# Getting A Square Edge



## scott lindsay (Jun 22, 2010)

I finished my cross cut sled. Now I have some plywood pieces where none of the edges are square to each other. How do I square up the edges on plywood just using a tablesaw? The size boards are not that wide, 14" by 23" long. I could try making another joiner sled however I need a joiner to make sure the edges of hardwood are straight and square.

-Scott


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## Steve Neul (Sep 2, 2011)

scott67 said:


> I finished my cross cut sled. Now I have some plywood pieces where none of the edges are square to each other. How do I square up the edges on plywood just using a tablesaw? The size boards are not that wide, 14" by 23" long. I could try making another joiner sled however I need a joiner to make sure the edges of hardwood are straight and square.
> 
> -Scott


When you make a sled before the glue sets up on the runners you need to test it for square and make adjustments if need be. About all you can do is remove the runners and do them over. 

No bigger than your parts are you could maybe square them with a miter gauge. Put a piece of wood that fits fairly snug in the other miter gauge slot and set a framing square against the wood and the miter gauge to get it set correctly. If your blade is sharp it should cut perfect.


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## GeorgeC (Jul 30, 2008)

I do not understand your problem. Is it the sled that does not have square edges? Or do you want to use the sled to cut plywood so that the edges are square.


If you have properly constructed the sled, it will do the job for you.


George


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## scott lindsay (Jun 22, 2010)

Steve Neul said:


> When you make a sled before the glue sets up on the runners you need to test it for square and make adjustments if need be. About all you can do is remove the runners and do them over.
> 
> No bigger than your parts are you could maybe square them with a miter gauge. Put a piece of wood that fits fairly snug in the other miter gauge slot and set a framing square against the wood and the miter gauge to get it set correctly. If your blade is sharp it should cut perfect.


It is not the sled that is not square. I did test cuts on pieces and that is fine. I took a 15" x 48" piece of 1/2" plywood I had laying around thinking at least one edge was straight like factory edge straight. I ran it through my tablesaw to cut down to 14" and then on my new cross cut sled I cut that into (2) 23" pieces. My new project is to make a light table for my daughter and I to use in our different other hobbies. Any way, when I checked the 14" x 23", they where not square. I checked the edge from that rest along the table saw fence ripping down to 14" and that edge was not all that straight. I am not sure how it happened since I only use my table saw to cut any thing. So, now I am trying to figure out how to get a nice factory type straight edge along the 23" side so I can make finishing cuts to 6" tall X 22" long. I watched one video showing that using hot glue a piece to a piece with a straight edge and then cutting it on the table saw and another video screwing a piece on top of a piece with a straight edge and running through the table saw against the fence to get that nice straight edge. I guess either of those would work. How about using double sided tape instead of hot glue or a screw? Any other ideas would be helpful.


-Scott


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## scott lindsay (Jun 22, 2010)

GeorgeC said:


> I do not understand your problem. Is it the sled that does not have square edges? Or do you want to use the sled to cut plywood so that the edges are square.
> 
> 
> If you have properly constructed the sled, it will do the job for you.
> ...


George, no it is not the sled. I wanted to make a board that was 15" x 48" cut down to (2) 14" x 23" boards. The ripping down to 14" along the 48" side must have been very straight and clean because I know have 14-1/16" x 23-1/8" at the top and 14" x 23-1/16" at the bottom. I need to square it up. My cross cut sled is 21" wide so I cannot turn the board and cut it length wise so I need to use the table saw without the sled. I need to make sure I have a nice clean straight edge in order to get to my final sizes which is 6" x 22" panels and a set of 6" x 17" panels.


-Scott


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## woodnthings (Jan 24, 2009)

*this is two separate questions ....*



scott67 said:


> I finished my cross cut sled. Now I have some plywood pieces where none of the edges are square to each other.*(1) How do I square up the edges on plywood just using a tablesaw?* The size boards are not that wide, 14" by 23" long. I could try making another joiner sled *(2)however I need a joiner to make sure the edges of hardwood are straight and square.*
> 
> -Scott


(1) A proper sled will have the fence 90 degrees to the blade and any cuts made will have 90 degree *corners*, and they will be square to each other. Starting with a board that has been ripped so the edges are parallel, just crosscut each end to make all your corners 90 degrees.

(2) To get *edges* that are square to the faces you CAN use a jointer OR the tablesaw, either one. On the saw, the blade must be adjusted so it's 90 degrees to the table surface. On the jointer, the fence must be adjusted so it's 90 degrees to the infeed table. Either way, this will give you edges that at square, which is different than corners that are square. 

