Saturday, February 26, 2011

The Blade CX2 Hero Cam

A few winters ago Doug got me one of the best Christmas gifts ever. It was a set of small remote control helicopters that fired infrared beams at each other disabling the other helicopter if it was hit. They turned out even better at driving Molly insane (Here). This evolved into a fully collective pitch RC helicopter that I spent hours trying to just hover. I got pretty good at it, but after a crash it never flew the same. The end result was it veering out of control and nearly killing Doug's roommate. It was a great crash and the end of my RC helicoptering for a year.

RC Helicopter #1


When winter came around it was time for another helicopter to occupy my mind during the cold months. I picked up a Blade CX2 for cheap off Craig's List. The Blade is co-axial meaning it has two counter rotating blades instead of a tail rotor to overcome the torque. It's smaller and easier to fly. The blades are made to self destruct if they hit anything so you don't have to worry about injuring personnel or property. I spent hours tormenting Molly (Here).

My evolution at Blade flying came to a point last fall where it was time to mount the Hero Cam to it. The problem was that the Hero Cam was too heavy and the Blade could barely get it off the ground. Mark, an expert on the matter, convinced me that a full rebuild was in order. I order the parts and got to work. It started with a rigid carbon fiber frame, powerful motors, and CNC cut aluminum rotor parts. The transformation was amazing.

The Rebuild






The new Blade CX2 had no problem hauling the Hero Cam around. If anything it made it slightly more stable because of the higher gross weight. The first project was to get some Heli Cam perspective of Molly. I did it on on a fall afternoon when Cruz was over.

Heli Cam of Tormenting Molly


The next project was to record a perspective that only a small helicopter could achieve. In the mall near my house there is a bike path that follows a creek under a busy road. It is surrounded by a pond and a grove of aspens. The aspen leaves were in peak yellow. There is no music to the shot, but I really like the perspective of the Heli Cam. When it flies down the creek it's like flying down a mini Grand Canyon. Another idea I have is find a tall building and fly out of an upper story window. The inside to outside transition will be really unique.

Heli Cam Perspective


Using my freshly honed skills I brought the Heli Cam to the Boulder Rock Club (an indoor climbing gym). There is no better venue for indoor camera mounted RC helicoptering than a climbing gym. It's open, tall, with subjects up high and down low. The Boulder Rock Club is the coolest climbing gym I've ever seen with 3 different rooms, caves, overhangs, and even a slide.

At the Boulder Rock Club


Now I'm the proud owner of an HD Hero Cam. The two problems with mounting the HD Hero Cam are it is heavier and not as "sacrificeable" if the helicopter gets away from me. I'll get the balls to mount it eventually, in the meantime I've tuned the Blade CX2 to be more agile. It's good fun outside, but really hard to land on people's heads now.

Blade CX2 Tuned for Agility


The Tradeoff is it's Harder to Land on People's Heads




Thursday, February 24, 2011

The Hack Mechanic

If you are not a car person, bare with me. There is a hell of a story buried in the jargon, just read on it's worth your time.

Last summer I replaced the clutch delay valve (CDV) in my M Coupe. The CDV is a restriction in the clutch line of modern manual transmission BMW's that delays the actuation of the clutch. Common wisdom is that BMW engineers did this to prevent novice drivers from burning up their clutch. The real world result is inconsistent clutch actuation that is annoying, frustrating, and down right infuriating! I removed mine. It was a bitch. The Z3 platform wasn't designed for the M division's S54 engine. BMW Motorsport GmbH literally shoe-horned it in. With Jonny V's help, after trying many different angles and body contortions I would the right angle to pinch two flare nut wrenches together to break the seal of the old line. After that the job was a breeze. I did the rest of the brakes while I was at it.

Flare Wrench Set Up to Break the Old Line


New and Old Clutch Lines


New Brake Pads, Rotors, Bushings, and Caliper Cleaning




I even engineered and built my own clutch slave cylinder bleeder out of parts from Lowe's.


I was feeling really good about my hack mechanic skills.

