# What is "dead on"?



## PhilBa (Sep 25, 2014)

I've been thinking a lot about accuracy and precision in wood working lately. I hear the term "dead on" a lot but have some trouble with this phrase because it implies zero error yet it has to be subjective. To be fair I've used it but knowing full well that I really meant "pretty darn good". If I got a loupe and looked, I'm sure it wouldn't have looked so close. Heck even the markings on a ruler have width.

How close does one need to be to claim "dead on". I know it's more about the limits of our perception than true accuracy. For example when you have a dark wood next to a light one (walnut and maple, for example), you can have a huge gap (say 1/64") and not be able to notice it very easily. Yet, between two pieces of maple, even 1/128" is pretty obvious. And a long even gap of 1/64" looks ok but if one end is 1/128" and the other is 1/64", the human eye can see the difference.

So, how you think about it? What constitutes "dead on" for you?


----------



## DaninVan (Jan 1, 2012)

Hey, Phil; great topic.
My perspective is that the accuracy is entirely dependant on the context.
In framing, a 1/16" is decent, but even then it depends on whether the wood is soaking wet or bone dry.
If you were a pattern maker, all bets are off...


----------



## Cherryville Chuck (Sep 28, 2010)

The human eye can see a difference of about 2 to 3/1000ths of an inch but it only does it if it's looking for it. It can also be fooled into not seeing much larger things. Dead on for me is about looking good enough and doesn't involve any specific number on any particular issue. One of the issues with light colored woods is using dark glue which will leave a visible line and that really stands out. A white or clear glue can either avoid it or minimize it. It also matters if the surface is vertical or horizontal. Things like that stand out more on horizontal surfaces than they do on vertical surfaces. A light colored wood against a dark one doesn't show much of anything because the joint is similar to a shadow line and the eye and brain tend to dismiss shadows. There is flush trim bit with a little v point on it that can be used to hide joints on something like a table apron. It creates a small notch which creates a shadow line which the eye dismisses. Reveals on trim around doors and windows is similar, you use the reveal to hide the fact that the trim doesn't run perfectly parallel to the jambs 100% of the length. If you look closely you can see it but usually the eye will just dismiss it.


----------



## PhilBa (Sep 25, 2014)

Good point (about context). For me, the context is "fine" woodworking.


----------



## Ghidrah (Oct 21, 2008)

I agree with Dan, "context" and how far into mental your willing to go attempting absolute. If scaling a pattern I set markers, (pointy compass needle), common pencil graphite oblates, the needle dimple doesn't. Mech pencils need adjustments but maintain the same diam. With the above method I achieve accuracy to 1/64', if I wish to go mental I'll use the glass and get 1/128". But for me this never translates to reality, I know me well enough at this point to assume they're coming and try to covertly sneak up on them. 

If the MC is low, the lumber is suitable to the project the last critic is your eye. When the error appears, spend the time to see if you can fix/cover it up before replacing.


----------



## Nickp (Dec 4, 2012)

Cherryville Chuck said:


> The human eye can see a difference of about 2 to 3/1000ths of an inch but it only does it if it's looking for it. It can also be fooled into not seeing much larger things. *Dead on for me is about looking good enough and doesn't involve any specific number on any particular issue.*


My feelings also...if my eye is happy, I'm happy. I've built decks without levels using other references such as the house across the street, the neighbors pool, the corner of the next house, etc... And yet, a miter will drive me nuts if the cut doesn't "disappear" when joined. Probably why I've not done any inlay work.

Alignments, on the other hand, seem to make me strive for "perfect". By that I mean that if I want the back side of the fence on the TS to be out 5/1000's, then 4 or 6 won't do. I guess it's more to do with what I expect at that time. Thumb and fingers feeling the edges are okay for lumber and framing but steel rule for any adjustment on the router table.

When I measure and mark it's more an issue of where "near" the mark do I actually make the cut...left/right of line, cut the line, a little to the left/right...? Depends on how the pencil marked when I measured...I use carpenter's pencil and it's not always as sharp as the .07mm mechanical...

What a great topic...when it comes down to it, I guess I really don't know what "dead on" really means in numbers but I "know it when I see it"...


----------



## PhilBa (Sep 25, 2014)

A while ago I stopped using pencils for marking final cuts and use knives instead. Incra rules make it really easy to get really close to what you want. It's amazing how fat a pencil line (even from a sharp pencil) looks after doing that for a while.

