Truing, As Best You Can, Shopsmith Table Tops

[dusty]

OK, I WILL ask the question.

Let's take a saw like the Grizzly G1000 series table saw.

grizzly cabinet saw.jpg

To my eye, which I admit is still noob, looks similar to a 520 ProFence system on a Mark V or 7. This unit has less rip capacity but more HP and costs 1500 dollars or so......



Would this "table" live up to one thousandth tolerance like is expected on our machines (I understand you can "align" the extension tables and achieve that, but when swapping them you find they are "off".

Would the grizzly be held to that much of a standard?

Secondly, it this kind of tolerance necessary for woodworking? I work with less tolerance when building a 350 horsepower small block chevy or Ford engine.

I am just amazed that we are even talking these kinds of measurements. Are they necessary?

Trust me, I am not arguing, I am just having to rethink my approach to making wood projects if this kind of tolerance is needed or desirable .....

I can't speak to the tolerances of this specific machine but I will make a couple general comments regarding this type of machine. If I had the shop space, I would have one. But mine would look like this:

http://www.tylertool.com/delta-36-l336- ... wwn36-l336

The tight precision that has been discussed on this forum is generally not required in wood working and especially not in the type of wood working most of us do. But if you are building something that is going to cover the expanse of a family room wall tiny errors make for big problems before you are done. Charlese has built several pieces of fine furniture that we have seen here on the forum. He says he is not into precision measuring but if he was not making precision cuts his furniture would not be so impression. Yes, precision is possible using a Shopsmith.

The big difference between my Shopsmith and my dream Delta Unisaw is the precision of the tables with respect to the blade. The Unisaw is a direct opposite arrangement. The tables move on the Shopsmith. Once that Unisaw is setup properly, one would not want to move that arrangement at all. The table is the reference surface. The arbor moves with respect to the table and the arbor is one fine piece of machinery.

The Unisaw is capable of handling large work pieces with the same degree of accuracy as it does smaller work pieces. This is a major factor in anything other than a home workshop. From my 400 sq ft garage shop, the Shopsmith makes it possible for me to get the precision I want and the versatility. The Unisaw cannot do that

You ask about tolerances. What are tolerances? Tolerances are limits that have been imposed upon a project. Imposed by whom? Imposed by the person who is finely going to accept and us the finished item. If a 1/6th of an inch (.062") gap is acceptable, then it meets the requirements. However, a slightly smaller gap at say 1/32" (.030") might look better. I shot for still tighter control. I look for 1/64" (.015") and almost always accept a lot less.

Glue lines not wider than .015" sounds more impressive than glue lines 1/64" wide.

[rjent]

OK, I WILL ask the question.

Let's take a saw like the Grizzly G1000 series table saw.

grizzly cabinet saw.jpg

To my eye, which I admit is still noob, looks similar to a 520 ProFence system on a Mark V or 7. This unit has less rip capacity but more HP and costs 1500 dollars or so......



Would this "table" live up to one thousandth tolerance like is expected on our machines (I understand you can "align" the extension tables and achieve that, but when swapping them you find they are "off".

Would the grizzly be held to that much of a standard?

Secondly, it this kind of tolerance necessary for woodworking? I work with less tolerance when building a 350 horsepower small block chevy or Ford engine.

I am just amazed that we are even talking these kinds of measurements. Are they necessary?

Trust me, I am not arguing, I am just having to rethink my approach to making wood projects if this kind of tolerance is needed or desirable .....

I can't speak to the tolerances of this specific machine but I will make a couple general comments regarding this type of machine. If I had the shop space, I would have one. But mine would look like this:

http://www.tylertool.com/delta-36-l336- ... wwn36-l336

The tight precision that has been discussed on this forum is generally not required in wood working and especially not in the type of wood working most of us do. But if you are building something that is going to cover the expanse of a family room wall tiny errors make for big problems before you are done. Charlese has built several pieces of fine furniture that we have seen here on the forum. He says he is not into precision measuring but if he was not making precision cuts his furniture would not be so impression. Yes, precision is possible using a Shopsmith.

The big difference between my Shopsmith and my dream Delta Unisaw is the precision of the tables with respect to the blade. The Unisaw is a direct opposite arrangement. The tables move on the Shopsmith. Once that Unisaw is setup properly, one would not want to move that arrangement at all. The table is the reference surface. The arbor moves with respect to the table and the arbor is one fine piece of machinery.

The Unisaw is capable of handling large work pieces with the same degree of accuracy as it does smaller work pieces. This is a major factor in anything other than a home workshop. From my 400 sq ft garage shop, the Shopsmith makes it possible for me to get the precision I want and the versatility. The Unisaw cannot do that

You ask about tolerances. What are tolerances? Tolerances are limits that have been imposed upon a project. Imposed by whom? Imposed by the person who is finely going to accept and us the finished item. If a 1/6th of an inch (.062") gap is acceptable, then it meets the requirements. However, a slightly smaller gap at say 1/32" (.030") might look better. I shot for still tighter control. I look for 1/64" (.015") and almost always accept a lot less.

