Category Archives: Hive76

Our New Laser Cutter!

The new laser cutter station in our classroom.

We are very happy to share that Hive76 is now home to a 45W H-Series laser cutter from Full Spectrum Laser! Members now have the capability to cut complex 2D shapes in wood and plastic in thicknesses up to 0.25 inch. If you can draw it on a computer, the laser can cut it. It’s great for engraving too:

Our New Laser Cutter!

Hive76 rocks!

We’ve just begun making test cuts and machine break in. Our next step is to develop a class for members to become laser cutter certified. I can’t wait to see what kind of cool projects our members will use this tool for. In the mean time, stop by our open house Wednesday nights 7-10pm to see it in action and find out how to become a member!




Our New Laser Cutter!

Laser guts.



DIY Music Night at Hive76 – Philly Tech Week 2015

Making things to make music.

On Thursday, April 23, our celebration of Philly Tech Week events continues as we open our doors for DIY Music Night (7pm-???). If you’re into music, making music, or making things that make music, you won’t want to miss it! If you’ve been to the space before, you’ll know that we run on a steady diet of tunes. And on Thursday, we’ll have all our audio and music-centric projects out in what is sure to be the noisest night of PTW. Come by and see the space, make some amplified noise, hang out, or share your own projects.

We’ll have guitars, amps, synthesizers, sequencers, oscilloscopes, speakers, fuzzboxes, tremolo pedals, signal generators, oscillators, speakers, drum machines, pickups, karaoke machines and probably alot more – all made at Hive76.

There will be snacks and beer.

A Twist on Tech!

On Wednesday, Feb 19th 5:30-8:00 p.m Hive 76 will be at The Philadelphia Museum of Art! 


Come out and support us on this PAY WHAT YOU WISH ADMISSION night. Let us share and explain some of our great projects while you view some of the Museum’s amazing collection for as little as a penny!

Correct Hive E-bast.

Hive’s Valentine Hackshop – February 9th


1:00 – 5:00 PM   $10/ at door

Leave a comment below for RSVP :)


Got a sweetheart?  Want to meet a sweetheart?  David and Leslie are back to share the Valentine’s love.  Make sweet gifts and  learn about 3D printing and paper circuits at the same time.   For the gamer in your life,  there’s  a Valentine  Creeper.  Got an inspirational do-gooder?  Here’s a movie inspired MockingJay pin.  Just want to show you care?  Well, they’re working on a pixel heart necklace/keychain, that is sure to please.


Val Creeper M SwallowJay Pin M












While your piece prints, make a Valentine card that will illuminate your sweetheart’s soul.  Bring some materials from around your house and combine them with a variety of papers, copper tape, LED and battery to create the perfect paper circuit.  If you love crafting and electronics, you are about to experience  maker heaven.  If you’ve never been here before, you can tour the space and find out more about other member’s projects.  Munchies will be on hand.  Don’t forget to comment below so we know you are coming!


Circuit Bending The Final Countdown, or: Dan’s Homemade Queso Dip

A few years back I received a birthday card that, when opened, played a 15-second clip of The Final Countdown. Before tossing it out, I tore the little board and speaker from the card. I knew nothing about electronics at the time, but I just thought it was worth keeping around.

The audible gates of Hell.

The audible gates of Hell.

Well I found the little device in one of my junk containers last week and immediately recognized it as something to be circuit bent. The board had an IC, a capacitor, and two resistors. As I learned from Nicolas Collins’ excellent Art of Handmade Electronic Music, one of those resistors was the freakout resistor. Following his “laying of hands” technique, I licked my finger and ran it around the board while the circuit was on. This actually worked very well as I immediately found the resistor that caused the sound to go all wonky.

The basic idea here is that the circuit operates at many cycles per second, at a rate determined by some resistor. If you change the value of the resistor, that rate will change and the audio clip will either speed up or slow down; this is the basic idea behind circuit bending. When you run a damp finger across the board, you’re making random connections and changing how components interact with each other. When you short out the clock resistor, it sounds like hitting the circuit’s main nerve.

