How close is close nough

[Robert Willing]

I am tuning my table saw and the blade and fense are to within 0.005 of being parallel. They each are tilted 0.005".

[Osvaldo Cristo]

I assume that is the difference between the extremes. Good enough. It is just slightly bigger than 0.1 mm, typical human hair diameter.

My own standard for great adjust is around 0.1 to 0.2 mm for woodworking.

[Edwin Santos]

I am tuning my table saw and the blade and fense are to within 0.005 of being parallel. They each are tilted 0.005".

That's pretty close, but if not perfectly parallel, you just want it open at the back, not the front.
Pushing into a wedge can encourage kickback.

The fence on your saw is easily adjustable, and worth checking from time to time. I'm assuming we are talking about parallel of the fence in relation to the blade.

[glenn bradley]

I'd say you're fine. I shoot for the best I can get but, I don't make myself crazy trying to achieve something the machine just won't do. As always, the real proof is in using the machine or tool and being brutally honest with yourself as to whether the result meets your requirements. I had no trouble getting my old C-man 22124 or my current Saw Stop to a delta of .001" as far as blade and fence planes. The tops had a difference (dish) in the .005" (or more) range. I have been much more tolerant of a contractor format saw as trying to align those through their range of motion leads to madness :D.

[Simon MacGowen]

I assume that is the difference between the extremes. Good enough. It is just slightly bigger than 0.1 mm, typical human hair diameter.
.

+1.

For reference, these are the factory tolerances for the SawStop PCS/ICS:

0.001″ Maximum allowable runout

Table flatness measured diagonally:
0.010″ Maximum gap

Blade alignment with miter slot:
0.010″ Maximum displacement

Deviation of miter gauge indexing stops:
0.010″ Maximum

Even if you saw is perfect, your techniques and the lumber may not be and so a perfect saw -- if it does exist -- won't necessarily bring the best results.

Simon

[Lee Schierer]

I am tuning my table saw and the blade and fense are to within 0.005 of being parallel. They each are tilted 0.005".

Is this in relation to the miter slot or each other?

[Matt Day]

Simon, there apparently isn’t a number for flatness of the SS fence. The one I’m working on goes back and forth from +4 thou to -4 thou as you move the dial indicator forward. Junk fence that i’ll Be replacing with extruded aluminum.

[Simon MacGowen]

I know for a fact that when the first batches of SawStop came out (10 years ago), they used second-rate or thinner plywood for the fences. Customer feedback may have driven them to using better quality of ply for the fences now. How good? I have no idea, and as you pointed out, they don't provide tolerance about that, perhaps because ply is bought and beyond their control. Bearing in mind that the saws are made in Taiwan and shipped to America, our humidity conditions probably have an impact on the fences, too.

Might be an auxiliary fence made of top quality ply would help.

I am not too keen on aluminum fences; I know of a few brake trigger incidents due to contact with an aluminum miter gauge.

Simon

[Edwin Santos]

Is there a slick facing on the outside of the fence material? That's the case with my Jet Xacta fence which has UHMW facings which are not perfectly flat.
But this is woodworking, and the deviations we're talking about should not be an issue.
Edwin

[Nick Decker]

Is there a slick facing on the outside of the fence material? That's the case with my Jet Xacta fence which has UHMW facings which are not perfectly flat.
But this is woodworking, and the deviations we're talking about should not be an issue.
Edwin

Yes, SS uses what I think is UHMW on the face of the fence. Mine has a slight waviness, but I haven't noticed it causing a problem.

I'd prefer an aluminum extrusion, myself. Straighter, plus easier to attach things to, if needed. The risk of running an aluminum fence into the blade wouldn't be as great as with an aluminum miter gauge.

[Simon MacGowen]

Is there a slick facing on the outside of the fence material? That's the case with my Jet Xacta fence which has UHMW facings which are not perfectly flat.
But this is woodworking, and the deviations we're talking about should not be an issue.
Edwin

That is why I check and tune my woodworking machines with squares, steel rules, etc. instead of micrometers, digital calipers, dial indicators and whatnot. The wood I cut will tell me how good those machines are, regardless of what the measurements may suggest. Even a perfectly flat or tuned fence may deflect when we use it. I don't lose any sleep over minute deviations when working with wood. In fact, I have things made not perfectly square and have yet to come across anyone -- a woodworker or not -- who checks them with a square when the builds are the topic of conversation.

