The Rultractor™: a Ruler, That Is a Compass, That Is Also a Protractor

Ever been tired of losing your ruler, finding it and then losing your compass? Well, this design is made to counter that. It is intended to be a compass, a ruler and a protractor at the same time.

My name is Max and I am a student studying at Sunway International School for grade 8 this year (I'm getting into high school next year so wish me luck ;D )

I rate this project as 13+ as we are dealing with hot surfaces and sharp tools. Please get your parents to help you if you're less than 13.

You will need:

A (not so) beefy computer

A trusty old 3d printer (And USB stick/SD card for printing)

Pliers and a knife to remove the print

Some 1.5mm screws

A pen with the clippy thing

Screwdriver

Sandpaper/dremel to help grind down your parts

Carving tools/Pen, paper & knife

A ruler (Yes, you will need a ruler to make a ruler... Wait what?)

Using Fusion 360, I made a very crude model of my tool. I didn't have the knowledge nor the time to make this more detailed, so, more work after printing I guess.

As with anything related to science and engineering, you are welcome to modify and improve my design, and you're also welcome to post them in the comments below.

You also might have noticed a thing sticking out of one arm. I wanted to screw a screw into that to make it the pointy thing on the compass, but as it turned out it didn't work and broke off as soon as I screwed a screw into it. Might as well cut it when you print it out.

Anyways, once you're done modifying/downloading the file, it's time to slice it.

Your 3d printer can't read STL or 3MF files. The format of files they can read is called "Gcode", which is basically a long string of text telling the extruder which coordinates to go to next. To convert your 3d model into Gcode, you need a slicing software. It is recommended to use ones that match with your printer. My school has 2 Ultimaker 3s, so I went with Cura.

Supports are required for the model that I made and I recommend layer height of 0.1-0.2mm.

After slicing, save the .gcode file to a USB stick/SD card (Different printer accept different file storage devices) and it's 3d printin' time.

Plug in the USB stick and get printing! Be careful when removing the print from the build plate. I recommend using a knife to carefully pry it off. Wait for it to cool first, though. I made that mistake of bending a component before it cooled completely a few days ago.

Get some pliers and remove the support. Trim the inner edge with sandpaper/dremel if the thing doesn't fit. Be careful though, PLA is hard but brittle.

Screw the screw into the hole. Reference the image for more info. Make sure the screw isn't too long and not too tight.

If you want your Rultractor™ to measure stuff, you can add the measurements. Using a ruler, carve the 1cm marks on the outer edge and draw a line across the circle in the middle, alligned with the edge. Draw a line perpendicular to that, and then draw the same thing but rotated 45 degrees. Now you have a protractor.

If you don't want to carve, you can also draw the measurements on a piece of paper and glue the paper on to the Rultractor™. That's what I did here.

You can reference the image above if you didn't understand me. I'm bad at explaning.

You might be confused as how to use this as a compass. Have a look at the image above.

First you clip the pen onto one of the arms, or hold it onto the arm. You adjust the size and set the other arm on the paper. This design is not even close to being optimal but it's good enough for a first try.

Make sure to spin the paper instead of the Rultractor™.

And there you have it. The Rultractor™ is finished! This project is ment to be more of a concept than an actually good design and I'm probably not getting first prize with this, but hey, at least I tried and learned something from it.

Some design changes that I could make is to add stoppers so that the hinge stops at 180 degrees. I could also have put a thing to hold pencils without the clippy thing. Another thing is that I could have made it transparent but since my school doesn't have a resin 3d printer, it wouldn't be possible. Overall I'm pretty happy with how this turned out.

Anyways, thank you very much for reading this Instructable and I hope you have a great day.