Trouble setting up new table saw

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"Chris Friesen" wrote in message

No shit? But apparently not without a $2000 cabinet saw set up to +/- .003, eh?

Yessir, it a damn crying shame that the lack of a $2000 cabinet saw, set up to .003, stopped the likes of Duncan Phyfe, and more recently old Frank and Sam's careers, dead in their tracks. :)
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RE: Subject
Remember the old saying, "A Flying Red Horse can't tell the difference from 1,000 ft"?
It applies.
Lew
PS:
Ask the guys in metrology about the magnitude of built in errors of single ended vs differential measurements.
Measurements under discussion are single ended.
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45 degrees is always described (by careful persons) as 45 +/- something-or-other. So the typical way to get a full circle out of 45 degree wedges is to join four wedges for the left half, join four wedges for the right half, and joint both halves to make the final joints fit. Another way is to temporary- mount the items side-to-side with the crack, run it through the table saw to open that crack to a straight 1/8" void, then close the joint. Kerfing was what Roy Underhill called it, though his technique used a handsaw...
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Very true! The words "dead on" are somewhat of a misnomer. Everything has some error if you look closely enough.

I've heard of this. It's a popular technique among those who do segmented turnings. The joints will all be tight but the circle becomes a bit less circular. The lathe guys end up having to make the walls of their turnings a bit thicker so that they can then turn them round.

In other words, cut both pieces at the same time. Yes, I've used this technique (long, long ago). You pretty much want to assemble the whole thing first. For something like a frame, where you have to maintain equal lengths on opposite sides, you'll end up cutting through all of the joints - gap or no.
There's a third option that you didn't mention. That is, cut the pieces accurately enough to avoid the gap in the first place. Then you don't have to use these or any other methods to rework the joint(s). It takes a bit more skill and knowledge but it's much faster and cleaner in the end. The other techniques are good for those who are not interested in developing their machinery skills.
Ed Bennett snipped-for-privacy@ts-aligner.com
http://www.ts-aligner.com Home of the TS-Aligner.com
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Thanks for the reply. An interesting technique, I'll have to keep it in mind.
Dan
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I would at this point suggest to first take Frank's advice and start cutting some wood. While exacting tolerances are a plus, sometimes we cannot take full advantages of these fine settings because of the quality of the material that we cut and or out technique can be sub par to the machine tolerances. First see how the saw cuts at a 45 degree bevel. If you don't see any kerf marks or burning you should be good to go. We often get a bit too wrapped up in using a dial indicator to measure "everything". If you are not happy with the cutting results call Powermatic and get them involved.
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Frank Boettcher wrote:

> The manufacture then rolls it over to 45 and checks the alignment

If the only problem is that the axis of rotation of the arbor is not parallel to the table, then shimming the table relative to the cabinet can fix the problem.
If there is other slop and play in the mechanism, I agree that there isn't much that can be done.
Chris
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On Thu, 20 Sep 2007 12:23:43 -0700, Dan wrote:

On a contractors saw, this problem is usually caused by the two trunnions not being parallel and the answer is to shim one side of one of the trunnions. I don't know if the same applies to cabinet saws, but they do have trunnions - perhaps someone else can comment.
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It's possible that you're cranking the blade too hard against the 45 or 90 degree stops. I might try cuts at 46 and 89 degrees, just to see if the stops are the problem.
Hard to imagine how the error can increase no matter which way you tilt the table.
John Martin
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wrote:

John-I finally worked it out with .025" shims, now I'm good to ~.003 on each. I think the error was that prying the table on one side didn't really replicate the effect of shims.
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Y'know - after many years of lurking and occasional posting in this newsgroup and having to deal with the seasonal trolls that surface, it's nice to be reminded of the good stuff - like someone actually helping someone else.
OK, enough sentiment - gotta go make some noise & sawdust!
Vic
wrote:

