Rip fence verticality

[Jbridge337]

Was ripping some 1x2 trim to 1/2” thickness and using brass block to set fence. I happened to notice it was more snug near top of blade/fence than at saw table.

checked the rip fence and it’s about .5° off of vertical when referenced to saw table and blade.

I haven’t seen a way to adjust that that won’t involve loosening screws that would undo its setting for parallelness with blade.

not a big deal for today’s need, but curious if there is a way to tweak the rip fence for verticality.

thanks

[LCHIEN]

I don't know of a direct adjustment of fence face to table perpendicularity. Never tried to adjust it.
I just did your experiment, Zeroed the gauge on the table and then checked the face of the fence and I got 89.81°
That's close enough for me. The typical claimed accuracy of these digital gauges is usually +/- 0.2 degrees.

Here's my best guess if I wanted to adjust it:
the fence is firmly attached attached to the black T-block by screws from the top. Slightly Oversized holes allow the wagging of the fence to the right and left to adjust the parallelism to the blade. But not to the right-left tilt of the fence.

THe fence T-block rides on the front rail and its left and right wings establish a plane to which the fence is perpendicular. I suspect you can make micro fine adjustments to the tilt of the rail, Remember there are two levers on the front of the saw that allow the rails to slide in and out, right and left, and then are tightened to secure it in place. Usually a quarter or half turn is sufficient to go from sliding to locked. The two levers lock a bolt into a T-nut plate. the plate fits into the slot at the back of the rail and the T-nut is slightly smaller than the slot so it won't bind. Maybe 1/32"

If you loosen the lever on one side and push the rail up or down you can take up the 1/32" play and tilt the rail to the right or left which will tilt the fence to make it perfect 90. You can then do the same on the other side in the opposite direction for up to twice the tilt.

By adjusting the right and left levers you can raise or lower one end and tilt the rail which directly affects the fence perpendicularity.

My engineering estimation is that you can get +/- 1/32" on both ends and over the distance between the two levers (about 12") you can get maybe +/- .3° verticality adjustment.

I would also make sure that the rails are clean (do not wax or lubricate) and that the T-block is sitting all the way down on the rail.

This is also a way to raise or lower the SMT and Auxiliary tables since they sit on the rails. For those tables you would also have to adjust the back rail to get exactly the leveling desired. This is for people who think their SMT is too high or too low.

[leehljp]

It has been a long time ago, but I remember this happening with two or three guys having this problem, seems like it was before 2010. I don't remember the specifics but it does seem like it was something along the lines that Loring mentioned in the first two paragraphs. IIRC, it seems like it had to do with waxing or spraying the rail, and when the handle was pushed down, miniscule uneven pressure on both sides or the directional pressure from the operator caused some twisting as it locked. but it had to do with the locking head, I think.

I could not find it with a 30 minute search, and not sure as to my answer being the correct answer for you.

[mpc]

The rip fence "front block" assembly (the "T" shaped piece with the operator handle) has two slides inside it, one on each side of the operator handle., attached via a single screw A thin bit of metal foil tape between the slide and the fence body will angle the fence face slightly.
The slides are item #16 in the exploded view/parts drawing of the fence.

mpc

[Jbridge337]

Thanks all - original owner and have never waxed or oiled rails. I’ll take a look at the various suggestions and play around with them

[LCHIEN]

The rip fence "front block" assembly (the "T" shaped piece with the operator handle) has two slides inside it, one on each side of the operator handle., attached via a single screw A thin bit of metal foil tape between the slide and the fence body will angle the fence face slightly.
The slides are item #16 in the exploded view/parts drawing of the fence.

mpc

That's a very good idea. Definitely more adjustment than what I suggested.

This photo is the bottom of the rip fence assembly T-block.

The two slides pointed at by the arrows can be used to tilt the rip fence slightly. I believe one can be unscrewed and a small shim inserted between it and the T-block. My calculation shows them to be 7.25" apart, a shim under one side of 0.063 " or 1/16th of an inch will tilt the assembly 0.5 degrees. The direction of tilt adjustment depends on which side you shim; you did not specify which way it leaned. you should shim the side to which it leans.

[LCHIEN]

1/16" seems like a lot, but I checked it twice and that's the number I come up with.
YOu can get probably get brass or other shim sheets from Lowes, Home Depot and hobby stores like Hobby Lobby. THey come in thicknesses like .005, .008, .010. .etc. You can cut with scissors and punch a hole in it for the screw. You can stack as many as you need.

