Adjustable Ruler Measuring Stop

I saw this small but useful tool once online, and I decided to make an Instructable out of it. If I find the website again, I will add the link to this Instructable.

Ever found it uneasy to check the distance of several marks from one border of, for example, a furniture? The Adjustable ruler measuring stop is my solution to that: this is a tool I use to quickly measure one or several geometries (such as holes) on a surface, from an even 90° edge.

It is basically a pocket-piece of wood into which you can insert a ruler, move it through and secure it with a knurled screw in order to make the desired measure.

It is close to a marking gauge, though it doesn't mark but only measure.

> All the units are in the metric system. To convert them to any other units, I use this excellent online tool.

Tools: See the photo for a global view of almost everything needed.

• A square
• A paper pen
• A saw and a mitre box
• A chisel
• A mallet
• A file
• TWO steel rulers
• An F-clamp
• Some wood glue and a brush
• Some finish and another brush
• A vise
• An Allen wrench or a flat screwdriver (depending on the nut)

• Optional: a circular saw or even a table saw

(This list gives you only examples of what you could buy)

Material:

• A fine wooden strip, around 12 x 30 mm section
• A manual screw with knurled surface, M6x15 mm
• An insert nut for wood, M6x10 mm (Allen or flat end)

I choose beech because I find it fine to work on: not too soft like pine.

When finished, the side surface of this tool, where the ruler go through, must be even.
Additionally, one of the main surfaces of the wooden strip has to be even as well, because you will glue two parts together later. And at last, both these even surfaces must have a 90° angle (see 3D image). Be sure to choose a proper piece of wood you know has good surfaces, or use a jointer to get these surfaces even.

You will have to cut the wooden strip in two equal parts that will be glued together, but first we must mark it to know where to cut.

• Both parts will be 50 mm long, as shown on the first 3D picture.
  

• Use a ruler on one border, from an end, and use the pencil to mark the wood at 50 mm and 100 mm.
  

• Use the square and the pencil to stroke two lines at the markings, along the width, at 90° angle from the length. These lines will mark the limits of the two main parts, I mark them 1 and 2 on the photo.
  

• On one of the faces, stroke two parallel lines that will limit the place where the ruler will be inserted. Measure the width of the ruler with another ruler and put that distance between the two lines. In the photo, my ruler's width is 13 mm.

These last lines must be exactly 90° from the length, so that the ruler is perfectly square with the even surface.

Now is a more delicate job. You will have to dig a groove where the ruler can be inserted.

• Use the mitre box and the saw to make a thin pre-cut along the lines drawn for the ruler. The cut must not be thicker than a millimeter.

> Depending on the tools you have, this step can be a bit tricky: in my case, the mitre box slots and the saw thickness are quite large, which made the precision work harder. The cuts may be done perfectly along the lines if you want your ruler to form a perfect square angle.

• Separate the parts, either with the saw and the mitre box, or with a circular saw.
  

• Fix the wooden part on which you want the groove into a vise. Use soft jaws or spare wooden pieces to avoid marking the wood.
  
• Gently use the chisel and the mallet to withdraw small layers of wood between the two cuts. Take your time and don't try to withdraw thick layers, as you risk to tear off more than you want. The groove must be a little deeper than the ruler thickness.

> Sometimes you can just use your palm instead of the mallet to have a better control of the force you put on the chisel.

• When the groove is formed, use the file to make its surface more even and correct the imperfections.

> The groove width must be the exact same width of the ruler, so that it can translate through it with no backlash.

I can honestly tell you I had to do these steps several times before to get a neat result.

This step is a little easier:

• Keep the part with the groove in the vise.
  
• Choose a drill bit according to the size of the insert nut, and make a hole in the middle of the groove.

> The drill bit must be the same diameter than the insert nut. If you're unsure you can begin with a smaller one, try to insert it, and make a slightly bigger hole if it's too small. Also, some insert nuts are sold with instructions of the right drill bit size to use.

• Turn the wooden part upside down in the vise and insert the nut on the opposite face from the groove. Screw it with the Allen wrench or with a flat screw driver, depending on the type of nut.

> The nut must be screw until it's fully inserted, but won't go out on the other side. 2 mm of wood must remain.

• Apply some wood glue with the brush on both parts. The glue must be on both side of the groove but not on the groove itself.

> When you fix both part together, glue will likely go out form the pressure. You want to avoid the glue to go inside the groove so that it won't interfere with the ruler later. So be sure to let 10 mm clear from glue on both side along the groove.

• Part the two pieces of wood together, groove inside. Before to apply the F-clamp, position the borders' parts against an even surface, so that both sides are exactly on the same level.
  
• Apply the F-clamp with two pieces of spare wood on each side, so you don't mark the wood.
  

• Remove the glue that went out with the ruler.
  

• Let the glue dry, according to the instructions on its package.

If you correctly glued the parts together, at least one side surface must perfectly even.

• Place the tool in the vise.
  
• Withdraw the dried glued with a chisel, on every faces.
  
• File the two non-functional sides, then sand them with a flat piece of wood. Don't sand the functional surface, as you may risk to uneven it.
  
• Sand all the sides of the newly formed part, except the functional border that is normally perfectly flat.

> You can apply sand paper on the borders to make them smoother.

Optionally, you can finish the tool (there are no photos for this step, this is a bonus):

• Put some paper-tape on the insert nut to cover it. You can also screw the manual screw and hang the tool to it.
  
• Wipe the dust on each part of the tool with a humid tissue.
  
• Finish the tool with a brush.
  
• Let dry the finishing, sand it (at least with a 120 sand paper), and apply a new layer of finish.
  
• Repeat this step for every layer of finish you want to apply.

You can now release the screw and insert the ruler, then tighten it with the screw.

This is it. You can know enjoy and measure everything you want.

Thank you for following these steps! This was actually my first Instructable. I hope you enjoyed it, and that my English was understandable.