Making Wooden Roubo Try Squares

Chris Schwarz showed us how to make Roubo-style try squares  in the February issue of Popular Woodworking.  These have the virtue of being easy to make in any size desired, are half the weight of a purchased square, and because they’re made from wood, they will not scratch the wood pieces being squared.

I thought I’d take advantage of this article as everytime I watch one of Rob Roziaeski’s podcasts I get square envy as he uses Roubo squares in several sizes and I just like the looks of them.  The more I use tools made from wood the more I want to use them so I see a fair amount of tool-making in my future.

Materials

I looked at what materials I had in the scrap box and came up with some hard maple, some cherry, and some red oak.  I cut enough pieces to make half a dozen squares, though I really don’t need that many.  The key, it seems to me, is that you must ensure that the faces and edges of each piece are flat and square to each other.

I’m fairly confident that maple and cherry will make good squares but I included the red oak as an experiment.  Red oak is known to move quite a bit which is not an attribute you want in measuring devices.  Time will tell whether this is a problem or not.

Making a Bridle Joint

The squares are pretty simple, involving a 1/4″ thick blade and a 3/4″ thick handle.  They are connected to one another with a bridle joint, which I pinned with a couple 1/4″ dowels.

Laying out a bridle joint is easy as the blade width determines the depth and the blade thickness the distance between the two saw cuts.  If there’s a “trick” to bridle joints it is to have practiced sufficiently with your saw to cut square and true.  I used my dovetail saw to make the two cuts in each of the handle pieces.   And I only screwed up one of them.

Some might wonder why I don’t use a tenon jig and run the handles through my table saw rather than do this slot chopping.  Truth is, it simply takes too long to set things up.  Doing it by hand is really fast as the two photos above indicate.  You simply hit downward on your chisel vertically.  Then, coming in from the end with the chisel and you can remove 1/4 of the material that needs to be removed.  I repeat this twice more, and then flip the stick so I can access the other side.  When I hit the piece with vertical chisel blow the last fourth pops out.  If you’ve made your cuts correctly, you’re done.

Glue the Joint

Obviously, if you’re going to rely upon a square to check square, it must be itself.  Thus, it is imperative that you glue the bridle joint absolutely square.  I use hide glue for this, knowing that I can easily undo the joint with steam if the result isn’t square.    Once glued, I left the squares overnight to completely set and rechecked them again before pinning the joints.

Pinning the Joint

I’m sure there are various opinions about how to determine where to put the pins.  I simply laid a straight edge between the inside and outside corner and measured in 5/16″ from each corner.  This looked “right” to me.  I drilled 1/4″ holes through the joint and used a wooden mallet to pound cherry dowels through the joint.  I used a flush cut saw to trim the dowels on each side of the joint.

One piece of advice for those who don’t own a flush-cut saw and want to buy one.  Avoid the Stanley saw.  Flush-cut saws should have no tooth set on the side of the blade that is flush with the surface.  The Stanley has set on both sides of its blade and it’ll scratch up your piece every time.  I use the saw from Lee Valley and it works great and costs only a few bucks more than the Stanley saw.

Making Them Fancy

At this point the squares will work just fine but they aren’t yet “kewl.”  I drew out some guidelines for cutting trim on the ends of each piece and then us my scroll saw (fret saw will suffice) to cut the decorative trim.  Absolute accuracy is less important than cutting smooth curves and square corners.  It’s ok to make happy sounds as you finish up this step.

Final Form

All I did to finish my squares was to give them a dose of boiled linseed oil.  I’d given the wood a couple swipes with a smooth plane before I started joining blade to handle and so no sanding was done.  Notice how I assembled one of the maple squares backwards.  Without screw ups, how else can one appreciate when things go well?

Cheers — Larry

larry@woodnbits.com