repeat the process until the screw heads on any one board exactly touch the screw heads on the other two boards. Once this is achieved, the screw heads on each board are in a perfectly straight line, and you can use any of the boards to check if a surface is joiner is flat.

Harder to explain than understand, especially without pictures.


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## Smitty_Cabinetshop (Mar 26, 2011)

^ "Do we really need to adjust a TS or jointer within a few thousand… What is acceptable and what is excessive and our quest for precision and accuracy?"

No, and, the project will decide.

The object of the exercise is not precision, but product. Getting there could mean power tools that adjust to the thou, or handplanes that shave a thou. Get the wood to the right fit and you're golden. Now for the part that will most assuredly stir the pot: unless I'm missing something obvious, mini-micro adjusters on stationary power tools are ridiculous for the non-production workspace. That capability is certainly not in my tool budget, and won't ever be. That tools are 'dialed in' to that level strongly implies parts that come from those tools are ready for finish 'off the tool.' And that's not true. You sand, or scrape, or plane additional material to make parts / assemblies finish ready, so why sweat cuts to the thou? Get material as square and true and you can, assemble for final fit, and move on to the next project that challenges. My .02


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## Doss (Mar 14, 2012)

*dbhost* said pretty much what I was going to say. I've always wondered why woodworkers chase tolerances of .001". I mean, it's great if you can get it, but worrying about it is a little much. I know we should make sure the wood is cut to certain sizes and that we have to make room for expansion/contraction, but that's more on the cut-to-fit side.

If you're building high-speed machinery, firearms, etc. on the other hand, I understand the concern over really tight tolerances.


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## b2rtch (Jan 20, 2010)

Brett, thank you for the idea but I do nothing that it would work: the piece of wood rests on the two screws but what in between the screws? How do you knolw that this piece of the table is flat? 
Do I miss something?


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## alba (Jul 31, 2010)

Bert, I use a 6' level

I like my machines set to work straight for

jointing panels and after coming off the

planer I still like to run the #7 along it.

Then comes putting my furniture together…......

well you know my stuff, it has a comfort fit. lol

I can cut square by eye, but I still mark with a

square, just so I know I'm reasonably close. 

jamie


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## 47phord (Apr 10, 2012)

One thing to remember while chasing all this endless perfection is that, as the person who built your project you know where all of the flaws are and consequently, you see them every time you look at it-while the average Joe looks at your project and sees the project as a whole. In other words, you're standing there cussing because one of the legs on that table you built was .01" shorter than the others and your miter joints didn't come out as tight as you wanted, while Everyday Joe is standing there saying "that's a nice looking table you built there. I wish I had your talent!"


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## ArlinEastman (May 22, 2011)

Burt

It seems everyone is talking two things here

1. Equipement
2. Wood

I like my tools to be within .002 to .001.
However, I have learned that my time as a machinest does not help me in wood. Wood requirements are way different because of the movement.

I also like my tools to be the best they can be because I make enough mistakes as it is. lol

Arlin


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## RogerM (Oct 31, 2011)

You might want to check out the Wood Whisper web site http://www.thewoodwhisperer.com/videos/jointer-setup/ on joiner set up procedures. Basically it is not an easy task but this video gives a very good and detailed description on how to effectively deal with many of the issues you are having with your joiner. Nothing better than experience.


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## knotscott (Feb 27, 2009)

About the only tool measurment I chase to 0.003" is the blade to fence alignment on my TS, and that's mainly to prevent binding/kickback situations, plus it helps me evaluate saw blade performance in the event I should test one.

I don't get too worked up about table flatness, the precision of my straight edges/squares, planer uniformity, etc…..if I can't tell a problem by using it, it's not a problem. It drives me nuts to read about folks wanting to return a perfectly good TS because the table flatness isn't within 0.02" across it's entire 40" span ….it could so easily be their measuring technique, or their straight edge….if it cuts well, it's good.


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## Smile_n_Nod (Jan 20, 2011)

Bert, I was trying to describe a technique I read about for validating the flatness of a jointer. If you have three boards with edges that match each other perfectly, all of the edges must be straight. If you have to boards with matching edges, it's possible that both edges are curved and fit each other, but if you have three boards that match each other, the only way this is possible is if they are all straight and flat.

You could hand-plane three long boards flat and straight and verify that they are straight, but using three (or more screws) equally spaced along the edge of all of the boards is a little easier because you only have to adjust the depth of the screws. True, you won't have a straight edge, but you'll have three screws (on each board) that are perfectly in line with each other. You could use this to verify that a jointer bed is level and straight.


