Sunday, April 1, 2012

Progress on the Velociryder V4

Circuit Board

After some Eagling:
Blank space for your comfort.
Using Dorkbot PDX's PCB printing service, kapow in real life!


The EAGLE (version 6) board files can be found in the appendix on the bottom of the page. Unfortunately, the finished boards didn't come in time for my trip. 

Mechanicals

In the mean time, I learned a lesson the difference between mathematically ideal chain sprockets and realistic chain sprockets.

Good sprocket on the left, bad sprocket on the right.
The mathematically ideal sprocket had extra tall teeth and too narrow spacing. The chain can only fit a few teeth before they become misaligned. Foo, wasted a bunch of steel.

But once the good sprockets were made, ghetto beveling with the drill and belt sander, as learned from Jamison.


Otherwise, the build went smoothly.

All the waterjet parts
Frame assembled
And add wheels.
Wheels and motors and shaft and duck shaft clamps were borrowed from Velociryder V2.

Battery spot goes in the top.

With the deck placed.
Since, during the build, I didn't have the PCB, I breadboarded an equivalent circuit using sensors from Velociryder V1 and an Arduino. Also, I figured out I did not screw up the strain gauge circuitry. Yay!
While in the picture I used a switching regulator to bring the main battery's 22.2 V down to 5 V logic, I had previously used linear regulators. Three 6805s in parallel did the trick for a few hours before they died. Just enough time for a quick demo to MTV and the Inventure Prize judges. Law of Demos (see below) didn't curse me this time!

To be continued as I accumulate more pictures.

Appendix:

Code: https://github.com/aaronbot3000/velociryder/tree/master/arduino
Solidworks: https://github.com/aaronbot3000/velociryder/tree/master/solidworks%20model
PCB: https://github.com/aaronbot3000/velociryder/tree/master/board

Law of Demos: Anything, during a demo, will not cooperate. Things that should work will not, and things that should not work will.