Introduction: Marking Gauge From a Printer Rod

About: If a tree falls in the woods...make things!

While watching a YouTube video from a good friend of mine, I noticed that he had a wheel marking gauge in his arsenal. While I don't think it was the first time I saw a marking device of that type, it intrigued me. A sharp blade, known as a wheel, slices into the wood and creates your mark. Now, I have a marking device like this, a mortise gauge, that uses a similar concept, except instead of cutting the wood with a wheel, it puts more of a scratch on the surface.

Some love this concept, I don't. I have been a fan of pencil wielding ever since I pushed my first block of pine through a bandsaw in Mr. Fairchild's junior high woodshop to create a salt shaker (or was it a piggy bank?). But one particular thing I enjoyed very much about that wheel marking gauge that wasn't a part of my mortise gauge, was the measuring feature. Set your mark, drag your line and your done. This removes looking for a ruler or a tape measure before setting the gauge, something I spend a lot of time doing.

The other problem I wanted to solve when I started this project was locking my marking device without actually turning a knob and bumping it out of alignment (call me clumsy), or, I'll say it, my infinite ability to be lazy. Instead of a knob, I used rare earth metal magnets to give it a little friction. It's enough to make it a bit difficult to bump out of alignment but not much effort to adjust it to the position I want it to be in.

Enough talk, let's get into this!

Step 1: Material List / Equipment Used

Materials
  • Printer rod: A 1/4" (6mm) metal (must be magnetic) rod approximately 9" long (23cm)
  • A square block of wood that's approximately 1 5/8" (4cm) x 1 5/8" (4cm) x 3 3/8" (8.5cm)
  • (2) 1/2" (13mm) round rare earth metal magnets
  • 6" (15cm) pocket ruler
  • 2mm stick of pencil lead, an 1" (2.5cm)
  • Glue
  • Metal epoxy

Equipment:

  • pencil
  • marker
  • Thin file (like a nail file but for metal)
  • grinder with cut off disc
  • chisel
  • drill press
  • bandsaw
  • 1/2" (13mm) forestner bit
  • forestner bit that's about the size or a little less than the rod diameter you will be using
  • salt
  • clamps
  • dremel with a cut off disk
  • hot glue gun
  • OPTIONAL: Sander (strip and oscillating)

Step 2: Printer Rod, or Something Similiar

The core of my handmade marking device is a rod from an old printer. If you have an old printer, laser printer cartridge or fax machine laying around (and they never seem to last long, so keep this instructable bookmarked (favorited) for when its time to get a new one) you're set! If not, use these dimensions if you want to purchase something online:

Rod dimensions:

  • Width =.236 = about 1/4" = 6mm
  • Length = 9" or 23cm

If you do purchase something else, make sure its steel and not stainless steel. In other words, make sure the rod is magnetic.

Printer Rod

Step 3: Preparing the Rod

If you're using a printer rod, remove all the attachments before starting this step.

In this step we're going to take a grinder and use a cutoff wheel with a thickness of about .064" or (1.62mm) to slice the middle of the tip of your rod. We're going to cut back about a half of an inch (13mm) before checking to see if a 2mm graphite lead will fit in. And when I say fit in, I don't mean tight or loose, just enough that it can be put in with a little resistance.

If you did as I did and used the grinder disc solely as a depth cut in the rod, you'll need to use a small file and file it enough where the lead will fit in, again, with some resistance. If, for some reason, you made the notch too big, you can always bend the 2 sides a little to get that snugly fit.

Notching A Graphite Holder

Step 4: Drilling Out Our Handle and Cutting

Now we need to find a drill bit that will drill a hole that's the size of our rod. Honestly, it doesn't matter if it's slightly smaller in size, we really just need the concave section that will hold the rod. Since we're using a square stock of wood, draw a line corner to corner on the diagonal until you've made an 'X' in the middle. Drill at the 'X' center all the way through. If you don't reach the opposite side, flip it and do the exact same thing on the opposite side.

Lines and drilling

After it's drilled, we need to cut through the center. Draw a line exactly down the center of the rectangular block and cut it. I recommend using a bandsaw as the kerf will be thinner and can't recommend a tablesaw as...I...used the bandsaw.

More lines and cutting

You'll notice in the video I used a carving chisel to clean the cut out a little. Not entirely necessary, but you could use a rounded file if you find the drill bit didn't clean it up enough.

Step 5: Magnetic Support

Now let's talk magnets, because it's such an attractive topic. That was bad, I know. Let's drill 2 1/2" (13mm) holes about an 1/8" (3mm) from both ends and forget my last comment. Except we're going to only drill the holes deep enough for the magnets to fit in and allow them to stay flush with the drilled hole. Doesn't that make sense? Check out the video link below. Once we've done that we're going to use a bit of epoxy and glue the magnets in. Allow it to cure before testing it out. These are important as the magnets will give the rod just enough to allow yourself the ability to move it, but not enough that a slight bump will knock it off.

A slight bit of magnet depth clarity...

Step 6: Spacers and Gluing

Now that we've glued in our magnets, let's do the same thing with both pieces of wood we cut earlier. The reason we cut the wood was to introduce our magnets, now that the operation has been completed, let's sew her back up and pretend like nothing happened. Except, of course, we have to account for the section of wood that was removed during the cut, known as the kerf.