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## b2rtch (Jan 20, 2010)

Brett, 
Thank you for your detailed explanation and for your time but what i need is straigth edge, I am on the verge of buying one.


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## AKSteve (Feb 4, 2012)

as for tools I like them to be precise but I don't care about the nth degree. the only real thing I care about in my projects is being square and level anything past that is adjustable. It's like when I made my bench, not all four legs were equal in height because of the mortise was not exact, but the bench is level, I level it by making the legs size up for the leveler. it is completely unnoticeable, even when I point it out to people. Plus dimensions on a project are only suggestions, I probably will never be able to come in exactly on my work. I do get close most of the time. I think my Deal is that I would rather use hand tools to build than power tools. Power Tools will get you closer to a stated dimension, but hand tools get you closer to a stated emotion. and in my opinion that is a far superior piece of work.


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## rance (Sep 30, 2009)

You gotta know when it is needed, and when it can be laxed. FWIW, you'd be surprised how useful(and straight) the factory edge on a nice piece of plywood can be. Even for what you are wanting.


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## ssnvet (Jan 10, 2012)

Can't go wrong with these straight edges from Lee Valley...

imo… AL is better than steel for jointer alignment, as you will holding the straight edge with one hand much of the time….

I got us the 38" one to use at work and it's a very handy and nice tool….

I have an 18" steel one by SPI that I got through ENCO as well… and I much prefer the Aluminum one from LV.


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## JGM0658 (Aug 16, 2011)

I have to agree with rance, you don't want a through tenon with gaps all around, so the precision has to be spot on on this. You also don't want apron tenons and mortises that are sloppy, your table will fall apart sooner or later.


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## pcott (Jul 7, 2009)

I have to say, much of this is personality. If you are a precise neatnik, then precision is needed, if only for your peace of mind. Your shop is likely pristine too. If you are me, then good enough is good enough. I get plenty of compliments as well. The best 2 woodworkers I know 1 has a shop that looks like bombs went off in tit, the other is messy but organised. one of them is very precise in his measurements, the other is like a boat builder "if it looks fair, then it is fair."


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## George_SA (May 4, 2012)

I agree with Eric's approach and I try to adjust the precision to the requirements of the project, but unfortunately I also tend to be a bit of a perfectionist at times. In the end I know about the imperfections whilst most people don't even notice it. My philosophy about the imperfections is that they are like the fine cracks leather that shows it authenticy.


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## bondogaposis (Dec 18, 2011)

I good cheap source for a straight edge is to get a piece of aluminum angle available at nearly any big box or hardware store. It will be more than straight enough for woodworking tolerances.


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## lazyoakfarm (Sep 28, 2010)

My father was very good at restoring old furniture and trunks, he used to tell me that if its perfect it looks like plastic. Thats hard for me, I like tools that are setup perfectly.


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## dhazelton (Feb 11, 2012)

Laminated shelving is usually pretty darn straight, that could work as a straightedge in a pinch.

I've never known a machine to become more aligned by itself, so if it pleases you and you need some time to tinker and clear your head, go for it.


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## DamnYankee (May 21, 2011)

I have long found it curious how as woodworkers we fight over precision…precision of tools, precision of marking. I particularly find the arguement between using a sharp pencil versus a marking knife. When in the end we are talking about a material that WILL change its dimensions while it is sitting there untouched not matter how climate controlled my shop might be.
I personnally shoot for the .001" precision when setting up my tools, but I am not going to get "stressed out" if I just can't seem to get there acroos the board.


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## devann (Jan 11, 2011)

Hello Bert, I have a expandable level that I have found many uses for tool setup. I use to setup roller stands for long material at the planer or router table. I also use it when I setup my miter saw on the job. I have a set of 8' and 12' "wings" that I attach to the saw giving me a 19' or 26' long work surface. I've been known to clamp it to the rip fence of my shop table saw when I need a longer infeed fence. It comes in handy when I want to know how long a board I need on rake wall situations and I need them plumb too. Just extend it until you get a plumb reading then lay down the level and measure it. I could go on and on but you get the picture. Here's what it looks like…

http://lumberjocks.com/reviews/1956

How much precision do we need? Just enough for a good tight fit.


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## b2rtch (Jan 20, 2010)

Devann, that's interesting, thank you.


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## fge (Sep 8, 2008)

Our shop standard is 6" levels and within 1/4" on everything, absolutely no excuses!

We use the 2 nickle test. If we can make the level show level using no more then 2 nickles thickness on either the left or right side of the level, it is call "Good to go!"


