All posts by chris

Model Rocket Build

The dooDad rocket fins are glued on the outside the rocket tube speeding assembly.
The dooDad rocket fins are glued on the outside the rocket tube speeding assembly.

For our end-of-July Castlemakers Kids project, we built model rockets to be launched in August. Nick Adams led the group in building the FlisKit dooDad model rockets, a good rocket that first timers can get assembled in less than 2 hours. It uses laser cut basswood fins that are assembled on the outside of the rocket tube, making it easier to put together in a short period of time. The basswood fins (vs. balsawood) reduces the chances of fin breakage – they are quite stiff!

The kits were simple enough for first time builders to figure out the assembly. In the background some parents discussed more elaborate designs.
The kits were simple for first time builders. In the background parents discussed more elaborate designs.

The build was also our first class/event in the new Castlemakers makerspace in downtown Greencastle. We’ve got a lot to do before it will be open for use as a makerspace, but it’s a great location that with some tables and chairs worked well for the model rocket build. With our laser cutter/engraver on order for the makerspace, I kept eyeing the fins on those rockets thinking that soon we’ll be able to make those…

The rocket launch for these (and others) will be at Big Walnut Sports Park in Greencastle on August 27th from 3-5 pm. Feel free to join us on the east end of the park, near the Frisbee golf course.

A special thanks to Nick for doing all the research into model rocket kits for first timers, the donation of kits to our group, and his time in helping everyone build the kits!

Summer Enrichment Program

Simple catapult testing built using 8 popsicle sticks and 2 wooden craft sticks.
Simple catapult testing built using 8 popsicle sticks and 2 wooden craft sticks.

Last month we were asked to do a STEM (Science Technology Engineering Mathematics) related activity with the Summer Enrichment Program at Gobin Memorial Church. It’s a great program which provides positive interactions for at-risk kids in Putnam County. Their goal was exposing these elementary aged kids to a STEM activity; I also wanted them to make something that they could experiment with at home.

We originally looked at doing something with Brushbots, but it turns out those kits are hard to find now & pricey. For Castlemakers Kids we built our own from scratch, but didn’t have enough pager motors on hand & ordering in bulk would take too long. So I settled on making catapults using wooden craft sticks and rubber bands.

There’s a lot of different craft stick catapult designs, but we went for simplicity. Had to, there were more than 60 kids in two sessions – plus only around an hour to build them. The large range of ages, 2nd through 6th grade, meant some would get the ‘lesson’ and others would have no idea what I talked about, but at least they were exposed to it!

Testing an alternate design which uses a stronger spring.
Testing an alternate wooden stick catapult design which uses a stronger spring.

After dropping a few names, like Galileo & Newton, I explained the basics of a lever using a see-saw example. Also mentioned Newton’s laws and apples falling from trees; then told them they were to decide which would hurl further – a marshmallow or a grape. This craft stick design can provide fairly consistent force input since everyone pretty much pulls it back all the way (who doesn’t want to launch it the furthest!).

The kids each build a catapult with 6-8 kids and 1-2 counselors helping at each table. It worked well, especially considering there wasn’t time to coach the counselors first. Everyone involved certainly had fun and when they’re exposed to levers and Newton in a more academic setting they will have heard of it. Lessons learned: Grapes have more mass than mini-marshmallows but don’t go as far & the model I made with a binder clip (stronger spring/more force) definitely shot things further. Mini-peppers… well things were degenerating at that point & we ran out of time.

We didn’t have enough bottle caps to glue on the throwing arm (they still work without them), and several of them were going to add when they got home so they could launch more. I also brought one with a longer lever (2 craft sticks), hopefully a few of them made those at home!

Paper Mechatronics

The June 20th Castlemakers Kids build project was paper automata.
The June 20th Castlemakers Kids project, paper automata.

This week we explored the world of paper mechatronics (sometimes called automata or Karakuri in Japan).  In the Castlemakers Kids meeting, using 2 sheets of paper cardstock, we created a cam/lever mechanism that caused a sheep’s head to nod when the crank was turned.

