LumberJocks

square plywood

  • Advertise with us

« back to LumberJocks.com Site Feedback forum

Forum topic by bear2 posted 07-11-2018 02:23 AM 396 views 0 times favorited 14 replies Add to Favorites Watch
View bear2's profile

bear2

21 posts in 3226 days


07-11-2018 02:23 AM

Can a piece of plywood be squared using a table saw?
1. I have changed blades.
2. I have squared the fence to the blade. Turning the blade and checking with a micrometer as I went.
3. I have squared the miter to the blade.
4. I have squared the miter to the fence.
5. I have squared the blade to the table.
6. I have squared the fence to the table.
7. As far as I can tell, everything is square to everything else.
8. I have taken ¾” Sande plywood, making certain that the edge against the fence has no high spots or low spots. The plywood is perfectly flush against the fence.
8.1. I then run the plywood through the saw and check for parallel edges. The edges are parallel.
9. I place one of the parallel edges against the miter and run an end through the saw.
10. I take the other parallel edge and place it against the miter and run the opposite end through the saw and check for parallel ends. The ends are parallel.
11. The corners are not square.
11.1. Should the corners be square?
11.2. If not, how should I square the corners.

-- It isn't always about being fast or even accurate that counts, it's being willing


14 replies so far

View TungOil's profile

TungOil

974 posts in 544 days


#1 posted 07-11-2018 02:46 AM

TS miter gauges are hard to get truly square. Most people build a sled for cross cutting on the TS. Google William Eng for a good description on how to square a sled to your saw.

-- The optimist says "the glass is half full". The pessimist says "the glass is half empty". The engineer says "the glass is twice as big as it needs to be"

View nutsandbolts's profile

nutsandbolts

3 posts in 2097 days


#2 posted 07-11-2018 02:53 AM

William Ng method to get perfectly square cuts, using a cross cut sled. The method is called the 5 cut method.

https://www.youtube.com/watch?v=UbG-n--LFgQ

View clin's profile

clin

880 posts in 1045 days


#3 posted 07-11-2018 03:13 AM

Another vote for using a cross-cut sled and for Ng 5-cut method for squaring it up.

After building a couple of sleds (very large, and a medium size), I rarely use a miter gauge. Aside form having something that is more square, the cut line in the sled make it very easy to line up the cut mark on your work. It also functions like a zero clearance insert. And, since the wood doesn’t move relative to the sled, there’s no tendency to skew the wood as you push it through the saw. Sometimes with a miter gauge, you can inadvertently slide the wood sideways as you make the cut. Similar to this, is the fact that the wood doesn’t rub on the table top, so again, contributes to the wood moving straight through the blade. I think this can make for a cleaner cut with fewer blade marks.

Bottom line, a cross cut sled is my #1 shop jig.

-- Clin

View enazle's profile

enazle

48 posts in 57 days


#4 posted 07-11-2018 03:18 AM

What are the size of the components? I assume you have cut your parts square then tilted the blade on your saw to cut the miter? If you cutting the point on top and variation the in thickness of the board will cause what you describe. If the board rises off the table even a tiny bit in the center as the ends droop off the table surface that too will cause the center to be wider than the ends. I may not be visualizing what your describing correctly but a better more durable corner can be achieved a capped rabbit joint. Here are two versions, 1st is standard grade, 2nd is premium grade. You and I can do standard grade, however, to do premium grade you need a veneer press so you can lay the edge band under the veneer. Here are drawings of both.
Standard grade capped rabbit corner:

Premium grade veneer over capped rabbit corner:

View Woodknack's profile

Woodknack

11994 posts in 2429 days


#5 posted 07-11-2018 04:06 AM

Step 10 is incorrect, keep the same edge against the miter gauge. Also you don’t say if the cut after step 9 is square. If not your miter gauge is not square or the wood is slipping during the cut.

