I’ve been experimenting with printing face-masks to wear during the pandemic.
The .STL file was downloaded from Thingiverse .com and then printed on my Prusa I3 Mk3S 3D printer. I love the Prusa 3d printer. It is so choice. If you have the means, I highly recommend picking one up.
A HEPA filter from a HVAC unit or a vacuum cleaner bag can be cut to make the masks filter unit. I don’t have flexible filament on hand so the the mask is rigid. A rubber weather strip gasket can be used to line the interior for a gasket effect.
One of my main reasons to acquire a Bridgeport milling machine and Grizzly lathe was to scratch this itch of mine to build model steam engines. It’s hard to explain, but I hear a calling to build these things. I got the idea to look for a model engine show for some inspiration and mentoring last February 2019, so I was very dismayed to learn that I had just missed one of the largest model engineering shows in my backyard by a few weeks: the Cabin Fever Expo held in Lebanon, PA. I marked Cabin Fever Expo 2020 on my calendar and waited with patience! After declaring my intent to attend this event, I was grateful to have my son state he was willing to tag along. After a somewhat grueling two hour drive on a blustery day into Pennsylvania in moderate sleet and snow we arrived!
The Cabin Fever Expo appears to be segregated into 4 areas, there are tool and part vendors, an ongoing auction with mostly model train parts for sale, a main hall with the model engines, a hall with consignment items for sale, and another hall with model boats, cars, tanks, etc.
We spent the majority of time in the main hall with the model engines. The craftsmanship is humbling. What used to be a practical trade has become a lost art of craftsmanship and manual precision engineering.
Obviously, we couldn’t leave empty handed! We purchased some lathe tool bit inserts, a coaxial indicator for the mill, a drill bit guide, and a beginner model engine castings kit.
Santa got us a Prusa i3 MK3S 3D printer for Christmas . I’ve seen the Prusa crew and their printers in action several times at the NYC Maker Faire and at other smaller MakerFaire over the past three years. Make magazine has printed several articles in their “best gear” editions and the Prusa printers are almost unanimously identified as the best bang for the buck.
The Prusa model comes in two options. There is a preassembled option for $999 and a build it yourself option for $750. I opted to go for the DIY built it yourself model. I’ve believed the only way to have a fully fundamental understanding of how the device works is to build it from the ground up. I also figured if the printer needed any future maintenance, repair, or installation of upgrades I would need this knowledge of how everything comes together.
The Build
I assumed the build would take a few hours (initially I just assumed less than 3). I was so naive! I read online that an average build time to put the 3d printer together can easily take 10 hours. I think mine took close to 16 hours. I really took my time with setting the tension of the belts and the final electrical wiring. If you are going to build your own printer from the Prusa kit I would recommend setting aside a large chunk of time (about 4 hours) over three days.
The kit comes with the infamous bag of gummy bears which seem novel at first, but rewarding yourself with the very specifically prescribed number when you finish the macro level sections of the build is surprisingly very rewarding and fun.
If you take your time, don’t rush, and read the instructions carefully, then almost anyone should be able to do this build. The final wiring up of all the servos, sensors, and power cables is relatively easy, it just requires a very slow and methodical attention to detail. I can’t tell you how relieved I was when the LCD powered on and fully successfully performed all of the calibration checks!
I did the majority of the build on the dining room table with my son and daughter watching closely beside tme. The build is an excellent way for young minds to see mechanical engineering principles slowly combine and manifest into a fully working device. As we built the printer we discussed concepts such as servo motors, the concept of a power supply, gears, set screws, linear bearings, hardened rods, extrusion nozzles, and sensors. I can’t understate the educational value of this build for young engineering minds.
Our first print was a whistle from the supplied SD card. It took about 20 minutes. After we got the hang of setting up the printer we printed a vase, a pug dog figure, and a gear set from files included with the SF card from Prusa. I am still amazed at the quality of the print. The detail exceeded my expectations. Simply unbelievable!
Since the main reason for getting the printer was to generate prototypes for combat robotics we pulled an ant-weight combat robotics .STL file from thingaverse to print. This print room about 6 hours. We let it run overnight, and like magic it was waiting for us there in the morning.