So now with the clock resistor found, the next step was to replace it with a potentiometer so that the clock speed could be manipulated with a twist of a knob. After removing the resistor from the board, I measured its value as ~400k and set out to find a potentiometer in the same range. I was very happy to find a 2 megohm pot in the parts hole at the space since it would slow the clock quite dramatically, producing some really cool roaring depths-of-hell sounds.

Trimpot between output wires.

Trimpot between output wires.

The board had an integrated 3V watch battery which I replaced with a 2-AA holder. There was also a mechanical contact on the board to turn the circuit on when the card was opened; I replaced this with a simple toggle switch. I also thought it would be cool to switch back and forth between normal mode and circuit-bent mode, so I used a DPDT switch to toggle between the original clock resistor and the circuit-bending potentiometer.

Lastly, I wanted to add 1/4″ output to the circuit. That way it could be amplified, distorted and subject to all sorts of effects and processing. I cut the wires leading to the little speaker and soldered them to the signal and ground leads of a 1/4″ output jack. This arrangement alone would have been far too much to run into an instrument amplifier, so I soldered in a trimpot to act as a volume control (and/or load resistor taking the place of the speaker) between the output wires.



I neglected to consider an enclosure for this project. However, I did notice an alarming surplus of queso dip at the space. Since apparently nobody likes queso, I emptied a jar, cleaned it out (probably the hardest part of the whole project) and drilled some holes in the lid to accommodate my components. A coating of white spray paint covers the Tostito’s logo for extra class. I actually really like this au-natural enclosure since you can see all the components and wiring just hanging there. Since nothing’s fixed down, I hot-glued all my solder connections to the board. I think I’d like to experiment with glass jar enclosures again, perhaps with some lighting involved next time.

In the process of building and testing I noticed that when I would touch the third, unused lug of the pot, I could get some cool scratchy AM Radio static sounds from the circuit, especially with the pot wiper all the way over in satan mode. So as a last minute little addition, I soldered a bare wire to the lug and ran it outside of the jar to retain this touch-sensitive flavor of noise.

And that’s how you make Dan’s homemade queso dip.

DIY Music Night at Hive76

Making things to make music.

Making things to make music.

On Thursday April 25, our series of events for Philly Tech Week continues as we open our doors for DIY Music Night (5pm-???). If you’re into music, making music, or making things that make music, you won’t want to miss it! If you’ve been to the space before, you’ll know that we run on a steady diet of tunes. And on Thursday, we’ll have all our audio and music-centric projects out in what is sure to be the loudest night of PTW. Come by and see the space, make some amplified noise, hang out, or share your own projects.

We’ll have guitars, amps, synthesizers, sequencers, speakers, fuzzboxes, tremolo pedals, signal generators, oscillators, speakers, drum machines, pickups, karaoke machines and probably alot more – all made at Hive76.

Plus we’ll have a handful of contact microphones to give away! We’ll help you turn anything into an amplified electric instrument in 10 minutes flat.

Hive76 Ultimate Open House and Expo


Our grand finale/blowout/party for Philly Tech Week will take place on Saturday, April 27. Everything from the previous week’s events will be on interactive display, and more. It’s an all-day exhibition of everything that goes on at Hive76 and everybody’s invited!

  • 3D Printing/OpenSCAD interactive demo
  • Fighting robots
  • DIY musical instruments, effects, snyths, amps, circuit bending, everything
  • Continuous open hack/project marathon: make whatever you want with whatever we’ve got
  • Open soldering workstations
  • Member’s signature projects on display
  • Gaming, arcade and pinball machines
  • Music
  • Karaoke!
  • Libations
  • Free food

We are located in the Arts Building at 915 Spring Garden Street. Stop by at any time during the day/night and dial 0519 at the callbox. See you there!