-- Rick M, http://thewoodknack.blogspot.com/

View Rich's profile

Rich

3169 posts in 639 days


#6 posted 07-11-2018 04:18 AM

With four factory edges, I slice off what I need plus a bit — maybe an eight to a sixteenth of an inch. I then set the fence to precisely what I want and flip the board around and cut it. That way I have two perfect edges that are parallel. After that, I cross cut my parts from it.

Getting a square cut is more challenging and you need either a good sled as mentioned above, a miter gauge that’s square, or a miter saw that’s set perfectly square. I use one or the other depending on various factors, but either will work if they are set up right.

-- Half of what we read or hear about finishing is right. We just don’t know which half! — Bob Flexner

View bear2's profile

bear2

21 posts in 3226 days


#7 posted 07-12-2018 01:46 AM

I tried the fence and miter gage method. About 65% of the time it would produce square corners but I need 100% of the time. I have an Incra 5000 sled system. I’m going to use the system square it up using the method described by William Ng. I want to thank everybody for their help.

-- It isn't always about being fast or even accurate that counts, it's being willing

View Woodknack's profile

Woodknack

11994 posts in 2429 days


#8 posted 07-12-2018 02:19 AM

Miter gauges are dead simple to square but you need a known good square.

-- Rick M, http://thewoodknack.blogspot.com/

View woodbutcherbynight's profile

woodbutcherbynight

5205 posts in 2458 days


#9 posted 07-12-2018 03:41 AM



Another vote for using a cross-cut sled and for Ng 5-cut method for squaring it up.

After building a couple of sleds (very large, and a medium size), I rarely use a miter gauge. Aside form having something that is more square, the cut line in the sled make it very easy to line up the cut mark on your work. It also functions like a zero clearance insert. And, since the wood doesn t move relative to the sled, there s no tendency to skew the wood as you push it through the saw. Sometimes with a miter gauge, you can inadvertently slide the wood sideways as you make the cut. Similar to this, is the fact that the wood doesn t rub on the table top, so again, contributes to the wood moving straight through the blade. I think this can make for a cleaner cut with fewer blade marks.

Bottom line, a cross cut sled is my #1 shop jig.

- clin

I agree. Since I made mine and stopped using a miter my accuracy has gone up greatly. Error is my fault for not paying attention to cut line or double checking measurements.

-- Live to tell the stories, they sound better that way.

View Rich's profile

Rich

3169 posts in 639 days


#10 posted 07-12-2018 03:42 AM

With that awesome Incra 5000 and the five cut method, he’ll nail it. Guaranteed.

-- Half of what we read or hear about finishing is right. We just don’t know which half! — Bob Flexner

View Woodknack's profile

Woodknack

11994 posts in 2429 days


#11 posted 07-12-2018 04:16 AM

I wouldn’t give up until you understand what mistake is being made with the miter gauge and know that you can use it correctly.

-- Rick M, http://thewoodknack.blogspot.com/

View bear2's profile

bear2

21 posts in 3226 days


#12 posted 07-12-2018 04:56 AM

I bought the saw used and I don’t think the miter gage was treated well.

-- It isn't always about being fast or even accurate that counts, it's being willing

View Woodknack's profile

Woodknack

11994 posts in 2429 days


#13 posted 07-12-2018 05:10 AM

That happens, but if the wood is slipping, a simple fix like 220 sandpaper glued to the miter gauge face will help considerably. I attach an additional piece of wood to mine to increase the width, also covered in sandpaper. It extends past the blade and helps reduce tearout. I hold my square snug against the blade and slide the loosened gauge up to it then tighten it down. Dead on every time. Sleds are nice but sometimes I want to make a quick cut.

-- Rick M, http://thewoodknack.blogspot.com/

View ArtMann's profile

ArtMann

969 posts in 865 days


#14 posted 07-12-2018 02:13 PM

I haven’t used the factory supplied miter gauge on a table saw in probably 10 or 20 years. I have an Incra precision miter gauge for odd angles but for right angle cuts I use a sled. The factory supplied miter gauge is too small and there is usually too much play between the miter slot and the gauge rail.

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com