Micro Adjustment of Table Saw Fence in increments as small as 0.001 inch
steven_woodward
| Posted in Jigs, Fixtures, Tips & Tricks on
Moving a table saw fence by very small amounts can be hit and miss. With a dial indicator at the right location on the fence, I found it is easy to tap the fence and move it by 0.001 inch at a time.
Locate the probe of dial indicator over the fence rail so that dial indicator does not change when the fence is tightened. See red circle in photo.
Video demonstration: https://youtu.be/MZu0JvW1g3k
A couple of times I have found this fine adjustment helpful:
1. Cutting UHMW runners to fit nicely in the miter slot for floats
2. Cutting mortise and tenon joints on table saw, to get a good fit.
For all other work I just use the measuring tape built into the fence rail. The table saw cut usually gets run over the jointer anyway.
Replies
I wish my woodworking was within 0.001”!
My crosscut sled itself has more wiggle than that, even after adjusting the guides.
I’ve used a dial indicator like this, when I wanted slightly more precision than tapping. I found tapping was just as fast for me. If I were a production shop maybe I’d be better at using these tools efficiently.
Or buy a proper table saw with not only a micro-adjustable fence for the ripping but a sliding carriage with a cross-cut fence sporting a micro-adjustable stop.
These adjusters have a screw thread with a 1 mm pitch, with the circumference of the wheel divided into 10ths (0.1 mm). The fences are precise with no slop so turning the adjuster by 0.1 mm does actually remove an extra 0.1 mm of wood, no more, no less. In fact, it'll remove 0.05mm if one turns the wheel from a mark to half way to the next mark.
Such saws don't cost that much over here. And no $372.99 for parts to make a jig that takes hours to make and may or may not work well. :-)
One day, when my very rich auntie I don't know about dies and leaves me a billion dollars in Amazon shares, I will buy y'all proper table saws. No .... don't thank me yet; she's not yet dead!
Lataxe
That's why I bought my SS without a fence and put on a Vega. As a bonus, it's a 4-speed!
Ummmmm
He's not talking about adjusting the width of cut, he's talking about adjusting acanted fence so it's parallel to the blade.
Sounds to me like he's talking about using a dial indicator instead of tapping the fence to move it. It looks like a regular t-square fence. He mentions the measuring tape on the rail... not the angle. Am I missing something?
I didn't watch the video, but after reading the post again, you are probably correct. I just didn't imagine that people would care about adjusting a tablesaw cut to 1/1000th of an inch. Or even 1/100th. I'm not making parts for jet engines. If my tenon is too tight, there are far better ways of trimming it than trying to do it on the table saw.
I should be interested in knowing what sort of accuracy CAN be achieved with a TS, and whether that accuracy depends on wood type, or saw type.
I don't want to spend all day tomorrow in the shop cutting wood and checking with my dial gauge, so if anyone knows the answer, it'd be appreciated
Rob,
The accuracy of a TS cut depends on many, many factors, with the ability to reliably micro-adjust fences just one factor. Basically, everything about the TS needs to be well made and solid, with no slop or vibration sufficient enough to cause one cut to be different in size to the next cut at the same settings.
Another range of factors is in the set-up of the TS, which needs all the usual things found in set up articles - rip fence parallel to the blade, table flat, arbour and blade without distortion, etcetera.
A third range of factors concerns the user's ability to operate the saw, including the use of various gubbins such as hold-downs, feather boards, shortened rip fence faces, push sticks et al. But also feed speed and avoidance of plank-handling faux-pas that will allow the plank to momentarily twist, stop, burn or otherwise lose a bit more wood than it should through user inattention or a cack-hand.
Then there's the wood/blade/type-of-cut stuff. Too many teeth when ripping will cause slow feed, burning and so forth. Too few teeth when cross-cutting will cause a rough cut and even a queer vibration that ends up with the plank-end being chewed in some cases. And some woods can be awkward, with variations in grain and density trying to move the saw blade as it cuts or letting loose tensions to bend the workpiece so it's no longer straight on a fence or on the table top; perhaps even pinching on the blade.
Yet a TS of decent quality used with care and understanding on most timbers can make cuts that can be varied as little as 0.05mm. I regularly do "sneaking-up" on a part that must fit width or length-wise very precisely into something else. I often go from "goes in but still too tight as it's slightly distorting what it goes into" to "a perfect fit" via taking off just 0.1 mm or (with small things like little boxes) 0.05 mm. The TS will do it, making only a small amount of very fine dust indeed.
