Resurfacing Table Saw Top

[JoeLee]

Have you tried checking the table when it is not bolted down?
From the marks made by the shear blade, you could get it considerably better by yourself, and getting the blade re sharpened if you made it blunt would be much cheaper than a table regrind.

I've never had the table off the cabinet.
You can see how the trunnions are bolted to the ends of the table. I took this pic when I had to remove the tilting arbor housing to remove the spindle to change the bearings.

JL...............

[BCRider]

Joe, that's what I sort of figured. The tops on our saws don't need to be "surface plate" flat but they do need to be flat enough. And I'd say that means no more than around .015 to .02 between any two points on the table. And even that might be enough to stymie us if it's just in the wrong place or abrupt enough.

[JoeLee]

As a woodworker who repairs machinery for fun and profit, I would never have that top ground. The miter gauge bar won't be right, nor will any off the shelf jigs or accessories. In addition. if the arbor is attached to the top, the added weight will change the shape (flatness). Just mounting that on a magnetic chuck, will change the shape and when they grind it, they may release tensions in the top and again it may change shape when you put it back on the saw.

I am known for "supertuning" my machines and this is not where I would go. I have medium sizes tools. 12" table saw, 8" jointer, 25" drum sander, etc.

Wood is not stable like steel. Make a cut, go to lunch and when you come back, measure it with a micrometer and it will have changed. Tensions released, moisture content changed! I have friends that make furniture that sells for 6 figures and I do work on their machines and they are not dealing with dimensions much under 1/32" or occasionally 1/64". The wood moves more than this.
Peter

I'm well aware of all of this. The slots aren't real bad as far as slop. I did make new bars for my three miter gages and some other fixtures. I had to file / stone teh curse out of the slots and then grind the edges of the bars for that perfect fit. I did that probably ten years ago or more. If teh top is ground and the slots are not cut deeper then all the bars I have will have to be ground to surface level. One thing leads to another. I also fine tune all my machines.

JL................

[The Metal Butcher]

I pretty much have done what your describing here. I've had both the trunnions out. They have three bolts. The trunnions are pretty heavy and solid. I did check the mounting surfaces or faces and they were al even.
I find it hard to believe that the top is being bent by the weight of the wings and if I remove them it will spring back to flat.

JL.................

I can bend my lathe bed just by leaning on it. Not much, but some theoretical amount. That table will definitely bend with additional weight, especially cantilever beam style weight, which has quite high mounting forces. Probably not the amount it's off by, but certainly a measurable amount. Cast iron wood tools are also prone to creep. I believe that Frank Howard and others have had badly sagged drum sanders by storing weight on them for long periods of time.

I agree with Paul Alciatore, the first step is to level it and adjust the leveling feet to be in as even of compression as possible.

[JoeLee]

This pic was taken last year when I was checking the table for flatness. Thats an 3/8" x 3/4" 18" piece of ground 01 sitting on the table. I was running into issues ripping some boards that I wanted to glue up. Notice the gap on the right.

JL...................

[genea]

. . . I was running into issues ripping some boards that I wanted to glue up. Notice the gap on the right.

JL...................

My recommendation is to delay wanting to glue them up until after you've run them through a jointer.
After seeing that last photo I do understand your desire to have a flatter surface though. That gap looks > 0.01".

[bborr01]

I haven't read all the posts but here's what I've got. I'm with some others that the wear in the table probably isn't that big of a deal but if it bothers you that much maybe try lapping in flat. I've seen surface plates and other larger areas brought into flatness by lapping with a lapping plate. Might be worth checking out. It may take a while to lap .010 out though.

Brian

[Arcane]

I have a saw that's similar in looks, and age. Mine is a contractor's model, several pay grades below this one. Similar design and trim make me think they're from the same factory. The table is also warped, bit it's low where Joe's is high. On rip cuts, it's not very critical, but when making miter cuts, like for a picture frame, it gets tough to make a nice job. In my case, I was getting a dish effect. Once I figured out what was happening, I was able to work around it to some effect. I'm pretty sure Dad never had any problems with this while he used it on construction job sites. He did high quality finish work, but used a high end miter box for trim work.

Thank you. My experience with cutting wood is limited to circular saw territory and rough carpentry so it's nice to know why such a small amount of warp can create a problem.

[dian]

" the 24" blade off my shear. It's flat and straight withing .0002." :

how do you know?

[Joe Rogers]

It looks to me like the point of sag is right at where the wing is attached. Could you build some sort of jack screw legs to slowly raise the wing and edge of the top?
Joe

[Doozer]

My recommendation is to delay wanting to glue them up until after you've run them through a jointer.
After seeing that last photo I do understand your desire to have a flatter surface though. That gap looks > 0.01".

Standard procedure to run wood through a jointer for proper fit up.
Trying to make a table saw finish wood like it came through a jointer
is a bit over the top as far as expectations go.

-D

[JoeLee]

" the 24" blade off my shear. It's flat and straight withing .0002." :

how do you know?

I checked it on my surface plate. I mentioned that in one of my previous posts.

JL................

[metalmagpie]

Have the top + wings Blanchard ground as a unit. Yes, the slots won't be as deep afterwards. My friend did that with his table saw and it came out great. The swirling grind marks were amazing.

Scraping would work too but it would take FOREVER to scrape ten thou off that big surface.

metalmagpie

[JoeLee]

Have the top + wings Blanchard ground as a unit. Yes, the slots won't be as deep afterwards. My friend did that with his table saw and it came out great. The swirling grind marks were amazing.

Scraping would work too but it would take FOREVER to scrape ten thou off that big surface.

metalmagpie

I don't want a blanchard grind finish. I know the swirls look pretty but not for me. Cheap saw tops were blanchard ground because it was quicker and cheaper to do.

That rough finish also causes some increased friction when moving wood across it.

JL................

[Moxiedad2001]

Although I agree that 0.010 can make a difference in woodworking, the skeptics here have offered some valid reasons why regrinding may not be worthwhile. You may be better off applying the money to a better saw. I suffered with a "top-of-the-line" Craftsman for 30 years. It's most irksome (but not only) problem was that the blade was parallel to the miter gauge slots at only one height. Raise or lower it, and the blade would run off in either direction. It could not be adjusted out. By the time I could afford a Powermatic I was done with most of my woodworking. Life is too short to suffer with poor tools.

And I agree with one poster that a sawn surface is not a proper glue surface. You need to joint the edge anyway, so invest in a 22- or 24-inch jointer plane (assuming you don't have a power jointer). An older Record or Stanley would be dandy. The new Lie-Nielsens are very nice, of course, but salty. There's a reason why they are called "jointers" and saws are called "saws."