Incra LS Positioner

This is my Incra LS Positioner. It’s a different type of fence positioning system using a fence mounted to a center spar, that slides through a carriage mounted to a cross bar, that is secured to a front a rear rail. Using a precision thread stock that runs the length of the center spar, the LS allows for exceptionally precise, easy to locate fence placement. Seems like a lot of parts, but they work together seamlessly. As mine is set up, I can make cuts almost 32” wide to the right of the blade.

The front and rear rails are hard mounted to the table saw table. They come in two different lengths to allow for differing stock widths and/or to allow for the carriage mounted cross bar to be positioned in two difference places along the rails. This allows for the LS to be repositioned and used for both the table saw and a router table, as I’ve got mine set up. To allow this, a stop bolt is placed along the rails. You can see it below…center of the front rail, silver stop bolt/block.

The carriage cross bar has two black handles (both front and back side). By loosening them, the carriage and cross bar can be slid down the rails and come to a positive stop. Tightened back down, the LS is now in position for the router table. This is an awesome feature that makes the LS an exceptionally versatile tool. The only downside to this is that going back and forth from table saw to router table (if using the LS on the router table) requires moving the carriage cross bar back and forth. I’ve jimmied mine with an extra scale to allow some cuts to be made on the TS even when the positioner is set for the router table, but it’s a bit limited in that position. This hasn’t been a real issue for me, but I guess it could be.

The LS’s central spar is a unique extrusion that supports the fence in the center which keeps it from racking as it’s moved. Unlike a Biesemeyer style fence, the central spar supports the fence (to avoid racking) but the fence also has retainers attached to the front and rear rail which keeps it anchored down to the rails, which means there are effectively three contact points forcing the fence to be square to the blade. During initial setup, the fence can be shimmed to ensure squareness against the blade. The spar also has five tape slots. This is for use with the Incra positioning tapes and their Joinery Templates. Used with the router table, these templates allow easy positioning of the fence to create a multitude of dovetail and box joints of various styles and dimensions. It’s pretty amazing.

The joinery templates are plastic and slip into place. They’re held in place by friction, but I’ve never had an issue with them moving. A steel rule is held in one slot via magnetic strip when used for the table saw. This allows for easy movement of the steel rule if you want to change blade thicknesses or use a dado blade. It’s actually really easy to set. You just zero the fence against the edge of the blade, then slide the steel rule into its zero position. If the blade is a little tight or loose against the fence, the precision dial (spoken about below) makes for easy adjustment. I labeled my slots and keep a couple different style rules in them for use with both the table saw and router table, so all I have to do is move the carriage and the rules are already in position.

The carriage’s locking mechanism itself is pretty magical. The large red paddle (they call it MagnaLock) on the rear of the carriage engages against the threaded stock in the spar. This allows for exact placement, verified by the indicator window on the carriage. As the thread stock has fixed distances between threads, there’s no guessing about where the fence is positioned. If the red paddle is set to the half-locked position, it allows for adjustments by 1/1000th using the red precision dial at the end of the spar against the fence. Once the precise change is made, locking the red paddle all the way forward secures the entire fence into a locked position. 

The fence itself is an extrusion with multiple slots, both on the front and on top, to allow for T-bolts to anchor accessories. I’ve got the Jess-em Clear Cut precision stock guide track mounted on top, for use with the table saw, and can quickly mount the Incra Router Table fence to the front for use with the router table. These two coexist without an issue so I’m not taking off or putting on parts very often.

Overall, I can’t imagine using another fence system. I’ll grant you, once you buy into the Incra system, they kind of have you locked in. I’ve bought their router fence accessories, as well as some other accessories of theirs. They work so well together that it’s hard to get away from them. I particularly like the precision, repeatability of the threaded stock and the way it locks into place. It makes very precise, repeatable cuts a breeze. The system is also easy to modify and re-zero when needed for changes of blade thickness, etc. Incra isn’t cheap, but I believe it’s a great value.