protractor

3 Articles

Digital Protractor Makes Angular Measurements A Snap

March 3, 2019 by 7 Comments

Old school vernier calipers served engineers and machinists well for a long time — and did a perfectly good job. Digital models then came along and were easier to read. They now rule the roost, despite their thirst for batteries. Humans are naturally wired to make the least effort possible at all times. That’s why you always drive to the store that’s only a few blocks from your doorstep. In this vein, you may find a digital protractor preferable to the classic printed type.

[Nirav Jadav]’s project is a simple one but serves as a good learning experience for those getting to grips with microcontrollers. An Arduino Pro Mini serves as the brains, reading signals from an MPU6050 gyroscope. Measured angles are displayed on a small OLED screen.

To use the protractor, first the reference button must be pressed, then the device may be rotated to measure the angle. Relying on a gyroscope means that it’s likely less accurate than a printed device, particularly if it isn’t recalibrated every few measurements to account for drift.

However, like many projects to grace these pages, its value lies not in its usability, but in the journey of creation. To build such a device requires programming ability, an understanding of interfacing with external peripheral devices, as well as how to drive a graphical display. These skills are highly useful in a wide variety of projects, and they’ll serve [Nirav] well in projects to come.

Once you’ve built your digital protractor, why not have a stab at building a digital measuring tape?

[Thanks to Baldpower for the tip!]

Clever Approach To Stylus Alignment

March 6, 2018 by 25 Comments

Digitally stored music is just data. But not long ago, music was analog and required machines with moving parts. If you have never owned a record player, you at least know what they look like, now that there’s a(nother) vinyl revival. What you may not be aware of is that the player’s stylus needs to be aligned. It makes sense, that hypersensitive needle can’t be expected to perform well if it’s tearing across a record like a drift racer.

There are professional tools for ensuring alignment, but it’s not something you’ll need each day. [Ali Naci Erdem] shows us his trick for combining a printable template with a mirror to get the same results without the professional tool costs. Instead of ordinary printer paper, he prints the template on a piece of clear plastic and lays it across a small mirror. These are both items which can be picked up at a hobby store, which is not something we can say about a record player mirror protractor.

We love music hacks like this informative introduction to circuit bending, the wonderful [Martin] from Wintergatan, or if you want to get weird, an organ made from Furbies.

Electric Compass For A Plasma Cutter

March 22, 2016 by 26 Comments

If you are a Maker space or individual lucky enough to own a Plasma Cutter, this electric protractor compass could be handy. The folks over at [MakeItExtreme] built this circle cutting tool to help cut circles and rings in thick metal sheets using their plasma cutter.

The whole thing is built around an electro-magnet, so the jig will only work with magnetic metals. There are not a lot of design details, but it’s possible to infer how to build one looking at the video and the photos on their blog. There’s a couple of nice hacks along the way. Since the electro-magnet is stationary while the rest of the jig rotates, the main mounting bolt had a hole drilled through it to help route the cable. The rotating protractor arm is made from a slab of aluminium and holds all the other parts together – the drive motor, the central hub and the plasma head. The motor used appears to be a 60rpm AC synchro motor. These types usually have an RC phase shifting network between the two coils to allow direction reversal. Friction drive is used to rotate the jig, with the friction coming from a pair of rubber tube bands attached to the electro-magnet and the motor drive hub. The plasma head holder has a rod-end with a roller bearing attached, acting as a caster wheel, ensuring the arc gap is maintained as the jig rotates. A few switches to activate the electro-magnet, motor forward / reverse and plasma enable complete the setup.

Their blog, and YouTube channel has a lot of other interesting projects that they keep building. Check it out.

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