setting a lousy fence with high accuracy

[CarvedTones]

Don't do this:

Do this:

That's my $6 HF caliper, but a more expensive one may work just as well :rolf:. Put the fence tight against the blade, measure over both (be sure you are over the teeth if the tips have overhang) and zero the caliper. Now move the fence slowly out to the size you need and go back and forth to both sides of the blade to make sure the fence is parallel to the blade. Doing it this way gives you a much longer surface resting against both the fence and blade as well as across the top of the fence to help you keep it level. If you want to get even a little more dead on, mark the the top of the fence using a square to get a reference line.

 

[b4man]

Andy, that is a great tutorial! Thanks!


Barbara

 

[Gotcha6]

Does the HF caliper also have a depth rod that comes out the back/bottom end of the unit? Could it be used in the same way?

 

[CarvedTones]

The cheap compsite one does not have a depth gauge, but that would take away the 3 flat surfaces (back of the fence, top of the fence and side of the blade) I am using to get reasonably square.

 

[DaveD]

What you should really be doing is to set the blade dead nuts parallel to one of the miter gauge slots (really setting the arbor 90 degrees to the miter gauge slot). Measure to the same tooth/spot on the blade when doing this setup. Or get a precision parallel and put it up against the blade and measure from it to the ends of the miter slots to get even more accuracy.

Then to set the fence parallel all you have to do is measure to the slot. A span of (lets say) 24" (front vs back of fence/slots) will give you much more accuracy than trying to measure to a blade that at most may give you a span of 8" or so.

I had a crap fence on my craftsman 10" table saw for years and just set the arbor to the slots and used a tape measure to get the front and back of the fence parallel.

When doing your setup you should also use the same teeth/part of the blade to do your measurements or make sure the blade isn't warped.

If the blade isn't parallel to the miter slots then your crosscuts will be off too.

 

[CarvedTones]

I agree that you should tune the saw from time to time and get the blade parallel, check it for warping, etc, but...

Crosscuts I measure to the sled kerf which was cut by the blade. If the blade isn't parallel, the kerf will be wider than it has to be, but straight at the edge.

Two of the things I try to eliminate in the way I do it are math and reading a ruler which IME are probably the two biggest sources of errors. The fewer chances I have to make mistakes, the fewer mistakes I will make.

Now I will make a couple of statements that I cannot definitively prove but I doubt you will disagree with: Most people who have a lousy fence and are interested in tips like this almost never change blades. Many have never adjusted the TS at all beyond height and tilt, if they have even used tilt. This tip is about ripping accurately by setting the fence accurately to what ya got...

I am not saying your are wrong, because your way works. But it is not the only way that works and I have a preference for the way I do it.

 

[DaveD]

I will agree that your way is one way.

 

[DavidF]

Another way which I like is to take a piece of wood, say 1" x 1" x 12" and using the mitre fence in the right hand slot, move the wood to the left until the end just touches the front of the blade, hold or clamp the wood to the fence, rotate the blade so that the same tooth is now at the back. If the blade is parallel to the mitre slot the wood will touch the same. with the same set up and at the same time, you can bring the rip fence up to just touch the other end of the 1 x 1 and again it should touch the same at both ends of the fence. So one piece of wood and no measuring.

 

[CarvedTones]

That's a pretty good trick. A similar one is to raise your blade to 2.5" or so and cut a kerf in a 2x4 that is on its edge pushing it through at 90 degrees, swap ends and try to push it through again in the same kerf. If you can't, the blade is either not at 90 or not parallel to the slot. Y'all (Dave and David) are proposing ideas to get the saw perfect first. Yes, that is best but it is not absolutely required and I don't want someone to give up on this method because they can't (or don't want to) get the blade parallel to the slots. It will increase accuracy, reduce the chances of bnding substantially and make for a safer cut if the fence and blade are parallel, regardless of wheher the miter slot is also parallel to them or not.