Lataxe
It seems discussions about accuracy and precision in joinery have been going on for many years. Perhaps even as long as man, tools and wood came together to make furniture. For what it's worth, take a look at this article: "On Precision in Joinery," Alan J. Boardman, FWW #25, Nov-Dec 1980.
“[Deleted]”
With my contractor style Rockwell saw, with the motor hanging out the back, there is lots of vibration, so no matter what blade I use, the cut surface shows some saw marks. That puts a limit on the accuracy.
When I switched to a SawStop ICS model, I was surprised to find that the same old blade that I was using on the Rockwell contractor saw, was giving quite smooth finish on the ICS.
When I want to, I can set the SawStop ICS fence with a resolution of 0.001 inch, as demonstrated in the video. But resolution is not accuracy. I find that accuracy is rarely required in woodworking. No one will question the quality of table by precisely measuring the length of the legs, but they will question the quality if the legs are not all the same length.
The precision challenge in woodworking is usually to get a good fit to another piece, rather than the absolute dimension. Measuring with a good ruler is sufficient for accuracy. However if cutting something to fit into a groove or joint then adjusting the fence by tapping with dial indicator can be helpful to quickly get the fence to the right position.
https://youtu.be/MZu0JvW1g3k
Seriously? .001 of an inch in woodworking?
I just measured the thickness of a cheap pamphlet with paper so tissue thin that I can literally see my hand on the other side. It measures at .002.
I've been woodworking for forty years and don't envision the day where I'd need a dial indicator to make an .001 adjustment on what can be done by locking your fence where the stock just kisses the tooth on the blade.
But hey, there's a hundred different ways of doing things I guess.
My table saw can do 0.001mm ... truly - measured on a DRO.
I have two micro adjusters: one on the rip fence, and one on the crosscut fence.
The table saw is a Hammer K3 slider. This may be used as a traditional cabinet saw. In this regard, there is a micro adjust with a Wixey DRO ...
https://i.postimg.cc/Y0v4fWw7/1.jpg
The slider has a crosscut fence, and I built this micro adjuster for it ...
https://i.postimg.cc/W4shYKPX/6.jpg
https://i.postimg.cc/x1DkM8pr/7.jpg
Of course, this is in the adjusting. I rather doubt that any of this means anything. Even though I can achieve a glue ready rip using the slider wagon, I very much doubt that this would be possible with the rip fence .... unless you are also using a JessEm hold down ...
https://i.postimg.cc/kgwrH4TV/Y1a.jpg
This forces the panel/board against the rip fence, and creates a smooth cut.
Regards from Perth
Derek
I worked for about 10 years as a production machinist. I sometimes made precision bearing shells and shafts to half a thousandth of an inch out of steel of various sorts, also titanium. Plus or minus .002 was not unusual. Trust me, wood is not a material you can achieve that kind of repeatable precision at. Nor are woodworking machines generally capable of that, whatever dials or gauges they have. I imagine that very high end sliding table saws may come close, but you also have to consider that when ripping a long board, you are not going to be able to keep it consistently guided along the fence to within .001, nor is it likely to be flat and square to that precision.
Dial indicators are great for alignment. And they are also good if you want to make sure you don't overtap. But don't kid yourself that you're going to start making parts to that degree of accuracy. Or that you should -- remember that wood swells and shrinks all the time with changes in temperature and humidity.
Amen. I aim to get parts the same length -- opposite sides of table aprons, for example. But I do that by feel. Stack the two aprons and feel if they are equal. But if they are off from the plans by a whole bunch of thousandths doesn't matter in the least.
I recently finished a piece that was almost a half inch narrower than my design. Because that's how wide my boards were. I wasn't doing a glueup for a half inch.
AMEN brother! I was a tool designer/draftsman for many years. Not a machinist but far from lost in a machine shop either. Most people don't even know how to measure that accurately, don't understand what it take to work to anywhere near that precision and really don't understand tolerances.
I quit wasting time wading into these discussion but glad to see someone else on here that REALLY understands.
A Mr. Woodard, I seriously doubt your blade and/or arbor runout is .001”.
My response to you is woodworking and machining wood are not the same thing.
There is a school (usually beginners) that says “cut all the parts to such and such” then when it doesn’t fit together like it’s supposed to, the frustration/self flagellation begins. BTDT got the T shirt.
Then one day you realize things like what John said, and start mark from reality not rely on measuring.
Besides, by the time you learn this, you can’t read the ruler as well, either.
It's a commonplace remark in woodworking forums and websites - that wood doesn't need the precision of metal working; and that it isn't possible anyway with wood. However ....
