Help build a massive Rosie the Riveter sculpture, and learn about 3D printing

On Monday, May 7th, Nova Labs kicked off a two-part event to help print out a 6-foot-tall statue of Rosie the Riveter. Calling all woman makers to come out next Monday, 5/14, to help print a part of Rosie!

You can sign up for a part here:
You’ll need a Google account so they can track who has what part 🙂

If you need help printing, we’ll have printers and helpers on hand Monday, May 14, 2018 from 7-9pm; we’ll also have a rack of printers dedicated to the project at Nova Labs in the Orange Bay.

You can mail in the parts yourself, or leave them in the Rosie Box and we’ll mail a batch in. Please send an email with your part # to – he’ll send you the tracking number when your batch ships.

Sign up here for next Monday:


ed note: As of 5/8/18 at 2:15pm, Paul and the Nova Labs community is at the top of the leaderboard for number of parts printed!

All the Nova Labs parts are being tracked in this Google Doc.

Marvo the Magnificent

Ed. Note: Blog post contributed by [Nick Carter], Maker, retired electrical engineer, who is active in the Robotics Meetup, DIYBio Meetup, Artificial Intelligence Meetup, and pitches in with STEM programs whenever needed.

I had wanted to play with voice recognition for a long time, ever since the group I was in at ITT Research Center, many years ago, did some telephony voice related applications – a dial by voice system and an automatic switchboard attendant (U.S. patent 4608460 – I may be partly to blame for the ”Press 1 for..” menus  J). I have also held a long interest in robots and have an interest in making machines act somewhat human-like in responses, so when I saw the EasyVR VR-3 speech recognition shield for the Arduino I decided this was my chance.

The shield was around $50 (sadly, now out of stock?), and provides a reasonable functionality and a very nice graphical programming interface for the Arduino.  The VR-3 needed some soldering assembly but it was not too tough, basically soldering headers and recognition board to shield board. 

Initially to teMarvo1st it I made a “magic 8 ball” toy with only speaker dependent trained commands including some holiday season fortunes and I decided it would be a wizard looking into his crystal ball, hence Marvo was born.  One time I showed it at Nova Labs, one small girl tried it and asked it if she was going to get a puppy for Christmas, and Marvo told her yes – and I think she believed him. I am probably in big trouble. With the voice operated electronics these days, it is going to be difficult getting kids who grow up with them to distinguish real responses from toy responses (and true from untrue) – especially the more they act humanlike.

Later I refined Marvo, for a maker fair in Haymarket giving him some LEDs and an actual ball (bouncy superball with embedded stars), backlit with LED. I also added a second set of commands using the “robot” speaker inMarvo2dependent set. And added responses to try to get kids engaged and try the various commands.  You can see a video here which also shows the robot training the user (me).

You can see the difficulty in recognition sometimes and how it has to train the user to speak properly for good response.  It did not really like my English accent. I also found that it is very sensitive to external noise and in the Haymarket fair environment it really had a tough time although once I moved to a quieter spot and tweaked some recognition parameters it did a bit better.

For a practical application, this would work fine in a quiet home environment and for controlling things for people with disabilities who could still talk well.

 To start, you create a speaker dependent trigger word that starts it into the program. I put “Hey, Marvo”. The speaker independent trigger is “Robot”. Each speaker dependent word/phrase has to be trained 2 times and can be tested for recognition accuracy within groups of words.Marvo3

To make the speaker dependent recognition more robust you can add additional entries in the word lists what are the same phrase spoken by different voices. The program may flag them as duplicates if the recognition template is the same.


It has a built in speaker independent Robot oriented set of command groups and you can make your own groups of speaker dependent commands that you can train to your own or multiple voices.  The key here is to only include in command groups words or phrases that are readily distinguishable.  There is 1 trigger word to get its attention and then you can use the Arduino program to choose which group of words to listen for and what actions to take.

The additional “robot” command groups are movement directions, “up”, “down” etc. and the numbers zero through nine.

It will store up to 32 voice response messages that you can record but unfortunately not save off, once you have recorded them. The program itself and the recognition templates can be stored off for reuse.

You can make quite a sophisticated system with this; it has 16 word groups that you can train. There is also a tool that you can buy for ~ $200 that will convert the speaker dependent into speaker independent. If one was using this commercially it could be worthwhile but too much for me.

Once you have trained the commands you want, the EasyVR Commander program will generate an Arduino program template file with all the setup commands and the voice recognition menus you made set up as switch/case statements so that you can add the programmed actions to them. This saves a lot of work and figuring out. If you really want, the detail level commands are provided to talk to the board.

You can also  have it store sounds from wav files. It comes with a “beep”, and there is also a feature for generating “lipsync” parameters from the recordings as they play, for animatronic mouth animation.

All in all, this is fairly easy to use and works well enough to be entertaining – well, I had fun with it.