3d printed antweight combat robot body
Conclusions
Embrace technology! I’m excited for the moment when some small part breaks around the house and we can re-engineer a CAD file to print a replacement part on the spot. Just having the device here has me thinking about ways to use this new in-house (pun intended 😉 ) capability. The Prusa 3D printer models are the best value for your dollar and are an affordable foray into on-the-spot design and manufacturing. Building the unit from the parts level is a labor of love and an experience to be cherished.
I was able to pair up a family trip to Disney with a side trip to the Orlando Maker Faire. My parents who had previous plans to take the Amtrak Auto Train from DC to Florida were gracious enough to let me pack my power racing series go kart into the back of their van for the ride down to Orlando. This allowed me the good fortune to participate in the final and grand finale race of the PRS season. (Not that I had any chance of winning anything, I’m still towards the back of the pack. It’s hard to describe how much fun it is to race in these events though).
Black and Yellow Tubs!
The race organizers for this location decided to skip the traditional orange and yellow jersey barriers and tried out a track border consisting solely of water filled Stanley Tool tubs. The corners and turns of the track were plated with plywood shielding to deaden impacts.
This Stanley tool tub track border setup had pros and cons. The tubs sit lower to the ground and allow greater visibility of the entire track for the spectators and the drivers, but when you crash into the Stanley tool tubs they spill a lot of water onto the track making it a mess while racing. This phenomena also creates a negative cascading effect as the track got more slippery more track border impacts occurred. I was soaked after every race (but it was FUN!).
Ooogah Horn!
The only mod to my vehicle for this PRS race was the addition of a Harbor Freight oogah horn. I added a small momentary switch button to the steering wheel and mounted the horn to the exterior of the electronics enclosure. This is the first time I’ve raced with a horn and found it comes in handy when passing slower cars on the corners.
Robot Ruckus: Combat Robotics
Maker Faire Orlando was also hosting a combat robotics event called Robot Ruckus this weekend. This was my family’s first exposure to combat robotics and I think my son was hooked on this event after watching the larger robots battle it out in the big arena. I ordered a battle bots 101 book when I returned home for some future research.
This was my third year attending this event and it has grown considerably year over year. The event this year hosted a blacksmith, educational tech talks on a variety of topics, and my favorite – pumpkin trebuchets!
It’s my hunch that the race here this year served as a geographical proxy for the abruptly cancelled New York Maker Faire for many teams. Many of the individuals I spoke with mentioned the extreme disappointment upon hearing NY World MakerFaire was cancelled. There were 12 working teams in attendance. The track is unlike the others – it’s on dirt, grass and gravel and the drifting was superb in this environment. Who doesn’t enjoy a little cart drifting?
Upgrades
I added a 48V to 12V buck converter to my power series race car and used this to power a brushless 12V electronics fan in order to cool the speed controller which had overheated inside the ammo box at the Atlanta race. (An attachment fastener is missing in this video clip)
Results
The new brushless motor setup combined with the cooling fan worked excellent. My car was finally starting to be quasi competitive. I occasionally pass a racer or two! The first race I had transponder issues but believe I came in fourth or fifth place. Much to my surprise I came in 3rd on the second race of the day and got my first legit podium appearance! For the third race of the day I had two collisions on the track and my speed controller was acting abnormally and I was unable to finish the race.
After a long days drive from New Jersey I rolled into Georgia State Stadium for MakerFaire Atlanta for the Power Racing Series. My mini electric vehicle named RhomBUS (pun intended thank you) did not perform well at MakerFaire Detroit and I’ve been hungry for redemption. Current improvements include a more firmly mounted seat, a 12S (48V) battery pack – (actually two modules of Nissan Leaf battery cells wired for separate 6S charging, and then daisy chained into series for 12S – 48V) a new the MY1020 motor and a 200amp Kelley controller.
The Atlanta Venue in the stadium grounds is excellent and I was especially impressed when the organizer informed me Maker Faire Atlanta is free entry for all to enable accessibility of STEM events to all young adults regardless of their financial situation. Very Cool!
Saturday
Sunday
I cooked my DC brushed motor on Saturday. Fortunately a team member from the Lazy Gecko team was able to allow me to acquire a brushless DC motor and motor controller at market price. With the new motor and controller installed my car was back in business and ran noticeably faster.