Simon

[Andrew Seemann]

Other than the arbor, which I replaced, I'd be amazed (and thrilled) if anything on my 50 year old Unisaw was within .005 I think it was in a production cabinet shop before I bought it; everything is pretty worn. For the most part though, it hasn't affected quality of work.

[Pat Barry]

That is why I check and tune my woodworking machines with squares, steel rules, etc. instead of micrometers, digital calipers, dial indicators and whatnot. The wood I cut will tell me how good those machines are, regardless of what the measurements may suggest. Even a perfectly flat or tuned fence may deflect when we use it. I don't lose any sleep over minute deviations when working with wood. In fact, I have things made not perfectly square and have yet to come across anyone -- a woodworker or not -- who checks them with a square when the builds are the topic of conversation.

Simon
If out of square works for you then it sounds like you are probably doing carpentry and not cabinetry.

[Simon MacGowen]

If out of square works for you then it sounds like you are probably doing carpentry and not cabinetry.

I'm afraid you have been fooled or misled by all the "dead square", "dead straight" preaching often seen in books and magazines. Out of squareness happens all the time in fine furniture making. When we build cabinets with inset doors, we use techniques to get the doors or drawers done with perfect reveals, regardless of whether or not the carcases are perfectly square. I know because I have done that many times.

Same for dead flat, unless you work with sheet stock. Wrong, even if you work with sheet goods, flatness is not guaranteed. I know because I have made long/large tables or desks with both veneer sheet stock and hardwood lumber, and they are rarely "perfectly" flat. By the way, I use long aluminum straight edges, not steel ones to check flatness.

Simon

[Warren Lake]

not really misled to want to pay attention and identify machinery tolerances.

ive fit stuff beaded inset and had time wasted because some small step was out a tiny bit like the sliding table first generation of one brand could not cut consistently square, Set up dead nuts square cut a few more gables one out a tiny bit which puts a tilt in that gable which then makes it more difficult to fit to tight tolerances because that minimal of out of square now has the tilt aspect and its only one one gable which is even worse. If you are lining bottom edge of a drawer to the top edge of he one below now you have more fun. If there are beaded rails between then more forgiveness as you are working to a round and it wont stand out the same way.

I know a guy who had a pretty high end company he has said to me its woodwork its not supposed to be perfect. I dont buy it and its not that it has to be perfect, I dont like chasing my tail cause equipment is not true and creating more work in steps after. At the big volume level they sometimes make jigs so when they sand a door rather than fit each one everyone is the same and sometimes clamp face frames on a jig so they are all the same.

[Mark Wooden]

+1 with Simon
I've been a carpenter for over 40 years and always worked within square, level and true parameters, and always close enough to be above question. It's how I, and many others, were trained.
I've also been working in architectural millwork for many years, another form of carpentry. Same specs.
What's out of square? 1/128" in 24 inches? 1/4" in 50 feet? 1/2" in 150 feet. Of course the answer is all are out of square- and 98% of the world will say "close enough". The other 2% will go blind and crazy trying to get that 1/128" out- while I go fishing.
Blanket statements stating things like carpentry is out of square are just not true and annoying.

[Pat Barry]

I'm afraid you have been fooled or misled by all the "dead square", "dead straight" preaching often seen in books and magazines. Out of squareness happens all the time in fine furniture making. When we build cabinets with inset doors, we use techniques to get the doors or drawers done with perfect reveals, regardless of whether or not the carcases are perfectly square. I know because I have done that many times.

Same for dead flat, unless you work with sheet stock. Wrong, even if you work with sheet goods, flatness is not guaranteed. I know because I have made long/large tables or desks with both veneer sheet stock and hardwood lumber, and they are rarely "perfectly" flat. By the way, I use long aluminum straight edges, not steel ones to check flatness.

Simon
If it works for you, fine. Ill take square anyday over "close enough". I've built enough both ways to know that out of square does nothing except create problems. If your case isnt square, then your shelves, drawrts, doors, etc all need to be made non square to make things fit. If you consider that to be the height of your craftsmanship, because you can fool around and overcome your sloppy casework, then have at it.

