Main Table Stability....in Saw Table and Drill Press Modes

[DLB]

And a great summary in those linked posts from Ed Reible:

Now comes the burn. Lean on the main table................

That, in a nutshell, captures main table instability. Another one that has stuck with me. I'm no ME but an ME I used to work with on aircraft system integration told me: "Think of everything as a spring..."

Drawing a bold line between Model 500 and earlier (500-) and 510 and on (510+), virtually everything related to the table is completely different except the tubes themselves are similar. On 500- the tube to tie-bar connection is very solid, there is no simple way to remove the tubes and I'm not personally familiar with the hard way. On the 510+ this is more a slip fit with the tubes then held in place with tapered pins driven parallel to the tilt axis. My modification, which failed, added countersunk machine screws through the the tie bar and threaded into the tubes. Two 1/4" screws per tube, installed 90 degrees to the tilt axis, one on each side. Unfortunately this resulted in binding between the tubes and carriage and only about a 25% improvement in stability. (And I didn't baseline the table I tested, I'm comparing it to a completely different table assembly. Not ideal.) There is some intel in all of that, but I'm not pleased with the results.

I'm going back to woodworking using connector tubes now.

- David

[Ed in Tampa]

Fact a standalone tablesaw has absolutely no table movement. The fact that the SS does whether .001 or 1/4 inch is a problem. Fact once aligned most table saws can not be bumped out of alinement. Fact the SS can be bumped out whether it is .001 or 1/4 is a problem.

Now how serious of a problem it is can only be determined by the user. To some users any movement it too much, to some .001 is too much, to still others any that exceed a 1/8 inch is too much.

To me the movement in my SS table drove me crazy. Through years of usage I learned how to minimize it. I can not truthfully point to any project I did and say it would be better if I did not have to deal with table movement. But the fact remains I did have to deal with table movement and it made me always less than satisfied with the SS.

Fact: Table movement was never in my thinking when I was deciding to buy a Shopsmith, had it been and had I realized there was table movement in a SS I would have never bought the SS.

[RFGuy]

Fact a standalone tablesaw has absolutely no table movement. The fact that the SS does whether .001 or 1/4 inch is a problem. Fact once aligned most table saws can not be bumped out of alinement. Fact the SS can be bumped out whether it is .001 or 1/4 is a problem.

Now how serious of a problem it is can only be determined by the user. To some users any movement it too much, to some .001 is too much, to still others any that exceed a 1/8 inch is too much.

To me the movement in my SS table drove me crazy. Through years of usage I learned how to minimize it. I can not truthfully point to any project I did and say it would be better if I did not have to deal with table movement. But the fact remains I did have to deal with table movement and it made me always less than satisfied with the SS.

Fact: Table movement was never in my thinking when I was deciding to buy a Shopsmith, had it been and had I realized there was table movement in a SS I would have never bought the SS.

David,

Great investigation and appreciate you attempting to improve table stability and for reporting your results here. IF anyone comes up with a better solution I think many of us would like to hear it, though I think the only real solution is aux table anchoring through connector tubes. Thanks.

Ed,

Thanks. Well said. I have had (and continue to have) difficulties with my Mark V's main table stability, so I agree completely with you here. I would also have opted for a standalone cabinet TS had I known/understood this fully at the beginning of my woodworking journey.

[edma194]

On the 510+ this is more a slip fit with the tubes then held in place with tapered pins driven parallel to the tilt axis.

Did you start with a 510 and upgrade to 520? If you did that were the trunnions loose on the table leg tubes before you upgraded? Did it get worse after?

I haven't noticed that to be a problem on my 510 tables. They don't fit well interchangeably between carriages which I think means the leg tubes don't seat straight in the trunnions. The carriage lock is a different matter. The 500 carriage could lock tighter. Maybe I could tune up the carriage locks but it does seem to allow some play. I will emphasize 'seems' in that statement, I have done nothing to test it.

Off topic a little, I think I have turned legs around on a 500 table. Definitely removed them from extension tables using a heat gun. It's not that hard with a steel peg in an aluminum hole.

[JPG]

I have perceived this 'discussion' as pertaining to table lock being not reliable.

Most comments are about different issues.

The reason this is not an issue with most cabinet saws is that any play in the saw mount is not exposed by placing large items on the table. i.e. the slop is not stressed.

All here are concerned re relative positioning of the blade to the work piece under load. That positioning deviation is exacerbated by the movable table(tilt) and movable both headstock and the table carriage. Lotsa places for slop to occur. And then there is the 'spring' factor. Stuff will deform temporarily under load.

Ya want rock solid. Get a saw made out of granite.

[DLB]

On the 510+ this is more a slip fit with the tubes then held in place with tapered pins driven parallel to the tilt axis.

Did you start with a 510 and upgrade to 520? If you did that were the trunnions loose on the table leg tubes before you upgraded? Did it get worse after?

