Are Your Extension Tubes Straight

[robinson46176]

You're right here, Dusty. Some discussions on this subject get too convoluted when the real point is woodworking and getting things done safely. Ripping wood requires careful attention to alignment.

Yes...
I tend to think in terms of three main causes of kick-back / grabbing. I am not sure what order these three things really belong in. Dull or gummy blades enter into all 3. These are causes not solutions.
#1 is fence alignment and the cut being pinched in one way or the other.
#2 is stuff like a loose block etc. moving around between the fence and the blade.
#3 I think is a big one and often ignored and that is simply the operator getting too casual with the board and seldom having a good solid grip on it. This also includes things like pushing a board through a cut with a spindly little push stick (like even I used to use) and having NOTHING holding down the board at or past the blade. I can't begin to tell you how many cuts I have seen made on TV wood shows where the operator was probably unaware that the camera was showing the board lifting 1/2" to 3/4" up off of the table surface as it passed the blade. They were holding down the back of the board but letting the front edge lift...
I see them over and over place a board on the saw and manage it like they were icing a cake. You are not icing a cake you are controlling a potential monster... Get an iron grip on it and be ready.
I get called on to tell small groups of scouts etc. about keeping horses. One of the things I tell them is why I am always petting the horses neck as we are standing there. I explain that they can whip their head around my direction violently in an instant if a fly or something bites them or something spooks them. By having my hand already there and pushing gently on the side of their neck or face I have a defense built and ready and that the arm I am using is not nearly as relaxed as it looks. In those first few inches of motion I can easily stop their head. Once it moves near 90 degrees it is moving too fast with too much momentum to stop it.
It is the same sawing. Once that board has moved 1" it is too late, you have already lost control of it...

BTW, I also think that a sharp blade with a good amount of set (clearance) is far less likely to kick back than a not so sharp one with less clearance (like a hollow ground blade) with equal amounts of pitch build-up on the sides.

.

[foolish...]

I keep thinking that I need to slow down and stop by my favorite metal supply and pick up a 'stick' of 1" OD tubing to cut my own extension tubes. They won't be plated, pretty, shiny, but would sure give the ability to set up custom lengths. I'll bet they will not be perfectly straight, but my metal supply guy likes me and will let me pick and choose what 20' stick I want. They will need a good wash off with mineral spirits, or something, and a JPW and buff job for protection.

Anyone else ever tried this?

I would offer this solution

https://forum.shopsmith.com/viewtopic.php?t=10797

http://www.ebay.com/itm/200788730409?ss ... 1555.l2649

[JPG]

I would offer this solution

https://forum.shopsmith.com/viewtopic.php?t=10797

http://www.ebay.com/itm/200788730409?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649

Yes you are . . . . . . . . . . . . . . . . . . Alta-tech1 I presume!;)

[dusty]

Nope but I am trying to resolve that.

I saw here on the forum that Reible had ordered them so I did. I did not even wait for his review.

I need straight tubes and the ones I already have don't do the trick so I ordered these.

If they turn out to be what I need, I'll cut these to replace my short extension tubes and may order another set to serve as 5' tubes.

Since I built the shorty and moved the belt sander to a position on the left end of the full size Mark V, I have much less need for 5' tubes.

[keakap]

...There is enough slop (if you will) in the relationship of the fence rails to the connector tubes that a bend of less than a couple of degrees (many thousandths deflection) will have virtually no effect.

(My $0.0125, adjusted for obamanomics):
In my essperience the slop factor itself is the killer. A little slop here, a little slop there, here a slop there a slop everywhere a slop slop, and next thing ya know a slightly, almost invisibly bent connector tube can be the last straw-slop that makes a good alignment (in a particular scenario let's say) impossible.
The table(s) can be a little off, as in not level, not uniform thickness, rail support bosses ground unequally, for examples, then there's yer basic SS frame irregularities or alignment issues, which may, btw, appear similarly to uneven floor- a possibly significant factor alone. Then there's the matter (huge) of different size rail tubes in some cases, different rail mounting systems even within a model type (!), etc.
And then there's the "better is worse" syndrome. As you go along over time and usage you tighten this spec, fine tune that adjustment, correct a wee error in one setup, find a more accurate setting in another, and next thing you know you are (oh my dog!) 'expecting' perfection, at which point a barely detectable bend in a conn tube can ruin your hole day.
I'm almost at the point now- after having gone through some horrendous "alignment" difficulties (which ended up in a lot of very costly new replacement parts)- where when I stumble upon a minor alignment anomaly I let it go as long as I can work-around without the introduction of a "larger" or heavier "fine tuning" device. A few years ago I would not have believed that I could be so comfortable with good ole, basic, run of the mill-- slop.
* and I should add, while getting some of the best cuts etc. from this SS that I ever have befo