I don't spend a lot of time fussing to get exact measurements but figure if there's a way to be more accurate, I should do it. Errors tend to add up.

Nick, miters on inlay are easy to get "dead nuts on" by beveling the bottom of the inlay material so the super thin tops smush together and you sand them flush. But yeah, miters are a real test of accuracy.


----------



## woodknots (Mar 7, 2012)

"Dead On" compared to what?

Your tools could be "dead on", meaning they are calibrated as well as they can be, but even then, there are acceptable tolerances so they aren't "dead on".

Joints in furniture, cabinets? It depends on who is assessing them. Is it James Krenov or Sam Maloof or Norm Abrams examining them or is it your wife or daughter or the guy next door who comes over for the occasional beer?

Can something with the instability of wood be dead on, and at what point in time is it considered to be dead on? Wood moves, fluctuates with temperature changes. So, something that may be dead on today may not be dead on tomorrow.

Take a photograph - enlarge it to a size of 24" by 36". If you view it from a foot or so, you will likely see the pixels. But, is that photograph intended to be viewed at that distance?
No, so is that "dead on" or is that acceptable?

Lastly, how important is it for something to be dead on? Is it the space shuttle or an Airbus A380 or is it the carpenter's square in your shop?

I'm not sure you can define "dead on" as a stand-alone quality.

Vince


----------



## DaninVan (Jan 1, 2012)

"...but I "know it when I see it".."
-Nick


Exactly right, Nick. Well put!


----------



## MT Stringer (Aug 15, 2012)

I think I am in the group of "Pretty darn good". 

These days, as I get older, and my eyes get worse, it has become more difficult to read, measure, and cut my stock and be very accurate. Heck, I only have a couple of tools that measure greater accuracy than 1/16th of an inch.

I guess I never will be one of those fine woodworking fools. :frown: :grin:

Disclaimer. I will say this, I use stop blocks anytime I need to cut multiple pieces to length. Whether they are longer than needed or shorter, at least they will all be the same. :grin:

Same goes for table saw rips.

Mike


----------



## DesertRatTom (Jul 3, 2012)

Not a lot to add to the comments already. I shoot for as close as possible to exact measures. My table saw fence, for example, is about 3 thousanths out at the top, thanks to a dial guage. That seems to be as close as I can get. My table saw blade is 90 or exact, because I can use a Wixey to zero it out. If the tools are accurate as to angles, the parts will turn out OK. 

Then its just a matter of how well you conceal any minor mistakes, and whether you got the 45 perfect on the miter jig or shooting board, how sharp your shooting plane or block plane is and whether the blades are perfectly level. So much wiggle room. And then, someone puts the piece in a different environment, or moves to a wet climate, and then all the precision won't save your piece if you didn't leave a little room for expansion, or over glued the piece so it can only split.

So much for dead on. Darn close to dead on, with a little wiggle room for adjustment and expansion/contraction, is about as good as it gets, at least to me.


----------



## Quillman (Aug 16, 2010)

I don't use the term.
This drill press fence is built to a tolerance of ~+/- .002".
It is essentially screwed together.
Its registration is based on its fasteners and hole centers.
Miss 'em and you can't fix 'em.
In this instance it is the satisfaction of the thing fitting together
and working.
The precision of woodworking is vague, comparatively. Fuzz, slight tearout,
coarse grain or even chip dust can obscure a measurement.
Moreover, a good finger can detect a .0005" shoulder.

This pile, before gluing and screwing had no perceptible shoulders.
Now after a couple of years you can feel the changes here and there.
The all aluminum fence has no such strangeness factors.
I like jig plate.


----------



## furboo (Oct 12, 2015)

"Dead on" is a bit better than "perfect", which is a bit better than "good enough" :smile:


----------



## Arcola60 (Jul 4, 2009)

"Dead on" in woodworking, for me:

The ability to pursue my passion.
Precision tooling, and setup.
Striving for perfection, and almost getting it.
Designing a project, and achieving better than expected results.
Reading all of the posts in this thread.
Sharing techniques with everyone.
Learning techniques from everyone.
Being proud of my projects, and how far I have come.

It is not an exact science. It is what we all have inside.
Thanks for sharing.:smile:

Ellery Becnel


----------



## Stick486 (Jan 4, 2013)

Nickp said:


> I guess I really don't know what "dead on" really means in numbers but I "know it when I see it"...


hear hear...