*Square* means different things, depending on the application ... just sayin' :vs_cool:

Then you said this:
_It is not the sled that is not square. I did test cuts on pieces and that is fine. I took a 15" x 48" piece of 1/2" plywood I had laying around thinking at least one edge was straight like factory edge straight. I ran it through my tablesaw to cut down to 14" and then on my new cross cut sled I cut that into (2) 23" pieces. My new project is to make a light table for my daughter and I to use in our different other hobbies. Any way, when I checked the 14" x 23", they where not square. I checked the edge from that rest along the table saw fence ripping down to 14" and that edge was not all that *straight.* I am not sure how it happened since I only use my table saw to cut any thing. *So, now I am trying to figure out how to get a nice factory type straight edge along the 23" side so I can make finishing cuts to 6" tall X 22" long.* I watched one video showing that using hot glue a piece to a piece with a straight edge and then cutting it on the table saw and another video screwing a piece on top of a piece with a straight edge and running through the table saw against the fence to get that nice straight edge. I guess either of those would work. How about using double sided tape instead of hot glue or a screw? Any other ideas would be helpful.

_Now you've thrown in a new term *"straight"* .....:surprise2:
A properly set up table saw with the fence parallel to the blade will give you a parallel edge on the cut side. This is a must. You need to keep your workpiece's straight/factory edge registered against the fence all the way through the pass. If you are not getting parallel edges, you need to reset your fence to blade relationship. It is the tablesaw's normal ability to make straight cuts because the blade is a "plane" and the fence is a "plane" ... straight and flat by definition.
If you are getting "curved" cuts on your boards, you have curved boards to start with OR your method of operation is not correct. :|


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## Steve Neul (Sep 2, 2011)

scott67 said:


> It is not the sled that is not square. I did test cuts on pieces and that is fine. I took a 15" x 48" piece of 1/2" plywood I had laying around thinking at least one edge was straight like factory edge straight. I ran it through my tablesaw to cut down to 14" and then on my new cross cut sled I cut that into (2) 23" pieces. My new project is to make a light table for my daughter and I to use in our different other hobbies. Any way, when I checked the 14" x 23", they where not square. I checked the edge from that rest along the table saw fence ripping down to 14" and that edge was not all that straight. I am not sure how it happened since I only use my table saw to cut any thing. So, now I am trying to figure out how to get a nice factory type straight edge along the 23" side so I can make finishing cuts to 6" tall X 22" long. I watched one video showing that using hot glue a piece to a piece with a straight edge and then cutting it on the table saw and another video screwing a piece on top of a piece with a straight edge and running through the table saw against the fence to get that nice straight edge. I guess either of those would work. How about using double sided tape instead of hot glue or a screw? Any other ideas would be helpful.
> 
> 
> -Scott


Don't use hot glue for anything connected with a table saw. That is a recipe for a major accident. There is very little strength in hot melt glue and very undependable and likely to come unglued while you are making a cut. 

The only thing I can suggest is to cut the wood to the 6" finished width and then cut the board to it's 22" length with your sled. If it were me using solid wood I would rip the wood 6 1/8" wide and take a sixteenth off each side on the jointer and then cut the part to length.


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## johnep (Apr 12, 2007)

My first exercise at school woodwork class was making a square edge piece of wood using a hand plane and square.
johnep


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## Maylar (Sep 3, 2013)

Sure, double sided tape can hold a straightedge to your panel and use that as a reference against the rip fence to rip one side. Then remove the temporary straightedge, flip the panel over, and rip the opposite side to width. Those 2 parallel edges can now be used as a reference edge on your crosscut sled to make the panel square.


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## Ron_J (Sep 22, 2014)

It sure sounds like the sled is not square. Try this to make sure it's square...


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## GeorgeC (Jul 30, 2008)

I think that Scott is confusing the terms square and parallel. That is causing him and us confusion.


You get the two edges PARALLEL by ripping. Two opposite edges (sides) of the board are always parallel to each other.( at least they are not if you want a square or rectangular figure.) Ends and edges are SQUARE to each other. You get this cut on the sled. The two ends would also be parallel to each other. 



George


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## andr0id (Jan 11, 2018)

Square EDGE = the edge of the cut is 90 degrees to the surface of the material. Example: The narrow edge of a 1 x 4. Made on a jointer with fence at 90 or table saw with blade at 90 angle to top.


Square CUT = A cut that is exactly perpendicular to another side on the same piece forming a 90 degree angle. Made with crosscut sled or miter guide on table saw or 0 position on a miter saw.


Parallel SIDES = sides that are same distance from each other wherever measured perpendicular to one side. Rips cuts against the fence of a table saw that is properly set up. 



Parallel FACES = Uniform thickness board often made by running lumber with one smooth flat side through the planer.


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## FrankC (Aug 24, 2012)

To straighten the plywood cut you need to make a carrier for your table saw;

http://www.benchnotes.com/Taper and Straight Edge Jig/taper_and_straight_edge_ji.htm

If you don't have any plywood with a factory edge most lumber yard sell partial sheets of plywood, select one with a factory edge and use that for your base.

Once you get one straight edge you can then rip it to have two parallel edges, the square cross cuts will be done with your sled.


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## NewBi (Mar 23, 2017)

FrankC said:


> To straighten the plywood cut you need to make a carrier for your table saw;
> 
> http://www.benchnotes.com/Taper and Straight Edge Jig/taper_and_straight_edge_ji.htm
> 
> ...



This is your answer Scott, I hope you see this post.

Gary


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