[Pat Barry]

+1 with Simon
I've been a carpenter for over 40 years and always worked within square, level and true parameters, and always close enough to be above question. It's how I, and many others, were trained.
I've also been working in architectural millwork for many years, another form of carpentry. Same specs.
What's out of square? 1/128" in 24 inches? 1/4" in 50 feet? 1/2" in 150 feet. Of course the answer is all are out of square- and 98% of the world will say "close enough". The other 2% will go blind and crazy trying to get that 1/128" out- while I go fishing.
Blanket statements stating things like carpentry is out of square are just not true and annoying.
Carpentry is not furniture. Ive seen plenty of work like that. Leave your out of square walls and doorways for someone else to desl with. Afterall the sheetrock will hide most of it, as will a few shims in the doors.

[Simon MacGowen]

If it works for you, fine. Ill take square anyday over "close enough".

So you know, your "square' could be someone's "close enough."

But I agree with you that we all have different definitions of fine woodworking or craftsmanship, whether as a hobbyist or production woodworker who makes furniture for a living. I, for one, use a lot of hand tools and do not feel I can compete with a CNC machine no matter what or how I do when it comes to dead [fill-in-the-blank as you may].

When I look at a piece like this: http://thekrenovarchive.org/inc-item%20(1)/a%20(13).php , my thought is not much about if it is constructed square (enough) or straight (enough) or flat (enough), or if the assembly can measure up to what my best precision measuring tools might say. Or if the pair of doors is hung perfectly well (it is not if one uses a steel rule to check its parameters. Is it the doors or the carcase that has an issue, I don't know and I don't care.). I am not obsessed with measurements. But I like its overall simplicity, its clean lines, its knife hinges, and above all, its relative ease of construction. I simply don't care it is square or not -- when measured against a square with the accuracy of 0.0001" per inch of length(?). I do know "dead square" and "dead straight" are considered very important by some.

Having said that, I am more concerned about twist, and my winding sticks are among the most used tools in my shop.

Simon

[Johnny Barr]

When I got my PCS I measured the blade/slot alignment to be 0.01" and contacted SS and they said that was within their recommended tolerance but the cuts were smooth parallel and square. It was bugging me so I followed the instructions and got it to 0.001", in fact it was closer to 0.000" but once again the quality of the cuts was no different. Same with my previous saw, a Laguna fusion. Out of the box it was 0.002" I stupidly tied to get this better and I ended up with 0.007" but once again the cuts were no different between those two settings. I think this setting is really overrated. Some books I've read even say its should be zero and that can change overnight with temperature and humidity. So I think 0.005" is fine but let the quality of the cuts be the deciding factor.

[Simon MacGowen]

Blanket statements stating things like carpentry is out of square are just not true and annoying.

Funny that the word "carpenter" or "carpentry" elicits different reactions or interpretations.

I have been called a carpenter (which I am not) when people learned that I have a shop and I build all kinds of things (except outdoor stuff) out of wood. I am not a carpenter because I have not received any training or have had the skills or experience to do all a carpenter can do.

I just work with wood and the title of hobbyist woodworker fits my bill. Yes, I build furniture (a lot) but I also build boxes, trays, picture frames, and even ladders, which I don't think fall under the category of furniture. So I am not a furniture or cabinetmaker per se

Simon

[Derek Stockley]

Simon, there apparently isn’t a number for flatness of the SS fence. The one I’m working on goes back and forth from +4 thou to -4 thou as you move the dial indicator forward. Junk fence that i’ll Be replacing with extruded aluminum.

My SawStop PCS fence face was so wavy that it was telegraphing quite badly into the cut quality. I bought it used, so I have no way of knowing if that was its original condition or if the previous owner caused it. I ran a dial indicator along the face of it and I was getting more like +10 to -10 thou over the middle 24" of the fence with most of the dip in the middle near the blade. I took the face off and found the steel tube was actually very straight and it was just the wood part. So I made a replacement face board out a bit of scrap 1/2" baltic birch, laminated on both sides with white plastic laminate like Formica. That did the trick - cut quality is now excellent and I have a total indicated runout on the fence face more like 2 thou now.

[John Gulick]

We do not live in a perfect world, nothing we work with is absolute 0, or square, or whatever. I have not seen OCD mentioned here. From my perspective as small business owner and craftsman, we have produced millions of dollars of very good quality work over 50 years, perfect probably not, but who among us is?

