Yes — I sat in on a Nixie Tube Class.  Mike Lensman presented.  This class was for members only, I had heard that it was a beta and that Mike was getting the kinks out of it.  I thought the class was top notch and full of information.  Let me recount some of the things I learned.

This is Mike — He looks excited about the subject matter, that made me want to pay attention.

High Voltage

Mike took high voltage seriously.  Even though the students wanted to joke and play around, Mike wouldn’t have it.  That was good, it gave me the sense that High Voltage could cause some serious damage to ones person.  Here are some safety rules and guidelines I took away from the class:

1. You don’t want to be the shortest path to ground
2. If it connects to the wall, you don’t want to mess with it
3. Work unplugged
4. Work with only one hand
5. Don’t wear jewelry
6. Watch for capacitors — Monitor and Televisions  (and monitor tubes, are capacitors!)  these things can stay charged for months
7. Work to a plan  – that is have a design, and know what you are going to do

See the photo?

This is the High Voltage end.  Off to the right the wires go to your normal 120 volt AC outlet.  The thing in the lower right hand corner that looks like a switch, that’s not a switch.  That is a circuit breaker.  That is one of the grand tips I learned.  Work with a circuit breaker, the smallest that you can get by with.  That way if you do manage to draw a high voltage shot, the circuit breaker may throw and save your life.  In the middle of the photo is a transformer.  A transformer will electrically isolate the circuit from the Earth.  The Earth it seems is part of a normal AC circuit and is called ground.  The transformer will isolate that, now the Earth ground will not be the ground in our DC circuit, this makes it harder for us to get a high voltage shock.

Now on to the left of the photo.  Here we see a bridge rectifier, this takes the AC signal, flips half of it, and with the capacitor shown there, gives a fairly steady DC current.  From 120 volts RMS — we can get 160 volts DC.  nice.

So What is a Nixie Tube?

Basically a nixie tube is an “old school LED”.  WHAT?  Well they were used to give a digital readout in an analog word.  Instead of using a meter face, nixie tubes were used to show a value.  They are vacuum tubes.  You put a high voltage current through them, and they glow.  They will glow in the shape of a number from 0 thru 9, depending upon which leads on the tube you run the current through.

There is one anode and many cathodes.  One cathode for each number.  A switch, relay or transistor can be used to complete the circuit.  Now at this point in the lecture Mike mentioned that he didn’t have any slide ready to project so he used the white board.  In my expert opinion, the white board was better than any slides he could have prepared.  he was able to draw the circuits and explain them as he went.  This kept the attention of the class, and also instilled a sense of mastery of the subject.  I got the feeling the class could have continued on for hours, down many detailed sidelines.

Let’s look at the Schematics

So, the big rounded box in the middle represents the vacuum tube, aka nixie tube.  You can see at the top that there is some high voltage coming in.  A resistor is used to limit the current.  We don’t need much current to make the tube glow.  Too much current will light up other numbers in the tube, or will cause a fuzzy appearance or maybe even destroy the tube.  So use a current limiting resistor.

Now which ever of the “number” is shorted to ground will glow.  And t appears that will be the number THREE in the above schematic.

Well, we don’t want to have to manually move a wire from each cathode to ground.  What would be the point of that?  And besides this is high voltage we WOULD get hurt doing that.  So Mike told us about the MPSA42.  This is a transistor that may be used like a switch.  We just connect on of these to each of the cathodes to ground.  YES we do this working according to our plan, with the electricity disconnected following safety rules.

So the collector is connected to the tube, the emitter is connected to ground.  And guess what?  YEP!  Not one of the digits will be on.  That is where the base comes into play.  We can connect the base to 5 volts or ground.  When it is connected to 5 volts the transistor will “turn on” and high voltage current will flow through the nixie tube and illuminate the numeral that it is attached to.  pretty neat.

Here the transistor is put into the circuit.

Microcontroller to the rescue

So we still have to connect wires for each numeral to light up.  Without the transistor we were connecting a high voltage line to ground.  With the transistor the high voltage line is always connected, we just need to connect a low 5 voltage line to the transistor to turn on a numeral.  Still who wants to do that?  Not me.

So we can use a Microcontroller to do this for us.  Mike used an Arduino in class.

