"Been doing professional set-ups of machines long before that gizmo was marketed to homeowners. In my opinion you are throwing your money away. You can buy an indicator more than suitable for the application from www.use-enco.com for $15. You could scew it to a block of wood for the application you have in mind. You might want to pick up a pair of 6" dial calipers while you are at it. Nice for measuring shims and and such...usually about $12. One can also learn to read the cut from a piece of MDF. One place I worked had a Giben beam panel saw and that was the only way to tell if the saw was set right. Both pieces will have heel and toe lines from blade for correct setting. So you don't even need that expensive TS aligner after all."

Well, if all you want to do is blade and fence alignment on a table saw, then this is good advice.  I call this the "dial indicator on a stick" solution and have recommended it countless times.   Here's an article comparing the "dial indicator on a stick" to a TS-Aligner Jr. Lite.  I do take issue when he says it is "more than suitable for the application."  That $15 Enco dial indicator isn't going to come with anything.  All by itself, it's not suitable for aligning woodworking machinery.  You will need to devise all your own fixturing and mechanisms to adapt it for use on woodworking machines.  You will need to figure out all your own methods and techniques for alignment because no instructions will be included.  Essentially, you will need to replicate all the work I have done over the last 16+ years.  The TS-Aligner products are nothing more than mechanisms and fixturing that adapt the dial indicator for use in making precise adjustments to woodworking machinery.  Instructions (and video demonstrations) are included! 

I have no objection to his final sentence.  People have been aligning machinery since before TS-Aligner was invented.  In fact, people have been doing fine woodworking since before the carbon steel was invented.  So, not only is there no need for a TS-Aligner, but there's also no need for the machinery that it is intended to align.  "Expensive" tools like table saws, jointers, band saws, miter saws, etc. are not needed for even the finest woodworking.  Just like a TS-Aligner, these machines  just save a lot of time and effort.

"You can do a decent job of aligning without a dial indicator. Take a thin slat of wood, 1/8" thick or less, raise you blade to full height, Mark a tooth, place the slat in your miter gauge and move it into the tooth you marked. Move the blade back and forth so the tooth barely touches it, rotate the blade until it is at the extreme back of your saw, move your miter gague holding the slat firmly all the time to the back and check."

This is what I call a "feel the rub" method.  If you are good at making subtle subjective judgments between two relative rubs of a stick against a blade tooth then it is possible to obtain respectable blade alignment using this method.  It becomes a bit more difficult when doing fence alignment.  People often modify this method by including feeler gauges in an effort to improve the results but it's still pretty subjective.  The technique is adequate for blade alignment, not quite as good for fence alignment, and no good for anything else.  Personally, I prefer comparing objective measurements using a dial indicator.  The process goes a lot faster and involves no guesswork.  And, if the dial indicator happens to be attached to a TS-Aligner it's going to help out in many other adjustments and alignments around the shop.

"I saw it demonstrated at a show and it's over kill for woodworkers. I measure the wood and not the blade to set my angles. Most saw blades aren't perfectly flat so it's better to reference from the wood to tweak adjustments http://www.starrett.com/catalog/catalog/groupf.asp?GroupID=148  I use a device similar to the above posted but it's made by Enco and cost me $40. I do metal work as well and it suits my needs just fine. Frankly I think the gadgets for woodworking has gotten out of control. When I started WW 30 years ago we made a lot of our own special jigs and tools. I even do a lot of machine tuning for other WW and get just as good results without the TS Aligner and such."

If you have read my article on "Trial and Error", you will recognize this method.  Measuring the test cut improves the process tremendously but it's still tedious trial and error.  Even if you can measure the error precisely you are still left guessing about the proper amount of machine adjustment.  The TS-Aligner eliminates trial and error by facilitating the proper machine adjustment.  And, it doesn't depend on a test cut or blade flatness to accomplish the task.

"As far as setting to 90 degrees goes, I use a simple plastic drafting triangle to get my initial blade adjustment, then proceed to do test cuts and fine adjustments until I get it perfect (you know, cut a piece, turn half of it over, and re-match the cut, any gap indicates not 90 degrees yet).  With this method and only one crosscut, a 100th degree error would combine to be twice as bit when the wood's turned over.  Could I see that?  Dunno!  Might take another pile of scrap wood to get it that close.  But I'm willing to bet that once you got the gauge set to 90 + 1/100th, it would work flawlessly from then on."

One thing that proponents of "trial and error" methods often neglect is proper stock preparation.  You can't just pick up any old scrap of wood in the shop and expect good results.  This particular method fails miserably if the stock used for the test cuts does not have perfectly parallel faces.   The error observed might be from the test cut or it might be from poorly prepared stock.  Also worth mentioning, "plastic drafting triangles" are designed and manufactured for drawing lines on paper.  They are not accurate for machinery adjustment (as evidenced by this person's need for subsequent trial and error).  Finally, it's not likely that any machine setting will continue to "work flawlessly" after the initial setup.  Thermal variations, vibrations, and shock from normal use and storage will cause most adjustments and alignments to change over time.  Having a precise alignment tool will reveal this and make any corrections quick, easy, and accurate.  

"One very important lesson i learned from doing some work in a tool and die shop is that you are only as accurate as your weakest link. as we all know, woodworking machinery isn't as precise as metalworking machinery so money spent on extremely accurate measuring tools is not necessary if your machinery can't hold the same tolerances that they are made to. if you really want accuracy then what you need is a sine bar and a set of gauge blocks. that's what a machine shop will use when they need extremely precise angles, but like i said before, it would make no sense because no woodworking machine is built to operate with that kind of precision."