There is virtue in aiming for precision in many styles of furniture but also in most joints of a certain kind: the show-joints. These tend to be prevalent in a lot of Arts & Crafts styles, known as "honest" joinery (meaning it's visible for all to see rather than hidden away behind some decorative gadrooning or similar.
There's also a modern style of furniture making advocated by, amongst others, Robert Ingham and some of his contemporaries, known as "wood engineering". The aim is to achieve precisely the sort of 1 - 2 thou precision supposedly impossible in woodworking.
https://duckduckgo.com/?q=robert+ingham+woodwork&iar=images&iax=images&ia=images
Some of those who pooh-pooh the possibility of such precision with a table saw are quite prepared to accept it from a plane. 1 thou shavings are commonly referred to and very possible with a well set up hand plane. So is an absolute precise fit for stringing and banding, marquetry and parquetry and some other styles in which an absolutely perfect fit of one thing to, or into, another is essential.
Of course, many table saws (and many of their users) won't be capable of such precision. But that doesn't mean it can't be done. Nor does it mean you shouldn't try. Honest joinery that "fits like a chicken's top lip" is good to see in some styles of woodwork and not impossible to achieve.
Lataxe
Agree with all @lataxe's points. Wondering though, what is the smallest readily noticeable gap in woodwork?
Depends on how close I am, or if I forgot my glasses.
Yes. Also, errors compound.
I think you highlighted the places where we should focus on precision. Inlay, stringing and so on also involve contained surfaces. I would imagine that if you can cut a 1/32" channel for stringing, that a string that varies a bit over the 1/32 will compress into it. Probably have at least 0.002 leeway there, no? That's quite a different issue than saying we're going to rip a bunch of boards whose edges are not contained to be within .001" of each other.
When we say we want a plane that cuts thousandths, we don't pretend that the surface will be flat everywhere to within .001. We also know that however we adjust our plane, if it's a figured wood, that the denser areas will cut differently than the less dense areas.
I'm all for precision and accuracy, two things I had no choice with as a production metal machinist. I try to make my wood projects as precise as makes sense. That means worrying as much about square as an exact dimension in my experience. For example, if I'm making a 48" high bookcase with a rail at the bottom and another rail a the top, the two rails can probably be within 0.01" and the sides will flex to accommodate that difference and the eye will not notice. However, if the ends of the rails are not square by even 0.005" it will probably be visually obvious. I'm guessing here about the actual amounts, but I think the principle is sound.
Points taken, LatAxe, veneer, marquetry, exposed joinery aside, there’s also point where it’s a pointless process of perfectionism, only serving to satisfy personal ideals.
This type of approach can really turn our ww’ing into a quite frustrating, unsatisfying hypercritical exercise.
I’m as guilty as the next guy, but I am forced to come up for air, reminded by myself I’m a human being, not a CNC machine.
Yes. Marquetry is a whole other animal. But for regular woodworking, tolerances vary.
For instance, I want tenons to be a very particular tightness. The tolerances are very small, but I have no idea what the measurement is. But I get the final fit off of hand tools, not the table saw.
Once upon a time, I would spend too much time dialing in the right sawcuts for a perfect tenon. I'd do a couple of practice pieces, and it was perfect. Then I'd cut a whole bunch for real. Some were great. A few were way too loose.
Maybe if I had an incredible saw it would be fine. Maybe not. I just stopped trying to chase perfection off a machine. All my tenons start off a wee bit over, then I make adjustments with a chisel, plane, or shinto saw rasp. I always get an ideal fit, never have to shim, and it's much faster and more enjoyable.
I think some of you are missing the point.
The OP shows us a nice shop-made jig that can be very useful when you need very precise fence adjustments.
Who amongst us has not been frustrated at the “bump and pray” method of fence adjustment? I certainly have.
It is easy to measure your work and determine you need to remove, say 0.030” from your work. Using “bump and pray” that may take several cuts. Using the OP's device, that could be achieved reliably in one cut.
So I think it is a great idea and one that many of us might find useful. I for one may try making something similar in the near future.
OTOH it may not be something that suits everybody. We all have different wants and needs.
I want to thank the OP for taking the time to post his idea.
Hendo,
A point is being missed, as you say.
Those not keen on the idea of a precise mode to alter fences and other guides on jigged tools, because wood can't be cut as precisely as metal, are making the fallacious assumption that there is therefore no need to attempt precision with wood. Some even seem to be suggesting that modes of working that allow imprecision are in fact better, as they suit the nature of wood!
