The $1 Marking Center, Circle Maker and Shelf Pin Layout Tool




Introduction: The $1 Marking Center, Circle Maker and Shelf Pin Layout Tool

About: Hello, my name is Kevin. I like to tinker in the workshop transforming the ideas I've engineered in my head into reality. My professional background is in automotive mechanical restoration and I run a tiny...

Yes, this layout tool can be made for $1 !!! I bought this framing square at the dollar store and decided to make it into a marking center and shelf pin layout square. What are those things? Well, a marking center helps to find the center of square tubing or a wooden board. A shelf pin layout tool is basically just way to easily mark 1" increments. It can also be used to draw a circle! In this Instructable I'll show how I turned a $1 framing square into a very handy shop tool.

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Step 1: Layout Where to Drill

Take the framing square and lay a piece of tape along the wider 1.5" side. Then mark at one inch increments. This is super easy because the framing square is already marked! I used a combination square to get my lines straight. I also marked a center line along the length, again using the ruler marks on one edge and a mark I measured out on the opposite end. Once the marks are made, use a centering punch to make a mark for drilling.

On the thinner 1" wide side of the framing square no tape was needed. I center punched at the very tip of the ruler marks, which luckily happened to be in the center of the width.

Step 2: What Size Holes to Drill?

Here I'm at the drill press making some holes. Not much to explain here, probably the biggest question is what size holes to drill? I chose to drill 1/4" holes on the 1.5" wide side of the framing square. I chose 1/4" because that's a common size for shelf pins and a common size for bolts, which is how the marking center portion of the tool is used. More on that later. On the 1" wide side of the framing square I chose to drill a 17/64" hole because the point of a sharpie fits through well and that's what I use most for layout on metal. 17/64" also works well for my non automatic centering punch. Really the hole size just depends on what tools you use for marking or perhaps what you have laying around.

Step 3: Holes Drilled (and Fixing My Mistake)

Here's the framing square after I drilled some holes. The larger holes on the wider side of the framing square are 1/4". On the thinner side the holes are 17/64". I included a picture where I messed up while drilling. Fortunately it was at the end of the thinner side at the 7" ruler mark. To avoid using that hole by accident in the future, I went ahead and cut off the end.

Also notice I scribe marked a center line down the length through all of the drilled holes. This simply makes a nice reference later when using the tool.

Step 4: Center Punch and Drill Some More Holes!

After drilling out the larger 1/4" holes on the wide 1.5" side of the framing square, I then marked off the 1/2" ruler marks and center punched. Here I drilled 3/32" holes. I chose a 3/32" bit because it fits a fine point sharpie tip and also my automatic centering punch.

I decided not to use my drill press for this step. Honestly, I shouldn't have used the drill press for the 17/64" holes. At least not my ancient drill press. On smaller bits I find my press not to work as well. Hand drilling offers a more precise feel with the smaller drill bits.

Slightly off topic... Notice the old Sriracha bottle I'm using to hold my drilling/tapping oil. This is an excellent reuse of these bottles. The tip works far better and is far less messy than the standard square tip that folds into the cap.

Step 5: Using the Tool

We're all done making the tool, now let's test it out! First up I use the tool to mark the center of this 2" piece of square steel tubing. This is done by placing two 1/4" bolts through the holes and twisting the framing square until those bolts touch the edge of the work piece. Then simply mark the center using a fine point sharpie in the 3/32" hole and drag the whole assembly down while holding carefully with the opposite hand. It takes some practice and coordination, but once you get the hang of it, it's pretty simple. The nice part about this tool is that it is adjustable and can mark wider material too. This may of course require finding a better way to hold the bolts into the framing square, but it's certainly doable. Please see the captions in the pictures for more details.

The other pictures show how I use the thinner 1" wide part of the framing square to quickly mark some points 1" apart on a piece of 1" square tubing. Here I simply use my hands to line it up by feel and then take the sharpie and peck down into the holes. Quick and easy layout.

The layout tool can also be used as a circle maker. Simply add a push pin, small nail, or the appropriate sized drill bit through one of the holes and then secure the tool onto the material. Then use that point to rotate around to draw a circle while using a pencil/scribe in another hole.

Step 6: More Tips and Thoughts About Using the Layout Tool

I wanted to add a few more tips and thoughts about using this layout tool. First, can it still be used as a framing square? Yes, it can, but you'd want to check the accuracy of the framing square before actually using it as a square. There is a way to do this, and videos can be found on youtube that explain the process of how to check a framing square for accuracy. Keep in mind that a lot of center punching has been done and holes have been drilled, so this can disturb the accuracy of the framing square itself.

The scribe mark along the length that connects all the holes can be used to align with the center line that you marked. This is why I went through the trouble of making the scribe mark in the first place! It's simply another way to check and to stay accurate.

If marking a wider piece of material and you can't hold the 1/4 bolts with your fingers, they of course can be bolted in place. The issue here is that now it raises the layout tool off of the material because of the nuts. I've found a better way to deal with this is to temporarily hot glue the bolts on the layout tool. Also tape works okay. Without having the full support of your fingers, simply be gentle and go slower so as not to knock loose the temporarily secured bolts. If however, you are always marking the same stock over and over again, a dedicated tool can be made and then simply tack weld the bolts onto the framing square.

If using on wood, the 1/4" holes can just be lined up and drilled. If you have a good enough eye, or simply want to get some pins marked on the quick, then the square itself can be used as a drill jig. I don't however, recommend doing this as it's just too thin to actually guide a drill bit. And there's a chance the drill bit can get caught on and twist the framing square. It would be better, in my humble opinion, to use this to make a drilling jig out of thick aluminum stock. Or purchase a commercially made jig. This tool is intended as a layout tool, not a jig.

The $1 framing square also has metric markings on the opposite side. So if you're a metric user/fan then of course you'd adjust the marks accordingly.

I hope you've enjoyed this Instructable! Thanks so much for stopping by!

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    4 Discussions


    2 years ago

    A plastic one would be even easier


    Reply 2 years ago

    I've seen plastic speed squares, but never a plastic framing square. Though it probably exists and certainly would be easier to drill. I don't think the material matters so much, tbh. In this case, the dollar store framing square is stamped steel. It's thin enough that it doesn't take a whole lot to drill.

    DIY Hacks and How Tos

    Nice. I am surprised that this isn't how they make all squares.


    Reply 2 years ago

    Thanks, DIY! I agree. It would be such a simple thing for a manufacturer to do and would add a lot of versatility to the framing square. I forgot about using it to draw circles too, so added that information this morning. Anyway, thankfully this is a very easy tool to make. I'd estimate maybe 15, 20, 30 mins tops depending on the tools available. Glad you enjoyed it!