teaching – Composite

Wheelchair and Scooter Hack Day

October 3, 2012September 24, 2022 Liz

The Hackability group met up at Noisebridge this weekend to work on modifying, maintaining, and otherwise hacking our scooters and wheelchairs. This first meetup was just 4 of us, Ian, Zach, Susan, and me. Ian and I talked first about projects we would like to do for his powerchair and my scooter. Susan is an engineer, inventor, and hacker who has some great ideas about improving power and making a regenerative braking system for my scooter. Zach came prepared to give us a really great talk which I’ll try to describe from my notes.

Zach made the point right at the outset that we can think of scooter hacking as falling under two categories. The first is for comfort and repair; things that are necessary. The second category is mods and upgrades; in other words, extra fun stuff. About comfort and repair: He talked about how long it took him to really listen to his body and pain levels and know what was irritating about his mobility devices, rather than accepting what he was given as “just how it is”.

For him, stability is an important factor. Parts wiggling on his scooter caused more pain for his back and legs, while rattling was distracting and annoying. He then took the seat off his scooter and I demonstrated my seating as well, to show how you can stabilize the seat housing pole. Mine was vastly improved simply by wrapping in a few layers of duct tape. Now, on the bus, my seat doesn’t wobble back and forth forcing me to use my low back muscles to cope with the sway of the bus plus the erratic seat motion. Many of Zach’s other mods were done with cheap and easy to find, objects like zip ties, heat shrink tubing, and blocks of styrofoam. He is a genius of finding free or cheap things to hack! His repairs look sturdy, neat, and durable. (Unlike my cardboard and duct tape repairs which are such a hot mess.)

He had recently put a bigger motor into his scooter frame. The motor heats up and has a fan to the side next to one wheel. Jacket sleeves, backpack straps, and other stuff was getting caught and tangled in it. Zach ended up replacing the fan with a blade from a computer’s cooling fan, and making a curved metal guard for it out of what looked like a thin plate of metal from a hard drive casing.

We digressed for a while into talk about batteries, their expense, how many amp-hours our batteries have, ideas about bolting extra batteries onto the side of my scooter and wiring them into the existing removable battery case. The lack of cheap smart chargers means that most people with mobility scooters have ineffective chargers which shorten the batteries’ life and effectiveness. My batteries, new in March, are already dropping in voltage output capacity even when fully charged, so my scooter is laboring going up hills or for any significant distance. Susan has plans to design an affordable smart charger. We’ll see how that goes! For more on batteries and charging, read up on Battery University.

MOving on to our second category of mobility device hacks: The fun extras. Zach showed us some of the cool stuff on his mobility scooter, like how his wire mesh basket is stabilized with a flat metal plate with screw holes and some hot glue. I suggested black latex paint might be a good alternative to hot glue, and may try that for my own basket, which squeaks annoyingly against its brackets. We talked about alternate handles for scooter grips and controls then admired Zach’s fancy lights. On the more simple DIY side of things, he has a small battery operated LED light meant for a bike, velcroed onto the side of his scooter dashboard. Advice: use the real Velcro not the dollar store kind! As a quite complex lighting hack, he has strips of LED lights which are wired into his scooter’s main power supply and through a homemade circuit board which steps down the power.

Another complicated hack we discussed was in building our cruise control switches and stabilizing the forward and reverse levers which make the scooter go. These levers on most mobility scooters use a non-precision potentiometer. The screw on these things goes out of whack, which can be very annoying.

I have to digress for a minute to explain scooters, or at least the scooters I’ve used and seen. They have levers on the handlebars which connect to a trim pot and the main power supply from the battery. The power also obviously goes to the motor. There are no brakes. There is a solenoid of some kind which stops the motor. There is no neutral gear so if the motor stops, the scooter stops. But there is also a printed circuit board in the mix which has “safety features” programmed in. In practical terms this means if there is any interruption or big fluctuation in the power supply, or you hit a huge bump in the sidewalk, or I don’t even know what else, the motor cuts off. When you start your scooter and the centering of the levers controlled by the potentiometer is just a little bit off, the motor won’t start. To adjust and fix the potentiometer’s screw, you have to take the entire plastic housing off of the scooter’s controls.

Anyway, Zach’s approach to this problem, from advice from our friend Jake who is a fabulous hardware/electronics hacker, was to add a 50K trim pot in parallel with the existing one. He placed it so that its screw faced outwards, and drilled a hole in the plastic casing so that he can adjust it with a screwdriver without taking apart the scooter. Brilliant!

His other mods include a USB charging port on the dashboard and a scooter-charging port also on the dashboard rather than low on the scooter frame. We ended up discussing charging a lot more, and what gauge of wire is necessary, but I don’t have good notes on that.