Here we see the blue Arduino board.  It has a usb cable leaving out the bottom of the photo.  This cable powers the Arduino and pushes the program to be run into the micro controller We see an orange and a black line going from the Arduino to the white bread board.  The black is ground.  The orange comes from one of the digital output pins on the Arduino.

The orange is connected via a current limiting resistor to the base of the transistor.  The black is connected to the emitter of the transistor.  And finally we get to see an actual nixie tube.

Sadly I didn’t get any photos of the tube when the numerals were illuminated.  So if you want to see that.  Sign up for the class when it is offered again.

Thank you for reading about this class.

I didn’t intend to “reteach” the class.  I wanted to give a quick overview of what you might learn when you take the class.  Mike also went into how to multiplex the cathodes so you can get by with fewer transistors.

Recently, a team comprised of FamiLAB members won the regional round of the International Space Apps Challenge – now they’ve posted their video for the global judging – and it is AWESOME!

Check it out…

I recently got asked to come up with project for Scout Day.  I had never heard of Scout day even though I was in the Cub Scouts and Boy Scouts.  So after a little googling I found that its a mix between a carnival and a Maker Faire.  After watching my son play angry birds I settled on miniature catapults

The first catapult mock up was clunky and was used to determine the arm length, positions of the rubber band holder, and the arm stop point.  Most of this was scrapped in the second prototype, but the locking mechanism and swivel base remain unchanged. These are the small circle in the upper right and the odd square with the [[  shapes inside.

Prototype 1 fully assembled

The next prototype involved cutting away everything not needed and give it smoother lines. Also added a handle so kids could rotate the catapult (yes they could shoot at each other, and did).

Prototype 2 assembled without basket.

After a few more tweaks to the design (7 revisions), I was satisfied that they were working and durable. Although I only planned for 5 in the final design, I cut parts for 6 so I would have a  “spare”.

The pieces fit together snug, and with a little wood glue they were nice and sturdy.

Here is the catapult assembled and painted with the Cub Scout Blue and Gold colors. The only purpose of the gold trim was to hide the assembly slots.  It also kept the axel for the armature in place.

Catapult arms did not survive their first test.  I glued the ‘basket’ to the arm after I had painted the individual parts so the first test shot sent the basket flying.  Two small wood screws fixed that issue.

Here is the base for holding the catapults fully assembled.

In this shot you can also see another assembly, this is for the target wall.  I figure a wall with holes in it would be simple and…boring.  Creating the door mechanism was a pretty straightforward.  I used the same .25 inch dowel for the door ‘hinge’ as I did for the axel in the catapults.

On to the target wall.  I was originally going to paint this as a castle and have  the odd shaped ‘holes’ knocked out of the brickwork.  After some cutting I decided to mix it up.

Add in the cut outs and the hinge mechanism with lots of wood glue.  I wasn’t sure how this would take the abuse, so I covered the contact points in glue.   It looked like a mess but held together no worries.

A quick test to measure the range of the catapults,  worked okay after doubling up the rubber bands.

Blue targets painted, but I had no string for the reset mechanism.   While I was out at Skycraft Pat and Tom put on an extra coat of paint. Thanks Guys!!

Here is the completed target wall ready to go.  With a pull to the strings hanging out the side, you could reset the top row or the bottom row.

Off to the Scout Show where Pack 42 assails the wall with bean bags.  This was the slowest period of the day, we usually had kids waiting in line. Not 15 minutes into it the first catapult broke.  The basket snapped off, but after plugging in the spare catapult everything ran for the remainder of the day with no issue.  Of course we did run through half a bag of rubber bands 

Here you can see the magnets that were used to keep the panels in place.  There is a Magnet on the target wall and a small metal washer on the door.

Thanks goes out to the Familab members that offered suggestions, help, and testing.

All the files are uploaded to Thingiverse!!

http://www.thingiverse.com/thing:81846?

Build and Enjoy,
Simply7

FamiLAB members Mike, Jamie, Jessica, and Pat smile for the camera after they won the Kennedy Space Center regional competition as part of the International Space Apps Challenge.

From the Kennedy Space Center website article-

“Astronauts traveling to an asteroid near the moon, to Mars or other near-Earth locations may have a stop off point to gather fresh fruits and vegetables to sustain them during their space voyage.

