A Little Geneva Drive Made of Wood

MDF Geneva drive in action

Long ago, before servo motors and linear actuators were common, clever mechanical devices were what engineers used to produce the needed motion for their processes. The CNC-cut Geneva Drive may not be fit for industrial use, but this type of device has been used in everything from film projectors to rotating assembly tables. The constant rotation of the driving wheel is translated into intermittent motion by the [Maltese cross] driven wheel.

The drive and Maltese cross section of this particular drive are made out of MDF with the exception of a putty material that the motor shaft press-fits into. The article claims that this is the only Geneva drive in existence made out of MDF, however, we’d love to see that proven wrong in the comments!

If you’d like to make one of these yourself, CAD and G-code files are given for the hand-cranked version that this Drive is based off of in a separate post.  If you’re not familiar with how a drive like this works, or would just like to see everything in action, be sure to check out the video of it after the break! [Read more…]

Floppy autoloader takes the pain out of archiving 5000 Amiga disks

floppy-autoloader

Archiving data from old floppy disks can be a tedious process at best. Poorly labeled disks combined with slow transfer speeds put it high on the list of things we would rather not do, and it turns out that [Dweller] was of the same opinion. With an estimated 5,000 floppies in his collection, he finally decided it was time to clean house.

With no idea of what was stored where, he decided the best way to go about the process was to read all of the disks, archiving everything, saving the sorting process for later. He originally started by building a floppy autoloader out of Lego Mindstorm parts, which looked good on paper, but performed pretty poorly.

He came across an old floppy duplicator on eBay and figured that since the machine was built for handling gobs of disks, that it was the perfect base for his autoloader. He pulled the mechanical bits from the machine, incorporating them into the rig you see above. He swapped out the duplicator’s brains for an Arduino, which allows him to batch copy his disks and save a picture of each label with little effort.

He says that the system works great, making his life a lot easier (and less cluttered!)

Check out the video below to see his floppy autoloader in action.

[Read more…]

Glue Stick + Servo = Linear Actuator

glue stick linear actuator

What do you get when you cross a glue stick with a hobby servo motor? A linear actuator, of course! Although this could be done with other household implements, the form factor of this glue stick seems perfectly suited to sit on top of a servo horn.

The servo, as you might have guessed, has to be converted to rotate fully instead of the 180 degrees or so that is typical of these types of motors. The trick to this, and what really makes it shine in our eyes, is that instead of attaching two resistors in a normal continuous rotation mod, the potentiometer is used on the glue stick allowing for position feedback.

The resulting force from this gear-reduced actuator is quite impressive, giving an “err” (over 3 Kilograms) on the scale used for testing. [Gareth] or [Chiprobot] gives a great tutorial of how to make one of these after the break, but if you’d rather just see it in action, skip to around 8:20! [Read more…]

[Aaron] shows us what life would be like if [Bob Vila] started hacking headphones

construction-headphones

[Aaron Horeth] had a pair of headphones that had seen better days, and before he tossed them out, he realized that he could use them to build a set of custom cans. He had always wanted a pair of headphones with a detachable cord to prevent damage when tripped over, and thought that his old set would be the perfect donor.

He swung by his local hardware store to peruse their collection of construction earmuffs, eventually finding a set that looked decent and didn’t cost an arm and a leg. Using construction earmuffs as the framework for his headphones gave him the durability he was looking for with the added bonus of being designed to deaden extraneous noise. Once he got them home he pulled the drivers from his old set of headphones installing them into the earmuffs, but not before he wired them up to support a breakaway input cable.

There’s no doubt that the modifications are simple, but we imagine they come in pretty handy when tinkering around the shop.

Antique Electromechanical Calculating Machines

electromechanical calculator Hamann 505

The decision to use electronics for our calculating machines has long been decided.  However, that doesn’t mean that mechanical engineers didn’t put up a valiant, if ultimately futile, fight. [Dvice.com] has an interesting article comparing the calculating technology of the 1960s, such as the [Haman 505], to today’s iPad.

This comparison and pictures were made possible by [Mark Glusker]’s excellent collection.  These models can be divided into two categories, rotary calculators, and printing calculators. According to [Mark]‘s site, the printing calculators stayed on the market a few years after the rotary calculators, which were off the market by 1970.

Although we may never see machines like these made again, anyone even a little bit mechanically inclined would be hard pressed not to be inspired by this collection. Be sure to check out the video of a [Madas 20BTG] calculator after the break to see what one of the rotary models looks like in action! [Read more…]