The kids cut out the parts from 65 lb cardstock then used glue and folds to create the assembly.
The kids cut out the parts from 65 lb cardstock then used glue and folds to create the assembly.

For thousands of years people have created mechanical toys and dolls out of metal, wood, or in our case paper. The primary use seems to be for entertainment and amusement, but it also offers incredible opportunities to teach people about levers, cams, gears, linkages and other mechanical mechanisms. Ever looked inside a mechanical watch, clock, or older film projector? You’ve probably seen a Geneva stop or Maltese cross (along with a lot of other mechanisms), but may not have known what to call it.

A completed paper sheep that nods it head when you turn the crank on the side.
A completed paper sheep that nods it head when you turn the crank on the side.

We made a design created by Rob Ives, who has an UK website on cardboard cutouts, called “Agreeable Sheep”. It’s a cute model and uses a single cam along with a lever which nods the sheep’s head when the crank is turned. I can also heartly recommend the book Karakuri by Keisuke Saka if you decide to try a hand at making mechanical paper models.  He covers how they work and has a wonderful gallery of karakuri that he and high school students in Japan have created. The tips and instructions for basic mechanisms are worth the price of the book if you want to try make different models or creations of your own.

I’m sure we’ll be doing this in the future again, there are plenty of other things to try. My mind is already buzzing about scaled up models could be made out of big sheets of corrugated cardboard…

What’s a Makerspace

It’s been a busy time for Castlemakers this last month; we received our first grant a few weeks ago for equipment. A group of us have been working very hard to create a physical location for Castlemakers, a makerspace, and watch for an announcement soon.

Map of Artisan's Asylum in Somerville, MA
Map of Artisan’s Asylum in Somerville, MA.

Several years ago I wrote something about ‘what is a makerspace’, which have become even more popular since then.

Their numbers and importance has grown since that first post, with the White House proclaiming this week in the US as a Nation of Makers  and hosting a reoccurring Maker Faire this coming weekend (June 18th & 19th). If you visit different makerspaces, as some of us have, it’s a very entrepreneurial movement with many different makerspace models. You’ll find makerspaces as community co-ops, ones associated with libraries, ones that are affiliated with science and children’s museums, and even some at universities.

One of the main halls in Artisan's Asylum. Besides all the workshops, space can be rented for people working on their projects.
One of the main halls in Artisan’s Asylum. Besides all the workshops, space can be rented for people working on their projects.

Perhaps one of the largest and most successful makerspaces is Artisan’s Asylum in Somerville, MA which I visited last year. Started in 2010, it’s grown from a 1,000 sq ft “hole in the wall” to a 40,000 sq ft facility with over 600 members! What impressed me the most in my visit: the projects being built & how they bridged different disciplines along with oozing creativity and innovation. The sheer size & scope of the current facility was also impressive, but the people involved & what the makerspace environment seemed to be the key why it works.

Locally we’ve been making great strides in creating our own makerspace here in Greencastle. Thanks to a June 2016 grant from the Putnam County Community Foundation we’ll be purchasing our first major piece of equipment, a CO2 laser cutter. Of course we’ll need a place to house it, and we’re very close to that.

Making Chicago

Chicago's Maker Lab on the 3rd Floor in the Harold Washington Library downtown.
Chicago’s Maker Lab on the 3rd Floor in the Harold Washington Library downtown.

While in Chicago last month to see the Strandbeest exhibit we took two maker classes. The first  class was creating a greeting card using an electronic cutter and the second an acrylic keychain with a laser cutter. Both were hosted at public makerspaces, although the largest was called a Fab Lab (alternate name for a makerspace).

vinyl-cutter-CPL-makerlab_IMG_0457
Psychedelic flying pig being drawn by a vinyl (electronic) cutter on a greeting card.

The Chicago Public Library (CPL) Maker Lab workshop began by teaching Inkscape to design the greeting card. They supplied a blank template, then using a laptop with Inkscape we added text and art for the card. The saved file was put on a flash drive, imported into the electronic cutter program (Silhouette), and then drawn on the card (the cutter’s blade was replaced with color felt tip pens).