At that point we looked at Ian’s powerchair and discussed some of its features and problems. It is a much more complicated beast than a scooter, and a couple of orders of magnitude more expensive to buy and get repaired. Powerchairs have two motors controlling the wheels so that they can turn in place, while scooters tend to just have one motor, with forward and reverse. Powerchairs seem to have much more powerful batteries and have more complicated control boards hooking up the joystick or other single-hand control with the power supply and motor. Ian’s chair has a fancy color screen hooked up to the joystick control but it seems unhackable. Or at least not without risking ruining the chair’s software. It seems a shame that it is not easier to to software or firmware mods that we could experiment with and roll back the changes if the experiments don’t work out.

The thing we worked on was a power plug in the back of Ian’s chair. It is an Anderson connector and didn’t work, maybe from being shorted out, or maybe because it is wired wrong. We thought about cutting the wire and replacing the plug connector or reversing how it was wired. We took off the back plate of the scooter housing to see if there was anything obvious to do that wouldn’t mean we had to take apart the entire chair. Hooray, there was a fuse between the plug and the battery, and it was blown. Zach found us a new fuse from the many tiny parts bins in the Noisebridge hack shelves. Ian replaced the fuse and put everything back together. It tested out okay with the multimeter this time! But the plug that he wanted to use with it, which is a DC/DC power converter from an electric bike company, wasn’t wired the same way. We concluded it would be best to either buy a new part ($50) or cut apart the bike part to reverse its wiring to the connectors.

Thanks very much to the role playing game group in the other classroom who moved most of the tables out of the room for me before our meetup!

It was a great meeting with a mix of lecture, discussion, theory, and hands on practical demos and work. If you would like to join our mailing list, here’s the link: Hackability mailing list, for DIY hacking, modifying, and fixing existing wheelchairs, scooters, powerchairs, and other mobility or accessibility devices. If you’d like to come to our meetups in San Francisco, you are very welcome. Please join the list and let us know!

Noisebridge circuit hacking

July 19, 2012 Liz

I’ve been helping out lately at Noisebridge during Circuit Hacking Monday. One week, some people showed up expecting the event and no one was there to run it, so I ran it for someone I knew from She’s Geeky, her friend and teenagers, and a couple of extra adults who were here from Norway and Denmark for Google I/O. I had just been pawing through the soldering supplies, organizing them a bit as I searched for what I needed for my project (messing around with a LilyPad Arduino), and had found a little bag of cheap LED light up badges shaped like teddy bears. So we used those tiny kits to make blinking badges. It was chaotic, but fun.

I talked with Mitch Altman to find out where his kits for sale were and if it was okay for me to sell them while he’s out of town, and then send him the money. I might, though, just order some kits as cheaply as I can find them, and keep them independently to avoid hassle. As I end up giving tours to lots of new people, many of them from out of town or overseas, I could do them a favor by giving them something geeky to do in the space rather than sit and check their email!

The next week things were back to normal as Miloh and Rolf were at Noisebridge to run the class. Before they showed up, a teenage volunteer helped me set up soldering stations. More and more people kept coming in so the situation got quite chaotic again as we were giving them tours of the space and trying to find room. I realized that next time I would approach things differently — clearing the whole area of people who were working, and setting up 20 or more stations ahead of time, so that we weren’t doing setup and giving tours at the same time.

During the event Miloh and Rolf really took over the teaching aspect. I was somewhat trapped with my scooter in a corner because of the number of people, the table arrangement, the many chairs and the backpacks all over the floor. So I also would like to look at making the central area of Noisebridge less cluttered with tables, chairs, and stuff for the future so that I can participate. In my corner, I again hung with some kids and the teenage volunteer, and a guy who couldn’t hear well. The kid didn’t have a computer to look at the instructions for his kit, and needed a lot of one on one help as he was maybe a bit non neurotypical. The guy who hung out with us could not hear well in a situation with background noise. I’m in the same boat — I’m in my 40s and just can’t hear in a loud, chaotic situation. The kid fixed his Mintyboost and then made a tv-b-gone. The other guy made a blinky badge then was hooked and got one of those big name LED badges, I think. He appreciated the How to Solder comic book print out that I happened to have on me because he missed all of Miloh and Rolf’s explanations. I thought it was interesting that, marked out as somewhat different and disabled, I ended up doing more one on one work with people who had particular access needs.

Our volunteer also was super helpful in that capacity and seemed unusually alert to access issues, like that chairs or cables were in the way of my scooter or that it might be hard for me to get up to get supplies on high shelves. After the event when his dad came to pick him up I saw that his dad had one arm and walked with a cane. So growing up with a parent who has some mobility issues he might be more tuned in than others usually are.

