Category Archives: STEM

Holiday Light String Theory

Mini holiday incandescent light experimentation.
Mini holiday incandescent light experimentation.

Raising questions and seeking answers can be great learning. When given a trash bag full incandescent holiday mini-lights last year, it raised the question “when one bulb burns out the string stays lit, but why do they all go out when you remove it?” That led to a lot of learning about holiday light strings and the bulbs they use, more than can be covered in this blog post!

Resistance is not futile, it's a feature of circuits.
Resistance is not futile, it’s a feature in circuits.

And resulted in the topics for the last 2 months at  the Castlemakers Kids meetings. We started with simple electrical circuit diagrams, schematic components, and voltage/resistance in November. With a volt-ohm meter we were troubleshooting incandescent light strings pretty quickly. By December’s meeting we got into diodes and LED’s, along with Ohm’s law, to make our own LED lights for packages. And learned why lithium batteries can power an LED, but alkaline batteries can burn them out!

Removing piezo from candle lighter.
Removing piezo sparker from candle lighter.

It’s safe to say everyone there learned something, including the adults. Few of the adults for example had heard of anti-fuse’s, one of the features of those small incandescent bulbs that let them burn out yet still keep the rest of the string lit. Who would have guessed that the piezo sparker from a butane candle lighter or gas grill could restore a burned out light string to identify the bad bulb? Too much to cover here, I’ll link to a longer blog post after the holidays detailing some of the experiments and what we found. In January’s meeting we’ll be continuing experimenting with LED’s and components – join us!


Girl Scouts / Makevention

Central Indiana girl scouts learning about electronics & Arduinos.
Central Indiana girl scouts learning about electronics & coding.

This last Saturday we had 2 events going on in 2 different cities, a bit of a landmark for Castlemakers. In Greencastle we had our first STEAM class for the Girl Scouts of Central Indiana. 15 girl scouts and parents from Indianapolis learned about sensors and coding using Circuit Playground Arduino based boards.

2nd Floor Main lobby of Makevention, but a lot more in other rooms and first floor.
2nd Floor Main lobby of Makevention, but a lot more in other rooms and first floor.

At the same time, in Bloomington, we had a booth at Makevention, our 2nd year there.  Makevention is a little harder to describe. If you’ve ever been to a Maker Faire that’s close, especially this year since they added workshops and presentations. Makevention is a celebration of the Maker Movement, you can learn about all kinds of DIY/making – from robotics to soap to swords/knifes to lock picking to…

Makevention Makerspace panel which included Castlemakers.
Makevention Makerspace panel including Castlemakers.

At our booth we had some of the PuttCode robots which we used on the CoderDojo mini-golf hole, although several other holes from previous Putt Putnam County events were there also. The other booths were also interesting, it’s a great event for seeing what other groups in the area are doing and making. It’s usually the last Saturday in August and definitely worth attending.


Indiana VEX Robotics Championship

Indiana VEX Robotics Championship on 3/10/18
Indiana VEX Robotics Championship on 3/10/18 at Lucas Oil Stadium.

If you missed the Indiana Vex Robotics State Championship in Indianapolis last Saturday, you missed a great event. This was the first time it’s been held at Lucas Oil Stadium and despite stadium size with over 300 teams participating on 6 stages it seemed like the right choice!

One of the middle schools competing in the competition.
One of the middle schools competing in the competition.

Indianapolis has hosted VEX robotics competitions for at least 6 years – an initiative that came out of the mayor’s Office of Education Innovation. Each year it’s grown and with Techpoint Foundation for Youth’s (TPF4Y) statewide elementary school initiative, they became the host for 2018 event which combined 3 separate events (elementary, middle school, & high school) in 2017.

With over 900 teams in Indiana, I was unable to find anyone that made it to the event from our area. Should Castlemakers help organize a local event to encourage more teams? Comment or send us an email ( if you think we should!

It’s Not Rocket Science

First stage of the model rocket that Nick launched in the fall of 2016.
First stage of the model rocket that Nick launched in the fall of 2016.

