Replies

1. 
   Ricks503 | May 16, 2005 06:43pm | #1

   look for Starrett, Bridge city or another engineering supply shop. 

   Rockler and Woodcraft both sell some nice ones,  The INCRA is spendy but they guarantee the accuracy - can sometimes find these items on eBay

   1 - measure the board twice

   2 - cut it once

   3 - measure the space where it is supposed to go

   4 - get a new board and go back to step 1

2. 
   bladeburner | May 16, 2005 07:06pm | #2

   There is a procedure to 'set' framing squares. Harder to explain than to do, but you peen the inside or outside corner of the 'L' with a punch to open or close the square. Combination squares have little tabs in the slot of the hand held part that you file down to adjust for square.

   Joe

3. 
   HowardAcheson | May 16, 2005 07:08pm | #3

   No matter how much you spend for a device, you still don't know if it is square. I ran a large tool and die shop and we purchased a number of Brown & Sharp and Starrett devices and some of them where not "square". We had "standards" that our quality department periodically had validated by an outside service that we then used to verify the worker's tools.

   One day, one of our designers brought in two plastic drawing triangles he had purchased at a local art supply store. He had them compared to our standards and they were as accurate as the tools could measure. The triangle cost a couple of dollars each. They would certainly serve very well as the "standard" in any woodworking shop to validate and/or adjust other devices.

   An excellent way to validate the accuracy of the plastic squares is to use two squares on a flat surface. Get a $10-12 plastic 30-60-90 drafting square. To prove it's exactly 90°, take two to a glass counter, put the shorter legs on the counter and face the longer legs away from each other and butt them together (like a teepee). If the legs exactly butt, you can assume you have two perfect 90° angles. Using one of the plastic squares, do the same thing using your other tools. Any that mismatch, means that the tool is not square. You can also take the plastic square with you whenever you go to purchase another tool. Keep your "standard" somewhere where it doesn't get banged up.

   Finally, remember that the wood you are using will expand and contract a couple of thousands from one day to the other. Does't pay to get too uptight.

   While we are at it, I also only purchase the cheapest of adjustable squares. I square them with a drafting triangle and an auger file until they are square across 10". And I own a Bridge City square that isn't that accurate. Stainless steel machinist's squares are only square until you drop them. I have had several over the years and each has found a away to drop to the floor.

   The key is to NEVER use your best square on for day to day measuring. Use it only as a reference tool to verify your other day to day tools.

   Howie.........
1. 
   Jellyrug | May 16, 2005 07:48pm | #5

   Howie,

   Thanks, that was a good post.

   I find to set up any of my woodworking machines, such as the miter gauge on the table saw, the crosscut sled, or my compound miter saw, etc., one has to be pretty close. When this is not done properly, it shows the first time one does any kind of joinery, where the boards are 8" wide or more. Even a 1/64" gap shows quickly, when the pieces mate together. Or, try and cut a 3 1/2" tenon perfectly square in the center of an 8" board, then fit it into a mortise, with no gaps showing around the shoulders and cheeks.

   I usually do a small cut on the edge of two boards, then flip them and fart around until it's perfectly in square.

1. 
   HowardAcheson | May 17, 2005 07:35pm | #13

   Jellyrug,All the woodworkers in our shop did exactly the same thing before they needed to make precision cuts. I first learned that many years ago. There certainly is not the need for the various "alignment" devices being marketed these days. But, I wish I was making the money.Here is something to keep in mind:"The less sophisticated the woodworker is, the more sophisticated the tools he thinks he has to have." Marc Adams, Marc Adams School of WoodworkingHowie.........

1. 
   Jellyrug | May 17, 2005 08:05pm | #15

   "There certainly is not the need for the various "alignment" devices being marketed these days. But, I wish I was making the money."

   Yep, you are so right. My alignment device is a 24" poplar board, with one straight edge and a sharp pencil. You draw an accurate line, flip the square and check. For woodwork this is just fine.

   Incidentally, I priced a 12" x 7" Starrett Master Precision Square and fell off my chair. $300 !!!!

