Thread: Tuning a tablesaw - how close is close enough?

May be a silly question so forgive me if it is - have you made sure the saw table is at 0 degrees when checking the blade is at 90 degrees?

Originally Posted by Lappa

May be a silly question so forgive me if it is - have you made sure the saw table is at 0 degrees when checking the blade is at 90 degrees?

I’ve got my saw on my portable cart, which I doubt is a perfect flat bed, hence why I’ve got my gauge just on the blade and not touching the table in the chance the table isn’t flat.

My logic was if I remove the insert plate and have the gauge only on the blade, it should remove any issues should the table itself not be flat (I think it is?).

89.97° is close enough. if you were to make a cut 90mm high, the top face would be smaller than the bottom face by ~0.0471mm which is slightly less than 2thou. For what it's worth, I use an engineers square to re-calibrate my own saw. I tilt the saw over a bit so the blade leans away from the square. I rest the square up against the blade making sure the square is perpendicular to the blade. Then I wind the blade over until I see the light gap between blade and square disappear. Winding the blade over will move the square backwards a bit, maintaining contact at the bottom at all times. You are looking for the light gap at the top of square. If you see light at the bottom, you wen't too far.

I could do all sorts of other crap like cutting a slice off a board which has two parallel faces, flipping the board so the top becomes the bottom, and cutting another slice and measuring the slice thickness at the top and bottom. If it is the same, then the saw was square. That seems like a whole lot of work just for woodworking.

"if it looks square, it is square".

Originally Posted by Kuffy

89.97° is close enough. if you were to make a cut 90mm high, the top face would be smaller than the bottom face by ~0.0471mm which is slightly less than 2thou. For what it's worth, I use an engineers square to re-calibrate my own saw. I tilt the saw over a bit so the blade leans away from the square. I rest the square up against the blade making sure the square is perpendicular to the blade. Then I wind the blade over until I see the light gap between blade and square disappear. Winding the blade over will move the square backwards a bit, maintaining contact at the bottom at all times. You are looking for the light gap at the top of square. If you see light at the bottom, you wen't too far.

I could do all sorts of other crap like cutting a slice off a board which has two parallel faces, flipping the board so the top becomes the bottom, and cutting another slice and measuring the slice thickness at the top and bottom. If it is the same, then the saw was square. That seems like a whole lot of work just for woodworking.

"if it looks square, it is square".

I’m probably being pedantic, but chasing perfection is something I probably spend too much time on in the shop when it’s probably not always necessary. But as my shop space is tiny (it’s just my garage), my saw is my central tool as I use it joint and do as much as possible without having to commit to more tools.

But you have a point, the difference is minuscule. I’ve probably been watching to many William Ng videos, but even he may not be worried about a perfect 90 if it’s this close.

This is all really good information.
If got my eyes set on this exact saw when the dollars allow. It’s great to know that this level of accuracy is possible.


Northern Beaches Sydney

As the others have said, your accuracy is good enough.

My question re measuring the table then the blade is as follows:

If the blade is measured at 90 degrees with the digital gauge then that’s great but if the table is at 5 degrees then when you cut, the end of the timber will be cut at 85 degrees.

So when measuring your blade angle for 90 degrees using a digital gauge, it should be in reference to the table ie. if table is reading 5 degrees then the angle measured on the blade should be 95 degrees to get a 90 degree cut.

If you’re using a square then you are already referencing the blade to the table.

Originally Posted by Lappa

As the others have said, your accuracy is good enough.

My question re measuring the table then the blade is as follows:

If the blade is measured at 90 degrees with the digital gauge then that’s great but if the table is at 5 degrees then when you cut, the end of the timber will be cut at 85 degrees.

So when measuring your blade angle for 90 degrees using a digital gauge, it should be in reference to the table ie. if table is reading 5 degrees then the angle measured on the blade should be 95 degrees to get a 90 degree cut.

If you’re using a square then you are already referencing the blade to the table.

I think I get what you’re saying, but if I’m using one of these, doesn’t it avoid the issue?

Magnetic Angle Finder | Machinery Accessories - Carbatec

In the event the table was out by 5 degrees, how would correct this?

Originally Posted by MattB2085

This is all really good information.
If got my eyes set on this exact saw when the dollars allow. It’s great to know that this level of accuracy is possible.


Northern Beaches Sydney

If you have any questions let me know and I’ll let you know how I’ve gone with it.

Originally Posted by Mark_K

I think I get what you’re saying, but if I’m using one of these, doesn’t it avoid the issue?

Magnetic Angle Finder | Machinery Accessories - Carbatec

In the event the table was out by 5 degrees, how would correct this?

You should set your angle finder to zero on the table, then stick it to the blade and measure your angle; that way you're always setting your angle relative to the table, rather than to whatever internal zero the angle finder has.

Alternately, there should be a hard stop on the blade tilt at 90 degrees. If you adjust the hard stop to be exactly 90 degrees to the table (with a physical square, not a digital box), you can zero your angle finder on the blade when it's at the stop.

They're effectively the same thing, just 2 ways to go about it.

If you have managed to set a Delwalt to a true 89.97 deg, then you have set it up with the accuracy of Altendorf <.25 mm, and Altendorf manufacture the best quality and most accurate table saws on the planet

Originally Posted by Mark_K

I’ve got my saw on my portable cart, which I doubt is a perfect flat bed, hence why I’ve got my gauge just on the blade and not touching the table in the chance the table isn’t flat.

My logic was if I remove the insert plate and have the gauge only on the blade, it should remove any issues should the table itself not be flat (I think it is?).

Shouldn’t you be referencing off the table to get it square? When you are using the saw that is what will be happening so that is the only relevant point

Originally Posted by Beardy

Shouldn’t you be referencing off the table to get it square? When you are using the saw that is what will be happening so that is the only relevant point

I’ve done this to align my blade to the mitre slots as well as the fence to the mitre slots too. I used my square to reference square but assumed a digital gauge would be more accurate?

Im essentially doing this: YouTube

Originally Posted by China

If you have managed to set a Delwalt to a true 89.97 deg, then you have set it up with the accuracy of Altendorf <.25 mm, and Altendorf manufacture the best quality and most accurate table saws on the planet

This sounds like it’s good so I’m going to assume I’m good.

Originally Posted by Mark_K

I think I get what you’re saying, but if I’m using one of these, doesn’t it avoid the issue?

Magnetic Angle Finder | Machinery Accessories - Carbatec

In the event the table was out by 5 degrees, how would correct this?

No, it doesn’t avoid the issue. The digital gauge is measuring the blade angle in reference to a true horizontal which your table may or may not be at. See elanjacobs and Beardy’s responses.

You don’t have to correct the table bring out 5 degrees or what ever, you just have to make sure the blade is at 90 degrees to the table.

When using the digital gauge, follow elanjacob’s procedure of zeroing the gauge to the table before measuring the blade.