Guitar Stuff at Hive


Last year, I purchased a 1970 Telecaster copy for $120 from Elderly Instruments. The frets were no good and much of the hardware was corroded, so it seemed like a good instrument to hone my repair skills on.

The first thing I did was take it to Hive and bounced ideas around with some folks. One thing I really love is that no matter what kind of project or idea you’ve got, there’s at least one or two people at an open house who have some expertise to share.


My cigar box slide guitar would’ve been cooler with frets.

So I decided to give all the hardware a good cleaning and replace the bridge saddles – they were pretty sharp and very uncomfortable to rest my right hand on while playing.  I also chose, somewhat foolishly, to refret the guitar when in fact a fret dress job was all that was needed. But if this was to be a learning project, I thought I should learn what I could. It also seemed like a big step towards building more of my own stringed instruments, which up until now have not had frets (such as my cigar box slide guitar).

I purchased some new saddles from the nice folks down the street at Bluebond Guitars and installed them right away.  After doing some research on the refretting process, I learned that just about every luthier has their own method. I assembled my own procedure by printing out this guide and annotating it with notes from this series of videos and this forum post. Along the way I found that the general consensus on refret jobs is that it’s past the “DIY” border and well into the realm of  “just get a professional to do it”. But whatever.


Hammering in new frets.

I ordered some fretwire, end nibbers and sanding supplies from StewMac, and used a piece of aluminum channel left over from Such and Such as my levelling tool. I tried to get really econo and skimp on a fretwire bending tool ($90), opting instead for this technique ($0). It took a few attempts to start producing nicely curved fretwire. Unfortunately, this resulted in a pretty wide range of fret quality.

As I worked, the fretboard acquired all sorts of scrapes, marks, burns and excess glue which really ought to help produce those vintage tones. The uneven curvature I was initially producing in the fretwire caused many of the upper frets to sit higher than those at the end of the neck. Sanding and levelling couldn’t quite alleviate this, so I’m now relying on a slight forward neck bow under string tension as a remedy. Real professional stuff.

With a fresh set of heavy strings, there is still some fret buzz. But not enough to drive me completely insane. While I might’ve been better off sending it to a professional guitar tech, it’s still quite a playable instrument – possibly even more so than before. And as intended, this job was a great learning experience.


It’s more comfortable than it looks.

Another guitar project from the past month – this time a one-nighter -  was adding a tremolo arm to the old Sears guitar that’s been floating around the space. It was already equipped with a tremolo bridge, it just required an arm to get those bends and squeals so key to our late-night, burned-out-on-my-project jam sessions.

An old piece of aluminum tubing cut to length, pressed flat at one end and drilled out to accommodate a 1/4″ bolt and fender washer did the trick nicely. I wish I’d come up with something a little more inventive, but this’ll do for now.

Come by the space on Thursday April 25 for our DIY Music Night as part of Philly Tech Week. You’ll be able to see and play with all of the music gadgets built at Hive, including guitars, synthesizers, amps, pedals, speakers, noise makers, plus a really cool karaoke machine.

Fight, Robots, Fight! – “Such and Such”


Such and Such vs. Uberclocker Advance (credit: Charles Guan)

This past weekend I had the great pleasure of competing at NERC‘s Motorama Robot Conflict with my fighting robot Such and Such – built 100% at Hive76.

Though it might have looked a little boring, that was the most exciting match of the competition for me. After 2 years of on-and-off work, Such and Such, the most ambitious robot I’ll ever build, worked like a charm.

Some rough CAD layout of the bot.

Some rough CAD layout of the bot.

And still it only barely managed to eek out a win. To put it simply, Such and Such was not designed to beat other robots. At least, not on its own; it’s actually meant to fight alongside a partner hammer-bot, but weight limits prevented our tag team strategy. Rather, the point of Such and Such was to come up with the most overtly weird fighting robot possible, and then design it and build it.