If you walked by the Makerspace this summer and looked in the window, you may have noticed a very large model rocket. It was the first stage of a creation that Nick Adams, who taught our ‘build a model rocket’ class, built last year and launched. Several people have stuck their head in since it left and asked us where the rocket went. The short answer is he prepping it for an even higher/faster launch this Labor Day weekend in Kansas.

Earlier this year Nick asked if we could make something that would plug the air intake holes, the kind of project we love! When you go supersonic a flat surfaces creates even more turbulence, so for his upcoming flight he wanted a more streamlined version. Plugging 4 intake holes on the side of the rocket would help.

Different versions of the intake plugs.
Different versions of the intake plugs.

We initially fabricated a plug out of foam, using a hot wire cutter at the Makerspace, then scanned the piece so it could be 3D printed. Creating the styrofoam piece was easy, scanning… well the Makerbot Replicator we have wasn’t quite up to the task initially. Learned that covering the foam with masking tape helps (the foam color and irregular surface created problems), but it was still less than a satisfactory design.

Nick's QCC rockets assembled, the one on the left has black intake plugs installed.
Nick’s QCC rockets assembled, the one on the left has black intake plugs installed.

Then one of our younger makers, Ephraim, helped by creating by creating a quick model in Autodesk’s Inventor. That design came closer, but we missed measuring a few key dimensions like the chamfer where the plug goes into the rocket. We finally ended up redrawing with Fusion 360, which turned out to be the best solution. Although the program has a steep learning curve, it allowed us to make several more design changes quickly & easily to get the 4 pieces printed out last month.

This weekend Nick’s letting Castlemakers take the rocket to show off at Makevention in Bloomington, Indiana – an annual celebration of making things. Located at the Monroe County Convention Center, it’s open to the public and a great event! Stop by and see the assembled 12.5 foot tall rocket and also stay tuned to Nick’s YouTube channel. I’m sure he’ll have a video of the launch posted not long after the launch on August 30th!

Weed Whacker Teardown

Weed-Whacker-Engine-Teardown-IMG_1108As Castlemakers moves from a youth oriented makergroup to an all ages Makerspace, we’re not neglecting our roots – offering kids interesting hands-on STEAM activities. Last month, for on one of our ‘un-making’ events, we used weed whackers to expose kids to internal combustion engines. It seems like small 2-cycle engines are a throw-away commodity anymore, so after collecting 8-10 weed whackers (and one lawnmower engine) we had everyone tear them apart to see what’s inside.

Tear down days are always popular, and surprisingly the girls outnumbered the boys for this one. With everyone being warned in advance to wear old clothes we threw down several pieces of plywood and cardboard out back, put a bunch of tools out to help, then let them go at it with some occasional supervision & suggestions.

Doug points out the differences between 4 and 2 cycle engines.
Doug points out the differences between 4 and 2 cycle engines.

These single cylinder engines seem to be the perfect size for kids. We began by removing the pulley and clutch off the engine. After explaining how the piston pulls fuel into the cylinder, you can explain how an engine is a controlled fuel explosion. Centrifugal clutches & carburetors were another whole discussion. After piston removal everyone seemed fascinated by how the crankshaft/rod converts the linear piston motion into rotation. A few of the piston/rod/crankshaft mechanisms were saved (although several went home), it’s a good tie into the paper mechatronics we did last year.

Weed-Whacker-Engine-Teardown-IMG_1100Special thanks to Doug Salter, a 25+ year mechanic at Ryder Truck, who donated at least half of the weed whackers and also helped by coaching the kids on disassembly and how the parts inside worked. And another nod to Jerry Hecko, our makerspace automotive repair shop neighbor, who gave us the 4 cycle lawnmower engine for comparison and often has the right tool when we don’t have one.