----------



## Stick486 (Jan 4, 2013)

PhilBa said:


> A while ago I stopped using pencils for marking final cuts and use knives instead. Incra rules make it really easy to get really close to what you want. It's amazing how fat a pencil line (even from a sharp pencil) looks after doing that for a while.
> 
> I don't spend a lot of time fussing to get exact measurements but figure if there's a way to be more accurate, I should do it. Errors tend to add up.
> 
> Nick, miters on inlay are easy to get "dead nuts on" by beveling the bottom of the inlay material so the super thin tops smush together and you sand them flush. But yeah, miters are a real test of accuracy.


what can perceived as a ''gap'' today, w/ wood, it isn't tomorrow...


----------



## TwoSkies57 (Feb 23, 2009)

"Dead On": to be within tolerances. Some of us are just more tolerant than others..


----------



## roofner (Aug 1, 2010)

You got it right MT if part groups are cut with a stop block . I would consider it dead on.


----------



## billyjim (Feb 11, 2012)

Great question. My target is not a number, it is "the best that I can do" in the context of what I am working on. If I am putting up some shelves in the garage, 1/8 is plenty close enough, making a box...that doesn't fly. The bottom line would be my eyes and what they see and tell me.


----------



## JFPNCM (Dec 13, 2009)

Interesting discussion. As an old cabinet maker once told me, "dead on" is what you achieve with skill, "bang on" is what you achieve with a hammer. :grin:


----------



## firstmuller (Aug 28, 2014)

Should "dead on" be better then "Good enough for government work" ?
Allen


----------



## wormil (Sep 6, 2012)

Dead on is like love, if you have to ask then you don't have it.

-- Rick M


----------



## Stick486 (Jan 4, 2013)

firstmuller said:


> Should "dead on" be better then "Good enough for government work" ?
> Allen


you ever read the spec and schedule sheets for government work...


----------



## AndyL (Jun 3, 2011)

I reckon if you can fill the gap with filler, without having to glue an extra bit of wood in there, it's near enough dead on 

We all end up dead on eventually!


----------



## Stick486 (Jan 4, 2013)

AndyL said:


> I reckon if you can fill the gap with filler, without having to glue an extra bit of wood in there, it's near enough dead on
> 
> We all end up dead on eventually!


that qualifies for ''can't see it from my house''....


----------



## PhilBa (Sep 25, 2014)

Some interesting comments. As I thought, a lot of you all view it as kind of code for "I'm proud enough of this to show other woodworkers" (i.e. our most discerning critics). And I do agree that cutting to an exact number isn't that important but replicating actual sizes is (i.e. the stop block point). Repeatability is hugely important to quality work. 

It does make me think about the role of precision in an imprecise medium. Some say "it's wood, it moves". I get the sense they are silently adding "so anything you do to gain a little accuracy is futile". I don't agree with that sentiment because when I started paying attention to the little things that rob accuracy and repeatability (cleaning sawdust off work surfaces between cuts, quick sanding of parts between cuts, applying uniform pressure against fences, ...), my perceived quality took a solid leap up. Would be nice to have a list of everyone favorite techniques.


----------



## DaninVan (Jan 1, 2012)

Take off my glasses; project appearance improves dramatically!


----------



## Stick486 (Jan 4, 2013)

DaninVan said:


> Take off my glasses; project appearance improves dramatically!


turn the lights off for additional improvements....


----------



## Nickp (Dec 4, 2012)

PhilBa said:


> Some interesting comments. As I thought, a lot of you all view it as kind of code for "I'm proud enough of this to show other woodworkers" (i.e. our most discerning critics). And I do agree that cutting to an exact number isn't that important but replicating actual sizes is (i.e. the stop block point). Repeatability is hugely important to quality work.
> 
> It does make me think about the role of precision in an imprecise medium. Some say "it's wood, it moves". I get the sense they are silently adding "so anything you do to gain a little accuracy is futile". I don't agree with that sentiment because when I started paying attention to the little things that rob accuracy and repeatability (cleaning sawdust off work surfaces between cuts, quick sanding of parts between cuts, applying uniform pressure against fences, ...), my perceived quality took a solid leap up. Would be nice to have a list of everyone favorite techniques.