I thought both those things were interesting! And figured it is a pretty good role for me at CHM. If you have particular access needs or are going to bring a bunch of 10 year olds to Circuit Hacking Monday (Mondays at 7:30pm) then feel free to email me with questions and see if I can be there & be helpful: lizhenry@gmail.com.

Basic supplies are running low. We have lots of soldering irons, including a bunch that I think Jake, Lilia, and MC Hawking won in a contest, but they’ve seen very heavy use over the last couple of years. So there are a lot of kind of crappy soldering irons and a few decent ones. We might be able to clean them or swap the tips cheaply. We have lots of snippers and wirestrippers. We need solder, weighted holders with alligator clips and lenses, more of those weighted bases with copper wool for cleaning soldering iron tips, and more de-soldering braid. Plus it would be so nice to have a supply of many kinds of coin cell batteries. After I talked with Miloh about that he shared a giant complicated spreadsheet with me. I haven’t read through it yet! But it would be great to get particular donations for restocking our electronics supplies.

We have shelves and shelves of hardware junk, in bins, and a wall of tiny little parts in tiny drawers meticulously labelled!

Yesterday I spent some nice time in the afternoon doing a Dice Kit with my son. We couldn’t find any decent epoxy or glue, so went to the fabric store on the corner, but ended up getting a big tube of contact cement from the dollar store. I gave a lot of tours and hung out with my friend who came by to fix her headphone wires. We’re both going to help TA at Black Girls Code in San Francisco. She ended up also using the wood shop for another project – modifying wooden artists’ brush handles to make those long tapered sticks so useful for holding up long hair and especially dreadlocks. Claudia aka Geekgirl showed up too and told me about how she is going to Rwanda in September and has a job there teaching IT and computer programming to middle school girls. Nifty! Meanwhile, my son played with MC Hawking and read comic books in the library after he was done with the Dice Kit. Along the way he learned to figure out the values of resistors from the color code chart (and learned it is not hard to just memorize the numbers.) We looked at my LilyPad and he got to the point of comfort with the code to make a scale go up and down again and modify the time of the notes. I gave the world’s worst and briefest explanation of what a function is and what it means to pass it variables, but he caught on with no effort. I’m very spoiled as a teacher when I set out teach him anything! He gets the idea too quickly!

Anyway, I sat up far too long that afternoon, and sadly had to leave before Replicator Wednesday kicked off. It has been nice going out into the world a bit more, this last month, more than just for the grocery store and physical therapy.

One last note: this is what happens if you leave your bike blocking the elevator at Noisebridge!!! It gets put into the E-WASTE bin!

Blogging class at the Redwood City Library

February 27, 2007 Liz

I just taught a community education class at the Redwood City Public Library, “Start Your Own Blog”. Ten people pre-registered and showed up to the small computer lab in the Teen Homework Center. None had ever started a blog, but everyone had basic computer literacy and a personal email address. The blog-starters were all ages — from middle school student to senior citizen. Roz, a librarian, and Michele, who does IT stuff for the library, helped out. I believe Roz also started a blog, “Gardening by Flashlight,” as she followed along with the steps of blog creation.

Before the class began the librarians showed me their page for The Big Read, a community reading series happening in March, co-sponsored by Villa Montalvo. You can get a free copy of Farenheit 451 from the library. Some students from Mission College set up a very fancy web page with forums and a way to participate: load the page and click on “Confess” to answer their amazing questions about self-censorship. How many times today did you stop yourself from saying something? Did you pause before sending an email, or leave one unsent or unwritten? Good questions like that, and space to answer in. (I’m going to ask my English Composition students at Evergreen Valley College to participate for class credit.) You too should go and confess your moments of self-censorship to the Redwood City Library. Give them some love!

I began the class by explaining what a blog was: a web page you can update very easily, using web forms. We used Blogger. Two students had difficulty signing in, though they were using valid email addresses. The librarians helped them sign up for new gmail accounts, but that was pretty distracting for the other students!

As with any hands-on computer class, I sometimes had to pause, walk around the room, and get everyone back on the same page again. I also had to remember to say, at times, “Everyone please look up here at the screen…” to get people to look at my demonstration, rather than what they were doing.

What I didn’t expect was for people to be so excited that they wanted to write lots of long blog posts! That was cool! I thought people would write “First post” and “Um I don’t know what to write” and things like that. But no! I stood at the head of the room hearing the soul-warming sound of clickety click click of industrious typing, seeing the beautiful deep concentration on people’s faces. It did help to ask people at some point to stop, hit publish, and remember that they could go back and edit later. I busted loose with a speech about how you could edit stuff, disinhibited, empowered and freed by the control you had over your own words. Yay, that was fun! I saw some lightbulbs go off in people’s heads at that thought.

