New Table saw top not flat

[Mike Berrevoets]

I just bought a new table saw. I'll withhold the brand for now.

When I put the cast iron wings on and adjusted them with the cast iron top I couldn't get the left wing to match up with the main top. The main top is dished on the left side. The right side wing matches up pretty well but not the left wing. I went to the auto parts store to get a set of feeler gauges today so I could check how much the top is dished.

I can slip a 0.008 inch feeler gauge under the straight edge at the center. (Front to back) I don't have a good straight edge (starrett, etc) so I used a saw guide and a stabila level and flipped them over a few times to see if I would get any different measurements. Flipping them over and with two different straight edges and I ended up with the same results.

So my question is this: Is a top that is dished 0.008 inches on one side acceptable on a new saw? When I attached the left wing I split the difference. I don't know if it being out will really effect too much but it is somewhat annoying to spend that much money on a new cabinet saw and have it be out.

thanks,

Mike

[Myk Rian]

I believe most manufacturers consider .010" - .015" within specs.

[Mike Carino]

In my experience most tops are not flat.

[Jerry Miner]

I had this same issue with a Delta saw several years ago. Called the manufacturer and was told that .012" was within tolerance. By all means, call and ask, but you may have to live with it (probably not a big issue, really, but i feel your pain. Flat should be flat).

[david brum]

Mike, its not uncommon for wings to be misaligned with the top. When I set up my cabinet saw, the owners manual told me to expect to beat the wings into alignment with a dead blow hammer. I tried that, but it worked better to use clamps to flex the wings into submission. The reality is that cast iron is fairly flexible and can probably be forced into alignment with your table without much effort.

[Alan Bienlein]

I just bought a new table saw. I'll withhold the brand for now.

When I put the cast iron wings on and adjusted them with the cast iron top I couldn't get the left wing to match up with the main top. The main top is dished on the left side. The right side wing matches up pretty well but not the left wing. I went to the auto parts store to get a set of feeler gauges today so I could check how much the top is dished.

I can slip a 0.008 inch feeler gauge under the straight edge at the center. (Front to back) I don't have a good straight edge (starrett, etc) so I used a saw guide and a stabila level and flipped them over a few times to see if I would get any different measurements. Flipping them over and with two different straight edges and I ended up with the same results.

So my question is this: Is a top that is dished 0.008 inches on one side acceptable on a new saw? When I attached the left wing I split the difference. I don't know if it being out will really effect too much but it is somewhat annoying to spend that much money on a new cabinet saw and have it be out.

thanks,

Mike

I'll be brutely honest. Does it really matter. I never remember my father checking a saw for flatness and he did wood working for a living all his life. I never checked a saw for flatness and have been doing wood working for over 30 years. All the shops I have ever worked in have never checked a saw for flatness.

Put it together and use it. Your cutting wood. Tighten one end of the cast iron extension so it's flush with the main top, move to the next bolt and repeat until you get to the other side. It will flex some to line up.

[Mike Berrevoets]

I've known it was out for a week or so and it hasn't bothered me too much. I was trying to think of a scenario where it would matter and I couldn't come up with one. My sled doesn't catch on the edge. I rip most everything to the right of the blade. My old cheap ridgid contractor saw had wings that were never matched up and I never noticed a difference in the finished product.

But, it is a little disappointing to save up the $3,000 for a few years to buy the "dream" table saw and have it not be perfect but after some use it won't be perfect anyways. It was just that annoying little edge between the top and the wing that I noticed everytime I walked by the saw. If I can torture the wing to match up a little better and split some of the difference then I'll probably forget about it after a while. My only concern is that the top would continue to move over time. If that isn't a valid concern then I'll just move on to making more sawdust.

I guess I equate this to buying a new car and getting the first door ding in the side. It will happen sooner or later.

Thanks all.

[Jay Rasmussen]

Mike,
The last two Delta saws I bought, the last being a Unisaw. I would take .008 and be happy. You’ll be able to great work with it no doubt.