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## Cosmicsniper (Oct 2, 2009)

I believe precision is important for several reasons. First, a project is ultimately the sum of its cuts. Try piecing together several mitered boards into a hexagon and you'll see what I mean. Second, people overlook the efficiency of well designed tools. The value with my Incra table saw fence is not necessarily its precision, but the speed in which I can work with the knowledge that my tools are repeatable and predictable. Third, our work can be complex, full of variables, any one or many of which can cause flaws or misalignments. When you have a tool that cuts dead straight lines at exacting measure every time, then if something goes wrong you can better trace down the issue and correct/learn from your mistakes.

That said, like Lee posted so well, if you think it needs improvement, then perhaps you need more precision. But many people are so skilled at masking errors then perhaps it really doesn't matter much to them.


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## b2rtch (Jan 20, 2010)

Thank you Jay.
How did people did a beautiful work long before the Incra fence and digital displays?


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## Cosmicsniper (Oct 2, 2009)

Bert:

You can do beautiful, accurate work with a hand saw, plane, and chisel. It just takes a lot longer.

I can rip five cuts in some stock at 2.5", 4", 6 5/16", 7.643", and 10" to within a one-thou tolerance…and I can do it in less than one minute.

That's allows me more time to butcher wood with my chisels.


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## JGM0658 (Aug 16, 2011)

How did people did a beautiful work long before the Incra fence and digital displays?

Measuring and then cutting with hand tools is usually more precise and accurate than with bands saws or table saws. But it takes forever, pretty much the same argument about hand planing a board vs using a jointer. Both can be done but the hand plane job is a killer….


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## bondogaposis (Dec 18, 2011)

*How did people did a beautiful work long before the Incra fence and digital displays?*

They had apprentices to do the grunt work while the master concentrated on the fine details.


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## CplSteel (Jun 22, 2012)

Precise fit can be obtained, quite easily, withouth precision measurements. It just depends on how you work.

Based on the answers above, I bet more folks here have a digital micrometer than dividers. And that is fine. But just remember that there are other ways to make things fit correctly.

*How did people did a beautiful work long before the Incra fence and digital displays?*
They trued pieces to other which provides percise fit without any measurement.


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## fge (Sep 8, 2008)

Bert, I just realized I was totally off subject with my last post. Honest mistake, sorry for posting. I was just looking to provide light humor, but it seems I missed your subject matter all together so I am sure that is not funny at all. Sorry for being off topic.


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## OggieOglethorpe (Aug 15, 2012)

*How did people did a beautiful work long before the Incra fence and digital displays?*

They made pieces fit each other. Except in the rare occasion where I'm shooting for interchangeable parts, I still do this… It's "relative" vs. "absolute" woodworking.

I think it's important to separate machine setup from measuring work pieces. I own dial indicators, a reference edge, calipers, feeler gauges, etc… but they're not for wood.

Most measurement errors on interchangeable parts are eliminated by cutting them with the same setup. I don't care if a table's side aprons are 32", 31 15/16, or 32 1/8… if I've cut them against the same stops, it'll all work out in the end. Even on an entire kitchen, just cut a few extra parts for setup on future operations, and it'll probably all work out fine. Just know WHERE super precision is needed.


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## daltxguy (Sep 7, 2007)

As one instructor told me "Perfect is good enough"


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## davidroberts (Nov 8, 2008)

I've commented on this once or twice and was blocked by one LJer (at my suggestion), when I recommended he get help for his OCD. I think you have hit THE key point. When people do not know the outcome of a condition (in this case tolerance), they tend to strive for zero tolerance. And nowadays with the penchant for near zero tolerance, the latest greatest woodworking measuring devices have not disappointed.

The problem is that many amateur woodworkers, as I consider myself, rely on power tools and equipment for the final cut or finish. They want to make that 0.005 inch cut every time on a consumer grade table saw, or thickness to 0.005 with a lunchbox planer. They have not learned hand tool skills or how to sneak up on a cut. They (me) have little patience, or time for that matter, and want to make beautiful, tight joints, as quickly as possible, with little personal knowledge of wood science or ways of the hand tool. "Heck, I spend bazillions on this power tool, what more do I need to know. That's why I bought the power tool, so I don't need to know much more than how to flip a switch?" mentality. I finally learned you rough cut with power tool (or not, if you are unplugged) and refine the cut with hand tools. Same with the finish, i.e. power sander verses planing and scraping.

Until a woodworker learns hand tool skills and understands wood movement, there will always be a fear that anything less than 0.005" using power tools is just not good enough.


