any tips to verifying squareness of a shooting board?

[Steven Lee, NC]

Are there any tricks to verifying how square they are? I haven't bought an expensive triangle or square yet. Looking for something like the 4/5 cut method I used to square my tablesaw sled.


thanks

[Rob Fisher]

Drafting triangle. Cheap and accurate.

[Chris Vandiver]

Probably a good idea to own an accurate square or two.

[Jim Neeley]

One tip I've found handy when attaching the fence to the shooting board is to glue it in place first and then follow up with screws. That way it won't slide during the drill/screw process. But then, mine is disposable, with an MDF base and a strip of hard maple for the fence.

I used a square, with the thick piece against the plane and the metal against the fence. That kept any glue squeeze-out away from the square. You could do the same thing with a drafting triangle and a spacer block.

Jim

[Jim Koepke]

The easiest way to check it is with a try square.

Adjustments all depend on how it was built. One of mine is held together with screws. A few taps with a mallet brings it into square if anything changes with humidity.

jtk

[Steven Lee, NC]

ok thanks. Waiting for the woodcraft weekend sale to get a triangle/square

[Prashun Patel]

If you know your tablesaw and sled to be square, then cut a rectangular piece on it and use that to check your shooting board.

Alternatively, you can shoot the edges on two straight boards, then butt the shot ends against your tablesaw fence. Then clamp the pieces together, move the fence and check the jointed edges with a straight edge. Flip one of the pieces so that any skew will run the other direction, and repeat the procedure. If it's shooting square, the straight edge should be flush in both ops.

[Terry Beadle]

Just a comment. Your shooting board doesn't have to be perfectly square. Get it as near to square as you can but then use paper shims ( like postit notes ) between the fence or the base as needed to modify the work piece position. Then check the work piece with a try square. You should be able to get the work piece dead square in both directions fairly easily using this technique as detailed in David Charlesworth's Shooting Board video.

He also uses a pencil to scribe the work piece edge so it's quite clear when the cut is full.

Enjoy the process !

[David Weaver]

I would do what Prashun says. Getting a no-light perfect shooting board is not easy to do, but it's also likely that it's not necessary.

Checking two pieces that you've verified are jointed dead straight on the edge by placing them against something flat or on something flat will help you without relying on a machinist square.

I keep a box full of shims, just various junk that's different thicknesses (fake credit cards from advertisements, pieces of different weight sandpaper, all the way down to receipt paper). It allows me to make a chute board in about 10 minutes, and use it just as fast as one that would be as dead on as a machined casting. the shims also allow you to match other things when you're shooting a frame or something and you need to tweak.

[David Weaver]

Ooops..I just noticed terry already mentioned shims.

[Jim Koepke]

Get it as near to square as you can but then use paper shims ( like postit notes ) between the fence or the base as needed to modify the work piece position.
...
He also uses a pencil to scribe the work piece edge so it's quite clear when the cut is full.

I tend to use the shavings that are all over the place.

I sometimes scribe all around a piece with a knife if it is being trimmed to size/fit. Most of the time the shaving and sound tell the full edge is being shot.

jtk

[Steven Lee, NC]

nice, I'll use the tablesaw fence trick to test it and then shim :).

[Zach Dillinger]

The best way, in my opinion, to use a shooting board is to shoot to a knife line. If you do that, your squareness of your fence is largely irrelevant and the use of shims is unnecessary.

[Russell Sansom]

I'm with Zach. In my opinion, various boards can square up differently on a shooting board, depending on the plane and the board's dimensions. A little pressure here and there and it's easy to shoot perfectly to the cut line. My old-fashioned miter-vise-shooting fixture always wants some shimming...usually a couple sheets of typing paper.

[Steven Lee, NC]

got a chance to watch rob cosmans dovetail 2.0 last night and he showed how he makes his shooting boards. I guess I was thinking it was much more complicated than it is.

[Bob Glenn]

You should be able shoot the end of the board, then turn it over against the fence and shoot it from the opposite edge to see if there is any different cut.

[glenn bradley]

You should be able shoot the end of the board, then turn it over against the fence and shoot it from the opposite edge to see if there is any different cut.

Took the words out of my mouth. Starting with parallel long sides, shoot an end, draw a line along it and shoot it from the other end. The whole line should disappear . . . . oh, and buy a good square ;).

[Jim Koepke]

You should be able shoot the end of the board, then turn it over against the fence and shoot it from the opposite edge to see if there is any different cut.

That only works if the sides are perfectly parallel.

A good square is the best test.

My shooting board occasionally needs a few layers of tape at one end of the fence or the other to accommodate movement due to atmospheric conditions.

jtk

[Stanley Covington]

You should be able shoot the end of the board, then turn it over against the fence and shoot it from the opposite edge to see if there is any different cut.