DIYBio: Control a shark with your mind

Ed. Note: Blog post contributed by [Nick Carter], Maker, retired electrical engineer, who is active in the Robotics Meetup, DIYBio Meetup, Artificial Intelligence Meetup, and pitches in with STEM programs whenever needed.

Blog Contributed by Nick Carter, Maker, retired electrical engineer, who is active in the Robotics Meetup, DIYBio Meetup, Artificial Intelligence Meetup, and pitches in with STEM programs whenever needed.

The mind-controlled shark in action – view a video of it ‘swimming’ by clicking here.


While participating in the Nova Labs DIYBio meetings, I became interested in brainwave sensors and how brain activity can be applied. After some research the cheapest way to get into this seemed to be to buy a MindFlex game online. I got the MindFlex Dual because it has 2 headset/pickups. The EEG part is developed by Neurosky, who also sell their EEG amplifier/processing board for researchers. Initially I was just interested in looking at the game and the brainwaves and implemented a Bluetooth headset interface and could use an online program for Processing on the PC to display the filtered energy levels while playing the game.

After more research I came across a video of Open BCI developers controlling an air swimming shark – I decided to try that myself using the MindFlex game sensor instead. One major difference is that they used 5 players to control up/down/right/left and forward controls. I could only muster one or 2 inputs for control using the MindFlex.

After I got the game I found it was a great hit with both the DIYBio group and also the Saturday morning Maker Fun Project club (where I was volunteering) who asked me to make it control the LEGO Mindstorms EV3 robots.

I used that project as the proof of concept for the Arduino/remote control hacking before actually getting the shark. I implemented the hack into the remote controller and made a chatty Arduino game that let players interact with the EV3 from Putty on the PC using W, A, S, D keys. I have not yet integrated this with the MindFlex but the same ideas apply.

Breadboard interface between arduino and game device

Breadboard interface between Arduino and game device

Then I got a shark and hacked the controller; I used a small relay board I developed after taking the Nova Labs Eagle CAD course to control the remote’s switches, electrically isolating the Arduino and the Remote control.

Rather than taking the MindFlex headset signals and interfacing them with cable or Bluetooth directly to an Arduino to do my own signal processing, I decided to use the MindFlex game base processing and use the Brain signal intensity signals driving the colored LEDs on the game. I found these signals were Pulse Width modulated to vary the LED intensity so I had to smooth them to make an analog level for the Arduino to monitor and set thresholds in my program to decide if the LED was on or off.

Although I wired out the 2 sets of LEDs for both player headsets, I only implemented the drive, leaving the climb/dive manual control for later. There are Red, Orange and Green LEDs lit for 3 levels of detected Brainwave intensity. To get the ability to turn as well as go forwards I used the Green to go forwards and the Orange to turn, alternating left and right when returning to Orange after Green.

Testing the shark tail

Testing the shark tail

I tested this with the shark tail wagging and interface electronics off the shark leaving the shark assembly and inflation for later. Inflation requires a fair amount of helium, I was quoted around $15 so I did not want to do this until really ready, plus an anchored tail was easier to handle.

Finally I inflated and assembled the shark, using helium from a “Party Balloon Kit”, and brought it to Nova Labs’ July 10 DIYBio meeting.

It is not as controllable as the Open BCI version but still fun to drive (although as you will see in the video, some manual intervention is needed) and I had a lot of fun implementing it.

For more details, there’s a slide deck on the Nova Labs Meetup “file” area, or by clicking here.

How to build a working Claw Machine Halloween Costume

Ed. note: Nova Labs contributor [Alexander Romero] built this Claw Machine Halloween Costume for his son last year and wrote about it for his blog. This article re-posted with permission.

If you want to see or show off your Halloween creations, join us at Nova Labs on Tuesday, September 27, 2016 at 7pm. Details on our Meetup page.

Why a claw machine

My son loves claw machines, so when I casually asked if he’d be interested in being one for Halloween his eyes lit up and he jumped up and down proclaiming YES, YES, YES!!

Thus the two of us set out to create one for Halloween. This blog details how we built a working claw machine Halloween costume. You can see the finished product in this video.



The build

claw_machine_02First thing we did was to acquire two U-haul moving boxes that approximated the body of the machine. A top one for the main part, and a bottom one for the longer body.

Then I cut out the centers of each of three sides from the top part of the body, which is where the main part of the machine would be. I left about a 4″ border around the sides. Actually I left an 8″ border, but then folded it back at 4″ to make is stronger. I basically doubled up the border for strength.

Now the next thing to figure out was how to connect the two boxes. I could have glued them, but I didn’t love that idea, because I wanted to be able to take the two pieces apart. Also, I wasn’t sure if gluing it would be strong enough. So I cut out four pieces of thin plywood, glued them to the top box, and the bottom box, then I drilled holes and secured them with washers, nuts and bolts. That proved sufficiently strong, but also added weight. I also cut out a circular hole for his head, and some holes on the side for his arms.