[glenn bradley]

The seller can tell you what is "in spec". For example, my old zip code saw and my current jointer both state .008" as the max between any two points on the surface. You are right at that but, within spec per those two makers.

[scott spencer]

If it effects your cuts, it could be a problem.....measure the results instead of the tool, and see what you get.

[Tim Morton]

I am sure you can release the name of the tool, as most would be thrilled to know they are only 0.008 out.

[Mark Wooden]

I am sure you can release the name of the tool, as most would be thrilled to know they are only 0.008 out.

\
Yeah, what he said.
The castings for machines made today aren't aged before they're machined. It was a standard procedure to set castings aside for a year or two (or more) to let them flex,expand and contract until they stabilized. Then they were machined and would hold their tolerance. It's why old machines, if not worn from use, will have better tolerances than new.
Today, the tops and beds are machined almost immediately and while fresh off a grinder they're within .002, in a month they may be wildly out.
I bought a Delta Taiwan made jointer 12-15 years ago with a .010 dip in the infeed and when I complained they said the tolerance was .012; I was shocked.
About 8 years ago, I bought an industrial shaper from a dealer here on the east coast and when I asked for the quaranteed tolerance, I was told .010- for six months after delivery.

I've since started switching out all my machines for older iron that I restore.

Anyway, on a tablesaw, that amount would be considered minimal and shouldn't give you any problems.

[Al Launier]

I can understand your concern, although it's more a mental thing rather than a functional thing. If I had spent $3,000 on a saw I would probably feel the same way having been a Tool & Die Maker in my early years where tight tolerances get engrained into one's psyche and then to start working with wood where 1/64” might be considered “tight” is a bit different. Personally I prefer to have my TS flat as I used that as a reliable reference surface for setting up, or measuring, other things.

If you were of a mind to “fix the flaw” you could sequentially tighten the wing, as noted above, & if you had the access, you could drill, ream & dowel the wing to the table, or use roll-pins if reaming were not feasible. Or, if you really wanted a flat table & wing assembly, you could find a local machine shop with a Blanchard grinder & have them grind the entire assembly at the same time. If you were to do this, I would have them dowel the pieces together first so that if the sections were ever disassembled in the future, you could reassemble them.

Just my .02.

[Lee Schierer]

\
Yeah, what he said.
The castings for machines made today aren't aged before they're machined. It was a standard procedure to set castings aside for a year or two (or more) to let them flex,expand and contract until they stabilized. Then they were machined and would hold their tolerance. It's why old machines, if not worn from use, will have better tolerances than new.
Today, the tops and beds are machined almost immediately and while fresh off a grinder they're within .002, in a month they may be wildly out.

Quality manufacturers will stress relieve their cast iron parts before machining which does eliminate most internal stress from the casting process. However, in the haste to make a product for as little cost as possible, some manufacturers will skip that step with the result that parts will move as they are machined. The blanchard grinding done on the top to make it flat should get it flat within .010. Only surface grinding after all other machining is complete would yield a flatter part, but surface grinding is slow and costs more.

Aluminum cast tops are even worse than cast iron when it comes to movement during machining.

[Jeff Duncan]

I agree with the majority that the top is fine and should't be a problem. I've used the rubber mallet when aligning my Unisaws wings a couple times over the years, (different saws), and it'll get you a bit closer.

As far as wanting a perfect saw or comparing to a new car…..your doing an apples to potatoes comparison. Spending $3k on a saw is a large investment, however remember that there are high end saws that sell for well over $10k…..like a new Northfield that'll cost you in excess of $14k…..unless you want a rolling table that will get you closer to $35K Oh yeah, those saws will likely have flatter tables

At $3k your at the high end of entry level saws. That doesn't mean it's not a good saw or that it's not well made…..it's just about keeping things in perspective when talking about a "perfect" tool

good luck,
JeffD