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I am replacing one of my table saw wings with a bench dog cast iron wing (which fits a benchdog cast iron router lift).

The front of the wing has about a .005" gap when I put a straight edge from the saw to the end of the wing. This gets smaller as it goes to the back of the saw. When I measure from the back I can't get a .0015" feeler under the straight edge (but there is a little gap there I can see when I backlight it).

Would you try to shim the front, or do you think this is good enough. I try to be really picky about tool set up, but this thing is so heavy that it is going to take a lot of work to shim this, and I am not sure if there will be much to gain.

I am curious to hear from you guys with machinist skills.

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Brock Poling
Columbus, Ohio
http://www.polingguitars.com

Are you talking gap in flatness across the platen? In mismatch with the table level to the tablesaw, gap in bolting the tables together?

Sometimes reversing the relationship of the level to the work gives a variance too. The bench dog/table saw table may not be flat either.

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Billy Dean Thomas
Covina, CA

"Multi famam, conscientiam, pauci verentur."
(Many fear their reputation, few their conscience)

Yes, it is the gap in flatness. I am using a 36" straight edge to measure it.

The fronts line up pretty much flush. I can just feel a ever so slight hair rise at the front edge (not really enough to even catch your fingernail as you rub across it).

The outside edge of the front of the bench dog table is just a touch high.

I could possibly shim the front of the table but the gap is so small I don't know if it is necessary. It is REALLY heavy and (as you might be gathering) I am not excited about loosening up that wing.

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Brock Poling
Columbus, Ohio
http://www.polingguitars.com

I am not sure I understand your problem, but see if this applies. When I attached the cast iron table extension to my saw, it was bowed relative to the main table, so I thought the piece was defective. I called the factory, and they told be that regardless that the piece is heavy case iron, it flexes that much. So, I loosened the attaching bolts enough to force 2X4s on end under the table extension near the joint to lift it. First I got the middle lined up and tigthened the bolt. Then, I got both edges lined up and tightened them. Do not try to line up one end and move along to line up the other bolts, becasue the subsequent movement will put and "S' curve in the extension.

Now I am editing to add this. I also helped align the edges by clamping blocks of hardwood onto the extension, to act as hangers on the main table. You cannot do this in the middle, because no clamp will reach.

There are other setup related issues with tablesaws that matter much more.

I think 5 thou is 'acceptable'. My grizzly 1023 has a 7 thou dip in the middle of the left table and I have been using this saw to make all kinds of things that require super precise cuts for several years.

Making sure your blade is perfectly parallel to the miter slot(s) is crucial...nothing less than 'not measureable' here. Your distance from the fence to the front of the blade related to the distance between the fence and the back of the blade is also crucial. I use sleds a lot because I think they provide an increased measure of safety, as well as an increased level of accuracy.

Chris

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There is no difference between the man that thinks he can....and the man that thinks he cannot.

Thanks.

I have the blade dead on accurate to the slots, and the blade is perfectly 90 to the table.

The only other thing that I am not crazy about is the fence has a bow in it about .008". It is the Grizzly double locking fence. I like it except for the fact that it is not dead flat.

I have been thinking about changing it to the Besemeyier (sp) but I am not sure how much flatter those are... I need to look into the fence issues.

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Brock Poling
Columbus, Ohio
http://www.polingguitars.com

I've got a Biesemeyer and had to shim it. I would expect that with any fence.

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http://www.chassonguitars.com

Can you just loosen the low side a little and tap it up and re-tighten rather than shim?

.005 is small but it's enough to be seen and if working with tight tolerances can create a problem! As I understand it, it would only be a problem when using the router and the bench dog isn't really going to be used in that area is it?

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Billy Dean Thomas
Covina, CA

"Multi famam, conscientiam, pauci verentur."
(Many fear their reputation, few their conscience)

Yeah, that is an option too, but now the where the wing and the table saw meet at the front are flush, if I adjust it with the table bolts it will leave a lip where the wing and the table meet.

I am going to try and shim it I think.

On the fence, I can't really shim it in the middle because it is all one solid piece. I think I am going to try and build an aux fence to attach to it that I can get dead straight.

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Brock Poling
Columbus, Ohio
http://www.polingguitars.com

I don't know your area but about 15 min's from here we have a blanchard grinder. This machine is awesome for getting things flat, even large areas like table saw platens... . They could probably flatten your fence real nice like and it's typically not much money at all.

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Billy Dean Thomas
Covina, CA

"Multi famam, conscientiam, pauci verentur."
(Many fear their reputation, few their conscience)