The next step was easy, but took a while. I spray painted the whole thing red on the outside, and white on the inside for the inside parts one could see. If I did it again, I would probably just cover the outside with red wrapping paper. The spray paint took way too long. On the back of the top part I used a sparkle wrapping paper I picked up at Michaels. You can see it in the picture below.

claw_machine_03After this, it was now time to figure out how to make a working claw. For this I used a combination of Legos, a salvaged electric motor from a Nerf gun, and a tin can. First I built the assembly that I would tie the string to that would raise and lower the claw. You can see I made the spool that would wrap the string a wider diameter, so it wouldn’t take so long for the claw to go up and down.

claw_machine_04I mounted this to the ceiling of the claw machine. To do this I used a similar idea to how I connected the two boxes. I used plywood as the backing so that I could have a secure foundation to mount the assembly. This meant that I had plywood and screws popping out of the top of the claw machine. You can see how I covered those up with a third low profile box on the top of the machine in the finished product picture at the top.

claw_machine_05For the controls of the machine, I used an old Lego controller. I mounted this to the underside of a control panel made of plywood that was also painted red.

claw_machine_06You can see the control panel below. It has a joystick to control the up and down.

claw_machine_07It also includes two other items. On the front right is an on / off toggle switch that controlled the back lighting. For the back lighting I used a strip of LED’s powered by AA batteries and wired it to the on / off switch which I got from Amazon.

claw_machine_08On the side of the control panel there was a pressure kill switch. It had to be depressed for the claw to go up or down. I put this in because there is no auto stop for the up and down motion of the claw. Meaning, once the claw was fully retracted, it could get stuck and potentially break the assembly that retracts it. So the pressure switch gives the person wearing the costumer the ability to regulate the use of the claw and stop it if it is getting too close to the top.

Because I wanted the ability to disconnect the top and the bottom of the costume, I got a trailer harness connector from the auto supply store, and used this as the connector between the control panel, and the rest of the electronics. There were lots of ways to connect these components, but I found this harness to be the cheapest convenient connector.

claw_machine_09claw_machine_10For the claw, I used wire snips to cut triangles in a tin can, then used those triangles screwed to another tin can to form the claw.

My wife helped find some other decorations, like the “Win Me” at the top, as well as the prize door, etc. I printed these off on a color printer then used adhesive spray to affix them to the costume.

To say this costume was a hit is an understatement! It was admired by everyone who saw it, from kids to adults. See the video at the top of this blog for the mob of kids that wanted to check it out when my son wore it to the Halloween party.

claw_machine_11Because the costume was heavy, I cut an old foam pillow and then attached it using string to the undersides of the costume where it would rest on my son’s shoulders. This helped, but it was still a pretty heavy costume for an eight year old. You can see below where I positioned and secured the foam pillows.

Then with the help of my son, we filled up the inside of the claw costume with stuffed animals. To secure these from jostling around while the costume was being worn, we used fishing line and tied it to the bottom of the machine.

Things I would have done differently:

  1. Use red wrapping paper instead of spray paint. The spray paint just took forever. Several coats and more expensive.
  2. Just glue the two boxes together. I’ve never taken the two pieces apart, so in hindsight, I didn’t need to have them disconnect, which would have saved weight.
  3. Skip the connector harness. As discussed in point 2, I never disconnected the two pieces, so there was no need for this.
  4. Used lighter battery assembly. With some more time I probably could have used the same batteries to power both the motor and the lights. This would have saved weight also.

Lil Dragon v-tail quadcopter – developed at Nova Labs

Building a 250 quad racer from scratch

With 250 quad racing becoming more and more popular and local racing events starting to pop-up, Nova Labs member Fred Briggs decided to give it a try. Being a Maker, he didn’t want to buy the same ole’ frame that everyone else had so building from scratch seemed like the obvious way to go. Wanting something a little unique, Fred’s main goals were to develop something that looks cool, flies well, and is inexpensive to build. To meet those goals he quickly decided that Mongo, Nova Labs’ 100 watt laser cutter was a good option for cutting the frame. Having also recently finished building a 3D printer in Nova Labs Build Group 8, having some 3D printed parts seemed logical and a good use for the new tool. Fred also reported always loving the look of the V-tail quads so he settled on that design.

The design

250vtail2With that design criteria in mind the next step was CAD. Fred decided to use this project to learn OnShape which is becoming quite popular at Nova Labs. There were some frustrating moments with the CAD but the support of the OnShape User Group at Nova Labs helped through this portion. Once it looked cool in CAD it was time to make something!

20160131_135315Fred was able to get DXF files from OnShape and start to laser cut some wood frames which are simply hot glued together. This went through several iterations and this pic is of an early design. You can see the tabs that allow all the parts to key into place for quick and accurate assembly.

