I have a ShopSmith 510 and I've never been completely satisfied with the way the tables align. The tables on the 510, as you may know, each have 1-1/16" ID table tubes attached to them. The tables connect together with 1.00" OD connector tubes. The 1/16" difference results in a lot of free play, which is supposed to go away when the jackscrews are tightened. Well, no matter how hard I tightened the jackscrews or adjusted the tables, they never aligned precisely. When sliding the rip fence across where two tables join, my rip fence would catch, and clamping the rip fence there, or on a floating or extension table, would throw the rip fence out of alignment.
Why, I wondered, does SS use 1" connector tubes? Seems like the tables would align better if they used 1-1/16" tubing to better fit inside the table tubes. Well, there's only one way to find out.
It didn't take long to find 1-1/16" tubes. Home Depot and Lowes carry schedule 40 3/4" black painted steel pipe, the kind used for natural gas, with an outside diameter of 1.05". Perfect! And at $20 for a 10-foot piece, it's not very expensive either, and not a big loss if things don't work out.
The pipe is available in galvanized or painted black. Both types measured 1.06-1.07" diameter which is a tiny bit too big to fit inside the table tubes. I chose the black painted pipe so I could remove the paint to return the pipe to its 1.05" unfinished diameter. It would be impossible to remove the coating on the galvanized pipe. Waxing the tube after removing the paint will help prevent it from rusting.
After removing the paint, I test fit the pipe in each table. It fit the floating tables and extension table perfectly but got hung up in the main table. I discovered some rust inside the table tube, so I wrapped some sandpaper around the original connector tube and cleaned out the rust. Then the pipe fit perfectly.
I cut the 10' pipe into 4 pieces. I sized one pair to fit the main table with two attached floating tables, and another pair sized to fit the main table connected to the extension table (or one floating table). I use those configurations frequently so they work out better than the original SS connector tube lengths for me. I can also use all four at once to make a 5-foot table.
I'm amazed at the results. Now all my tables align perfectly. My rip fence slides from table to table without catching. The fence stays straight when positioned between tables, and keeps its alignment when positioned on the floating and extension tables. The top surfaces of all the tables align perfectly. An added bonus is the wall thickness of the pipe is double that of the SS connector tubes, so they are virtually impossible to bend and do not sag like the originals did.
Photo 1 shows the original SS tube alongside the new pipe, and how the tables now align perfectly. See the gap between the tables? That gap can be eliminated by grinding off the little "tabs" on the main table, which improves sliding the fence across tables even more.
Photo 2 shows the pipe diameter after removing the paint and waxing.
Photo 3 shows the type of pipe I purchased from Home Depot.