I think I have to disagree on one point, Phil...In reading the responses, I perceived that those that responded with "it's wood, it moves" actually implicitly preceded it with "do your best, deal with it accordingly and manage your expectations"...I did not read any responses where anybody thought it was futile to do what it takes to achieve their own version of "dead on"...

Thanks for raising the point...responses were educational and corroborative...


----------



## PhilBa (Sep 25, 2014)

Nickp said:


> I think I have to disagree on one point, Phil...In reading the responses, I perceived that those that responded with "it's wood, it moves" actually implicitly preceded it with "do your best, deal with it accordingly and manage your expectations"...I did not read any responses where anybody thought it was futile to do what it takes to achieve their own version of "dead on"...
> 
> Thanks for raising the point...responses were educational and corroborative...


It's not just here. I see this "it's wood" point a lot. And, while perhaps I somewhat overstate the level to which people may think "don't try" I do see a lot of minimizing the value of things like digital calipers and such. Contrast this with William Ng's fixation with getting down to < 10 mil accuracy. After looking at his results, I can't help but think that there is merit in the fixation.


----------



## DaninVan (Jan 1, 2012)

Again, Phil, it depends on what you're building. The thickness of two pieces of 6mil poly plastic on a big built in bookcase is a fantasy target. Not saying it _can't _be done, but why would you (bother)?
A realistic goal might be a 1/64"+/-
A full on cabinet shop with high end cabinet saws might be able to get much tighter tolerances on the build, but that all falls apart when the install takes place. That's where the craftsmanship really takes place; making it look seamless.

Most of the members just have to work within their tool budget, and adjust equipment to get the best possible performance without getting themselves stressed...*this is supposed to be a fun hobby!*
Remember the angst Jerry Bowen was suffering when he got started? Trying to work to metalworking tolerances? That wasn't fun for anyone.


----------



## PhilBa (Sep 25, 2014)

I dunno, I get a lot of enjoyment from constantly improving what I do. I'm a bit of a perfectionist and am never satisfied with "good enough". The engineer in me says "you can do better". I don't stress out over it, though because you eventually have to "ship" your product. And, given where I am today, I see a lot of years of improvement ahead!

As has been said, it depends on the context. 6 mil over a bookcase, wouldn't bother me but 6 mil in a box joint is close to where it might be too loose because it's about the fit, not the number. I know 12 mil is too much from experience. Also, I don't think tool budget is a reason to settle. Preindustrial wood workers made some amazingly tight joints with just hand tools.


----------



## TwoSkies57 (Feb 23, 2009)

philba said:


> when i started paying attention to the little things that rob accuracy and repeatability (cleaning sawdust off work surfaces between cuts, quick sanding of parts between cuts, applying uniform pressure against fences, ...), my perceived quality took a solid leap up. .


+1


----------



## DaninVan (Jan 1, 2012)

I think you misunderstood my point, Phil. It's not that we shouldn't aim high, but that getting obsessive about the precision can be a hobby spoiler.
If somebody has a Beaver Rockwell 8" TS from the 60's and they're happy with it, I'm the last guy that'd tell them they 'need' a 10" cabinet saw.
If they can tweak their existing TS and get a bit better result, well that's excellent.


----------



## Stick486 (Jan 4, 2013)

daninvan said:


> i think you misunderstood my point, phil. It's not that we shouldn't aim high, but that getting obsessive about the precision can be a hobby spoiler.
> If somebody has a beaver rockwell 8" ts from the 60's and they're happy with it, i'm the last guy that'd tell them they 'need' a 10" cabinet saw.
> If they can tweak their existing ts and get a bit better result, well that's excellent.


+1...


----------



## woodknots (Mar 7, 2012)

DaninVan said:


> I think you misunderstood my point, Phil. It's not that we shouldn't aim high, but that getting obsessive about the precision can be a hobby spoiler.
> If somebody has a *Beaver Rockwell 8" TS* from the 60's and they're happy with it, I'm the last guy that'd tell them they 'need' a 10" cabinet saw.
> If they can tweak their existing TS and get a bit better result, well that's excellent.


Yea, I have one :crying: and I'm "happy" with it.

I'm one of the guys that said "it's wood, it moves" - my point was not that it was futile, simply that I do my best to get as close to some obscure definition of "dead on" with my abilities and equipment. I don't obsess over it.


----------



## Cherryville Chuck (Sep 28, 2010)

As Pat Warner said not very long ago there is no such thing as perfect. It only exists in theory. There are many degrees of good enough instead.


