Main Table Alignment

[dusty]

I am asking for comments from as many folks as are willing to reply.

Are the left and right edges (sides) of your Main Table suitable for use as a reference surface during alignment? Mine were not!

Mine were real rough with what I believe was residue from the casting process. Using the conical disk, I sanded these sides smooth on one of my tables. Before I do the others, I need to make certain that they are perpendicular to the front (front rail).

[JPG]

I agree they are not a 'good' reference as shipped from the factory. They are not intended to be so. They are IMHO good enough to be used as a substitute fence by jury rigging a slide board to the workpiece.

Removal of any 'high' or rough spots would be beneficial, but I would not advocate significant removal of material for obvious reasons. I would also not get too excited about using a dial indicator to check it! Any use of it should include a bar/board to provide straight reference edge that eliminates local variations. Use the dial indicator on that bar if need be.

End of first reaction.

[algale]

The sides of my main table have two well formed solid rectangular protrusions one at the front and one at the rear of each edge I do not know what they are for, if anything. However, they are much smoother than the rest of the table sides.

My extension and floating tables are also rough on the sides and the edges may not even be perpindicular to the top.

[JPG]

The sides of my main table have two well formed solid rectangular protrusions one at the front and one at the rear of each edge I do not know what they are for, if anything. However, they are much smoother than the rest of the table sides.

My extension and floating tables are also rough on the sides and the edges may not even be perpindicular to the top.

I presume those protrusions are reference surfaces for machining purposes and should be suitable for our own referencing. The older tables are indeed tapered and not without open areas.

[benush26]

Interesting thought. I had planned to make the micro adjuster block a specific dimension so I could use the side of the table as a index / reference. Give some repeat ability when using it.

Regarding the quality of precision of the table, I had considered attaching T-track on each side. I have to admit that I was not concerned regarding the precise distance to the miter slot (or by similar thought, the saw blade), but that will now become a consideration.

With that said, any repeatable reference, as long as the distance is a known quantity, should suffice. If making a jig, even if the table were a trapezoid, knowing reliably the distance to and from all points should allow you to design a a jig with acceptable tolerances.

As you were writing about a table setting jig, I wondered if you used a saw blade, what would happen to the accuracy of the jig if the body or teeth of that blade were altered without your knowledge. Just a thougt.

Don't know if any of that helps.

Be well,

Ben

[dusty]

The sides of my main table have two well formed solid rectangular protrusions one at the front and one at the rear of each edge I do not know what they are for, if anything. However, they are much smoother than the rest of the table sides.

My extension and floating tables are also rough on the sides and the edges may not even be perpindicular to the top.

I do not believe they are perpendicular. I believe they slop in at the bottom a few thousandths. Check thickness and you will see that.

[dusty]

Interesting thought. I had planned to make the micro adjuster block a specific dimension so I could use the side of the table as a index / reference. Give some repeat ability when using it.

Regarding the quality of precision of the table, I had considered attaching T-track on each side. I have to admit that I was not concerned regarding the precise distance to the miter slot (or by similar thought, the saw blade), but that will now become a consideration.

With that said, any repeatable reference, as long as the distance is a known quantity, should suffice. If making a jig, even if the table were a trapezoid, knowing reliably the distance to and from all points should allow you to design a a jig with acceptable tolerances.

As you were writing about a table setting jig, I wondered if you used a saw blade, what would happen to the accuracy of the jig if the body or teeth of that blade were altered without your knowledge. Just a thougt.

Don't know if any of that helps.

Be well,

Ben

I am sensitive to the impact that the teeth would have on alignment.

Yes, Shopsmith obviously did not intend for the edges of the table to be used as a reference surface. It is a shame, really, because it would have been so easy to do so during the milling process.

There is something like this in my near future for use as a reference surface (positioned by a miter track). This would be precision milled and referenced off the miter track. While I wait for my turn at the mill, I'll probably do one of these (proof of concept) using MDF .

My oldest grand daughter's husband is schooling to become a machinist. I have a list if projects that I have offered him for the "learning experience". This is one of them.

[ATTACH]23334[/ATTACH]

Note: If you own a Tenon Master, take it apart and look at what you have. A milled steel plate attached to a short piece of miter bar. This two piece assembly is somewhat adjustable (loosen the two screws and play with it. You will find about .003" of slop in the miter track. With that in mind, it is a perfect "feeler gauge" for table to blade verification. Works just like the miter gauge with a rod for the feeler.

The rest of the tenon master, the face, is a perfect square surface that can ce used to set the table tilt to 90° to the blade. An excellent tool that has been gathering dust in my shop because I usually cut tenons on the band saw.

https://forum.shopsmith.com/viewtopic.php?p=35840&postcount=3

[Ed in Tampa]

I am sensitive to the impact that the teeth would have on alignment.

Yes, Shopsmith obviously did not intend for the edges of the table to be used as a reference surface. It is a shame, really, because it would have been so easy to do so during the milling process.

There is something like this in my near future for use as a reference surface (positioned by a miter track).

My oldest grand daughter's husband is schooling to become a machinist. I have a list if projects that I have offered him for the "learning experience". This is one of them.

[ATTACH]23331[/ATTACH]

Dusty
Now that is a snazzy idea! I love it. Let me know how ours turns out.

[benush26]

Does blade run out have a factor in this and if so can it be accounted for (or should it even be accounted for)?

Be well,
Ben

[JPG]

Does blade run out have a factor in this YES and if so can it be accounted for (or should it even be accounted for)?

Be well,
Ben

That is why you ALWAYS 'measure' to the same point on the blade(or disk).