I don't think it matters, 510 to 520, but mine was 520. Answering what I think you meant, both of the tables I've talked about are upgraded to (not manufactured as) DT, so the leg tubes have been replaced. The one I did myself got new pins. Twice, because the first set of tubes had a manufacturing defect. I was concerned about that, because the pins bite into the tie bar, but not an issue per Jim McCann. The other table was done by one of those PO characters. In any case, the tubes are slip-fit loose and easily removed as soon as you knock the pins out.

I haven't noticed that to be a problem on my 510 tables. They don't fit well interchangeably between carriages which I think means the leg tubes don't seat straight in the trunnions. The carriage lock is a different matter. The 500 carriage could lock tighter. Maybe I could tune up the carriage locks but it does seem to allow some play. I will emphasize 'seems' in that statement, I have done nothing to test it.

Some time later I will see if that table fits better in another carriage. Your comment reminds me though that there are two (at least) versions of 510+ carriage. On the early version the carriage casting completely encircles the table tube. On the later there is a small gap that allows the lock to tighten the casting and grip the tube. (I presume.) I also presume the version with the gap provides better table stability. I've had both types, only use the one with the gap.

Off topic a little, I think I have turned legs around on a 500 table. Definitely removed them from extension tables using a heat gun. It's not that hard with a steel peg in an aluminum hole.

That's how I would have guessed it works, simple interference fit.

Just to be clear, I don't think there is anything too unusual about mine. I think all, or at least 510+, Marks exhibit instability in the tilt axis that is inherent to the design. But to JPG's point, there are definitely things that can make one machine worse. Trunnion locks for sure being one of those.

- David

[algale]

I'm sure the science says the Shopsmith is too unstable to do fine woodworking.

But the proof is all over this forum that the Shopsmith is a fine woodworking tool. And I mean that in both senses. It's both a fine tool and it's a tool for fine woodworking.

I seem to recall that aeronautical engineers also concluded that bumblebees couldn't possibly fly.

[RFGuy]

I'm sure the science says the Shopsmith is too unstable to do fine woodworking.

But the proof is all over this forum that the Shopsmith is a fine woodworking tool. And I mean that in both senses. It's both a fine tool and it's a tool for fine woodworking.

I seem to recall that aeronautical engineers also concluded that bumblebees couldn't possibly fly.

Alan,

I agree completely with you (at least what is highlighted ). Every tool/machine has pros and cons. We are picking on the Shopsmith main table here on this thread, but there are pros I won't list to take away from this thread (by going off topic). My point is when does something in the cons category become a pain point, i.e. something that takes you to your frustration level or beyond? Main table stability can be that for some of us. Definitely for me, at times, and perhaps for others who chimed in on this thread. The simple answer is that other Shopsmith owners may just have a higher frustration tolerance...either that or they don't use their Shopsmith tools in the same manner (or on the same kind of projects) to where it arises for them.

[algale]

I'm sure the science says the Shopsmith is too unstable to do fine woodworking.

But the proof is all over this forum that the Shopsmith is a fine woodworking tool. And I mean that in both senses. It's both a fine tool and it's a tool for fine woodworking.

I seem to recall that aeronautical engineers also concluded that bumblebees couldn't possibly fly.

Alan,

I agree completely with you (at least what is highlighted ). Every tool/machine has pros and cons. We are picking on the Shopsmith main table here on this thread, but there are pros I won't list to take away from this thread (by going off topic). My point is when does something in the cons category become a pain point, i.e. something that takes you to your frustration level or beyond? Main table stability can be that for some of us. Definitely for me, at times, and perhaps for others who chimed in on this thread. The simple answer is that other Shopsmith owners may just have a higher frustration tolerance...either that or they don't use their Shopsmith tools in the same manner (or on the same kind of projects) to where it arises for them.

Is it also possible that some Shopsmith's have worse stability (or other issues) than others? I can usually get away with just using the table locks on my 520. If it is something really big and heavy I'm working on, I use the extension table and the connector tubes and that firms things up. And I've cut some big heavy lumber on it, too.

[RFGuy]

Is it also possible that some Shopsmith's have worse stability (or other issues) than others? I can usually get away with just using the table locks on my 520. If it is something really big and heavy I'm working on, I use the extension table and the connector tubes and that firms things up. And I've cut some big heavy lumber on it, too.

Alan,

That is a good point. I have wondered that with regard to other parts of Shopsmith components before on the forum when discussing other issues here. Every component has a manufacturing variance. What if some parts slipped through QA and perhaps Ed in Tampa and myself got 510 tables, fences, etc. that were out of spec causing issues that other 510 owners never saw? There could even be something at a system or design level, not manufacturing variance, that is unforeseen and affects some users and not others. I don't know how we quantify this, but I am glad you suggested this as a possible culprit. It could explain the starkly differing opinions on the forum for this issue over time.