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Porsche 714

August 1, 2016 3 Comments

My Entry for the LEGO Rebrick Porsche Contest.

This year, it seems like everything about LEGO Technic is about Porsche. LEGO created a 911, and started a contest for creating your own Porsche. Porsche is all everyone is building and talking about.

So I made one too. The Rebrick team posted a contest to design your dream Porsche, and thinking of the words of Mr. Porsche, “I couldn’t find the car I dreamt of, so I decided to build one myself,” I set to work. My dream Porsche lives in the spirit of the 914 and the 924: A compact, lightweight, mass-market, rear-wheel-drive sports car. It has a long hood, short overhangs, and a roofline that alludes to Porsches of today and yesterday.

I had six weeks to design a car. In a week I had the front and rear axle, and the transmission. The transmission is a similar unit to the one I had in the ATS. Six speed manual, with a single point shift lever. It keeps the gear changes quick with short throws. The rear axle is an independent suspension design, with short upper swingarms, and long lower swingarms. This changes the camber of the wheels as they move through the suspension travel, to keep a consistent contact patch around a corner. The limited slip differential is mounted longitudinally behind the axle. The front suspension is also independent with short upper and long lower swingers. The are mounted to a steering uckle that gives both Ackerman and caster geometry.

Because it was my dream car, I wanted a car that would be inexpensive, and teach me how to drive fast. A front engine, rear wheel drive is a less expensive car to design and build. Additionally, my car would have a Boxer 4 for lower cost, and an option for Boxer 6 for more performance. Since I can use some training to be a better fast driver, I though a roll cage would be necessary.

The remaining five weeks were spent working on the bodywork and the interior, which always takes more time than you think. I fit the cabin in around all the mechanical bits, and was able to add a glovebox and a manually adjustable tilt steering wheel. The seats are simple, but match the car interior well. I wanted to keep a couple of features that were iconic in my mind with Porsche cars: Round headlights, a full width thin taillight, a curvaceous roof, hunches over the rear wheels, and a taller greenhouse. After many drafts, I was able to get a design I was pleased with.

The car turned out how I wanted, and I felt it was a good contribution to the contest. The front of the car did not turn out how I envisioned it in my mind. The rear did not look as clean as I wanted. Mechanically the car works great. The suspension works perfectly, and the steering works flawlessly without hitting the wheel fenders. The transmission is great, and the limited slip differential continues to do the trick.

After all this talk about Porsches, I’ll take some off and build something different.

Happy Building.

Filed under Cars Tagged with 2016, Cylinder, Differential, Flat 4, Flat 6, Independent Suspension, Limited Slip, MOC, Porsche, steering, Supercar, suspension, technic, Worm Gear

OCTAN Air Racer

July 20, 2015 2 Comments

OCTAN is one of my favorite longitudinal themes of LEGO. It gives a little color and identity to many of the racing vehicles that have been produced by LEGO since 1994. I don’t know why it took me so long to start making MOCs with an OCTAN theme, but after last summer’s OCTAN F1, I figured I should do another one.

The full gallery including instructions may be seen here.

It was time for me to build another airplane, and I figured a0 small air racer would work well in the OCTAN colors. Right from the beginning, I was sure I wanted to make a biplane, and I wanted a radial engine (all real airplanes have propellers). From there everything was on the table. Off to designing.

I started with the radial. It’s not quite a radial, but rather two perpendicular boxer 4 cylinder engines. Each bank of two cylinders are mounted in a different direction; up, down, port, and starboard, and are connect by one common crankshaft. The side banks are one stud forward, and the up and down banks rear, so all eight connecting rods can fit on a common 5l axle. Two engine crankshafts are mounted at each end. The motor spins well, and quite quickly, but the connection is not exactly “legal,” as the pins on the cylinders are a little stressed.

Working backwards, I attached the leading edges of the wings, and the worked on the landing gear. Being an air racer (even a biplane), it had to have retractable landing gear. I connected the two wide spaced legs with a simple axle and bevel joint, and added a worm gear to articulate the action. It is a simply solution, and it functions well.

Just behind and above the worm gear is the joystick. The roll functions are connected to the bottom wing by gears, and the pitch function is connected by liftarms to the rear elevator. The rudder is fixed. The lower ailerons are connected to the upper ailerons by a simple 9L link. When you move the joystick, all four ailerons move. The cockpit is a little cramped, but when you are racing space is not a concern, only speed.

After the radial, the bodywork was the priority for the MOC. I have been slowly acquiring white and green parts over the last year. The airplane was designed as primarily white, with red and green accents. The red stripe worked well, as did the red tail, but I could not find a great way to incorporate the green. I added a little to the tips of the wings, and to the wing control surfaces. I used a couple more stickers that I had left over from set 60025, and the MOC was finished.

I was pleased with how the MOC turned out. The airplane looks strong, and the red and green make the white vibrant. I wish I could have found a better place to incorporate the green. The places it was added seems a little haphazard. The radial turned out great, but I feel a little bad about the illegal build. The landing gear works well, as do the control surfaces. I was pleased with how it turned out. Next up, maybe an OCTAN speedboat. Other ideas?

Happy building.

: OCTAN Air Racer

Filed under Aircraft Tagged with 2015, Airplane, Cylinder, Flat 4, Instructions, Joystick, MOC, OCTAN, Radial, technic, Worm Gear

OCTAN F1

September 30, 2014 7 Comments

In a bought of inspiration (or distraction) at work, I noted my old 6546 sitting on my desk. After years of looking at this small car I thought, I could make this bigger, and in Technic. Done.

The full gallery including instructions can be found here.

I decided the car should have a simple engine, four wheel suspension, and working steering. Recently, there was a good design that gave me an idea about how to do a smaller scale driveline for the car. I worked on the rear first, and once I had the suspension setup, I added a small flat four engine place directly on the bottom of the car. This would be the basis for the rear of the chassis.

I then started the front suspension design which would utilize the new suspension components from 42021. I first tried adding shock absorbers. Then I added rubber connectors. The first was too big, the second did not work to well. After monkeying with it for a while, I developed a simple torsion bar setup. The torsion axle is a 10l and provides the pivot point to the bottom control arms. They connect to the chassis behind the suspension to a fixed point under the steering wheel. The set up works well. Frankly, it works a little better than the rear as the rear could benefit from stiffer arms and suspension mounts.

Next came the body work. As I wanted to keep things similar to the 6546, the coloring would have to be white, green, and red. And it would need some stickers. I used the stickers from set 60025, so the car number would have to be changed from the original #4 to #5. The coloring and markings turned out well. I tried to make sure it was not too busy. Easy enough, and everything is easily acquired so you may build your own.

Fitting with my yearly planning I have now completed the two small builds I wanted to complete. It was quick, fun, and a MOC that is accessible for other builders. Feel free to build your own (make some new colors, and we can then have a race).

Happy Building.