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## longgone (May 5, 2009)

I have been a woodworker for over 50 years and started out learning all the basics and learned using hand tools only back then. You need a good foundation before you can add any skills and knowlege to your brain.
As time passed and my skills improved I added power tools to make my woodworking life easier but still use hand tools on a dialy basis.
In my opinion as to how much precision does a person need in woodworking… I would say that my work has never ever been hurt by being as precise as I can possibly get…regardless of the tools used. Super precision has never caused a problem for me and I find comfort and satisfaction in knowing that I have done it this way.


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## davidroberts (Nov 8, 2008)

b2rtch, I use a 6-foot Swan level I purchased at a good price just of this one task. The accuracy of commercial levels these days is pretty good. My jointed boards come out straight enough that I can't see daylight. A 4-footer should also work.

Not to beat a dead animal, I agree there is nothing wrong with being as accurate as one can be, given the quality of tools I own and the knowledge and skills I possess to use them properly. Accuracy is a trademark of craftsmanship, and the knowledge to get there a sign of wisdom. Doing it over and over to a high degree of accuracy (or low accuracy for that matter) is precision. My thesis is that standard hobbyist power tools alone do not provide for complete accuracy or precision. They may get you close, but how close is good enough, as with many past blogs, is the underlying question of this forum post.

As a woodworker of intermediate skills, I did not come ready made with wood wisdom. I recently made a shooting board and bought a #6 Stanley for the sole purpose of gainingn accuracy. I came to the realization not at the beginning, because obviously I would have built a shooting board long ago. On casework, I can get by with cuts off the tablesaw because if I'm a few thousandths off, (which is rare because hey fugetaboutit !) the wood will accommodate my error. If I'm building a small box and the intricate joinery and flush components are part of the aesthetics, then maybe I need a little more accuracy to close that joint screaming tight, or make the sides perfectly flush. That little bit extra, in my opinion, is only gained feasible, efficiently, by a well-tuned hand tool, a very well made jig, an expensive accessory, or a professional-industrial machine or robot. My pocketbook says go with the hand tool and pick up a few skills while I'm at it. I may learn something along the way.


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## HorizontalMike (Jun 3, 2010)

"...How much precision do we need in woodworking?..."

IMO, if you are cutting parts and fail to assemble/glue them up in a timely manner, all of the precision in the world could be for naught if you do not control the humidity in the shop.


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## inchanga (Aug 13, 2012)

If you require more precision buy a bigger hammer. anon.


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## b2rtch (Jan 20, 2010)

Mike what you say is true of anything with wood. Joint some board then let them seat for a week or so, you need to joint them again.
I make red oak boxes for my step sons, they use them to cover metallic electrical boxes. I made then ad they needed them but they told me me that I should make a bunch of them ahead of time. 
I listened the them but when it was time to install the metallic electrical boxes inside the wooden ones, these one had dried and shrunk so much that we could not get the metallic boxes to fit in.


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## Nick_R (Jul 7, 2012)

I believe that man, as a group, can create machines and materials that in turn create perfect things. China is a good example of mass producing perfect products for very little money. No one in this forum can produce anything comparable for the price and perfection that is created by these machines. Soooooooo, I believe our struggles and imperfections, and sometimes the accidental perfection, are what makes what we produce perfect in its own way.. Try for quality but don't obsess about perfection unless you want to be a machine. ;-)


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## b2rtch (Jan 20, 2010)

" Try for quality but don't obsess about perfection unless you want to be a machine" 
I am a perfectionist, I like what you wrote.


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## Dusty56 (Apr 20, 2008)

I use my 78" aluminum level for set-up of my long bed jointers…it's all I'll ever need : )
I use my 48" on the smaller machines. 
If you see a gap , flip the level over to see if the gap is still there or not , and to tell if it's your level or the machine bed(s).


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## AlaskaGuy (Jan 29, 2012)

I believe it's a personal thing. Be as precise as you want. When some one tell you this or that is good enough they are saying it's good enough for them but might not be for you. I have a 72'' Starret machinist straigth edge and have never been sorry I have it.

Get that straight edge and make yourself happy.


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## MrRon (Jul 9, 2009)

It is not a question of "how much precision", as we are working with materials that expand and contract, something that we have little control over. Precision is a personal matter. I think we should strive to work as precise as possible. We may never get to the exact precision we want, but at least it will put us very close. I always try to work to within a few thousands of an inch. I know I won't attain it, but if I end up with ± a few, it will fit well; especially important in making tight fitting joints, like box and dovetail joints.

If you remember in school, you were told to aim for an A and you will probably get a B or C+; but if you aim just for a passing grade, you might get a failing grade. It's just a good habit to get into.


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## davidroberts (Nov 8, 2008)

MrRon, reminds me of the saying that money can't buy you happiness but it will let you buy a porsche and I can drive up real close to it…just saying.


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