Unisaw Extension Table Warped

[Tom Dixon]

Hi all, I just finished building a full length outfeed table to replace the folding outfeed table on my Unisaw. The new outfeed table is dead flat and is made of two layers of MDF on top of a mortise and tenon SYP base I dimensioned from 8' 2x10s. What I discovered when connecting the new outfeed table to my Uni is that the existing accessory table is warped. It is high on the far end and low in the middle. Has anyone in this group ever rebuilt an extension table? If so did you re-use the surface or did you build completely new?

The existing table is a fir frame connected to a double laminated piece of particle board. I am thinking about using QSWO for the new frame and either reusing the existing extension table surface or building a new one out of double sided laminate covered MDF. I'm leaning towards the latter option. Any thoughts on this from the collective would be appreciated?

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My eventual plan is to add 3 rows of free standing drawer storage under the outfeed table.

[Andrew Seemann]

My extension table for my Unisaw is 1/2 Baltic Birch on a frame of oak (probably red, not quarter sawn) and bolted to the Biesemeyer rails and the cast iron wing. It has two coats of shellac on both sides with an additional two coats of poly on top. It works as well as it needs to. I made my extension insert, because my saw didn't come with one.

Any chance your fence rails are not level and causing the extension table to warp? If they are level, you probably could do a repair by adding some support rails to the underside of existing extension table to draw it flat. If you are really obsessed with flatness, a torsion box type extension would stay the flattest. You didn't mention how warped the extension was. If it doesn't affect your saw's cutting abilities, it might not matter. I've never actually checked my extension for flatness. Whatever it is, it works just fine. For that matter, I have used a Unisaw that had a 1/16" dip from the miter slots to the blade insert. When things didn't fit, it was almost never the saw's fault:)

[Tom Dixon]

Any chance your fence rails are not level and causing the extension table to warp?

If it wasn't for the new outfeed table being flat I would have never noticed the dip in the extension table and it wouldn't be an issue. As it is a board will bump into the outfeed table if it is long enough to reach the dip.I disassembled the extension table from the rails and attempted to raise/flatten it but I think gravity, stress and moving across country during the past 12 years has taken its toll. Building a new one is probably the only way to fix the issue.

[Jim Becker]

It's certainly not surprising to me that your right-side extension table might not be perfectly flat over time if it's made of a "wood product", especially if it was not sealed on all surfaces by the manufacturer. Honestly, there's no requirement for it to be perfectly flat if you think about it...it's intended use is to support stock while it's being cut and minor variations in the surface are not going materially affect that operation. Since the backsite isn't level with your new outfeed, you either need to straighten it with bracing below (perhaps with angle iron) or replace the extension table with a new one. Both of those solutions are relatively easy to work on.

[Mark Daily]

Beautiful shop Tom- I’ve been in operating suites that weren’t that clean! Lol

[Mike Kees]

Tom ,just build a new one. How you attach it or for that matter build it depends somewhat on what fence you have. I have built tables that screwed between the rails on Beismeyer fences. When I got my first Unisaw it had never been used and came with everything including an owners manual. There was a plan for the extension wing with a Unifence using the Delta hardware included. Basically two pieces of angle iron attached to a 3/4'' top on the bottom side. most of the extension tables I have built,I used 3/4'' good one side fir plywood with arborite on top. Lining up with another table can be a pain,my one friend just made a 45 degree edge about 3'' wide on the edge of his outfeed table to eliminate line up altogether.

[johnny means]

A couple of turnbuckles corner to corner underneath will give you some adjustment.

[glenn bradley]

If it wasn't for the new outfeed table being flat I would have never noticed the dip in the extension table and it wouldn't be an issue. As it is a board will bump into the outfeed table if it is long enough to reach the dip.I disassembled the extension table from the rails and attempted to raise/flatten it but I think gravity, stress and moving across country during the past 12 years has taken its toll. Building a new one is probably the only way to fix the issue.

I agree that it is probably easier to replace than to fix. The Saw Stop PCS side table is one of their rare weak points in design. I will keep the table top itself and replace their very-soft softwood frame so that the table will be able to retain its position. On my top the frame pieces are so soft that they "crush" a bit and allow the table to slip it position. careful retightening has only reaulted in repeat performances with the material crushing a bit more under use and over time until the table is misaligned once again.

[Andrew Seemann]

Lining up with another table can be a pain,my one friend just made a 45 degree edge about 3'' wide on the edge of his outfeed table to eliminate line up altogether.

It helps to have the saw top slightly higher than the outfeed table. On mine, I have a hinged torsion box that rests on leveling screws on a ledge on the outfield table. I have it set about an 1/8" above the outfeed table, so nothing can catch on the outfeed table edge.



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[Charles Taylor]

My extension table sags. It's the original "wood product" table, as Jim says, that came with my Unifence circa 2001. Building a new one is on my list. I'll build a torsion box version to replace it.

Your outfeed table looks good. I have a separate work table/cabinet built to the height of my saw, just like the photo in Andrew's post above, but I need to fashion a bridge as he did.

[Tom Dixon]

Well it looks like the consensus is to build a new extension table. I'm as of yet unsure if I'll duplicate the existing design or go with a torsion box design. I suppose I could even make the outer frame from steel angle iron. I'm going tho have to move this to the top of my project list so my Uni is 100% functional.

[Rege Sullivan]

I surely would rebuild that extension table. Probably from mdf and whatever laminate I could get free or cheaply.

One thing I learned from the frustration of not doing so.... is to put at least a 1/2 inch bevel on the outfeed tables edge facing the saw. Even when the tables are perfectly set occasionally the edge will catch on a squarely cut out feed table.

[Tom Dixon]

One thing I learned from the frustration of not doing so.... is to put at least a 1/2 inch bevel on the outfeed tables edge facing the saw. Even when the tables are perfectly set occasionally the edge will catch on a squarely cut out feed table.

Adding a bevel seems like a good idea but 1/2" seems a bit extreme. I can always increase it if necessary but I think I'll start with 1/8" considering how close the outfeed table is to the saw.

[Bill McNiel]

Torsion Box - Dead flat. I have a relatively small shop and wanted the TS/Router to serve as an additional assembly table as well.
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