If I understand the method Bob is describing properly, it will only work if the two opposing long edges of the board placed against the shooting board fence are very straight (easily verified), and very parallel (not so easy to verify).

I know of two tried and true methods to check the accuracy of shooting board's fence. The first one is quick and easy but requires a good tool. As I have mentioned in previous posts, a truly square try square is essential for checking working day tools like a shooting board. I prefer a precision ground and hardened diemaker's square (the fixed variety, not the type that measures angles). Shoot as wide a board as your shooting board will permit, and check it for square using your truly accurate try square. EZ PZ. If the precision of your square is questionable, time and material will be wasted and frustration will accumulate.

The second, more ancient method is to accurately true one edge of a board as wide as your shooting board can accommodate, and at least twice as long as your shooting board. Then crosscut it in half. With the same trued long edge placed against the fence, shoot the sawed ends of both pieces of the board (the ends that were formerly joined). Then set the trued long edges of the two boards tight against another truly reliable flat surface (such as a truly straight straightedge, or granite plate, or other reliable trued surface (i.e. awase jogi) with the formerly joined and now supposedly square edges butting up against each other. Any gap that appears between the two ends is double the error in your shooting board.

Shims were mentioned as a way to adjust an out-of-tolerance shooting board fence. Screws were also mentioned. These are both useful methods, but if you have a plane, and know how to adjust it for a fine cut, you have a tool that can quickly true and adjust the fence very precisely with two or three shavings. Of course, part of truing a shooting board's fence is planing it straight, something shims and screws cannot accomplish.

Of course, when you built your shooting board you rebated a small relief in the fence where it meets the base of the shooting board to prevent tiny amounts of sawdust and shavings from accumulating between the fence and the workpiece ruining the shooting board's accuracy. This rabbet is also critical to using a plane to true the fence when necessary.

If you need to true the fence regularly, there is a probably a problem with either its construction or the stability of its materials. Despite what the MDF smokers believe, a well-made solid-wood shooting board will be very stable and last a lifetime.

For what it is worth.

Stan

[Adam Cruea]

How do you think they did things like this in years past?

Make your own triangle using the Pythagorean Theorem.

http://upload.wikimedia.org/math/3/a/e/3ae71ab3eb71d3d182a3b9e437fba6ee.png

That makes a right triangle. With a little mathematical wizardry, you could also figure out the leg lengths to give you 2 45* angles or a 30* and 60*, etc.

With a little math knowledge, you can save yourself plenty of money if money is tight.

[Tony Zaffuto]

My method is verifying backer board and occasionally truing up the runner with my shoulder plane (then it takes a pass or two to put the ledge back in!). Beyond that, I gotten into the habit of always checking any thing I shoot in both directions with a square. Takes only seconds to do, once it becomes a habit.

[Paul Murphy]

One more method to add to the options...
Google "five cut method", and realize most discussion is intended for tablesaw sleds. The important point is that any error is additive, so on the 5th step you can set that edge in the shooting board, and instead of shooting the edge you measure the difference from "flush" at both ends of that edge [digital calipers depth rod, feeler gauges, dial indicator], and carry on with the procedure as discussed in the article.
http://www.evenfallstudios.com/metrology/five_sided_cut_method.html
http://benchmark.20m.com/articles/TheFiveSidedCut/TheFiveSidedCut.html
http://www.newwoodworker.com/basic/5cut.html

[Sam Stephens]

paul sellers has a nice video for making a simple shooting board that can easily be made quite accurate. rather than screwing/gluing the fence perpendicular to the sidewall, he uses a wedge for the fence that is housed in a dado (?). As long as the dado is accurately cut (90 degrees to the side wall) using a knife wall for example, you're good to go.

My other thought regards the need for accuracy and allowable tolerance. how wide of a board are you shooting? you don't need it to be w/in 0.001" over 24" if you're shooting 4" wide boards.

[Michael Ray Smith]

The best way, in my opinion, to use a shooting board is to shoot to a knife line. If you do that, your squareness of your fence is largely irrelevant and the use of shims is unnecessary.

Agreed. Who cares if the shooting board is square or not? It's the work piece that matters, and there are lots of ways of getting there. And lots of ways to create a work piece that isn't square, even if the shooting board is perfect.

[Jim Neeley]

First, to answer your question if you wish to know accurately I recommend Pauls 5-cut approach except using a known good square in lieu of the 5th cut.

That said, Michael has the best answer; don't go overboard unless it's just something you wish to do. If so, go for it but plan on chasing your tail once it's close.