At the point where we logged out and in again, people were confused by the choice between “New Blogger” and “Old Blogger”. They thought they were now Old Bloggers because they weren’t New anymore – they’d already gone through the process! That made sense, but I hadn’t expected it. So if anyone from Blogger/Blogspot is reading this, free user feedback for you, though you’ve probably already heard it.

Here’s what I would do differently for the class:

– Emphasize the step during creation of the blog of writing down on paper:
— Your login name (which is the gmail account that’s being created!)
— The URL of your blog
— The address you will go to in order to edit your blog in future (http://blogger.com)

– add a step for telling the instructor the blog name and your login name!

– Making a link. I’d write out instructions on how to do that with the “link” button rather than typing a href etc. etc. etc.

– Log out, quit the browser completely, and start from scratch to log in again, find your blog in one window, and open a new editing window.

– I’d consider making it a 2-part class, perhaps over 2 weeks, but better yet, Monday/Wednesday or Tues/Thurs.
— The instructor will have the list of everyone’s URLs and login names, in case someone forgot on the 2nd night.
— It could also work well as a 3 hour class with a coffee break in the middle, on a Saturday.
— It really does need a followup to help people have continuity and a little extra practice. It’s a lot of information to absorb all at once.

– An added note at the end to suggest that people go home and teach someone else, a family member, friend, or co-worker.
— That spreads whatever cool empowerment people can get from blogging
— Trying to teach someone else is a really good way to learn something in depth

– I forgot to mention other blogging services, some free and some not: Vox, WordPress, LiveJournal, Typepad, and for Spanish speakers Blogalia or Blogalaxia. With a longer class or 2 classes, I would do a quick tour of those sites. Blogger is lovely, but there are other options!

Maybe the students from the class will come and leave me a comment, so I can link to them. The ones I remember are:

Philip, who wrote a mystery novel, and who used to work in TV news, and who I think I know from past meetings of the Redwood City Not Yet Dead Poets: Philip’s Code.

Richard, who looked like he was in maybe 7th or 8th grade (but I could be wrong) and who came with his mom, and who is a huge star wars fan: Star Wars Freak.

A very lovely person whose name I have forgotten but who is a technical recruiter… I can’t remember her blog name

A dad and his high school or college-age son, and the son was super good at it all already, and the dad was starting a blog on his personal finance business for long-term care

Esperanzamj, who started a blog about hope and creativity

Gina, who was blogging in Spanish, ¡espero que me di su blog url aquí en los comments!

The woman who has a craft business and teaches classes and makes soap and beauty care products

And everyone else. That was really a lot of fun.

Technorati Tags: blogging, teaching

A girl can wield a mean soldering iron

January 24, 2007 Liz

When I was around 10 and 11 I was very into soldering irons, little electronic bits and pieces, and anything that made me feel nerdy and mad-scientist-y. I loved the smoky metal-hot smell of the solder and how scary it was… and making things that worked and were “real”. At first I just made different kinds of switches and circuits with tiny lightbulbs, and then advanced to collecting hydrogen in a test tube and lighting it on fire to make it pop. EXCITING! The coolest thing I ever learned about was electroplating. I copper plated every small metal object in our house, adding all sorts of weird stuff to the copper sulfate solution to see what effect it would have; my sister’s dollhouse toaster came out really well when I made a strong solution using tons of ketchup. And hello, what could be cooler than safety goggles and a voltmeter?

I had a point in here somewhere.

Erica Rios of Xicanista, a former instructor for Techbridge, passed on this job call for me to post:

Techbridge Program Manager

Want to make a difference in a girl’s future? Help change girls’
images of and experiences with technology and have an opportunity to work with a dynamic team of educators. Techbridge is an innovative program to inspire girls in technology, science and engineering. The program is hosted after school at elementary, middle, and high schools in Oakland, San Lorenzo, and at the California School for the Blind in Fremont. In these after-school programs, girls work on a variety of projects such as making solar LEGO cars, soldering, digital photography, and building robots. The girls also participate in field trips and meet with role models.

Under the supervision of the Program Director, the Techbridge Program Manager is responsible for supporting and supervising staff, coordinating and implementing our after-school programs, developing and piloting curricula, and leading professional development workshops for teachers, role models, and professional audiences. We are looking for an experienced and dynamic individual who has the ability to supervise a team of instructors, work with the Techbridge project director, and oversee the development of training and resources to teachers, professionals and partners.

It sounds like a GREAT job getting to be a nerd role model for techy girls. Write to techbridge@chabotspace.org if you’re interested in the job!

Now, part of my point was that I was extremely into the soldering and circuits and experiments, but I reached a point very quickly where I had nowhere further to go with it, and no where to go for information or leadership. Books from the library only went so far, and then information stopped. How to take it further? So — if you DO get involved with a program like this, or you know a young nerdlet, please try to find them mentors and books and extra information, to keep their interest going and feed their love of science and tech.