If you don't care about cars and you are sill reading don't give up on me yet, here's where the story gets interesting.

Enter Fletch and his 2001 M Roadster. Fletch had found a perfect example of an M Roadster. It was Estoril blue over an Estoril blue and black interior and a hardtop. With 21,000 miles it still smelled like new. He asked if I would replace his clutch line along with a few other things. Always happy to help out another Z3 enthusiast I obliged. Everything went smoothly and we were on track to go to a meet up with some other enthusiasts that night. All that was left was to bolt the slave cylinder back up.

Fletch's M Roadster




Hydraulically Actuated Clutch 101: The slave cylinder bolts to the outside of the transmission behind the bell housing. It has a piston that pushes against a release lever. When you push in on the clutch pedal this piston pushes against the release lever disengaging the clutch and the transmission from the engine.

Clutch 101


Actual Release Lever (item #3)


Bell Housing (the slave cylinder bolts to the part labeled #1)


The end of the release lever has a "cup" shaped indent that the clutch slave piston fits into. If the piston isn't aligned correctly into this cup then when the clutch is pushed in the hydro-mechanical advantage of the system will force the slave piston, spring, and clutch line fluid into the transmission bell housing. Think of it like blowing a dart out of a blow gun. It was August and Fletch's transmission was scolding hot. As a result I couldn't hold the slave against the transmission for very long before my hand would burn. A pair of mechanics gloves would have fixed this, but alas I'm the Hack Mechanic (i.e. no gloves). The slave felt good, but I didn't know any better.

With it all buttoned up we were ready to go. All that was left was to test the clutch a few times to make sure it was bleed correctly and lower the car. I sat in the driver's seat, pressed in on the clutch and... (long dramatic pause) ...with a bit of a pop it went straight to the floor. "That is odd"; I thought. I climbed underneath and saw hydraulic fluid dripping ominously out of the bottom of the bell housing.

Let's consider the situation for a moment. In my garage is a collector vehicle, that originally retailed for over $55,0000, leaking hydraulic fluid out of the transmission and it's my fault. To make matters worse, I've known the vehicle's owner for a total 2 hours and have no clue what I did wrong. It was an awkward moment. Doug and Jonny V were there, but the silence was deafening.

I went through several stages of denial, anger, fear, and frustration before I figured out what happened and, even worse, the only way to fix it. I spent an hour desperately trying to fish the slave cylinder piston out with a cheap grabber tool, but it was fruitless. The transmission, factory fresh with only 20,000 miles on it, had to come out.

It was getting dark. I gave Fletch a ride home and we pondered our options. The thought of pulling a stranger's transmission in my garage was terrifying, but in my gut I knew I needed to do it. It was the only way to make things right. The problem was it wasn't my decision to make. To pay a BMW mechanic to pull the tranny, clean out the slave cylinder components, and reinstall it all would cost anywhere from $3000 to $8000. The thought of all that money only made it more awkward between us. We collectively worked through the decision process and decided to pull it. While it was out we could replace the shift pin bushings, a known defect in ZF transmissions.

A week later after hours of research, gathering a long list of replacement parts (one time use nuts, etc), and a few special tools we set to work. The first part of the job was removing the exhaust, heat shield, driveshaft, transmission mounts, and disconnecting the shifter. It was drama free except for a clip on the shifter assembly that is called the "Bitch Clip". It took over two maddening, hand cramping hours picking at it to get it off.

///M Exhaust Mmmm


The Bitch Clip


Finally we can get to the Transmission


To get the transmission out it has to be unbolted from the engine and very carefully slid rearward to avoid damaging the pilot bearing or input shaft. Sounds easy right. Remember that part about "shoe-horning". The only way to get to the top bolts is to rotate the front of the engine up (clearances are millimeters) and lay under the rear wheels with 3 feet of socket extensions. It's arduous, but will be much easier next time now that I've done it. When we pulled the tranny out the clutch slave piston and its spring were sitting in the bottom of the bell housing. Luckily when it exploded into the bell housing no hydraulic fluid got on the clutch.

