Help! My Starrett is no longer square!

[Joe Unni]

What do I do?!?!?!?

Hey all,

For a few years now, my Starrett 12" combo square was the "square of record" in my shop. Referenced everything to it. It may have taken a tumble or two on a wooden floor, but nothing earth shattering. And am embarrassed to say I never really checked after the falls.

Fast forward to the other day when I was tuning the fence on my Grizzly 1018. I just couldn't believe that the fence was that far out so for kicks I did the parallel line test on the Starrett - typically reserved for framing squares.

Would you know that it's out of square by about a 1/16th - over 12 inches! I loosened the knurled nut, slid the head back and forth and then re-tightened. Same thing.

What's my next course of action, if any, except for chucking and buying a new one?

Any insight would be much appreciated.

Thanks,
-joe

[Jason Roehl]

You can send it to Starrett for calibration, I believe, or you can do it yourself by carefully sanding the little slide that the ruler rides on in the handle, and keep checking it with reference lines on a block of wood (close to the size of your square). Draw a line, flip the square, draw another line. If they are parallel, you're done. If not, sand that guide in the handle lightly on the appropriate side. You might also be able to take it to a machine shop somewhere, they might be able to help you out.

Jason

[Glenn Clabo]

Here's something for you Joe...
http://www.taunton.com/finewoodworking/pages/w00127.asp
And if you don't want to fool with it...send/bring it to Athol, MA
http://www.starrett.com/pages/442_calibration_repair.cfm

[Dave Anderson NH]

Joe, the first step is to disassemble and clean it. Often crud (scientific term) will build up inside the slot and a small bit of rust, a bit of sawdust, or grime will prevent the blade from seating squarely. Mineral spirits, an old toothbrush, and a few swipes through the slot with a MS soaked rag will clean it out. Then retest for square after cleaning and reassembly. If it is till out of square send it back to Starrett. I'd never throw it away since in the worst case you could scavenge the very nice ruler out of it for a straightedge.

[Howard Acheson]

You can send it to Starrett. They will recalibrate it at no charge but if it has been damaged from mis-use, then they will probably charge you.

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.

[Matt Warfield]

Joe,

First, check the rule for straightness. Drops on the floor will often bend the rule. This happened with one of mine and no amount of filing the head will take care of that. Fortunately, I use my starret for machine setup and reference check only. For every day tasks, I use a cheapo stanley that doesn't break my heart when it falls of the bench.

Matt

[Alan Tolchinsky]

Howard, You said, "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". Now this makes a lot of sense to me. I could never see spending a lot of money on a square when you could make a cheap one perform just as well.

[Barry O'Mahony]

My Starrett stays in thebox it came in until I need it, and it's then treated as carefully as any other precision instrument. I tend to agree with the situation to check the ruler for straightness first; it's alot more like to be bent in a fall than the cast head.

[Dale Thompson]

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.

Howard,
I've got two sets of those "cheap" drafting triangles (a 45/45/90 and a 30/60/90). One is in the area of 8-10" and the other in the range of 3-4". When I am doing really accurate cuts like for glue-ups, guess what I use to assure that the blade is "perpendicular" to the TS table? :confused: Yep! It's the $2 triangles. ;) :) The same holds true for the bandsaw, the scroll saw, the jointer fence, the router table fence, the Incra and other miter guages, etc.. :) :) My Starretts have their place but that place is "in the drawer" when I am doing MOST of my critical setups! :eek: :( Is there a lesson here? :confused: :eek:

Dale T.

[Joe Unni]

Thanks everyone - some very helpful information.

-joe

[Ole Anderson]

Starrett or not, when I need accuracy, I go the plastic drafting square route, I have a bright orange one so it is easy to find.

Why trust a sliding mechanism to get a 90 degree angle? Many precision squares are on the market that are machined from one piece of material, either steel, stainless steel, plastic or aluminum. Could be a square, rectangular, triangular or ell shape. I am sure Starrett sells many precision squares appropriate for setting a 90.

Combo squares have their place: Setting a repeatable offset dimension.