[LCHIEN]

One more suggestion:

as those digital gauges have a possible +/-0.2° error, I suggest instead using a machinists square to check the table to rip fence angle.
Machinists squares are basically two pieces of steel fastened together permanently is a very accurate 90° angle. You can get them 2, 3, 4,5, 6 inches and they are relatively inexpensive (under $10 bucks) and their angles are usually super accurate using jigs when manufactured. They only do one angle and they are accurate like I say. Even the cheap ones are accurate.




Typical 90 degree angle accuracy will be .001 to .004 degrees.
This will eliminate the accuracy of the digital gauge.
Typically the human eye can spot a gap of .001", on a 2 inch high fence a .001" gap is about .03 degrees.

I have a 3x4" and a 4x6" one i use for checking rip, Miter, Jointer, and other fences and drill press and bandsaw perpendiculars

[leehljp]

One thing missed in the discussions above - is it 90° vertical BEFORE clamping it down? It might help to find the solution if the origination of the problem is found. At what point does it go out of 90° vertical?

I looked, but I may have missed postings of the above notations.

[LCHIEN]

My last bit of advice.

If you want an absolutely square corner on a rip cut, the proper solution is to use a jointer and run the narrow edge against the table while keeping the face of the wide side against the vertical fence. That's what it was intended for. It has a taller fence that is adjustable (using tool-less hand levers and knobs, not screw and nut adjustments using tools) for exact registration to the table and cutter. I always set the jointer fence to 90° using an appropriately sized machinists square.

Back side of Jointer fence vertical adjustment designed for precise adjustment:


The table saw option is to rip a bit oversized on the table saw, and then do a last rip operation after making sure the saw blade is perfectly vertical (again, with a machinist square) and rip both edges with the flat side of the workpiece against the table, taking it to the final size in two steps.

[LCHIEN]

using a machinists square referenced to the table top, 1/2 degrees fence lean will result in a 0.017" gap at the top or bottom, depending on which way it leans. .017" is right at around 1/164th inch. Certainly easily discernable to the human eye.

When using a machinist square to check square between items you want to be square, I find it helpful to shift the square back and forth between flush with one side and then flush with the other side, it helps visualize the size of the gap. When perfectly square, there will be no shift between flush to either side.

[Jbridge337]

Thanks - haven’t had a chance to try to tweak things yet. Small machinist square coming today. Thanks for all the insight.

[LCHIEN]

I decided to do a test.

First I place a machinists square on the table and set the base of the digital Angle gauge on the wide leg and zeroed it.




I then took the gauge and placed the same reference base against the vertical leg. It measured 89.58°. This is 0.4° from the expected 90°



My conclusion: I tend to trust the machinists gauge as the claimed accuracy is about 100x times better. So that puts a real question mark on the claimed accuracy of the digital angle gauge of +/-0.2°

[LCHIEN]

maybe that speck of sawdust on the bottom leg is the source of the error?

[LCHIEN]

Fwiw, my protractor says 89.9°.

[Black walnut]

I'm late to the conversation but I recall years ago some folks had issues with their front block lifting when they tightened the clamping handle. The issue was wax on the rails. It is unlikely but what could be happening is the T-nuts that hold the front rail may be out of speck Try leveling the rails, after ensuring the saw top is level, remove the SMT first as it sits slightly proud of the main and acc tables. With the top level the rials should be level, making them co-planer, which actually is far more important than level.

Even if your rip fence is not perpendicular to the table top you can still get accurate rips as long as you use the stock you are cutting to set the fence distance. Mark the work piece with a knife, use that mark to line up with the edge of a saw tooth offset towards the fence. Of course if you are resawing, rather than just ripping this will not work. For resawing the fence needs to be spot on 90° from table top.

[LCHIEN]

He said he thought there was no wax, that had been mentioned. I calculate that the rail locks use 1" T-nuts in a t-slot that's like 1.032" so there is about 1/32 inch slop... at most you can move each end up or down at most 1/32" and I calculate with my trigonometry that can't give more than about +/-0.15 degrees change in tilt to the fence.

My final comment is that the squareness of the edge on your board is determined by the blade tilt, not the rip fence tilt. For cutting 1x or 2x lumber the fence tilt might make a rip width error, but given the relative thinness of the boards, if the rip width is determined at the base of the fence. a tilt to the blade of 0.5° would make a .006" width difference. I really don't think this is worthy of worrying about.