CoderDojo Growth

Maggie Cline & Courtney Lambert from TF4Y give Brian Howard & Chris Hebb new Dell Chromebooks for Castlemakers.
Maggie Cline & Courtney Lambert from TPF4Y give Castlemakers’ Brian Howard & Chris Hebb new Dell Chromebooks.

We’ve had so much going on lately that blog posting fell off the list. But with so much recent news to tell, we’ll start with a few shorter posts on events and recently made items that folks stopping by the Makerspace have expressed interest in.

One of the most exciting things – we received 10 new Chromebooks from the Techpoint Foundation for Youth. As our monthly CoderDojo has grown, we’ve been looking for ways to have more computers available for kids that aren’t able to bring a laptop to learn more about coding at the meetings. This wonderful gift allows us to have pre-configured Chromebooks for kids to use.

Saturday July 1st from 1-4 pm will be our next monthly CoderDojo meeting of the free coding club for youth ages 7-17. We’ll have programmers there to help, or if you’d like to help the kids learning programming please stop by also!

And if you like coding, the inaugural CoderDojo Indiana Hackathon will be in Indianapolis Saturday July 22nd from 9:30-4:30 pm. Anyone can enter & we’ve already got one local team entry going.

What is Castlemakers?

Hunter tries the Holographic Prism he just built with an animated jellyfish. The prism was made from a CD case and a laser cutter.
Hunter tries the Holographic Prism he just built with an animated jellyfish. The prism was made from a CD case and our laser cutter, a Putnam County Community Foundation gift.

If you’ve been following our blog, you might think Castlemakers is a just a kids focused nonprofit. That’s definitely how we started, but our mission is broader than that – providing and encouraging scientific and creative skills (i.e. STEM or STEAM) by creating opportunities for all. Much of our first two years has been providing youth-oriented opportunities, which is now being called Castlemakers Kids, but with our new makerspace downtown we can expand to all ages.

First learning to solder class, before we had a makerspace.
First learning to solder class, before we had a makerspace. Future classes will be for all ages.

One way we’re doing that is offering community classes to allow people to learn, try, and build or make things that they may not have experiences with. Certainly software and some of the new digital fabrication tools like electronic cutters, 3D printers, and single board computers(i.e. Arduino & Raspberry Pi). But also how to use more traditional tools and then combining them with electronics/soldering, sewing/crafting (clothing with sensors/electronics are popular), woodworking, and fabrication. Watch for our first community class at the makerspace to be offered in soldering and electronics in March.

At our last 3DPO meetup, Curtiss scans a robot while John sets up a Makerbot 3D digitizer.
At our last 3DPO meetup, Curtiss scans a robot with a Sense scanner while John sets up a Makerbot 3D digitizer.

A third way, using our physical makerspace, is a community location where people can share ideas, have access to tools and equipment, and create things. A place that will spur creativity and innovation in our community. Some of this is outlined on our what we offer page. You can also stop by and see for yourself, perhaps even build something if you’d like, by coming by sometime during one of our ‘open shop’ times where some of the people involved in Castlemakers can help you with a project or just explain/show you what we have. Better yet, get involved and participate – no experience is necessary and you’ll help our community grow!

Hydroponics Lab Tour

Airy Knob Farm Hydroponics Concept Lab
Inside Airy Knob Farms Hydroponics Concept Lab.

After the interest in the Subaru Indiana Automotive tour, a group of Castlemakers went on a tour of a Hydroponics Lab at Airy Knob Farm just outside Greencastle last month. The ½ hour tour, which was a science project for Victor & Linda Hunter’s grandkids, went over the basics of hydroponics in their proof of concept center for growing fruits & vegetables year round. There is a pretty big ‘concept center’ with over 500 plants growing when we visited & the kids did an awesome job with the tour.

After placing seeds into rock wool cubes, they are inserted into the growing unit.
After placing seeds into rock wool cubes, they are inserted into the ebb-flow growing unit.