The two main features of the robot that make it kind of unique are the walking and clamping mechanisms. A great deal of time was spent in the design phase figuring out how best, and in fact how easiest to implement these ideas.


There were a few reasons I chose to make Such and Such a walking robot. First, there aren’t enough walking robots and this was a way to make the whole thing wackier. Secondly, I wanted  to increase the bot’s traction (I was previously using omniwheels to accommodate the sideways motion of the clamping action – unfortunately, omniwheels tend to have poor traction, so omni-legs seemed like an acceptably ridiculous alternative). Additionally, walking robots are allowed a 50% weight bonus, and I hoped to have a little left over to afford all this additional complicated mechanical nonsense.

The walking mechanism is basically a set of three crankshafts with a series of cam profiles that ride in slots on three legs. The legs have a phase difference of 120 degrees, so each rotation of the shaft provides about three “shuffles”.

Prototype Leg

Prototype leg; UHMW cams and spacers sandwich onto a 1/2″ Al keyed shaft.

Many walkers of this type rely on eccentric circles for cam profiles, resulting in sinusoidal x-and-y movement of the legs. That is to say, the up-and-down (y) and back-and-forth (x) position of the legs is never the same instant-to-instant. This means that the robot’s frame will constantly be oscillating up and down above the floor as it walks forward. Since both halves of Such and Such are so far apart, I thought this might result in some weird binding forces on the clamping mechanism.

I wondered if there was a way for the robot to stay at a constant height off the ground as it walked. It would require the y-motion of the legs to switch and hold between “up” and “down” positions. That would prevent any binding of the clamping mechanism, plus it sounded like a pretty cool challenge. Conversely, the sinusoidal motion from a regular eccentric circle would have a leg continuously in motion between “up” and “down”, instantly reversing its travel once it reached those extreme points. After a bit of research and some time sketching on graph paper, I arrived at the following cam profile.

Y-Cam profile.

Y-Cam profile.

As it rotates in the leg slot, it holds the leg in the “down” position (in contact with the ground) for 120 degrees, then transitions and pushes the leg up for 60 degrees in to the “up” position. It stays there for another 120 degrees. Then the next 60 degrees of the leg return it back to the “down” position. With a series of 3 legs and cams 120 degrees out of phase with eachother, there would always be a leg being held in the “down” position, and the chassis would – in theory – stay at a constant height above the floor.

Click for animation.

Walking animation.

All of this up-and-down motion happens in conjunction with some back-and-forth motion to create a walking cam. Looking at the picture of the cams in the slots, it’s visible that the outer two cams are the binary y-motion (up and down) cams, while the center is an eccentric disk providing sinusoidal x-motion (back and forth). So as you can imagine, there’s quite a lot of sliding motion going on inside of these things.

Leg and cams

First test batch of waterjetted parts.

A big part of good design, or good anything, is to know your limits. Knowing that I could not make these cams and legs with the necessary precision, nor in the quantity required, I had the nice folks at Big Blue Saw low-taper waterjet them out of 1/2″ UHMW for me. Once they arrived I buffed all the sliding surfaces to get them to a smooth, low friction finish. After a quick test to verify the cam worked as expected, I ordered the rest of the batch.


The last version of Such and Such had a really cool pantograph-type clamping mechanism much like a scissor lift on its side. It was fun, but a pain to deal with the linear motion at either end of the linkages. Sliding joints are a little harder to pull off than a bunch of pinned joints, so I thought I’d like to avoid it altogether. I also wanted this version to have fewer links for the same amount of horizontal travel as it’s a slightly more efficient use of weight. I settled on the following mechanism:

Diagram of clamping mechanism.

Diagram of clamping mechanism with rear link driven by linear actuator.

Looked pretty cool to me. Only 4 links and a great deal of horizontal travel. But little did I realize at the time that there was a fatal flaw in the design… but more on that later. I kept the the linear actuator external to the bot so that each half can be as small as possible, only about as wide as the walking bits. Conveniently, there was a nice little space for the actuator betwen the links in both open and closed positions. I did a little bit of math to find an optimal-ish offset angle (α) for the actuator to drive the rear link at so that the clamping force is mostly constant throughout the mechanism’s whole travel.