The Slave Piston and Spring in the Bell Housing


The Clutch was Clean - Thank God!


The stress wasn't over when we got the tranny out. The next order of business was replacing the shift pin bushings. ZF transmission of this era had a run of bad shift pin bushings. The result was that the shifter would stick to the left or right instead of returning the center underneath 3rd gear. Incidentally the ZF company was formed from the remnants of the Graf Zeppelin Company, makers of the Hindenburg.

Getting the old shift pin bushings out requires slide hammering out the covers, removing the springs, and carefully prying out the bushing which was pressed in at the factory. You have to be careful not to etch the wall of the transmission. I made a special tool by grinding a jeweler's screw driver flat on one side. After stressful prying and picking I got the old bushings out. I irrigated the holes with gear box oil to flush out any metal shavings. A special drift is needed to hammer the new pins in, but anticipating my shift pin bushings would fail someday I had acquired a set when I got my car.

Shift Pins Disassembly


My Homemade Tool


Hammering the New Bushing In


Done, Only 4 More to Go


With the tranny serviced and the slave piston recovered it was time to put it all back together. It went smooth except for 1 bolt on the top of the bell housing, which look no less than 6 hours to get the right angle. When I reinstalled the slave cylinder I did it with the attention of a brain surgeon. When it came time to test the clutch my stress level was through the roof. I gathered all the bravery I could, got in the car, took a deep breath and pressed on the clutch pedal. It responded with a satisfying linear pressure. The job was done. What started as a two hour job finished 2 weeks later with 5 solid working days. Fletch got his shift pin bushings serviced, CDV deleted, and a few other odds and ends done. I garnered a wealth of knowledge and earned the title of Hack Mechanic. We both worked together to solve the problem and became friends in the process. With the hard work over it was time to go for a victory drive.

Victory Shots


Friday, February 11, 2011

October Aerotowing

It's been cold as Fuuuuuuuuuu since the new year and I've been itching for some warmer flying weather. Catching up the blog I'd like to re-live a great aerotowing day I had in October. It was a Sunday that didn't look too promising, but flying at Moose's is always I good time. The air on the first tow was sporty and I pinned off at about 7500' in a strong thermal. It was nice and juicy all the way to 9000', where an inversion took a couple attempts to break through. Once I broke through it was a smooth climb topping out at 12,800'. Getting close to 13,000' over the flats in late October was a gift and I enjoyed it until near hypothermia forced me to descend.

Thursday, February 10, 2011

Our Wedding - Dead Horse Point

It was Monday morning. The weekend and festivities were over. Sunday night we managed to score the last room in Moab, literally. It was the honeymoon suite at a bed and breakfast off Center St. We spent the morning relaxing and recovering.

Relaxing Morning


Packed Up


After getting packed we searched for a good mountain bike ride to finish the weekend. We wanted something new and mellow. Dead Horse Point State Park had recently opened a new trail system to mountain biking. It's a mellow loop that follows a cliff band around the northwest perimeter of the park. The riding was mediocre, but the views were spectacular. It suited our exhaustion level perfectly.

Dead Horse Point






Standing on the Old Hang Glider Launch


After Dead Horse Point we hit the road for the trek home. One last treat awaited, driving the M Coupe through Glenwood Springs Canyon. Keeping with the pace of the day I kept the speed down so we could take in the view.

Leaving Moab


Glenwood Springs Canyon



Saturday, February 05, 2011

Our Wedding - The Day After

I would like to say that on the day after our wedding we kicked back, relaxed, and enjoyed our first day of married life, but that would be a lie. It was a hectic morning of cleaning, packing, cleaning, and more packing. If I could have changed one thing about the weekend, it would have been to hire some help for the clean up. Just like the wedding, everyone chipped in and got the job done. We had originally planned a bike ride, but with everyone leaving at different times for different places it was easier to just go for a hike. Arches National Park, just across the Colorado River, was the obvious choice.

A Hike in Arches




(click on me for a larger image)




Quite a few car commercials are filmed in Arches, so I couldn't help taking a few obligatory M Coupe shots.