We went away this past weekend for a four day mini-vacation up the coast to Gibsons on the Sunshine Coast. We stayed at a great little B&B called Marian’s on the Coast. Its in a wonderful location and since they are “dog friendly” we took the two dogs Bailey and Cairo with us.

The B&B has a nicely equipped kitchen so we made our own meals most of the time. I made ham and cheese omelettes each morning and we grilled out for lunch. Dinner was usually fruit, cheese, and wine (or port – we had a nice Smith Woodhouse LBV with us).

We did have lunch in town once, at the Sweet Water Bistro (Urbanspoon link). We stopped in Mike’s Gelato as well, for a refreshing treat while poking around town. We didn’t get to Smitty’s but was recommended; next time we’ll go there for oysters for sure.

Gibsons is about 40 minutes by ferry, and the B&B is another ten minute drive. Highly recommended if you are visiting that area.

I uploaded some photos here, enjoy!

Today marked quite the milestone for my Outdoor Robot project. The last remaining mechanical parts to make for the drive train functional are complete! In the picture here you can see the brass coupler and a steel drive shaft. The gearbox from the RC truck was originally set up to use a “dogbone” drive shaft – a linkage that allows rotation plus slight shifts up and down without stressing the shaft itself. A real “dogbone” shaft has a ball on each end with a pin to fit into the groove of the receptacle socket. Mine were made on my lathe and aren’t quite as nice, but still functional.

The drive shaft is made from 1/4″ steel rod turned down at each end using my Sherline lathe. This was the first time I turned steel on it, and it was surprisingly easy to work with. So far I’d say brass and steel are better materials to work with than aluminum (at least on the lathe). I turned each end down to 0.2″ then proceeded to cut the end to be somewhat ball-shaped. I only needed a couple of these so eyeballing it worked really well. The pin is some brass rod I had, super-glued into place. I liked the idea of using a softer material so it can shear away if necessary to prevent motor or gearbox damage in case of excessive force.

The coupler has a socket at one end (to accept my faux-dogbone drive shaft) and a 6mm hole with set screw to attach to the motor shaft. I turned some brass stock down to 0.6″ then drilled out the center for the motor shaft. Mounting it on my mill gave me a good setup to drill the hole for the set screw and mill out the groove on the socket. A tapped hole in the side for a 8-32 set screw completes the job. Depending on how well this holds up I may end up making a new version out of steel.

Here is another picture of the coupler and drive shaft, showing how the two parts fit together. The last picture shows the parts mounted on the robot itself. This now means the mechanical part of the drive train is complete, and (with some batteries and electronics) the robot will soon be rolling around my yard.

I’ve made a number of additions to my Outdoor Robot project, including motor mounts and getting the steering set up.

The motor mounts are milled from half-inch aluminum plate, holding two GHM-04 motors plus shaft encoders from Lynxmotion. These motors should be plenty powerful enough and also have a good top speed for this application. It took me a few hours to mill out the two mounts using my CNC Sherline. I need to make some couplings and drive shafts to get the motors connected to the rest of the drive train.

The steering mechanism is from the original RC truck chassis, I just needed to do something about controlling the servos. I set up an ATMega88 that sends the necessary pulse train for servo control. Eventually this chip will communicate with the Overo over CAN, also talk to the the motor controller board I purchased from Pololu, and will have a custom circuit board. For today its only task is to control the steering servos, accepting keyboard input from a serial console.

I needed to calibrate the servo pulse train to the desired positions of the steering mechanism as its installed. Normally servos are a wide range of motion (most go 180 degrees) and accept a pulse train with widths between 1ms and 2ms. These servos do that just fine, except there was no way to know where “center” was in relationship to the wheels. I also wanted to make sure I was getting approximately the same angle on the front and back steering. I created a little jig using some right-angle machinist squares plus clamps plus a ruler. Finding the center position was easy, then I mapped out the servo position required to move the wheel indicator in half-centimeter increments. I ended up with a table of 25 different entries for the front and the back steering servos that give me consistent control. Given the slop in the steering mechanism from this truck chassis, I figured this was good enough.

Here is a little movie of the steering in action. I set up the camera on a tripod then was pressing keys on my laptop that instructed the microprocessor to move the servos to particular locations. I have fully independent control over the front and back steering, and it really looks awesome.

You might also notice in the top right corner of that picture my new Rigol 50Mhz dual channel oscilloscope. Its a nifty piece of equipment, lets me look at signals like the servo pulse train easily. I picked it up from eBay for a reasonable price and so far (having only used it for a day) am very pleased. I recently also bought a Saleae Logic analyzer that I’ve been pretty happy with. I’ve been using it with the “early preview” version of the Mac software. It has bugs but so far none have prevented me from getting the job done. I’d recommend both pieces of test equipment for your own bench.

Last night we attended Star Wars in Concert here in Vancouver. It was most excellent! There were a few people dressed in costume (not me or Eileen though) and the general atmosphere was energetic, sort of like seeing the original movie in the theatre many, many years ago. I originally thought the event would be showing the entire first movie, but later learned it was a composite of many clips from all six films.

I have no idea how it worked out so well but through the miracle of online ticket purchasing combined with some amazing luck we scored front row seats on the floor, right in front of the stage. If I’d wanted to, I could have jumped out of my seat and easily leapt on stage. I could have tackled C3PO (Anthony Daniels) if I’d wanted to. Fortunately I resisted this urge and therefore am not writing this from jail.

The event itself was really great, the music was wonderful and we were close enough to watch the individual performances of each member of the orchestra. The only somewhat disappointing part of the evening was having to sit through so many clips from the most recent movies (episodes 1, 2, 3). It really is painful to watch the stilted dialogue and terrible acting. There were plenty of scenes from the “good” films too, especially lots from episode 4.

Of course the famous cantina scene played, with the live orchestra giving a great performance. Even though the film clip was from the 1997 redone version, we all knew Han shot first.

Eileen and I went to the Canucks seat selection session last night to pick new seats for next season. The new season won’t start until October but we are still looking forward to it!

The seat selection process is both thrilling and depressing – GM Place has something like 18,800 seats for each game (sold out every night) and yet there are really only a handful of seats available when we get the opportunity to pick. We could have kept our same seats from last year, but we were looking for something a little better: less behind the goalie and more around the side towards the blue line. We also were interested to get closer to the front row.

We lucked out this year, there were a few seats that met our “upgrade” requirements: about half-way between the goal line and the blue line, and row 3. The picture here shows the view of the defensive zone net from our seat. Nice!

Its going to be a long summer waiting for the season to start!