Sunday, July 10, 2011

0.5 hours Pilot in Command

How do you know someone is a pilot?

They tell you. Again, and again, and again...

Today I managed to convince a different instructor (Peter Swift) in a different plane (1946 Aeronca Champ) at a different airport (Harvey Field, S43) that I'm highly unlikely to kill myself in a plane. So unlikely, that he hopped out and let me fly it myself for a half hour!

I never learned how to smile for a camera. And the sun was in my eyes too.

I'm pretty damn excited.

BTW, I'm getting a Sport Pilot license which requires about 50% of the time and cost of the Private Pilot license. I can fly planes like the one above, and the new flying car that should make it to market in the next couple of years.

Saturday, July 9, 2011

Abandoned: CNC Mill

I don't know about the rest of you, but I start a lot of projects that don't reach completion. I've become emotionally attached to the parts that I dragged around with me so I'm loathe to part with them, but I thought I would start documenting them.

Back when I lived in San Francisco and had full use of my arms I bought a Rong Fu RF-31 Mill/Drill from Enco:

I was having a blast with it and lusting after making it CNC. But then I got a repetitive strain injury and lost the ability to wrench the bolts that hold the head in place. The mill languished for a long time at my studio at the Cataclysmic Megashear Ranch. When I moved to Seattle I left the mill behind in the care of Jamie Nasiatka. This was back in 2004, I haven't been a great friend and slowly lost touch with him. But a quick search just showed that he finished what I always intended: converting the mill to CNC.

I've since purchased a Mini-Mill that fits my shop and arm capabilities. Due to my CNC lust back in San Francisco, I purchased a number of the parts needed to convert the mill to CNC.

The parts are totally useless for my Mini-Mill.

Mini-Mill, small but easy on the arms.

Here are my parts that I'm still trying to come up with a creative use for:

36V 20A Linear Power Supply for the Motors, also from Dan Mauch

Old Servo motor drives from Gecko

Servo motors with encoders from Dan Mauch

Parallel Port breakout card (sorta useless since I don't have a computer with a parallel port anymore).

Possible uses:
power drive for the lead screw on the 9x20 lathe. I doubt I'll cnc it, but it would be an mighty accurate power feed if hooked up to an arduino.

Friday, July 8, 2011

data geekery and tuning

I finally finished my data acquisition for the bike. I used an Arduino with an SD Shield to capture the TTL serial data as output by the Cycle Analyst.

Arduino with SD Shield taped to back of bike.

I actually took the bike out to run some errands. One of the annoying things is that I'm using the current and speed control on the Cycle Analyst. It uses a PID loop to do this, and the defaults are tuned for a bike with less power than mine. That means it oscillates. If you look at the image below, this represents me running on flat ground with the throttle wide open. You'll see the PID loop cranking the amps up and down and the speed oscillating about 3mph. I'm trying out Tableau so you should be able to play with the data.

Full run coming back from Bartells :

eBike construction details

I had a great time giving a talk at dorkbot-sea about my build. Lots of great questions.

A couple of people asked how the motor is attached to the controller. Here's a close up that shows the torque plate machined out of 1/4" mild steel along with the motor wires with a drip loop.

Torque plate on left side of axle.

Battery Management System showing fully charged (except for one cranky cell)