[Phil Mueller]

I doubt I have a single piece of furniture or cabinetry in my house - bought or made - that comes within .005 wherever I may measure. Might be wrong about that, but to my eye it all looks great. We all shoot for the tightest tolerance we can, but in the end, if it’s not immediately apparent, it’s close enough. I’m pretty sure if I was insistent on .001 or something in that range, I’d still be working on my very first project. And, as a hobbyist, that just wouldn’t make it fun anymore.

[Mark Hennebury]

How good is good enough?

It depends;

If you are in business, then it has to be good enough to keep your customers happy. Any more than that and its your hobby.

most woodworking is not not mission critical stuff, no ones life depends on cabinets being within a 0.001",

But the crazies have a legitimate right to be crazy, and the world would be a sad place if all we had was "good enough"

If people want to spend their lives chasing infinity, let them, support them, cheer them on, marvel at what they bring to the world, and just be happy that its not you.

Most of the truly great stuff in our world was achieved by the obsessive compulsive wack-jobs in search of absolute.

The relentless pursuit of perfection, is as legitimate a pursuit as good enough to get paid and gone fishing.

Each of has has their own path in this life,

Nothing is necessary in the grand scheme of things, not us, not what we do, not even the planet we live on. So make it up to suit yourselves, and try not to put down others that do it differently.

I have done some pretty high tolerance joinery, and used high precision woodworking machinery, so 0.005" is a lot to me and i would be one of the ones fussing to see how accurate i could make it.

Complex work requires high precision at every step or you will accumulate errors, it requires process and procedures developed to insure that each step is done to tolerance before continuing to the next. Any error will affect all of the following operations so each must be checked and referenced.
Jobs are project management; all you have to do once the tools and procedures have been set is have the discipline to follow procedure and all will fit together without any problems. If your settups are unreliable and you dont have a process to check and reference, you will have errors and problems and it will be a mess.

Supersurfacers generally take shavings about 0.002" thick and a foot wide, over a 13" long knife, the setup tolerance for the knife and chipbreaker and machine are very tight, and a few thou is a lot.

Furniture joinery

388367 388368 388369 388370

Credit card cases

388373

Supersurfacers


Blade / back-knife setting gauge
388381

Shavings

388380




https://youtu.be/p8phndWW2qQ

[Edwin Santos]

OCD might apply, but I like to think in terms of the Law of Diminishing Returns.
Whether your're a professional or a hobbyist, time is valuable for all of us. There is a point where you are just wasting it for no real benefit beyond a certain level of accuracy. Especially considering that wood is an organic material and will change and shift. There's a wide continuum between sloppy and driving oneself bonkers in the pursuit of perfection. The answer as with most things in life, is somewhere in the middle.

For me, I used to get too wound up about excessive accuracy and it was getting in the way of actually building things. I reeled it back, just a little and I get more done and enjoy the process more.
Edwin

[Simon MacGowen]

I doubt I have a single piece of furniture or cabinetry in my house - bought or made - that comes within .005 wherever I may measure.

I was intrigued by your point, and so went to my neighbor, Ken, for one of his precision tools: a steel straight edge by Bridge City Tool Works.

I know dry walls are not flat, but what about my bedroom furniture set (which cost a lot more than my SawStop) from a nationally known high-end furniture store (that has been around for over 80 years)?

The photos taken of two different pieces tell the story. (May be I should've borrowed Ken's Starrett square and checked the assembly's squareness too.)

I don't have all the equipment or the variety of skills that exists in that enterprise, but I am happy to report that my work is more than "close enough" if we go by the standard shown in those two photos.

If you want the John Economaki (aka machinist) approach in woodworking, be my guest. But I have been happy with the kind of "close enough" tolerances my machines and hand tools have offered me.

By the way, I use a 50" aluminum straight edge from LV for my large work and I think its tolerance is good enough for the non-machinist woodworking gang like me. I am sure I would rather spend money on lumber than on a better steel straight edge that would get me to within 0.001" flatness.

Simon

[john lawson]

I am tuning my table saw and the blade and fense are to within 0.005 of being parallel. They each are tilted 0.005".

I'll try to answer this in the spirit it was originally posted.

Woodworking is and should be an optimistic hobby, or endeavor if you do it for a living. When you approach a task like ripping a board or cross cutting you might have an error of let's say 1/64". That is probably okay for most applications. Most, not all. If you are fitting a precise miter it may look awful, if the cut is a piece of plywood going into the back of a cabinet you are good to go.