The point is that a precise means of altering a fence or other tool guide will give a better result when cutting ANYTHING than will the "bump & pray" method. Of course the wood is not a fine enough substance such that it can be milled as exactly as metal. But it can be milled more precisely with a precise adjuster controlling the cuts than it can be milled via use of an imprecise adjuster.
What degree of precision can be achieved with wood? It depends on the wood, the nature of the parts, the type of machine and the skill of the user but ..... I once more refer the doubters to various very precisely made pieces of wooden stuff. Look in the gallery pages of any issue of Fine Woodworking magazine. If you can find one these days, ask a pattern maker.
Do all wooden furniture items need to be as precise as possible? No. But some do.
Too much binary thinking is going on. There are many degrees of reality-features possible, including degrees in the precision of wooden parts for the many styles and qualities of furniture.
Lataxe
At my level of wood working, there are enough chances of a screw-up without setting my fence at the wrong position to cut the wood to the correct size. When size matters, I consider the dial indicator the most sensible and convenient tool to resort to. I don't apologize for the digital read-out on my thickness planer either.
Steven shows but doesn't mention, always pre-load the dial indicator to remove backlash.
If you don't have a dial indicator and don't want to tap, tap as Steven still does in spite of using the dial indicator, simply use the same type of setup with the appropriate feeler gauge(s). Insert the feeler gauge(s) between the stop and the fence and move the fence until it lightly squeezes the feeler gauge. Lock the fence in place and remove the gauge(s).
I am actually with the OP and do occasionally use a dial indicator to ensure that changes in the fence position are exactly what is planned.
I don't usually aim for a specific dimension though, rather an accurate adjustment.
I am lucky enough to have a fence with a good micro-adjuster though, which permits such changes to be made meaningful. Absent that, you are probably better with bump and pray methods.
His channel on YT is pretty good too, and worth a subscribe.
Here's an alternative to the precise-adjustment mode, though. It is the case, after all, that some styles of woodworking do go better with little or no regard paid to precision. Instead, there is something like an art (rather than just craft) employed to marshal disparate and often non-linear stuff into an attractive and functional whole.
Many years ago I had a period of green woodworking, including various classes (more like "experiences") with experts to get a feel for the tools & techniques. They often made things with the simplest of tools (an axe, froe, beetle and knife) with no measurement except by eye, feel and fitting the next part to the previous parts.
Some green woodworking items did involve a bit of precision. Sizing round tenons and the holes they fit into for ladderback chairs, for example, via a very precise lathe tool - to 0.1mm accuracy or better. But most green woodworking items are measured only with the human senses.
Perhaps the epitome of such "artistically formed" objects is the swill basket, made from strips of oak sapwood split from a 6-8" diameter coppiced oak trunk with axe, then froe then knife. To enable the working of the material it's also boiled in a huge tub until pliant enough to easily split into very thin strips that can be woven.
The art is in doing all this felling and splitting by eye and feel but mostly in the weaving of the basket into a myriad traditional forms. The results from this basically simple but skilful process can be very beautiful as well as highly functional.
Millions of swill baskets were made in Britain in the centuries before plastics replaced their many forms.
Lataxe
More swills.
Some finished swill baskets.
Not a micrometer in sight!
Lataxe
Nice. Baskets are on my list some day.
Wow ! The most comments on any post I have made.
I like to mention why I came up with this solution: I was adjusting the fence to cut runners for a table saw sled. It was a single runner sled so I wanted the runner to be snug, not tight, not loose, just right. I was cutting the runners from UHMW which is stable with humidity.
It took a dozen tries to get the fit just right. Why so many tries ? Because when tapping the fence, I had no idea how much it was actually moving and I would overshoot and then have to go back. Time consuming, frustrating, and wasteful.
Sure I could sand or plane the runners to get a good fit but why would I want to do that when I had proven that with the fence set just right I could consistently cut perfect runners.
The only problem was the time and frustration of setting the fence. With the dial indicator solution I found that the fence could be adjusted very predictably in increments as small as 0.001 inch as per dial indicator. This allowed me to quickly set the fence. Watch the video and you can see it.
I want to thank the OP for posting a link to his video of a very creative solution to add .001 inch precision to a table saw rip cuts. I purchased my SawStop PCS without a fence and added an Incra LS TS to have this capability. The OP has a portable solution that resuses a very important but little used Table Saw Setup Gauge with Magswitch MagJigs. This solution can be used with other fences (bandsaw, drill press, router table, shaper) in the shop to dial in that same level of precison. Hum ... I wonder if it would work on a planer? This should be submitted as a tip to FineWoodworking Magazine.
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