----------



## TwoSkies57 (Feb 23, 2009)

Perfection is not attainable, but if we chase perfection we can catch excellence.
Vince Lombardi

I whole-heartedly plan on wearing out my dial calipers


----------



## curiousgeorge (Nov 6, 2006)

I guess it depends on how anal retentive you are. I have a son-in-law that thinks "good enough" isn't.


----------



## TwoSkies57 (Feb 23, 2009)

Cinches the ole sphincter


----------



## furboo (Oct 12, 2015)

This discussion reminds me of my father telling me about the cabinet maker who spent 20 years building his own house, even though he worked on the house persistently. The reason was all of the woodwork, including the framing, fit the cabinet maker's definition of "dead on", rather than that of a typical carpenter.

I'm not sure this person existed; probably just another one of Dad's life lessons.


----------



## Nickp (Dec 4, 2012)

So what have I gotten out of this...

1. We are all apparently in "violent agreement"...
2. Dead On is completely subjective and has many facets...
3. We didn't spend any time discussing the factors that cause the subjectivity...for example, a FINELY tuned cheap miter saw will do as good a job as an expensive one...to the point of budget being a possible factor...don't think so. My cheapie Ryobi miter slices angles and dangles with the best of them. Point being I have spent a great deal of time making sure it does. On the other hand the average woodworker might not have the funds for a thickness planer so will be stuck with varying size wood. So cute things like self centering and mortising jigs will be frustrating and likely lead to "good enough" but sloppy to the "perfectionist". It is a poor craftsman who blames his tools.
4. Pride has no measurement in thousands...the two like boxes that are somewhat slightly different means nothing to the two daughters that receive them...nor to the parent that made them from the heart with limited resources.
5. It's not obsessive to want better but necessary to the craft if we're to improve our skills. But if you're going to lose sleep over which box to give to whom on the basis of which is "better" then it's time to build decks for money...(no offense intended to the trade...just acknowledging the tolerances are greater)

I'm sure there's much more to this theme so I'll leave it at this for others to add...

I've really enjoyed this thread...I, like others, think there's more to it than analog and digital watcyamacallits...

"Fingers can see what the eyes can't touch" (me)


----------



## woodknots (Mar 7, 2012)

@Nickp

I will agree with everything you said except your point #1. I didn't see any "violent agreement". If I had I would have dropped out of this thread.
What I did see and read is a variety of opinions and primarily, what others are comfortable with in terms of acceptability.

I too enjoyed this thread. One of the best things about this forum, besides the friendliness of the members, is the civility with which discussions are held. I value that.


----------



## craigwbryant (Jan 14, 2013)

Stick486 said:


> you ever read the spec and schedule sheets for government work...


Seen 'em? Heck I write them and I'm still not sure how we reach the level of specification that we do!


----------



## woodknots (Mar 7, 2012)

craigwbryant said:


> Seen 'em? Heck I write them and *I'm still not sure* how we reach the level of specification that we do!


Craig
I think you just found the answer


----------



## Nickp (Dec 4, 2012)

vchiarelli said:


> @Nickp
> 
> I will agree with everything you said except your point #1. I didn't see any "violent agreement". If I had I would have dropped out of this thread.
> What I did see and read is a variety of opinions and primarily, what others are comfortable with in terms of acceptability.
> ...


Well said...


----------



## TwoSkies57 (Feb 23, 2009)

I guess once a moderator, always a moderator.:no::no: I anxiously watched this thread, waiting for it to quickly go south and it never did. 
Over the years, I've watched this subject become heated and insulting. Never happened here...a testament to the quality and character of the membership...


----------



## woodknots (Mar 7, 2012)

TwoSkies57 said:


> I guess once a moderator, always a moderator.:no::no: I anxiously watched this thread, waiting for it to quickly go south and it never did.
> Over the years, I've watched this subject become heated and insulting. Never happened here...a testament to the quality and character of the membership...


Bill

I've been a member of a number of other forums on a variety of subjects. Seems every time a topic came up that solicited opinions, the discussions became heated and the member's would have been at each other's throats had they been in the same room.

Haven't been here long, but in my short stay, haven't seen that happen.

Knowledgeable, friendly folks, who are willing to share, and a sense of humor to boot - I like it here.


----------



## DaninVan (Jan 1, 2012)

I'm con-Vinced!


----------