CPL Maker Lab was the first publicly accessible maker lab in Chicago, created in July 2013 with a fairly large corporate grant and a 6 month trial/study. While a major portion is classes, they have plenty of ‘open shop’ times, at least 3 hours/day. They worked closely with the Museum of Science & Industry (MSI) in creating it, which was our other makerspace/fab lab visit.

MSI Fab Lab computer area for classes. On the far right wall are 3D prints and lasercut acrylic objects.
MSI Fab Lab computer area for classes. On the far right wall are 3D prints and lasercut acrylic objects.

The Fab Lab in Chicago’s Museum of Science and Industry goes back about 10 years and is part of MIT’s Fab Lab network. Located in the back of the MSI it’s easy to miss, I had walked past it on two previous trips to the museum and hadn’t noticed it was there! While not open to the public for personal projects or general use, the classes are available for a modest cost ($7-9/person in our case) once you pay the general admission to MSI. They do fill up, so consider booking in advance.

A lasercutter was used to cutout and etch the acrylic sheet for the participant designed keychains.
A lasercutter cuts and etches an acrylic sheet for the participant designed keychains.

The class was well run and began with an overview of the lab, which has a lot of equipment and well organized. We used Inkscape to create the drawings, like the CPL Maker Lab class, and a template to get everyone started. This was a much more scripted class, which was needed because of the 1 hour timeframe. There was plenty of assistants to coach folks through the lesson and very helpful to all, even offering suggestions to some indecisive younger kids! This lab caters more to the young, although there were adults like myself attending.

Main Fab Lab workshop area with some of the equipment. The 3D printers are in the foreground, the very far wall is an electronics area.
Part of main Fab Lab workshop; in the foreground are 3D printers and very far wall is an electronics workbench.

These were good examples of the Museum & Library-based models of makerspaces. There was significant institutional support in creating both and in these cases they have a massive potential user base to draw on. There are also many makerspaces in our region that started with extremely small budgets and even self-funded. One thing I love about the makerspace community is their willingness to share with others; I ended up with curriculum content and contacts that offered to help we move from a makergroup to makerspace in Greencastle.

Tetrahedral Kites

Several different tetrahedral kite drinking straw designs were tried to see what would be easiest to build.
Several different drinking straw designs were tried to see what would be easiest to build.

After the big winds a few weeks ago, we decided to build some kites for our latest Castlemaker Kids project. For those not familiar with tetrahedral kites, the engineering behind the geometric design and history of Alexander Graham Bell’s involvement is interesting.

Alexander Graham Bell saw the Tetrahedral Kite as a way of getting to manned flight. Just before the turn of the 20th century, there was a big debate in the scientific community on whether human flight was possible. Kites were being used to test aerodynamics and flight stability for possible aircraft. After Lawrence Hargrave developed the box kite in 1893, Mr. Bell designed a tetrahedral kite in 1895, which was not only very stable but simple to expand and easy to fly. Mr. Bell wrote a National Geographic article in June 1903 on his new kite structure that explains the development and gives a comparison with other designs. He eventually created a steamboat towed 12 meter (40’) long 3,393 cell model in 1907 that carried a man 51 meters (168’) above the water!

Prototype tetrahedrons and cutout tissue paper. Building a template helps considerably. We used string to tie the straws and cells together, but I'm working on designing a 3D printed connector to see if that would work.
Prototype tetrahedrons and cutout tissue paper. Building a template helps considerably. We used string to tie the straws and cells together, but designing a 3D printed connector to see if that could work.

There are lots of variations today – the design we chose was built using drinking straws, string, and tissue paper (Tyvek also works). Individual tetrahedrons are made out of straws, tissue paper is put on 2 sides, and then they are tied together in groups of 4 to make a building block. The 4 cell model can fly by itself but if you get ambitious 10 cell modules work well too, all of which could be attached together into larger tetrahedral kites. Instructions for a simple 4 cell model can be found here, but it can be tailored to the supplies available and what you’d like to build. To help with the kids’ attention span (and time constraints) we stayed with a 4 cell model.

