Circa 2008. At age 13 my adolescent mind desired a motorized bicycle. With absolutely no budget, I began brainstorming ways to cannibalize my seldom-used Razor E300 electric scooter with its rusty bearings and dry SLA batteries… This is the short story about how my DIY e-bike came to be.
It’s alive! The tricopter went under a few more revisions and prints before finally taking to the air. My old Rev One Quadcopter has been reduced to it’s (over-engineered) frame and nothing more. Its parts (motors, ESCs, batteries, Crius AIO, etc.) have moved on to become this very tricopter.
Currently (in the picture) it is set up to fly FPV sans-GoPro. There is an optional part available to replace the camera pan/tilt servo mount/hole with an alternative “use-what-you-want” vibration-dampened plate.
Keep reading for a couple closeups and highlights of the tricopter.
The frame is now prototyped and measurements are almost final. Several small changes were made to the source files as result of this prototype (now on internal-revision #24). These changes included primarily wider tolerances and smaller hardware requirements. Other potential ideas are still pending (in particular; optional “taller” landing struts, ESC/wire management, and AIO mounting).
Changes to the last update included primarily, universal motormounts. Now it’s not necessary to use a specific cross plate on a limited range of motors. I’ve adopted the standard 16/19mm hole spacing used on many motors appropriate for this size multicopter. Also, the mount’s face is now flat on both sides, so you can more easily mod them (drill holes) for a specific motor that doesn’t follow these standards. With this, you will need to use 8mm M3 socket cap screws (instead of the shorter, countersunk M3 screws often provided with your motors) to mount said motors to the mounts.
The arms fold back too!
The frame still needs to be prototyped on my printer, though I have modeled the finished project to get an idea of the size.
The distance between motor-centers is roughly 625mm when the two front 1/2″(12.7mm) wood dowels are cut to 350mm and the tail to 310mm (-40mm). This was necessary to accommodate the inline motor hinge that pivots on the axis of the tail arm. These dimensions, along with other things, are subject to change after the prototype gets printed.
I modified Thingiverse user ennui2342’s tricopter body, based off of David Windestål’s RCExplorer tricopter, to support the stronger, more common 1/2″ wood dowels. Other minor modifications to the body were made as well. I also loosely based my landing gear/motor mounts off of jphillips’ designs. The shock absorbing bottom plates (optional setups for FPV shown above) are unique to this tricopter.
I still can’t draw very well at all, that’s why I plot vectors!
Above is a 2D interpretation of Romero Britto’s “Big Temptation” sculpture. I started with a basic profile image of the sculpture and used Photoshop and Inkscape to trace it into a vector image. From there I did the same things mentioned in my Trinket contest post. See below for a video showing my 3D printer print parts of this image; it’s quite fascinating to watch.
After winning the Adafruit/Hack a Day Trinket contest I had to decide what to do with my new Trinket microcontroller. A few weeks went by before I came across this universal foot switch. With plenty of space inside it was just begging to be part of a new Trinket project. One thing led to another and then I realized that I am terrible when it comes to over-thinking the headings and greetings to my emails and other messages .
Thus came the Trinket Auto Greeter, or TAG for short; it types out a random greeting from a list at the push of a button. The code has been made available on the project page for anyone to use or edit.
Call me biased, but I think everyone should start their oscilloscope journey with an analog. Not only does learning how to use its many knobs and switches give you a fantastic skill, taking it apart for repair or curiosity becomes a new and detailed lesson each and every time you open it. Not to mention that most analogs are significantly cheaper then their digital counterparts, especially when you are concerned about bandwidth on a budget. Need long-term digital storage (DSO)? Just stick a camera in front of your analog oscilloscope and you’re golden.
On October 21 the Hack a Day blog announced a contest where readers can slap the blog’s logo on something and win Trinkets that were supplied by Adafruit Industries. There were
twenty 41 Trinkets to give away in this contest and preference was given to both the smallest and largest of the entries. The deadline was November 1st and being the busy college student that I was with not much time on my hands, I decided to just sit back and watch the entries roll in.
At around 9pm on October 31, with only three hours left in this contest, I suddenly got the urge to enter. Not a minute later I came up with a very simplistic idea for a universal pen plotter based off my 3D printer and the software I normally use with it.