Glue lines not wider than .015" sounds more impressive than glue lines 1/64" wide.

Ok, I get that. I have two observations from here.

One is that all of you guys have mentioned that you can get repeatability by using a said extension table on the same end every time. If I am wrong about that, then correct me LOL. If that is true, then mark your two extension tables "L" and "R" and you are done .

And second, that is a 3000 dollar retail machine that only does one thing. Seems like a lot of money for a tool that if the kind of precision that you are talking about is needed, but achievable with the SS, but just not convenient. And believe me, I totally understand your point about the tolerance that is needed to cover a wall, Pretty high precision is needed for that kind of job. But it could be argued that you could set up a SS 520 in a configuration similar to your "dream machine" and leave it set that way and have the same capability. Am i wrong? LOL Am I just not seeing the big picture. Once that "big" job is done, you then "take down" the SS "precision" setup and go back to the magic that is SS.

I need to think about this brother. You have bumfuggeled my perception ....

[BuckeyeDennis]

+1 on Dusty's comments.

As for high-end cabinet saws, I was lucky enough to buy a Powermatic PM2000 cabinet saw, still in the factory box, for a small fraction of retail. When I finally get it unboxed and moved from my garage to my workshop, I'll post a review. Jsburger also has one, so let's hope that he chimes in sooner.

Regarding the tolerances that are needed for woodworking, I think the honest answer is "It depends". When it comes to setting the height of your jointer blades, 0.005" is too sloppy. If you are building a deck, 1/8" is probably just fine.

A little background on manufacturing methodologies may help put the various opinions in context. In the old days, assemblies were all custom fit. An expert craftsman would modify individual parts as needed, by filing, etc., in order to achieve an acceptable fit. This method is no longer cost-competitive for volume manufacturing, but is just fine and dandy for one-off pieces. Many would argue that it is indeed the most efficient process in that circumstance.

Another methodology is "selective assembly". Here, components are produced in volume, but are not sufficiently precise as to be completely interchangeable. So the assembler sorts through the available components, and selects combinations that mate up acceptably. But since we hobbiests rarely make anything in quantity, this method is of little interest to us.

The modern method in volume manufacturing is to produce "interchangeable components". Through the disciplines of tolerancing and statistical process control, any component on the production line is guaranteed to assemble properly with any other. If you are making stuff for Ikea, for example, you had darned sure better produce interchangeable components, because it has to be assembled by an unskilled end-user customer.

With that background, I believe that the precise-tolerance debate is primarily between those who like the custom-fit approach, and those who like the interchangeable-component approach. With a background in manufacturing, I instinctively gravitate to the latter (often for no good reason, I suspect). And as a relative noob to woodworking, I don't know all the techniques for quickly and easily tuning dimensions. But personally, I find it satisfying to get a good fit on the first try, with no tweaking. And if I can figure out a good process for holding a tight tolerance, it will save me time in the long run.

But I suspect that as my woodworking skills grow, I will adopt custom-fit methods more often.

Wikipedia has a good overview of these manufacturing methodologies.

[dusty]

OK, I WILL ask the question.

Let's take a saw like the Grizzly G1000 series table saw.

grizzly cabinet saw.jpg

To my eye, which I admit is still noob, looks similar to a 520 ProFence system on a Mark V or 7. This unit has less rip capacity but more HP and costs 1500 dollars or so......



Would this "table" live up to one thousandth tolerance like is expected on our machines (I understand you can "align" the extension tables and achieve that, but when swapping them you find they are "off".

Would the grizzly be held to that much of a standard?

Secondly, it this kind of tolerance necessary for woodworking? I work with less tolerance when building a 350 horsepower small block chevy or Ford engine.

I am just amazed that we are even talking these kinds of measurements. Are they necessary?

Trust me, I am not arguing, I am just having to rethink my approach to making wood projects if this kind of tolerance is needed or desirable .....

I can't speak to the tolerances of this specific machine but I will make a couple general comments regarding this type of machine. If I had the shop space, I would have one. But mine would look like this:

http://www.tylertool.com/delta-36-l336- ... wwn36-l336

The tight precision that has been discussed on this forum is generally not required in wood working and especially not in the type of wood working most of us do. But if you are building something that is going to cover the expanse of a family room wall tiny errors make for big problems before you are done. Charlese has built several pieces of fine furniture that we have seen here on the forum. He says he is not into precision measuring but if he was not making precision cuts his furniture would not be so impression. Yes, precision is possible using a Shopsmith.