20160226_081607Then the “V” for the rear motors got 3D printed. While initially concerned that it might not be strong enough, some stress testing (i.e. crashing) has proven that the design is plenty strong and Fred hasn’t broken one yet.

Finishing touches

20160206_112645The frame was painted with a rattle can and then put together. To really make it look cool it needed a thermoformed shell and this was probably the trickiest part of the entire build. It required a CNC routed mold which was made from old 2X4’s that were glued together. After a little sanding and then some paint it came out really well.

Painted_shellOn to the thermoformer!!

20160219_11465720160219_115126Here is some video of the actual thermoforming process:

After trimming it fit great! The electronics are a very tight fit but it does fit.

20160219_21495220160219_220932Here is the finished product with a painted shell. Fred is really happy with the results and it meets all of his design criteria. It flies fantastic, it builds very easily and it gets attention every time it comes out at the field.

After looking at it Fred has decided to call it the Lil Dragon, and he hopes to run classes using the design at Nova Labs.

The final specs on it are 1806, 2300kv motors with 5” carbon props, 2200mah 3S battery and Naze32 flight controller. It gets about 12 minutes of hover and it is shockingly stable.

For more information please contact Fred directly at, or be sure to check out the Open Aeris booth at the NoVa Mini Maker Faire, Sunday, March 13, 2016

Is Nova Labs Open?

Visible in the side USB connector is a special LED dongle which indicates Nova Labs status: red for Closed, green for Open.

Visible in the side is a special LED dongle which indicates Nova Labs status: red is closed, green is open.

Need to get stuff done at Nova Labs but don’t yet have a key? There are some predictable hours when the space can be found open. The rest of the time there’s a chance a member is there but you had to monitor the website status indicator to see it toggle to “Open”. Well, as part of Ted’s Nova Labs Environment initiative he’s developed a new way to keep tabs on the Open/Closed status, an LED indicator on your computer.

At Nova Labs the light switch inside the front door currently toggles the website status indicator. Now Ted has also tied the switch to a USB dongle called Blink(1). If you own one and it’s properly set up then when the space changes status your LED will grow for two minutes: red for closed and green for open. It’s a wonderful tool if you happen to own a Blink(1) but a very cool idea regardless.

It’s these kind of hardware innovations that keep Nova Labs a fascinating place.

Click here to see the Blink(1) in action.

When a cool idea takes flight.

Our system for indicating whether we’re Open or Closed just keeps getting more and more cool.

Bob and Ted have been busy again. While developing the upcoming Laser 102 course, Bob collaborated with Ted to build an enclosure for the Nova-Labs Twitter Switch. After determining proper dimensions he used the Box Maker extension for Inkscape which did all the grunt-work by generating information needed to send to the Laser cutter. Bob found that paint stripper worked great as acrylic glue. In fine Maker collaborative fashion, Ted finished up by improving faceplate legibility and installing the wiring and electronics. It’s all open-sourced and checked in to  Nova-Labs github as well. Check it out …
Continue reading

Adding door status to Twitter

Since the dawn of time, man dreamed of a way to see if Nova Labs was open from anywhere in the world. That dream became reality on August 4, 2012 with the completion of our Open/Close Status Switch.

Now, a new era is upon us. One where we tweet every detail in our meager lives. And so, we have welcomed this era with open arms and now present …

The Nova Labs Open/Close Status Switch Twitter Integration!

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Layering Up from 2D to 3D

Layered laser-cut wood builds a 3D object.

The idea of going from a 3D model to a layered object was intriguing to Leon and me. Knowing that Autodesk’s 123 Make was supposed to simplify the process, we chose this free software as our tool. Choosing a 3D model from the Community Gallery we proceeded through the workflow. The type of model we wanted was Stacked Slices and we wanted it scaled to fit on four pieces of 24″x12″ plywood, quarter inch. After saving as EPS files we imported them to Corel to convert to DXF and from there imported to LaserCut. Now it was a simple matter of stacking and gluing the resulting pieces together.

More details and pictures are after the link. Continue reading

Building On Others’ Successes

Justin’s final touch to this chain of collaboration was burning the surface with the Nova Labs logo (which he was instrumental in having designed).

This beautiful project was only possible because of people building on prior successes.

Leon calibrated the mirrors of the laser to get it back to where it would cut an even depth across the entire surface, a key prerequisite for this project to be possible. Richard unearthed a beautiful lower layer of red wood in underlayment plywood we had in stock and documented the cutting requirements (for the record: speed 16, power 100). Nikolai came along with the ambition to create this beautiful hinged box which as you can see below, turned out fantastic. Justin was Nikolai’s collaborator and took it the last step to produce his version of the box which you see above.

Singlehandedly none of us could have done this; together we managed a lot! Continue reading