When you are setting up a machine for repetitive cuts the standard should be much higher. How high? That's up to you but if it's me I want the fence as close as I can get it after spending a few minutes with a digital caliper and a box wrench for the fence. I want to know that if my technique is good and consistent that all my pieces will be good. I also want to know that if I have ripped a number of pieces that the dimensions will stack up correctly, like ripping face frames for cabinets. I once asked a professional teacher at a prestigious woodworking school a question about this, about what constitutes the needed accuracy for woodworking. He used the example of hand cut dovetails and said an accuracy of 3 to 4 thousandths was required to cut good dovetails, though he emphasized that this was not necessary in most woodworking operations.

I won't waste a lot of time and obsess over a set up, but I will take time to check and adjust it until I'm satisfied that if I cut 10 or 20 pieces I can be confident I can use them without running into trouble later in the project. The other thing I will mention is that I have a habit of doing this to most of my equipment if I have been out of the shop for awhile, or I am starting a new project, especially a project that is either complex or expensive. It just makes me feel better when I start.

[Jerome Stanek]

If your working with wood it expands and contracts more then that and not all the same across the piece

[Brad Shipton]

Discussing this without knowing your machine is not great. If I were setting up a Martin where I have a perfectly rigid rip fence that does not deflect, then I think .005" would be terrible. If it is a contractor saw where the fence might flex or does not hold perfectly true each time I adjust it, then .005" would be fine.

[Bill Dufour]

realize that you should be able to estimate to 1/10 of the smallest division on your measuring equipment. All measurements are more accurate then the ability to make the item. Measuring and squaring to a great deal of precision is kind of a waste of time in wood.
Do a little study about precision metal measurement and you soon realize wood workers ignore almost all the rules. Biggest one I see is temperature control. I have never seen wood measuring tools with thermal insulation pads. No instructions say wear gloves to hold the tool or the work. In metal the measurements really should state at what humidity and temperature.
How do you compensate for gravitational sag of your work and the measuring tool.
Bill D.

[Robert Willing]

First I would like to thank all of you for your comments. I originally posted this as a question to the group was that I needed to check my TS. It was pushing the wood away from the fence, but than I saw a YouTube video stating how to put pressure on the fence to correct the fence Parnellism. So, I tried that process and it appears to work based on my measurements with a dial indicator relative to the miter slot. I have not checked the actual operation so far due to other projects tying up the saw. By the way this is a SS TS Contractor saw, which has a very poor fence to start with. So, other reviewers tell me.

[Simon MacGowen]

First I would like to thank all of you for your comments. I originally posted this as a question to the group was that I needed to check my TS. It was pushing the wood away from the fence, but than I saw a YouTube video stating how to put pressure on the fence to correct the fence Parnellism. So, I tried that process and it appears to work based on my measurements with a dial indicator relative to the miter slot. I have not checked the actual operation so far due to other projects tying up the saw. By the way this is a SS TS Contractor saw, which has a very poor fence to start with. So, other reviewers tell me.

Interestingly (coincidentally?) enough, a blogger has covered this topic in his post today: http://www.rpwoodwork.com/blog/2018/06/25/setup-accuracy-vs-outcome-accuracy/

Simon

[Robert Willing]

Great article.

[Phil Mueller]

Hmmm. I didn’t think someone would actually take a straight edge to their fine furniture, but thanks for doing that Simon. It got me curious and I checked a few of our finer mahogany antique pieces...inside drawer frames and case outside corners with a Woodpecker mini square and Starret square. I may have to eat a little crow, because I have to admit, they were pretty darn square :o

[Simon MacGowen]

Hmmm. I didn’t think someone would actually take a straight edge to their fine furniture, but thanks for doing that Simon. It got me curious and I checked a few of our finer mahogany antique pieces...inside drawer frames and case outside corners with a Woodpecker mini square and Starret square. I may have to eat a little crow, because I have to admit, they were pretty darn square :o

Flatness over a large surface is harder to achieve than squareness (esp. when the assembly is small because we can clamp/force it to square -- just align the clamps till the diagonals meet). On the other hand, large hardwood boards react to seasonal changes and there is only so much you could do to keep them flat in a carcase. At least that's my experience.

I have various tops that were machined flat (taking alternate passes on both sides) checked against my 50" straight edge. But they can be "less" flat depending on the season.

Simon