Hydroponics grows plants in a mineral rich water solution without any soil. Because the plant’s roots don’t have to use energy seeking out nutrients, most of the growth goes to top portion of the plant with the root ball being significantly smaller and a much bushier, more compact plant. Supplemental lights often help that growth when it’s used in practice today (hydroculture goes back to Babylonian times & the 1600’s in Germany).

Our hosts show how water/nutrients are added to a nutrient film hydroponic system.
One of our hosts show how water/nutrients are added to a nutrient film hydroponic system.

We learned a lot, including 3 different types of irrigation systems used there, the process of germination to harvest, and how the lighting & cooling systems are used to control plant growth. The kids on the trip put seedlings into the larger growth units & also could test the nutrient solution used with the plants. With the water/nutrient solution recirculation, this type of plant growth uses a lot less water than traditional farming!

Testing the growing solution is very important for larger scale hydroponics.
Testing the growing solution is very important for larger scale hydroponics.

There’s a lot of innovation going on with hydroponics, including the addition of raising fish with the nutrient solution used for hydroponics (called aquaponics, there’s a lab down at South Putnam High School). Castlemakers also has a very small hydroponics unit at the makerspace. There’s been some interesting open source printed systems & Kickstarter projects for Hydroponic systems, projects anyone?

Castlemakers Model Rocket Launch

Ty launches the first rocket of the day, one he built several weeks earlier in the model rocket class.
Ty launches the first rocket of the day, one he built several weeks earlier in the model rocket class.
One of the later launches

Despite the forecast, it was a beautiful sunny afternoon at Big Walnut Sports Park after we delayed the rocket launch a week. Besides the DooDad rockets built by the Castlemaker Kids, we had others show up with their own rockets, creating quite a show. We ended up with multiple launch pads and variety of different sized rockets and objects becoming airborne.

No that's not a flying saucer. It's actually two interlocking plastic plates floating down after launch...
No that’s not a flying saucer. It’s actually two interlocking plastic plates floating down after launch…

The ‘objects’ part are a little hard to describe, although they all used rocket engines. There were various polyhedrons and cardstock printed lawn darts (no chute, but colored with crayons by some younger kids – landed with a ‘thud’ nose first). Then there were the flying plates…

Recovery is much quicker & easier when you have an energetic chase crew!
Recovery is much quicker & easier when you have an energetic chase crew!

All of the kids (and a few of the adults) learned the proper setup and launch procedures before launching the model rockets. Thanks to the Greencastle Parks & Recreation Board (along with the Putnam County Airport) for letting us use Big Walnut Sports Park for launching the rockets. And a special thanks to Nick Adams for teaching the class, bringing his launch equipment, and teaching/supervising everyone  who launched that day. And to Jonathan Green for bringing his tub full of objects, it definitely added some more fun to the event!

Setup area for launching with a few onlookers at Big Walnut Sports Park.

Subaru Indiana Automotive Tour

Some of the kids that went on the trip pose in front of a vehicle in their lobby. Photography is not allowed in the facility for group tours.

Earlier this month we arranged for a Subaru Indiana Automotive (SIA) plant group tour in Lafayette, Indiana.  The 2.3 million sq. ft. plant was officially opened in 1989, but has undergone some remarkable expansion the last few years to a facility that has now almost doubled in size. Cars were coming off the production line every 63 seconds when we visited; it will be under a minute by November.

We had 29 people sign up for the tour, which takes you through the stamping, robotic welding, paint, inspection, and assembly areas. Most of the tour is in the overhead catwalks, which offers a great view weaving between the 16+ miles of overhead conveyors hauling parts and vehicles. You get a chance to see body parts made from giant rolls of steel, a symphony of over 800 robots welding and assembling car frames and components, and then it all coming together into a finished product that’s driven off the assembly line. With over 4 million square feet of building space, we hardly saw it all but it still left both young and old amazed at how this small city of over 5000 workers creates  soon to be 390,000 drivable vehicles a year!

Thanks to SIA for allowing us to book the group & giving us the great tour. Everyone that could make it loved it and we seem to have enough interest to do other group tours in the future.