Are Your Extension Tubes Straight

[reible]

I'm working on this same issue however I'm a week or two away from wanting to post about it.

I will show you the method I'm using to look at the condition of my tubes.

String and corks.

This will only show you inside bends but it quite good at it. I marked 4 locations on the tube ends. One at the weld and then 90 degrees from that.

Put the string in the tube, slide cork in, on the opposite side sting in and as the cork goes in it tensions the string.

[ATTACH]17873[/ATTACH]

If the string looks like this the tube is either straight or you are on the outside of the bend.

[ATTACH]17874[/ATTACH]

When you are on the inside of a bend you will see something like this.

[ATTACH]17875[/ATTACH]

I do this in a vertical plane so gravity has no effect on the string.

One of my tubes is very close, the other was not, mostly due to a bit of a situation I put it in.

I have ordered some tubes off ebay for inspection and testing and I hope use. I'd like to think they will be here next week but with the 4th who knows.

My brother use to have a three wheel machine to do this but I'm not sure if he still does. If so sometime in the fall I might have a shot at trying it and see how well it works.

You all have a good day.

Ed

[dusty]

I'm working on this same issue however I'm a week or two away from wanting to post about it.

I will show you the method I'm using to look at the condition of my tubes.

String and corks.

This will only show you inside bends but it quite good at it. I marked 4 locations on the tube ends. One at the weld and then 90 degrees from that.

Put the string in the tube, slide cork in, on the opposite side sting in and as the cork goes in it tensions the string.

[ATTACH]17873[/ATTACH]

If the string looks like this the tube is either straight or you are on the outside of the bend.

[ATTACH]17874[/ATTACH]

When you are on the inside of a bend you will see something like this.

[ATTACH]17875[/ATTACH]

I do this in a vertical plane so gravity has no effect on the string.

One of my tubes is very close, the other was not, mostly due to a bit of a situation I put it in.

I have ordered some tubes off ebay for inspection and testing and I hope use. I'd like to think they will be here next week but with the 4th who knows.

My brother use to have a three wheel machine to do this but I'm not sure if he still does. If so sometime in the fall I might have a shot at trying it and see how well it works.

You all have a good day.

Ed

How perfectly simple and ingenious.

Maybe the first tool one should consider is a piece of string. Even the Egyptians used it.

[Ed in Tampa]

I'm working on this same issue however I'm a week or two away from wanting to post about it.

What is the issue? I assume it is that same issue Dusty is working on. And from Dusty's comments I assume it is an alignment issue.


I'm of the opinion that unless the bent tube is so bent that the bend can be readily detected visually it will not cause an alignment issue with the Stopsmith.

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.

[reible]

In my case I have one tube that is bent. I can tell by looking at it. As I attempt to fix it I have to have a reference to see if I'm making any progress.

I had been set up in a routing situation with the shopsmith main table as a connection point and the legs out on supports. When I was taking the set-up down I had bent down squat style to twist one of the legs to take the weight off it in preparation of taking it off. As I went to stand my knee that will on occasion "act up" decide this was a good time to do it again. Without thinking I grabbed the now not so supported tube to help myself out. As soon as I did it I knew it was a bad idea but by then it was all over. I didn't even examine it then, just put it away.

It had been a long day, about 11 hours into the days project so I was over extending myself but sometime you have to do that to get things done. Sometimes you pay for it. In this case a sore knee and bent tube.

Before this I was happy enough with the tubes, they were not perfect but close enough. I don't know at what point a bend starts playing into misalignment but if gets too far one should begin noticing it and take corrective action.

I am rather sensitive to the condition of my machines, I pretty much know when something is even slightly off. I find my alignments to stay pretty well with years between anything major needing attention. So the next time I went to use the long tubes I was not surprised when it was clear that something was wrong. Had I not know the tube was possible bent I might have started a set of adjustments to fix the situation needlessly. I could also have just forced a fit but that is just not the right thing to do.

It is not even clear at this point if I will attempt a new alignment in search of the holy grail of being able to use one extension table on both ends of the machine. Maybe someday. Right now I just want to get back to having a good working set of 5 foot tubes.

Ed

[Ed in Tampa]

It is not even clear at this point if I will attempt a new alignment in search of the holy grail of being able to use one extension table on both ends of the machine. Maybe someday. Right now I just want to get back to having a good working set of 5 foot tubes.

Ed

That is in fact the holy grail of Shopsmithdom.

[dusty]

You guys might see this as the holy grail but I see it as a curse. I believe I ought to be able to align those extension tables on either end and move them to the other end with NO adverse effect.

I have come to accept that this will probably not occur (except maybe with a Dual Tilt Upgrade) but I want (need) to understand why.

Despite all of that, I now have my go to machine all put back together and properly aligned. This has been another fun excursion that resulted in absolutely no saw dust to clean up and involved no refinishing.