A design concept for a space-based greenhouse called the Deployable Independent Greenhouse System, or DIGS, which could be stationed near the moon, was selected as the top winner of the 2013 International Space Apps Challenge (ISAC) from Kennedy Space Center in Florida. It also received “People’s Choice” recognition. The event was part of the worldwide ISAC on April 20 and 21.

The event, held at the Center for Space Education at Kennedy’s visitor complex, brought NASA engineers and scientists together with 21 professionals and students from a variety of non-NASA backgrounds to solve challenges relevant to improving life on Earth and in space. Kennedy was the first-ever NASA center to host the challenge.

Worldwide, more than 9,000 people and 484 organizations came together in 83 cities across 44 countries, as well as online, to participate. When the event came to an end on Sunday afternoon, there were more than 750 solutions submitted for 58 challenges.

Kennedy’s winning presentation in the Deployable Greenhouse challenge came from a group of people with different backgrounds and interests in space exploration: Jamie Szafran, a developer in Launch Control Systems Project in the Ground Systems Development and Operation Program; Jessica King, an employee from Valencia College; Pat Starace, an animator and mobile application developer from Orlando; and Mike King, an audiovisual design engineer from Orlando, brainstormed and collaborated with others online and a Kennedy subject-matter expert on the greenhouse design. They also analyzed how it would be deployed into space before presenting their concept to a panel of three judges.”

 

If you are a space geek, make sure to check out the DIGS project files on the Space Apps website, where you can find awesome CAD drawings like this one…

Oh yeah, we’re in…

Learn more about the 2013 Red Bull Creation contest – you have until May 5th to build your awesomeness with the Turbull Encabulator, so get to it!

Many of our members & friends will be at the Security B-Sides conference this weekend. If you haven’t been to a Security B-Sides event, it is ”a community driven event seeking to bring together anyone with a passion for making, breaking or protecting. We welcome newbies and experts and anyone in between. Even if you don’t work in information security you will be sure to find topics of interest.”

Learn more about the event at the B-sides Orlando website - and make sure you check out the awesome electronic badges!

Worked on the Haas this weekend with some goals in mind.

1) Fix the switch
2) Establish Serial communication
3) Receive serial data from mill
4) Send serial data to mill
5) Execute simple gcode
6) After all the above is completed – start cleaning more

1) First arriving at the lab, I couldn’t turn the switch on the back of the Haas off so I could not open the door. It took three of us (Thanks Ted and Scott) to finally get the door opened. Found the rod that activates the breaker switch was pretty twisted up. Took it off heated it up and peined it back to shape. Re-installed the shaft and found the breaker switch tab was broken off. This was a whole story, but needless to say it’s fixed and that’s awesome.

Second round of heating up the switch shaft, it’s almost straight here. Just a little more peining and it’ll be great again.

The switch all finished.

2) Establishing serial connection was needed to be done so we can test the machine further. Major propps go to , Ted, Mike B, Tom for their help. This was my third attempt at serial connection to the Haas, and I wasn’t giving up till it was a success. I tried many configurations and nothing seemed to work. I finally put an oscilliscope on the serial out of the haas to see if the signal went high when a send command was issued. This technique worked and I proceeded with this method all the way down the chain (db25>9 adapter, two db9 cables, usb>serial adapter).

3) After the above was completed, it was time again to test sending data from the haas. Nothing worked. RRRGGGHH. I did more net searches and found yet another pin configuration to try. I reversed pins 2>3 3>2 with a null modem adapter to 2>2 3>3 and it WORKED!!!! When the data started  streaming into my serial sniffer, I was like Tom Hanks in the movie Cast-Away, jumping up and down shouting “FIRE”, “I Made Fire!”

4) Sending data to the Haas is another small feat as the Haas format is very specific in what the machine considers good code. When receiving unusable code the haas doesn’t display an error, it just sits there and does nothing. This made troubleshooting a matter of hit or miss. I tried to resend the gcode data the haas sent to the pc, back to the haas, and it didn’t even like it’s own code. After some more net searches I found a few things to look for, tweaked my test gcode and the haas received it and logged it into it’s program list. WOOT!

5) I deleted any motor and spindle commands from the test gcode. (we don’t have a toolholder and the air wasn’t hooked up). It’s a simple 2.5 axis circle cut.

FamiLAB’s Haas VF-1 starting to come to life.