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Well this has been an eye opening thread and I think I've seen the light. You see, when I needed to upgrade my table saw I went back to "salvage" (the place where freight damgage, dealer inventory resets, individuals who do not believe in the laws of random variability, and the rare individual who actually has a real problem send their units back to) and asked Jerry if he had a Unisaw. Says Frank I've got this one that came back "alledged defective" (the usual RMA cause) but I've checked it and can't find the reason (the usual outcome) it's within specs., so I say let me go pay finance and I'll back my truck up. I never checked the saw for alignment that day or ever.
Now that was 13 years ago or so, and I've made a whole lot of furniture since then with this saw and while my friends and realtives comment favorably on my work, as the builder I know where all the flaws are that they don't see.
I've always assumed that the flaws were human error, where I measure a little wrong, or skipped a step here or there, or whatever. But now I'm beginning to think I can blame all those flaws on the saw.
So I guess I need to get one of those gadgets that Ed sells and get to tweaking this saw so I can achieve the perfection that I know exists out there somewhere.
Frank
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I built a 12"x12"x12" box made with 1/4" plywood, and 4 of the edges were joined with a box joint. I built a prototype before I had Ed's tool, and then built the real one after. It was a LOT easier getting everything lined up precisely square after using the TS Aligner Jr.
Ed even helped me figure out how to align the cross-cut sled precisely. This "just make sawdust" is fine for some jobs. But when errors are multiplied, adjusting a fit afterwards can be a PITA.
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For many years I used my father's tablesaw (still in use today) but the first table saw I purchased was a Sears Crapsman (about 25 years ago). I learned a heck of a lot of woodworking on that machine and never received a single negative comment from anyone about the quality of my work. There was always a healthy amount of test cuts, re- working joints and "creative fixes" involved in the process and I figured that it was all a matter of skill (and a lack thereof). If I could refine my skills enough then these problems would go away. But, it didn't quite work out that way. Instead, I learned which tasks and design elements proved to be the most troublesome and time consuming so that I could avoid them. It struck me one day when I was trying to talk a customer (an interior designer) out of doing what she wanted me to do (mitered corners). I was being a brainless moron: going nowhere and doing nothing. Pretty soon I'd be making kitchen cabinets as a sub-contractor instead of furniture for designers.
Having the benefit of a formal education, I had the ability to work through a problem in a logical manner. I could examine symptoms, recognize specific causes, and develop systematic solutions to resolve them. I purchased the proper instruments (dial indicator, magnetic base, calipers, etc.) so that I could examine my machines to determine what could be done to reduce or eliminate the test cuts, re-work, and "creative fixes". Basically, I had decided to devote myself to improving my machinery skills.
It didn't take me long to recognize major problem areas. The first thing I did was replace the rip fence. It proved to be an astoundingly amazing improvement. So much so that I decided that the entire saw was a lost cause. I replaced it with the Unisaw that I have today and realized yet another quantum leap in the quality of work that came right off the machine. I probably could have continued to use the Sears saw and optimize its performance but I was impatient.
During this same time, I was developing tools and techniques for eliminating test cuts and rework. With the help of a machinist friend and some engineers, I combined these tools and techniques into the first TS-Aligner. That was in the spring of 1990 - more than 17 years ago. I tested it on a commission from a designer that I would have flatly turned down a year earlier: a night stand made in the shape of an "A". Every joint came together at a compound angle (including the dovetailed drawer sides). I pulled it off without a test cut. No re- work. It was done to budget in record time.
For years I had fought against a poorly maintained junker saw thinking that my woodworking skills were deficient. In reality, it was my machinery skills that needed help. The quality of my wood work was never the issue, it was the enormous time and effort that went into making anything that went beyond simple square joinery, stock molding profiles, curves, angles, shapes, etc. I was wasting time and effort fixing everything that the machine did wrong - leading me to avoid projects that could stretch and develop my woodworking skills.
There are a number of people who want to turn this into flame fest against machinery and its proper alignment. They cite their personal anecdotes about how many years they have been producing fine woodworking without any regard for alignment. In addition to being exasperating, this is nothing more than a straw man argument. The issue has nothing to do with $2000 saws and alignment to within a "thousandths of a gnat's ass". Amazing woodworking has been done for thousands of years before table saws were even invented. Nobody is saying that you have to spend a certain amount of money, or have a certain machine, or align it in a certain way before you can do fine woodworking. People who rant and rave on this point expose themselves as extremely insecure.
This thread is about helping one person to make the most of a recent machinery investment. It's about helping him to learn and apply some machinery skills. It is not a waste of time; it is a way to avoid wasting a lot of time and effort. People who can't sit by without ridiculing him and continually citing examples of how well they get by without any machinery skills are saying a lot more about themselves than they realize.
Ed Bennett snipped-for-privacy@ts-aligner.com
http://www.ts-aligner.com Home of the TS-Aligner
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"Ed Bennett" wrote in message

That's real sweet, Ed ... but the way you keep it going it's starting to sound a whole lot more like pious, holier than thou, spam.
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Sorry about the delay in responding. I've been pretty busy and haven't even been able to manage even one post per day.
Hmmmm....and I was thinking that the thread was starting to sound like the glorification of ignorance. Funny how two people can look at the same thing and get two completely different impressions.
Spam? No, it was just a story - much like the one that Frank told. I wrote it with the hope that I could inspire some to approach their woodworking in a more intelligent manner (and perhaps discourage others from ridiculing them in the process).
I received a number of email messages in response. This one pretty much represents the overall sentiment:
"I hope the idiocy here doesn't prevent you from participating in the future. It generally prevents me, but I learn a lot just by watching. I learn because folks like you dare to participate, financial interest or not."
The group used to be a lot more active and it was pretty rare that people would get flamed and ridiculed for asking legitimate questions or making a genuine request for help. At the worst, people would get told to search the archives. It would seem that things have become a bit stifled.
Pious? Holier that thou? Hmmm....again, two people can see things in completely different ways. The situation reminds me of how Galileo was treated when his innovative ideas threatened the pious ignorance of the time.
Thanks, Ed Bennett
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Oh no - you're not going to get up on some gilded throne, and try to proclaim that the world is really round now... are you?
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-Mike-
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OK, I've spent all day looking for one of these gilded thrones. Nobody in Boise has any in stock (no surprise there!). They all say that they can order one (gee, I could have done that for myself, so what purpose do the local shops serve?). So, until the throne arrives we will just have to live with a flat world located at the center of the solar system. I'll keep you posted on any progress. In the meantime, we need to get hold of someone in Rome and let them know about the delay. We certainly don't want any councils declaring anything rash before the actual proclamation occurs. After all, if they arrest me before the throne arrives then I'll be charged with crimes that haven't yet occurred. What a mess! Next time we'll need to think of a better platform for these announcements; something that can be obtained locally. ;-)
Thanks Mike,
Ed Bennett snipped-for-privacy@ts-aligner.com
http://www.ts-aligner.com Home of the TS-Aligner
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"Ed Bennett" wrote in message

Only if you don't recall the "Bennet War" flamefests that polluted this forum, ad infinitum, at one point.

Well Galileo, go back and re-examine your public mea culpa from the above ... you're slipping back to your old ways.
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