The big difference between my Shopsmith and my dream Delta Unisaw is the precision of the tables with respect to the blade. The Unisaw is a direct opposite arrangement. The tables move on the Shopsmith. Once that Unisaw is setup properly, one would not want to move that arrangement at all. The table is the reference surface. The arbor moves with respect to the table and the arbor is one fine piece of machinery.

The Unisaw is capable of handling large work pieces with the same degree of accuracy as it does smaller work pieces. This is a major factor in anything other than a home workshop. From my 400 sq ft garage shop, the Shopsmith makes it possible for me to get the precision I want and the versatility. The Unisaw cannot do that

You ask about tolerances. What are tolerances? Tolerances are limits that have been imposed upon a project. Imposed by whom? Imposed by the person who is finely going to accept and us the finished item. If a 1/6th of an inch (.062") gap is acceptable, then it meets the requirements. However, a slightly smaller gap at say 1/32" (.030") might look better. I shot for still tighter control. I look for 1/64" (.015") and almost always accept a lot less.

Glue lines not wider than .015" sounds more impressive than glue lines 1/64" wide.

Ok, I get that. I have two observations from here.

One is that all of you guys have mentioned that you can get repeatability by using a said extension table on the same end every time. If I am wrong about that, then correct me LOL. If that is true, then mark your two extension tables "L" and "R" and you are done .

And second, that is a 3000 dollar retail machine that only does one thing. Seems like a lot of money for a tool that if the kind of precision that you are talking about is needed, but achievable with the SS, but just not convenient. And believe me, I totally understand your point about the tolerance that is needed to cover a wall, Pretty high precision is needed for that kind of job. But it could be argued that you could set up a SS 520 in a configuration similar to your "dream machine" and leave it set that way and have the same capability. Am i wrong? LOL Am I just not seeing the big picture. Once that "big" job is done, you then "take down" the SS "precision" setup and go back to the magic that is SS.

I need to think about this brother. You have bumfuggeled my perception ....

Hear me now. This is very important. THERE IS NO BIG PICTURE! At least not one that is pleasing to every one. Your shop is YOUR SHOP. It does for you what you want it to.

Furthermore, you are right about the left and right wings being calibrated and marked exclusively for that use. I already do essentially that except that I typically don't have a left wig. My jointer occupies that slot.

So why all of the discussion??? Because it is a phenomena that "bugs me". The way the Shopsmith is constructed, those tables should swap back and forth with "no deviation" but they don't. You tell me why.

[dusty]

+1 on Dusty's comments.

As for high-end cabinet saws, I was lucky enough to buy a Powermatic PM2000 cabinet saw, still in the factory box, for a small fraction of retail. When I finally get it unboxed and moved from my garage to my workshop, I'll post a review. Jsburger also has one, so let's hope that he chimes in sooner.

Regarding the tolerances that are needed for woodworking, I think the honest answer is "It depends". When it comes to setting the height of your jointer blades, 0.005" is too sloppy. If you are building a deck, 1/8" is probably just fine.

A little background on manufacturing methodologies may help put the various opinions in context. In the old days, assemblies were all custom fit. An expert craftsman would modify individual parts as needed, by filing, etc., in order to achieve an acceptable fit. This method is no longer cost-competitive for volume manufacturing, but is just fine and dandy for one-off pieces. Many would argue that it is indeed the most efficient process in that circumstance.

Another methodology is "selective assembly". Here, components are produced in volume, but are not sufficiently precise as to be completely interchangeable. So the assembler sorts through the available components, and selects combinations that mate up acceptably. But since we hobbiests rarely make anything in quantity, this method is of little interest to us.

The modern method in volume manufacturing is to produce "interchangeable components". Through the disciplines of tolerancing and statistical process control, any component on the production line is guaranteed to assemble properly with any other. If you are making stuff for Ikea, for example, you had darned sure better produce interchangeable components, because it has to be assembled by an unskilled end-user customer.

With that background, I believe that the precise-tolerance debate is primarily between those who like the custom-fit approach, and those who like the interchangeable-component approach. With a background in manufacturing, I instinctively gravitate to the latter (often for no good reason, I suspect). And as a relative noob to woodworking, I don't know all the techniques for quickly and easily tuning dimensions. But personally, I find it satisfying to get a good fit on the first try, with no tweaking. And if I can figure out a good process for holding a tight tolerance, it will save me time in the long run.

But I suspect that as my woodworking skills grow, I will adopt custom-fit methods more often.

Wikipedia has a good overview of these manufacturing methodologies.

Very interesting contrast comparison of the methods.

I can't place myself (or any of my projects) into any one of those classifications though. I would like for every project to be quick, perfect and cheap.