2. 
   Ricks503 | May 16, 2005 08:04pm | #6

   Another drafting square that is useful is the one that can be adjusted to differant angles. I have first tested my 30-60-90 drafting square as you describe then use it to test the adjustable at those angles and then use it to set the angles on my table saw - works great1 - measure the board twice

   2 - cut it once

   3 - measure the space where it is supposed to go

   4 - get a new board and go back to step 1

4. 
   Daggs | May 16, 2005 07:16pm | #4

   I use my drafting T-square for all of my layout now.  It is very nice, the 'T' portion is graduated out to 3", so making parallel lines  is a breeze, it is 24" long, and it is guaranteed square by the mnf.

   try this link  http://store.artcity.com/drafting-supplies-t-squares--parallel-rules--etc--alumicolor-steel-edge-t-squares.html

   
   

   ---

   Edited 5/16/2005 12:19 pm ET by Daggs

5. 
   bones | May 16, 2005 08:21pm | #7

   Heres a link to a set that my kids got me for fathers day last year. They do not cost an arm and a leg and come in a case.  I have the three piece set that comes in a wooden box. I use them to check my other squares. 

   http://www.woodcraft.com/family.aspx?familyid=3730

1. 
   Yogi | May 17, 2005 05:03am | #8

   That's a pretty good deal, if......  Have you checked them against another "guaranteed square"?  If so, I'm liable to pick up a set of those myself-  Thanks-

1. 
   MarkRD | May 17, 2005 02:25pm | #9

   Last night I did the "back to back" test with most of my squares (forgot to test my framing squares). I use my tablesaw as the reference surface.My Starrett (adjustable) and my machinist square (like the one pictured in your post) measured up perfectly with each other and with my plastic drafter's square.My rosewood/brass with steel blade square is out by 1/32" in 10" :-(Anyone have a suggestion on how to fix the rosewood square?Mark
   

   Measure it with a micrometer, mark it with chalk, cut it with an ax.

   View Image

1. 
   HowardAcheson | May 17, 2005 07:36pm | #14

   >>Anyone have a suggestion on how to fix the rosewood square?Don't fix them. They make pretty decorations hanging on the wall. Just put a coat of wax on them periodically.Howie.........

1. 
   MarkRD | May 17, 2005 08:09pm | #16

   Interesting. I might just do that.
   Thanks
   Mark

   Measure it with a micrometer, mark it with chalk, cut it with an ax.

   View Image

2. 
   bones | May 17, 2005 02:36pm | #10

   Being a sceptic, I checked them myself. I have an incra square (small triangle square for quick check of a saw blade), and a second machinist square from work.  I had asked for the Incra's and suprisingly the ones from woodcraft have been acceptable.  I liked the padded case as well. Makes it easy to store safely, and they have a sheet of that paper that draws moisture away.  I think they were worth the money. 

   Edited 5/17/2005 8:39 am ET by bones

1. 
   Jellyrug | May 17, 2005 07:29pm | #12

   Thanks to everyone for the input.

   This is what I have done:

   Got my cheap Lowes combination square, "square" by filing, but the ruler fit in the head is so bad, that it's really not worth it. It will probably end up in the trash.

   Got the framing square very close, with a hammer and an anvil, but then one blow in the wrong spot spoiled it. Next time maybe I'll get it right, this one ended up in the trash.

   My Aluminum rafter square seems to be square enough, this one seems to be the only cheap square which will be afforded space in the shop.

   Ordered a Starrett Metric/English combination square with a satin chrome blade from Texas (I'm in California) for around $100. Ouch!

   Finally, the next struggle is to figure out whether to convert my whole shop to metric, when I add, subtract, divide in mm, I don't even need a calculator, and I make no mistakes. If I don't work off a drawing, and I have to do math with 3/16 and 1/8 etc. that's when the little errors slip in. I guess this is a different subject, but after all the square comes with graduations.

6. 
   Routerman | May 17, 2005 02:55pm | #11

   My Tee- Squares are made and verified to .001"/length of blade (or better) on day of  shipping.