It is true that woodworking machinery isn't as accurate as metalworking machinery.  And, there are examples of particular machines that are not accurate enough to justify the use of a dial indicator jig.  But, most woodworking machinery can hold some very respectable tolerances.  Think about it.  If the machine can hold the correct setting after a long and tedious session of trial and error, then why can't it hold the same setting after a quick and easy adjustment with a TS-Aligner?  If such a task is so impossible, then I suppose that I have been using my TS-Aligner to perform the impossible on a daily basis for more than 15 years!

"I don't think there is anything that will guarantee you a perfect setup first time and, as others have noted, your angle-setting device is just one of several components that all have to be set correctly."

Proper calibration of one's measurement instruments is very important.  But, when used properly, the TS-Aligner products do guarantee an accurate setup on the very first cut.  Unfortunately there are a lot of poorly designed products marketed to woodworkers which make sweeping claims of precision and accuracy.  People end up getting a little skeptical after having tried many of them.   

"As someone who has worked on tuning woodworking machines in industry for years before all thes gadget were available I wouldn't waste the money. The folks selling those gadgets talk about accuracy most metal shops don't even bother with unless workong on space shuttles and such.  A set of feeler gauges and a $12 dollar dial indicator from Enco will work fine.  It's knowing what to adjust and how to get a feel for it that's worth paying for.  I'd recommend bying a few books as a far better alternative.   Duginske and White would be good start and probabably all you need.  I have a set of tools for setting up machines that can be put together for around $120  including a 6' straightedge and that's at todays prices not 20 years ago."

From my experience, it would seem that this particular person has no knowledge of what goes on in a "metal shop"!  TS-Aligner products are designed to provide the accuracy needed to eliminate the need for test cuts - no more and no less.  This degree of accuracy is considered very ordinary and mundane in virtually all metalworking machine shops.  No "space shuttle" tolerances being claimed here!  As for cost, I'm sure that the books and tools would surpass the cost of a TS-Aligner Jr. and still leave a person wanting for solutions adapted to woodworking machinery.

"The table saw is one of the final steps towards good joinery. It is not the final step. What you sell treats it as though it is. That is wrong. Do you really think that a tenon cheek is ready for the mortise when it comes from the saw? Do you really think that a cut edge is ready for butting to another as it comes from the saw? Preposterous! If the face, or edge has not been worked, it is not finished and can only fail. The tablesaw is in the same category as the planer, it attempts to level the playing field. The real work of joinery comes after the rough work is done. I'm not saying that it does not help to have a perfectly set up table saw - I'm saying that it is a snapshot of reality and that the project goes on beyond it. Set a saw up perfectly and then run some interesting wood through it for a day.
Then, test it again - what has happened? It is a roughing tool, not a finishing tool - and it should never be treated as such."

I suspect that this person isn't familiar with the results that can be had from a properly tuned machine using a sharp blade. If I had been using hand tools all my life to clean up the poor quality and inaccurate results that come from a misaligned table saw using a cheap blade then I might just share his opinion.  This really is more a commentary on his machinery skills than the machinery itself. 

The table saw is definitely not the final step for some joinery (dovetail joints for example).  But, I don't have any problem ripping "glue ready" butt joints on my table saw.  I've had many people look at things I've made and admire the tight joints in tabletops, desktops, panels, etc.  All my tenons have been ready for the mortise and none have ever failed.  I've got hundreds of such joints in my house that came right off the table saw.  Some have been together for nearly 30 years.  None have ever failed.  Many have moved from humid and warm climates (SF Bay Area) to dry and cold climates (Idaho).  I know it's only anecdotal evidence but I'm really having trouble believing what this person says.

There is definitely more to any woodworking project than a table saw. Even a well tuned table saw isn't the end-all and be-all of woodworking projects.  But, it's not exactly fair to blame the machine for such poor results.  I have no doubt that the settings on a table saw (or any machine) can drift after a hard days work.  The skilled woodworker will quickly see this as yet another good reason for using a precision alignment tool like TS-Aligner.  The error can be detected and corrected long before it becomes a problem (requiring rework with hand tools).

"I own one... I used it once and I haven't taken it out of the box in two years."

Those that have said that they used their Aligner once or very infrequently probably bought it only for table saw blade and fence alignment.  They prefer to do most of their woodworking by trial and error with lots of test cuts.  I have a Jr. in my shop and use it all the time.  Whenever I need to square something up (like blade, miter gauge, drill press, etc.) I grab my Jr.  It's a lot easier and faster than trying to sight tiny gaps by eye with a square.  And, it saves tons of time in making precise angle adjustments.  Setting cutter heights is also a snap.  Sharpening jointer knives is no longer a dreaded task.  If you like fiddling around with machine adjustments and making test cuts then you probably won't find much use for an Aligner.  If you are frustrated by machine adjustments and find yourself making little progress on your projects, then you'll learn to appreciate what an Aligner can do for you.

"I do not own one... but like you though about purchasing one UNTIL I saw the price...  Come on... My saws cut very well and I do have to say That once in a while I will run into problems with rough cuts etc but nothing big time..and nothing I can not check using simple tools around the shop... If I needed one even 3-4 times a year I think I may buy one... But Sheeze I have been making sawdust for over 40 years and survived this long without any problems... "

Again, TS-Aligner (or any other alignment jig) is not absolutely necessary.  Everything that the Aligner can do for you can also be done without it.  The Aligner just makes the process a lot easier, faster, and more accurate.  In the same way, a table saw isn't really absolutely necessary.  Neither is a router, jointer, or a drill press. Everything that they do for you can be done just as well without them if you invest enough patience, time, and effort.  In fact, a whole bunch of fine woodworking was done long before carbon steel was first invented.  If you decide that your time is not worth the price of a TS-Aligner, then you are probably best off without one.