November 4, 2016 Leave a comment
In what is becoming a little bit of a theme, I submitted another design for a Lego contest. In the long line of Eurobricks.com contests, the Technic Challenge 10 called for a pneumatic build. Challenge accepted!
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The contest had very few constraints other than the build had to use Pneumatics. As I have mentioned before, working with pneumatics is not my preference. I don’t like them, so it was good for me to step out of my comfort zone.
I was feeling especially creative this time, so I thought about a number of concept ideas. Pneumatics do not tend to work smoothly when lifting arms so I decided against an excavator and a loader early. Additionally, I was not willing to invest in additional parts for this project. After a couple of drafts, the idea of this bulldozer was born. Taking some inspiration from some of John Pope’s design, the basic idea was there. The dozer would have different tracks, a three movement blade, a crazy engine, and a forward thinking design.
I started with the tracks. After moving the axle points four wheels countless times, I came up with a design I liked. I made another one, and linked them together. The I worked on the blade. The dozer would have a lift, tilt, and side to side angle adjustment. After playing around with some idea, I found a solution I liked. Two pneumatic rams were on the front to lift the blade on the top. Then two links were connected low on the two sides of the blade, and then on each side of the dozer. These points on the dozer were moved fore and aft by on pneumatic ram each. These side rams would move the blade left or right individually, or together they would tilt the blade up or down. Additionally, it allowed all the tubing to be internal.
I added a small compressor powered by a Power Functions M motor, and the battery box under the cab, and added the 16 cylinder engine (coupled V-8 and Flat 8). The cab was easy to get the shape I wanted, and gave me some space for another pneumatic ram to open the hood. I then decided to add a ripper since I had one pnuematic left. The new 1×11 ram a great addition, but a little more power could have been used for the ripper.
I was pleased with the look the bulldozer. The functions worked well, but on reflection, the were not exciting enough to be competitive for a contest. After two pneumatic builds in a row, I find some of the frustrations I have with them remain, but I am discovering some charms as well. We’ll see what comes next.