Brian holds up his completed kite by the bridle. He used just one longer string for the bottom layer, the rest of us built individual cells and tied them together.
Brian holds up his completed kite by the bridle. He used just one longer string for the bottom layer, the rest of us built individual cells and tied them together.

Finding non-bendy straws locally turned out to be a challenge, each 4 cell module takes 24 straws. The rest of the components are pretty straight forward, it’s just a matter of time and patience to assemble a kite. Once you figure out the pattern, the most difficult part is tying together the individual tetrahedrons with the string, in the version we used. There are several other versions if you search the internet, including one that uses flexible drinking straws, but the individual cells in the folding model are wired together. This makes assembly a bit more challenging and I found it harder to put and keep together, although the folding feature is nice.

A tetrahedral kite’s advantage is the low weight to sail ratio. Because of the shared trusses, as you add additional cells performance improves – what Bell saw in this design over other types of kites. And it’s easy to put multicolored paper on the kite, making a good looking kite. Don’t be surprised if you see some larger ones in the sky this summer in Putnam County!

Teaching With 3D printing

The whistlers share their designs and prints. The train whistle in the foreground didn't turn out as planned, something every engineer has experience!
The ‘whistlers’ (Ben & Carlie) share their designs and prints. The train whistle in the foreground didn’t turn out as planned, something every engineer has experienced!

A high school Principles of Engineering class I visited last week is providing a great example using a 3D printer to teach the engineering design process and critical thinking.

Mr. Shields at Greencastle High School inherited a 3D printer when he took over a new class this winter. I had contacted him to see if he or his students were interested in a community 3D printing competition that Castlemakers is putting together. He was able to take the basic idea we had and turn it into valuable classroom experience for the students. Plus provide a pilot test for a future community 3D printing event!

Another student demonstrates his 3D printed frog, which resonates sounding like a 'ribbet' when a stick is rubbed on it's back.
Craig demonstrates his 3D printed güiro, a frog which resonates ‘ribbet’ when a stick is rubbed on its back.

The challenge was to 3D print a functioning device that would make noise or music. They had to walk through a seven step design process, print the part, and then write a report that included evaluation of their prototype by others.

The projects they made were impressive with whistles, a drum, ribbiting frog, and of course musical instruments. While all of them were good, perhaps the most impressive sounding was a musical instrument that 2 students collaborated on – Mattia designing and making a mouthpiece while Dalton did a horn. You can hear the mouthpiece/horn in this video.

Justin B assembles his banjo/ukulele. One of his tuning keys broke but of course another can be printed!
Justin H. assembles his banjo/ukulele. One of his tuning keys broke but of course another can be printed!

Piaget would be proud of the constructivist learning going on Mr. Shields’ classroom. It really shows how hands on learning and the maker movement can improve learning in the classroom. IU School of Education is embracing the movement, opening a new a makerspace(The MILL) last fall in the Wendell Wright Education building just for teachers. Not all learning goes on in a classroom however, and people need tools/equipment and a place to practice – one of the reasons that Castlemakers feels Putnam County needs a makerspace.

Building A Robot at Wonderlab

Wonderlab/Bloominglabs workshop on building a light seeking robot from motors, switches, and a few electronic components.
Wonderlab/Bloominglabs workshop on building a light seeking robot from motors, switches, and a few electronic components.

Another good regional resource for kids STEM activities is Wonderlab in Bloomington, Indiana. Besides being a fun place to visit, they also offer summer day camps for kids through 6th grade (and mentoring opportunities for those older) that can range from crazy contraptions and electronics/engineering to TV technology. They also have occasional special events, often on weekends or during school breaks, that anyone can sign up for.

A completed 'BrainBot' - light seeking robot based on the SunBEAM seeker robot.
A completed ‘BrainBot’ – light seeking robot based on the SunBEAM seeker robot. These use $7-8 in parts and the robot seeks out light using the two photosensors that drive the rear motors.

Bloominglabs, the community makerspace in Bloomington, put on a 3 hour Brainbot building workshop over spring break at Wonderlab for kids and adults. Since we had some experience teaching kids to solder, ended up helping with the workshop and now helping to improve the workshop instructions. Bloominglabs also helps the Monroe County Library with speakers for the summer Make It Digital series, put on Makevention every year, and have an open shop night every Wednesday evening for those interested in making.