To find out how much wood was removed from whatever practice you chose to split that wood in half with, we'll place the blocks together and center them over rod, measuring the distance of blank air space on one side. From that measurement we'll cut a slim piece of wood on the tablesaw to fit the gap. I used padauk to give it a little artsy flare.

Now we'll glue both sides together and add a pinch of salt onto both halves to keep the wood from moving around before clamping. Be very careful that the glue doesn't seep over and attach to our rod. Also, make sure the rod moves freely between the 2 pieces of wood before adding the glue.

Gluing, clamping and a bit of salt to taste.

Step 7: Dividing the Top Plate From the Body...

As the top of the wood block needs to be flat, I sectioned that part off before I shaped the rest of the body. We'll speak more on finishing the business end of the handle later, as it is extremely important for it to perfect for measuring. I gave myself about a 1/2" (13mm) on the top and used a miter gauge on my tablesaw to cut it on all 4 sides. Note that the blade only went about an 1/8" (3mm) deep.

Divide and conquer

Step 8: Scratching, Marking and Cutting

Before I shaped the body, I went ahead and started working on the printer rod. If you don't plan on adding a measuring stick to your marking tool and want to measure externally with some sort of measuring apparatus, this and the next step will be inconsequential.

I took our previously cut block, fresh out of surgery and inserted the rod. With the slot in the wood, I took a file and ran it down the slot, giving myself a nice scratch the length of my measuring stick. After that I ran my marker along the new scratch and then used a cutoff disc with my dremel and cut a nice, even 1/8" (3mm) depth the length of that measuring stick.

SMC In action!

Step 9: Epoxifying My Metal to Metal

Before we do the epoxy thing, let's first make several notches down the part that will be glued into the other part. The measuring stick should have notches cut out to give it a little extra hold. You only need to cut about a 1/16" (2mm) in, so don't get crazy with it. But make absolutely sure you decide which side will be glued to the rod, there's no going back once you've started notching!

Notching, notching, notching!

IMPORTANT NOTE!: As we are setting this next part, be sure that the beginning (0 on the measuring stick) of the measuring stick sticks into the opening of the notch (we ground in step 3) on the rod, HALF the size of the lead we're using. Since we are using a 2mm lead, we'll leave about 1mm inside. Look at the picture I have included...it is critically important that the place where we put the lead have 1mm of the measuring rod inside of it. This will make it possible for us to have an accurate reading. It will also keep the lead in place as it will serve as a barrier from the lead popping out.

Now then, onto the metal to metal epoxificationing (yes, my word). I used a metal epoxy, or, rather, an epoxy that's suppose to be really good at gluing metal together. I filled the freshly notched rod with epoxy and centered my freshly notched measuring stick into the middle of it. After I was quite certain it was perfect and where I wanted it, I used a little hot glue to allow it to hold the rod in place.

Epoxificationing!

Not in the video: I even used a little hot glue to hold it upright on my workbench as it all set.

Step 10: Cleanup

After the epoxy has set, after we are sure everything looks good, we'll clean up the squeeze out with a chisel by lightly scraping off any part that has epoxy on it, that shouldn't. Maybe this doesn't deserve it's own step...except that it's extremely important to make sure catch cleaning up at a good time. Too early isn't good as the epoxy will obviously stick to anything you use to clean up, and too late can mean that it has cured and is too difficult to cut off.

Scraping with a chisel...

Step 11: And You're Done! Sort Of...

All that really remains is to find a scrap of wood that will fit into the opening of the lead orifice that will put a slight bit of pressure on the lead to help keep it in place. You might even be able to use something like a match stick or put a little hot glue in there (these graphite leads last a long, long time).

"But wait! The handle is just a square block of wood!" This is where your own artistry comes in. I used a screw driver and basically drew an outline on the block from the handle and took it to the bandsaw and also the sander (well 2, the strip sander and the oscillating Ridgid sander). Cut and sand it if you want to, but it'll work exactly how it is as a block of wood.

Keep in mind these thoughts as you whittle it down (if you choose to do so):

  • Do not cut below the groove in the wood where the measuring tape resides.
  • Remember, there are magnets inside that you don't want to hit as you carve.
  • Do not cut on the upper portion that we sectioned off.

My own whittling down...

Step 12: Calibration

If you set everything where it should be, you should be good to go. If, when you measuring something out and draw a line, you find the mark isn't where the measurement says it should be by using a ruler, don't panic! You still have options. That upper plate we sectioned off can be calibrated very easily.

Measure out about 2" (5cm) from the plate to your measuring stick. Draw a line with your marking gauge. Measure it with another ruler. IF:

  1. ...you find that the line you drew is proud of the measurement (bigger than 2" (5cm)) take a file and sand the measuring side of the plate (Black arrow in the included picture).
  2. ...you find that the line you drew is short of the measurement (shorter than the 2" (5cm)) take a file and sand the writing side of the plate (White arrow in the included picture).

Be sure to sand in a straight light and to do very little amount of sanding until you get it perfect.

Step 13: Thank You!

If you made it this far, thank you so much! It takes a lot of time and effort to write these things out and it means a lot when people take a look. Check out my YouTube channel as well as my instagram feed.

And keep Making Things! Life is so much more fulfilling when you make things with your own hands!

www.instagram.com/makethingswithrob/

https://www.youtube.com/c/Make_things

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