Jessem micro fence adjuster question

[John Sayen]

Hi all,

Recently installed Jessem's new micro adjuster with the TA fence included in the ultimate excel package - as this is my first router table I have a question about it's generalized functionality.

The instructions say to lock the left-from-forward side of the fence, keep the right-from-forward side of the fence unlocked and utilize the micro adjuster to do precision alignment. While this works great, it sort of breaks my brain to think that the fence is now cock-eyed/not parallel to the front of the table as well as the front miter slot. The website says only one micro adjuster is necessary - is that a normal thing to do with router table fences? I am clearly missing something.

Thank you.

[Jacques Gagnon]

John:

...it all depends on what you are trying to do. If you are following the fence (longitudinal operation) the relative position of the fence relative to the miter slot is irrelevant.

If, on the other hand you are moving perpendicular to the fence you will need to use some form of square jig that rides against the fence, so that the piece being shaped then becomes perpendicular to the fence.

[John Sayen]

John:

...it all depends on what you are trying to do. If you are following the fence (longitudinal operation) the relative position of the fence relative to the miter slot is irrelevant.

If, on the other hand you are moving perpendicular to the fence you will need to use some form of square jig that rides against the fence, so that the piece being shaped then becomes perpendicular to the fence.

I've also got their miter slide kit which rides along the fence to ensure the crosscuts are perpendicular to the fence, so I'm not too concerned about that, I guess what I'm trying to ask and it seems like it is the case is, does the outfeed side of the fence really not matter it's position relative to the infeed side? It must not, since the microadjuster only goes on the indeed and controls the infeed?

Thank you

[Paul F Franklin]

I've also got their miter slide kit which rides along the fence to ensure the crosscuts are perpendicular to the fence, so I'm not too concerned about that, I guess what I'm trying to ask and it seems like it is the case is, does the outfeed side of the fence really not matter it's position relative to the infeed side? It must not, since the microadjuster only goes on the indeed and controls the infeed?

Thank you

It does seem somewhat counterintuitive, but yes, relative position of the fence to the table makes no difference as long as you are not using the miter slot (or the edges of the table) as a guide/reference. The cutting edge of the bit makes a circle when the bit is spinning and all that matters is how far the workpiece (and your fingers!) are from that circle. Get yourself a straight bit and some scrap and set the fence at various odd angles and try it yourself. It will make more sense.

[Jacques Gagnon]

...thanks for the info about the cross-cut - I was wondering if you had one.

In terms of the « outfeed » side of the fence, as long as you keep a portion of the edge intact, it will make contact with the fence after the cutter has removed the desire profile. This assumes that both halves of the fence are coplanar.

I have been using the Jessem system for years and really like it. My micro adjust device is a left over from my old LeeValley system. Works great.

[John Sayen]

Thank you for the all of the knowledge, I very much appreciate it. It spurs another question, why does the left (outfeed side) rail for the fence have a scale, and why was it important to calibrate it when calibrating the right side? It feels like based on all of this that the left scale and outfeed side of the fence are basically moot, as long as they're in a generally OK position?

[Jacques Gagnon]

Thank you for the all of the knowledge, I very much appreciate it. It spurs another question, why does the left (outfeed side) rail for the fence have a scale, and why was it important to calibrate it when calibrating the right side? It feels like based on all of this that the left scale and outfeed side of the fence are basically moot, as long as they're in a generally OK position?

As you know there are many operations you can do on the router table. One type involves the removal of material on the « bottom » face of the piece e.g. running a rabbet or a dado. Another type involves removing material on the side (or edge if your prefer).

When working on the edge the position of the cutters can be such that it removes only a portion of edge (e.g. quarter round profile) or that it removes the entirety of that material (e.g. a cutter that would remove material on the full height / thickness of the piece). In this latter case once the piece is pushed to left of the cutter it will « float » until the right end of the piece of wood passes through the cutter, at which point it will create a step. Your adjustment knobs allow you to gage the movement of the fence towards the front in order to close the gap. It is almost the same principle as when you work on the jointer. If the outfeed table is below the top position of the knives you will create a similar step (or snipe).

The knobs allow you to « predict » how much you are moving the fence. You could get the same result by running partially your piece of wood through the cutter and stop the motor. While keeping the wood tight on the right side of the fence, move the left side until the fence just touches the wood. You have now created two parallel planes that are offset in such a way as to fully support the wood on both sides of the cutter.

Sorry for the long text. I am not a good enough writer to draft a shorter one .

[John Sayen]

I feel pretty foolish, I didn't realize the sub-fence moves independent of the primary fence, that makes total sense now with the jointing adjustment knobs on the TA fence. Thank you again!

[Danny Nevala]

Hey John, I don't have anything to add to what others have written, but I bought that package from Jessem too. It's the nicest tool I own.

[Wes Grass]

Re the miter slot, Derek made a good case for leaving it out. http://www.inthewoodshop.com/Powered...augeTrack.html

Since you have the miter slide, it's not really needed anyway.

As for the scale on the left, it gives you a reference to setting whatever offset you need for a given bit. Fine tune by shifting the right a tiny bit. Doubles the accuracy of your adjustment.

Personally, I have them zeroed on spindle centerline. And when I put a pilot bearing bit, like a chamfer cutter, in there I set it slightly shy of 1/4" (for a 1/2" bearing) so the fence acts as a safety device guiding the piece on to the bearing. It will 'bump' up on to the bearing just slightly, like a 64th or less. That prevents fumble fingering the piece straight into the bit where it can get chewed up, or worse. And of course the fence has a dust collection port wrapped around the cutter, which is self explanatory I hope.