As we work towards creating a Putnam County makerspace, the robot building workshop is a good example of what Castlemakers will offer. Of course a makerspace is much more than just classes. But the goal is sharing/helping people to learn skills with arduinos/microcontrollers, mechanical devices, 3D printers, and more. And with the right physical location that may include welding, woodworking, jewelry making… all things that makerspaces in other cities offer.

Strandbeest Exhibit in Chicago

An earlier Strandbeest, Animaris Apodiacula. On the far wall you can see a picture of his workspace and that room is full of parts used to make them.
An earlier Strandbeest, Animaris Apodiacula. On the far wall you can see a picture of Theo Jansen’s workspace and that room is full of parts used to make them.

Spring break turned out to be more of a making experience than expected, starting with the Strandbeest exhibit in Chicago and then taking a Chicago Public Library makerspace class and later one about laser cutting at the Museum of Science and Industry’s Fab Lab.

If you haven’t heard of Theo Jansen’s Strandbeests, and even if you have, the Chicago Cultural Center has a fabulous exhibit for anyone interested in mechanical creatures. You get to see what an eccentric artist can do when combining engineering and art. Jansen’s wind powered beach creatures have evolved over the last 25 years, getting more sophisticated by storing wind energy, sensing when walking into the water, and even self-correcting to prevent them getting stuck. Some even anchor themselves if they detect a storm, all without any electronics just plastic pipe, cloth, and recycled bottles.

Close-up of the Animaris Suspedisse before the walking demo. Over by the windows you can see visitors walking a smaller one.
Close-up of the Animaris Suspedisse before the walking demo. The plastic pipe you see in the foreground hanging down with red tips is part of the propulsion system from the plastic bottle stored air. Over by the windows you can see visitors walking a smaller one, here’s a video.

Check the schedule if you go, you can watch a 42’ long Animaris Suspendisse walk or they might actually let you move an Animaris Ordis by yourself! The exhibit also included the evolution of the creatures and a small case of what other inspired people in the making community have done with his designs. Hamster powered Strandbeest anyone? How about 3D printed Strandbeests? The Segway like device inspired by a Strandbeest was pretty impressive too! Anyone interested in building a Strandbeest here?

The Chicago Cultural Center is a beautiful building itself and just across the street from Millennium Park – you can see Cloud Gate from many of the windows on the east side of the building. Make sure you check out the other exhibits in the building and look at the incredible dome on the 2nd floor of the Center.

I’ll cover the workshops on making your own greeting card using a electronic (vinyl) cutter and making a custom acrylic keychain with laser cutter in a future post…

Catapulting a Wild Boar

Yes, that is a flying pig in the photo! After working through the calculations of a hurling a wild boar, the students got to try firing various animals at a castle wall.
Yes, that is a flying pig in the photo! After working through the calculations of a hurling a wild boar, the students got to try firing various animals at a castle wall.

Yesterday, in conjunction with The Castle, we did a class workshop on catapults with the 7th grade science students at Greencastle Middle School. They were challenging sessions with both physics and mathematics involved, but the kids in the 7th grade science classes on Friday worked through the calculations to solve whether a 150 pound wild boar could be hurled across a 100 yard moat using a catapult. Their current curriculum was in the Newton’s laws of motion section, which they had to use to help answer the question.

With only a 43 minute class period to work with, we had to reduce the scenario to a fairly short calculation. The groups were given the wild boar launch velocity (100 ft/sec at a 45 degree angle) and had to calculate the flight time so the total distance traveled could be determined. For those that finished the problem quickly they could try to figure how the distance would change if a cow was instead launched, but that was a bonus item that most didn’t get to. We finished up by test launching a few stuffed animals in the classroom to see a simple catapult in action.

Special thanks to Mr. Wickerman for letting us into his classroom, to Kara Jedele from The Castle for arranging the workshop, and both Kara and Emily Knuth for helping in the classroom.