I came across a news highlight photo of the Philadelphia Kensington Kinetic Sculpture Derby in 2017. The photo was of a two person team driving a bike contraption across a thick mud pit surrounded by cheering crowds. I was instantly hooked on the idea.
When I looked up the event on the web in 2018 I had just missed the opportunity to enter the event and vowed to make an attempt at mud pit glory in 2019. Fortunately when late March 2019 rolled in I was ready to start building my kinetic bike sculpture for the May event.
Most of my research centered around freak bikes, cargo bikes, recumbent bikes, penny farthings and any of those ridiculously zany bikes you see riding across the playa at burning man festival. Back in 2011 I built a recumbent bike using plans from Atomiczombie.com which also served as a good primer on bike mechanics for the task at hand.
I have the good fortune living near the Trenton Bike Exchange which is one the best kept secrets for acquiring gently used and sometimes fully refurbished bicycles at a tremendous value. Most bikes there retail from $40 – $100 per bike and the children’s bikes can range from $20 to $40 per bike. I went to the exchange and acquired one adult bike ($60) and two children’s bikes ($20 each).
Primary concept: Faux Farthing
I settled upon a plan to take the mountain bike, remove the steering stem, flip the bike 90 degrees upright and then weld a steering post chopped from another donor bike and then weld the remainder of the frame to the steering column. The genius of this plan was that I could entirely reuse the existing drivetrain, existing rear brake (which is now the front brake) and reroute all of the shifter knobs and brake handles to the newly attached steering wheel directly above. Voila’!
Concept attempt 1)
Faux Farthing with a long body and single wheel. To be honest I don’t know how good this concept was because it didn’t get much “run time”. I had welded the front and back part of the frame to the tubing holding the seat. On the first trial run I got about ten feet down the driveway before the tubing sheared away from the bike seat post essentially snapping it in half and sending me unexpectedly onto my backside. Another observation, although I was about 3 feet higher than a regular bicycle, it felt uncomfortably high and very unstable at slow speed. I had to start by placing two Home Depot buckets adjacent to the bike on each to step up onto the seat. The Kensington kinetic sculpture derby is in an urban environment and I was unsure how much stop and start would be required. Stability and mounting had to be a design consideration! This idea of a two wheeled tall bike for this application ultimately proved untenable because a two wheeled tall bike becomes unstable and terrifying at slow speeds or even worse stopped.
Concept Two) Faux farthing with long tricycle frame.
The second iteration had a long frame with small rear wheels chopped from the donor part kids bikes welded to a back frame member. A giant adult tricycle. This variant worked but, a second design flaw emerged, the turning radius of the bike was too great. Turning was just too wide and I was certain I would not be able to navigate those tight Philadelphia alleyways will agility. Getting onto this monster was still also a problem without some sort of foot stool assistance.
Concept 3) Faux-farthing and giant tricycle hybrid.
I ended up chopping the frame down to a much shorter “tail size” and rewelded it to the primary frame member. I finished this final iteration about 3 days before the Kensington derby which gave me a modest day or two to learn how to ride this contraption. The pressure was on!
Trial Run
The flat back rear frame served as a perfect step ladder onto the seat. The biggest challenge was getting used to the front wheel drive wheel that also is the steering wheel. You have to pull the steering shaft on the side that you are pedaling to keep the bike going straight which takes getting used to. It’s weird at first, but after a few attempts I got the hang of it.
Finishing Touches)
I used a can of pink and a can of neon green spray paint laying around my garage to spray up the frame to give it some flair. The bike easily comes apart and disassembled into two parts at the steering stem and was able to be easily fit into the back of our van.
Derby Day
The entire build took longer than expected so I was unable to make any other freak bikes for the family. To add some flair my wife and daughter went with a French girl theme and we put my son in an old Sriracha costume we had in the house.
The derby was an excellent experience! Who doesn’t love a warm spring festival? There are several obstacles the parade participants must traverse, my favorite being the foam and bubbles area and the dodgeball segment with the color dust being thrown at you. The crowds cheering on the derby participants was uplifting. Definitely the most exciting bike ride I’ve ever taken with my wife and kids.
The Mud Pit
My son was able to bike through the mud pit with ease. I on the other hand was not able to make it across unscathed.
Someone on social media actually to turned this into a meme.