Mechanism parameters, after a few iterations.

Mechanism parameters, after a few iterations.

Clamping force as a fraction of actuator force over the course of the mechanism's travel.

Clamping force as a fraction of actuator force over the course of the mechanism’s travel.


Construction commenced on December 1st 2012, just as I finished up my 8mm Projector Tremolo project. I made simple drawings of all the frame members and got to cutting all the lengths of 3/4″ angle and 2″x1″ U-channel that comprise the frame halves.

Angle brackets after the first day's work.

Angle brackets after the first day’s work.

Next, all the frame members were drilled out to accomodate brackets and bearings.

Frame members cut and drilled, ready for assembly.

Frame members cut and drilled, ready for assembly.

After testing on a prototype leg and cam set, I ordered a full batch. One of the most time consuming parts of the project was cutting, drilling, and mounting the 48 little roller brackets onto the legs.

Leg with brackets for rollers.

Leg with brackets for rollers.

Next came the delicate task of stacking the three sets of UHMW cams, legs and spacers on three shafts, and then repeating the process for the other half of the bot. I decided not to lubricate the cams since most references indicated that polished UHMW is sufficiently self-lubricating, and grease may only trap dirt and debris. I drilled some well-oversized holes to allow some play in mounting the self-aligning bearings for the camshafts – since the phase of the cams was of utmost importance to the mechanism, I let the timing belts locate the bearings’ exact position.

Frame and walking bits assembled.

Frame and walking bits assembled.

After another order of waterjetted parts (this time aluminum), I assembled the linear actuator and attached linkage pivot points to the frames.

Linear actuator.

Linear actuator.

Two halves assembled and linear actuator installed.

Two halves assembled and linear actuator installed.

With the frame halves and walking mechanism mostly taken care of and smoothed out, I switched my focus to the clamping mechanism.

Links cut and drilled.

Links cut and drilled.

However, as soon as I laid out the links in front of me, I realized I’d made a grevious mistake. What I failed to realize in the design phase is that the linkage has way too many degrees of freedom. What that means is, I could move that one link back and forth all I want with the linear actuator, but the rest of the mechanism is gonna flop around however it likes and not clamp at all! As a mechanical engineer, this is quite the oversight and really really embarassing. In my mind, I just had assumed for so long that the two halves of the bot stayed parallel to eachother as the mechanism opened and closed. In reality, there was nothing constraining them to this kind of motion. 3 weeks out from the competition I had to come up with a quick fix in the form of some secondary links and a sliding pivot in the center of the whole thing. If these parts look like an afterthought, they were!

Linkage in place, with secondary links.

Linkage in place, with secondary links.

After such an embarassing mistake I found it helpful to walk away from the build for a little and let my mental faculties simmer down a bit. Thankfully all the major hurdles in the build had been crossed by this point and before I even realized it I was ready to install drive motors and wire it up.

Actuator installed, wires run and ready for electronics.

Actuator installed, wires run and ready for electronics.


Done and ready for Motorama!

Done and ready for Motorama!

I even had time to add a neat hinged battery compartment to make charging way easier. Before I even got to the competition, I had considered the build a success: it walked and it clamped. I came up with just about the wackiest idea I could, I built it, and it worked. So now it’s back to cheap, simple robots. Maybe.

Here’s another video – this time with Charles Guan‘s incredible Uberclocker Advance, during which Such and Such spends alot of time off the ground.

(Check out Mike Jeffries’ YouTube channel for basically all the fights from the competition!)

Huge thanks to NERC for putting on great events, Alan Young for his generous help with blown up motors, Josh Frisch for being a patient teammate, my Dad, Michael Jeffries for the video, Hive76, and the entire robotics community for being such a righteous bunch of folks.