This is so AWESOME!!! We can further test, clean and reassemble the Haas. Soon we’ll be cutting Aluminum 3D Printer frames, rocket parts, and what whatever you could imagine.

6) After I came down from the initial high of seeing the Haas moving by gcode program, it was back onto cleaning. I brought in some parts cleaner (mineral spirits). Daniel, thanks for the gloves because the metal chips are real sharp, and the shower curtain to keep the gunk off the machine.

Tool-Changer before.

Tool-Changer shroud after.

That about wraps it up for now, We could use some help on cleaning and re-assembly. If you could help out please let me know, and thanks in advance.

FamiLAB is now a 501(c)(3) Public Charity, which means that your donations (including membership fees) may be tax-deductible*.

This is an exciting step for FamiLAB as we continue to grow and work to improve the communities around us.

A copy of the IRS exemption determination letter is located here: http://goo.gl/xHzR9 - Please note that this exempt status is as of September 20, 2010, our original date of incorporation.

*Please consult your tax professional for more information.

For some time, we’ve wanted to make a FamiLAB kit that could be used for soldering classes, and then extended by the students as they moved into learning microcontrollers or other topics.

As with most things in life – it took someone with some passion and drive to make it finally happen – kudos to Mike Bakula for prototyping a kit, getting input from the community, and then producing our first kit!

This kit uses an ATTINY to light up the LEDs on the end, and when waved back & forth or spun, you can read a word of text!  Mike built the first PCB during the April Open House and then passed it around for everyone to enjoy  We still need to do a production run, order all the parts to populate the boards, and design a new class using the boards – stay tuned!

Here’s the breadboard version for testing…

The ATTINY is programmed using the Arduino ISP, in this case with a ZIF socket on a protoshield. Adafruit has a kit to build this kind of shield if you want to try this at home…

The PCB design after some community input…

Here’s the first PCB from BatchPCB before any components were added…we had a silkscreen error, so no FamiLAB logo on this board – but it will be there on the production run!

I wanted to share a project I did for my booth at the Orlando Mini Maker Faire. I wanted a set of Tiki’s as a backdrop to my singing pineapple and singing toucan. I could have ordered something like this, but they would have never gotten here it in time, and the thought of making my own was exciting.

Deciding what they could painted on was challenging as they had to be big enough to be seen at the faire and portable enough to fit in my small car. I decided that ‘Science Display Board” was the way to go. Display Boards  are 36 x 48″ tri-fold, and if I stacked one on top of another I’d have a whopping 4′ wide by 6′ high… GREAT!

Science Display Board can be found at Staples, Office Depot and any office supply store. $7.99 each and you can find multi packs for much cheaper.
http://www.officedepot.com/a/products/434415/Office-Depot-Brand-80percent-Recycled-Tri/

I sketched out the design, and started blocking in the colors in acrylic. Light brown was the first color I painted.
The boards were stuck to the wall with the removable 3m stick tape used to hand pictures.

Next, the yellow was painted.

The next color was yellow ocre, and a golden yellow.

Magenta and blue were painted next. I like the corrugated display board. When it get’s a little wet, you can see the corrugated texture coming through the paint.

Red was next and this is really starting to pop.

Washing in some darker brown for the background.

And the same to the other one.

Lightly add some shadows.

Black paint for the eyes. Little problem here. The acrylic paint had a slight sheen from some angles and it was runing the effect of a dark and ominous tiki eye.

*** CORN STARCH TIP ***
If you ever need to dull down paint to make it egshell, semi-gloss or even flat, just add some “CORN STARCH”. Test it out.
first, and I’m sure you’ll be amazed. This was a great tip I had gotten from my dad.

Next was a rather fun part, doing the black detail work. I wanted a rough textured look, and markers or a paint brush wasn’t going to give me the look I was going after. I had some “Oil Paint Sticks” lying around and gave them a try. The oil stick against the corrugated board gave me exactly what I was going for. Now, I just hoped I had enough to finish the job.

One Tiki is finished with the “Oil Stick” and I’m really happy how they’re coming out. Now onto the other.

Both Tiki’s are finished! YEAH!!!

And here they are at The First Orlando Mini Maker Faire.

If you have any questions on parts I might have forgotten… just ask.

I hope you’ve enjoyed reading this.

Pat Starace