[charlese]

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.

[reible]

Hi,

If all you use your extension tables for is support then only a close resemblance to the same height as the main table is all that is needed and of course getting the tubes to fit if you want the extra stability.

One of the reasons to upgrade to a 510 or 520 is the larger table but the rail systems was also included that allows you to do more then use the system as "support". It allows you to add both floating and fix extension tables. The addition of being able to put a rip fence all along the way. This requires that the mounting system will keep the fence and blade in alignment. The alignment requires adjustment.

This is just like someone who might only use the miter gauge for the things they do, they would not understand why one would want the rip fence to be adjusted. It all depends on what you need or want out of your system

If you do not use these features then forget about it, it doesn't apply to you.

If you do use the features then it maters.

For me I use the features. And I'd like to add even more flexibly to my system so I have an extension table that I use to the right and one I use to the left. I have two systems configured that way, that is how much I want that flexibly, I spent the money to do it.

It would have been nice to have one extension table that fits both left and right but I could never get them close enough so the rip fences aligned "perfectly" as defined as close enough by me.

Now does any of this make sense?

Ed

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.

[JPG]

Hi,

If all you use your extension tables for is support then only a close resemblance to the same height as the main table is all that is needed and of course getting the tubes to fit if you want the extra stability.

One of the reasons to upgrade to a 510 or 520 is the larger table but the rail systems was also included that allows you to do more then use the system as "support". It allows you to add both floating and fix extension tables. The addition of being able to put a rip fence all along the way. This requires that the mounting system will keep the fence and blade in alignment. The alignment requires adjustment.

This is just like someone who might only use the miter gauge for the things they do, they would not understand why one would want the rip fence to be adjusted. It all depends on what you need or want out of your system

If you do not use these features then forget about it, it doesn't apply to you.

If you do use the features then it maters.

For me I use the features. And I'd like to add even more flexibly to my system so I have an extension table that I use to the right and one I use to the left. I have two systems configured that way, that is how much I want that flexibly, I spent the money to do it.

It would have been nice to have one extension table that fits both left and right but I could never get them close enough so the rip fences aligned "perfectly" as defined as close enough by me.

Now does any of this make sense?

Ed

Yep! . . . . .

[charlese]

Hi,

If all you use your extension tables for is support then only a close resemblance to the same height as the main table is all that is needed and of course getting the tubes to fit if you want the extra stability.

One of the reasons to upgrade to a 510 or 520 is the larger table but the rail systems was also included that allows you to do more then use the system as "support". It allows you to add both floating and fix extension tables. The addition of being able to put a rip fence all along the way. This requires that the mounting system will keep the fence and blade in alignment. The alignment requires adjustment....


For me I use the features. And I'd like to add even more flexibly to my system so I have an extension table that I use to the right and one I use to the left. I have two systems configured that way, that is how much I want that flexibly, I spent the money to do it.

It would have been nice to have one extension table that fits both left and right but I could never get them close enough so the rip fences aligned "perfectly" as defined as close enough by me.

Now does any of this make sense?

Ed

Yes, Ed Your explanation makes sense to me only as it pertains to one extension table and two floating tables.

I have a fixed extension on my miter gauge, about 20" long. Yes, I often set up so the extension rides across the 510 table and floating table with the same gliding pressure. I usually have my 5' extension tubes through the extension table passing through one or two floating tables and the main table. My experience is: So what if the extension table and/or floaters are a little raised or tilted on the offeed side. It is only on the front side I am concerned with.

Therefore I feel free to use the same extension table on either side of the headstock. Once again, all I need is to have fairly close alignment on the front part of all tables. After the workpiece passes the blade there is no need to expect exact parallelism to all tables.

I'm not talking about large differences in elevation, just around 1/8" or less on the back side. If the infeed side of any axillary tables is level with the infeed side, there is no need to hold that precision after the workpiece passes the saw or dado blade. If the extension table when used on the left side is tilted sideways or out of level toward the back there is no problem with making an accurate cut. If the table is tilted toward the side all I need is for the high edge of that table to be parallel with the main table. I don't need 6" of support, only an edge will do!

I have therefore eliminated the need for an extra extension table and freely use the one as fitting both sides. I've never found the need to do more than one alignment. Once done, the infeed side of any table is easily aligned to the main table. My one extension table works fine on both right or left sides.

It is my firm belief that as long as the infeed part of all additional tables are in the same plane as the main table and that plane continues to the lead edge of the saw, The alignment is complete. If just an edge, the high edge of a table is true to the pland of the main table, the alignment is satifactory. The outfeed side does not affect the accuracy of a cut or dado.

Devoting much time to full alignment (co-plane) of all areas of added tables is kinda a dis-service to the machine. There is no need to make the necessary alignment so complicated. My goodness! The Mark V works just fine without extreme measures.