Another contest, another build. LEGO Ideas posted a contest to build your idea of the Volvo construction vehicle of the future using LEGO Technic bricks. This was my entry for the contest, which did not win, but was a design I was happy to complete.
The design was inspired by the Volvo Sfinx and the Hyundai HFex Concept as I was interested in trying the various tracks, and a foldable boom. I started with the track sections, with four idetntical modules. Each are connected to the center turntable with a worm gear assembly for individual track movement. The system is enough to hold the full MOC, but not overly strong.
Next came the superstructure. I created a conventional cab on the left, and added some fuel cells on the back. These cells can slide out the back of the superstructure to be easily replaced. Next came the boom. I wanted a three section boom that would fold, and extend in a variety of directions. Each of the three pivots is operated by a worm gear mechanism. The best manage the length of the boom, the main boom used a worm and 48z gear, the second used a worm and 24z gear, and the final boom used a worm and 8z gear. I added a ball join at the end of the boom to allow for multiple attachments.
The entry did not win the contest, but I was happy with the result. It was creative, and functioned well. I like the way it looked, and was happy with the track setup.
My favorite vehicles to build are garbage trucks (Ok, maybe trial trucks). I enjoy the many functions that I can create. I enjoy the diversity of shapes, sizes and colors, and I enjoy how ubiquitous they are. But I have not built many. So it was time to fix that.
I was originally going to do a large scale truck, but as my temporal limitations are becoming ever more apparent, I decided to do something smaller this time. The 13 stud wide truck is popular in the Technic community, so I decided to go with that. I very much enjoy the Volvo FE, so that was my truck. Since my last truck was one with three axles and Power Functions, this one would have two axles and be manually controlled.
I searched high and low for garbage box that would work well: Gesink-Norba, Heil, McNeilius, EZ-Pak, Dennis-Eagle, Ros Roca. All required a compactor that would need a round base for the trash to collect. Curves are hard to do in LEGO. I had some trouble with refuse compaction cycle working well on the Axor due to the floor curve on the hopper. I wanted a compaction cycle that was more simple and more reliable. So I designed my own.
It’s dead simple.
There is a angled elevator in the hopper that goes straight up and down. The center gear on the outside of the hopper that moves the elevator. When refuse is placed on the elevator and lifted, the refuse will fall over an internal wall at the top of the cycle. The refuse falls into the compaction bin, until the rear hopper is opened. Bigger parts sometimes gets stuck on the cross axle.
Inside the compaction bin, is an extraction plate. Turn the gear down near the front left wheel, and you drive a mLA to move the internal extraction plate. Everything works well for small LEGO refuse parts. I built the side of the compaction bin with slopes and tiles. After a number of panel attempts, this one seemed to be the best looking option. I very much enjoy the shape.
Since I had a little more internal room, I added a driveline to the truck. A rear differential powers a small fake inline 2 cylinder engine under the cab. To check it out, the cab tilts forward. The steering axle serves as a friction connector so the cab does not open unless you intend it to tilt. The doors open, and the bodywork was designed to mirror the Volvo FE 2011 body style. I built a small red refuse bin to show off the functions of the truck.
This may be my favorite build of the year. All the functions work perfectly, and the model looks great. I think I could add a tilting bin function, and add another mLA to give more strength to the extraction plate, but other than that I am not sure I would change anything. I will keep this one built for a while.
I find myself on diecastmodels.co frequently as it inspires many of my future builds. Most of the time the site gives me reference pictures, and sometimes it shows me something I have never seen before. This is the result of one of those late night browsing sessions.
See the full gallery at Brickshelf and on Flickr. Instructions may be found here.
I wanted to make a scraper, and once I was browsing this site, I came across the K-Tec. It was a different set-up that I thought looked fun. I was hooked. Early I decided the MOC would be perfect for the newer 49.5×20 tire, so the tire set my scale.
I started with the suspension for the tractor first. I did not have too much room to work with on the rear, so I set two differentials together, and connected them via two 20T gears. The rear one connects above to a 12T gear, which transmits rotation to the fake motor in the front. The two axle assembly pivots at this gear connection and connects to the rear wheels, so no u-joint is needed. The middle axle connects to the rear assembly through the differential connecting axle. This simple set-up allows for all four wheels to move freely, and independently.
I then added the front cab. It is not too complex with a differential fixed for the front axle, and a two-cylinder fake motor above it. A HOG gear is above the cabin which pulls a liftarm for the steering. A turntable is used to provide articulation between the cab and the rear chassis. Then a simple body was made, and off to the scraper.
I then worked on the scraper part; kind-of. I knew when I started this project I would need a bunch of 1×6 arch bricks in yellow for the front gate. There are not many of them, so I started ordering them over the course of three months. As each would arrive, I worked on the scraper. I first set the dimensions and worked on the lifting mechanism. It was a little tricky to find the correct geometry while not taking too much room, and keeping the upper pivot point small while using to mLAs for the movement. I found a good solution, but a little more stiffness in the assembly would have been great. I added an extraction plate at the rear driven with a worm gear assembly resting between the rear wheels. Another stud of travel would be great, but it was not worth adding another four stud gear rack to make that happen. Finally, all the parts arrived for the front gate, so I installed it. Because the walls of the scraper are only one stud thin, I did not want to mess with the thickness of the sides to much by adding a mechanism for the gate movement. Each assembly I tried with a mLA or a worm gear set-up looked clunky or bulky. I ended up with a friction pin with a gear to move it. It is not very fancy, but it works well. At this scale, it is all that needed.
All in all, the MOC turned out OK. It would have been better to have a stiffer hitch arm, and I would have liked a different solution for the entry gate. I was pleased with the size, and I enjoyed packing a number of features into the small (but long) MOC. Finally, for some reason the MOC does not please my eyes as much as those first pictures I saw on diecastmodels.co. Maybe it just needs to be a little bigger.
Thirdwigg.com 