[rjent]

OK Dusty, that is a relief. there is no big picture

I come from a lot of backgrounds some high precision some artistic and some a combination of both. My automotive endevors were always precision oriented with some very definite goals (horsepower, longevity, shift points, etc). I was both working for the public as well as regional racing teams where we were rebuilding transmissions for customers, and building racing automatics, every week, while customers expected 100000 mile longevity, we most of the time had to rebuild the racing trannys every week.

I worked for Lockheed Aircraft on the ground stages of the shuttle program in the early 70's. Talk about precision!

I then, at age 29, got into Information Technology, it wasn't called that then, and we didn't really have much to work with (looking back on it), but the software development that made my living for decades was a very artistic endeavor wrapped up in an absolute unforgivable precise programming language. I reveled in it. Growing up a farmer and cowboy required precision in the farming aspects, but working cows was pretty much by the seat of your pants in the saddle.

I now find myself in the world of woodworking. When I cut a groove in a rail and stile for a panel I have made and it all fits and looks good, it is just as rewarding to me as anything I have ever done, but I never thought about how precise it has to be (or not). Sometimes I need to "trim" with a sander or shave with the table saw. I find that part of the artistic side just as rewarding. I am wanting to do a wall of paneling like the old English libraries in the house. I know that precision is needed, but I have some idea as to how to make it work. This is to be in the next 4 or 5 years, but I am thinking (mulling) about it now.

I guess, just as long as you get the job done, it doesn't matter how you got there .... just like everything else I have done .....

Interesting topic ....

[dusty]

I wouldn't say it matters not how you got there but the important thing is that once you are there, you are happy with what you see. Remember, you will see evidence of your minor mistakes when the rest of us won't. You are your own harshest critic.

No one knows other than you that in all of those beautiful mortise and tenon joints are 3/8" tenons sticking into 1/2" mortises that were only suppose to be 7/16" deep. If only I had checked that depth stop setting one last time.

[jsburger]

I caught all of that John. I was just looking for a different verification of your conclusions. If your conclusion is correct, would this end casting now be covered by warranty?

OK, I did not check since the measurement was the same with two different tables.

As far as the warranty I don know. The PP/DT upgrade is 3 or 4 years old but SS is very good about correction manufacturing defects no matter the age within reason.

[jsburger]

Since this has evolved into a Wixey discussion, please clear up a couple of things that are 'bothering' me.

First, does the slope indicator do as Dusty stated(diamonds[squares] on both sides of the slope pyramid when 'dead level')? The manual pix shows that, but in the display description section only.

Second your pix show the slope indicator to be reversed from the manual description. When the virtual 'spirit level' indicator places the bubble right(indicating the right side is 'high'), the slope indicator in your pix is also on the right which should mean the right side is low.???? That is reversed from both the manual and 'intuition'.

Glad you got the 1/8" nailed down.

I am concerned re the right base casting spt bores not being normal to the way tubes. Could that be caused by slop/clamping?

OK, I have played a bit with the Wixey. I will attempt to explain what I found as I see it.

Not answered in the order of your questions.

First, the spirit level is a true spirit level. It is not effected by zeroing the gauge. The small digits represent the deviation from true level. They have nothing to do with the large digits which are the relative reading from the previous zeroing. The small digits do not tell you the direction but only the amount of deviation from true level. The bubble tells the direction.

Second, the diamonds and triangle have nothing to do with the spirit level. They only indicate the status of the relative reading (large numbers) from the previous zeroing. To quote the manual..."Indicates direction of tilt from relative 0.0". There are no little triangles when the relative reading is 0.0. I suspect the manual is just showing that the diamonds can be on either side of the triangle.

I agree that at first look things are not very intuitive. However, once you understand how it works things clear up.

As far as the right base casting, I don't know. It has been about 3 1/2 years since I did the upgrade. I did remove the left casting and head stock last week when I replaced the bad carriage. I can tell you it was a very good fit on the way tubes. No slop and a very snug fit.

[jsburger]

To be honest Dusty, I am in awe that this kind of precision is possible, much less required for cutting wood. I was fascinated by what you guys were talking about (and I did ask one question ) but felt inadequate with my still (but growing) limited experience with these machines ....

After following this from the beginning, it makes me wonder how a high end cabinet saw would live up to this kind of scrutiny ... like a Grizzly or even a lesser Steel City. It would be interesting to compare .....

Well, this discussion is about aligning two or three separate tables to each other. A cabinet saw does not have that problem. Yes, my Powermatic PM2000 has two bolt on cast iron wings but once you bolt them on they don't move. On the other hand, my Powermatic 14" band saw has an aux table on the left side that is separate from the main tilting table. It was a real pain to get aligned with the main table. IMO, mostly due to the way it is mounted and adjusted. However, once aligned it will never be moved.