[keakap]

There are many threads and posts dealing with the need to have perfectly aligned extension tables and floating tables. ...
Question - Why is there a need for such alignment?

Question - What purpose is enhanced by alignment of the extension table?

Once the main table is aligned vertically and horizontally with the saw blade, other alignments of smaller outside tables seems to be trivial. To me it's only function is support.

I have sawn many large and long pieces, all square, while the extension table is definitely tilted one way or the other.

I may have a piece of the answers, and to Dusty's "why" the grail is unreachable (in some cases). First to that last- the legs. Imho the SS legs are simply not substantial support for that kind of compatability twixt opposite ends' Extension tables. This with ZERO knowledge of whether the new Double-Ender fixes that condition. But with solid conviction of its reality.

As for who needs it? I do have one specific instance where I've needed to mark up two specific tubes in order to get a good clean repeat setup. In my case it involves a third party "jig" or "fixture", so it may not be open to consideration in this thread, although the device is made for and with the enthusiastic cooperation of ShopSmith.
Other than that I've also toned down requirements that I lay on the Extension table usage, to mostly a "general" kinda support, either to hold up long workpieces or to "4-point support" the Main table.

[dusty]

There are many threads and posts dealing with the need to have perfectly aligned extension tables and floating tables. Seems to me such frustration is really not necessary and these alignments and expense(s) are really way beyond any need for accuracy. This leads me to ask a couple questions.

Question - Why is there a need for such alignment?

Question - What purpose is enhanced by alignment of the extension table?

Once the main table is aligned vertically and horizontally with the saw blade, other alignments of smaller outside tables seems to be trivial. To me it's only function is support.

I have sawn many large and long pieces, all square, while the extension table is definitely tilted one way or the other.

It is possible that I am the only one who feels a need to do this sort of alignment. The subject was first brought to surface during the Sawdust Sessions. I became "engrossed" with the concept and have not given up the quest. If others don't feel the need, they should either tell me to go elsewhere with the discussion and I will or they should just ignore this thread as superfluous information.

Probably the only purpose for having the extension tables aligned is that the rip fence may end up attached there. If the extension tables are not aligned, the rip fence won't be either.

Then, there is my obsession to do it if it can be done OR understand why I can't do it.

I now believe I know why I can't do it but I can't afford $400 to prove that belief one way or the other.

[keakap]

Originally Posted by JPG40504

I am not even sure there was an intention of being able to do so with the Mark 5 either. Any one seen an 'official' pix of the fence mounted on an extension table at the left end with the purpose of being a rip guide?

Refer to this thread.---see post#3
https://forum.shopsmith.com/viewtopic.php?t=9014

With the standard Mk 5/V table system, you have to set the extension table to the left of the headstock and push the headstock as far to the right as possible to be able to get the maximum stated ripping capacity of 48".Dave

Somewhere, I think in one of the SS Training Guides, maybe in PTWWFE, perhaps in other instructional material, but Certainly in SS or SS authorized stuff, I seem to remember at least one instance where I had to say "whoa", backup and re-read a section because it gave the quite distinct impression that the "Normal" arrangement was to have The Extension Table mounted on the Left (see above) as OPPosed to the right. And I DO remember a definite SS note that said (in effect) NOT to expect left-right compatability. (This may have come from Nick. If so it may have been not a declaration but rather an inclusion in a broader subject.)

[keakap]

...At 48" you are likely sawing sheet goods.

...

If not, may I please have the name of the lumberyard supplying those magnificent boards?

[keakap]

... If I succeed, I will have accomplished nothing that is of interest to this community ....

You GOTTA be kidding!

If you do this thing I will fly out there to witness the miracle first hand!