Off Road Knuckleboom Truck


It was time for another truck! Free instructions can be found at Rebrickable.

I have been building a lot of tractors and construction vehicles lately. I love building them as they offer a lot of movement and features. But it was time to build another truck. LEGO truck MOCs are beginning to coalesce around the “Mack Anthem standard” which is a 15 module wide truck in about 1:20 scale. Many MOCs are being designed in this scale as it is a good playable size, and fits the scale of some of the more recent LEGO trucks that have been released. I wanted to offer another truck in this scale, with some fun playable features.

I started with a chassis that uses a simple pendular suspension on the rear axle, which is damped by 2×1 rubber connectors. The rear axle drives a simple I3 fake engine under the cab through a two speed transmission. The transmission changeover is on the right side of the truck. Front steering is controlled though the HOG light on the top of the cab.

I have found a simple way to add a three way tipper bed in my trucks, and I have used it many times before. A mini linear actuator moves simple linkage under the bed that can pivot in three different directions. Each corner of the bed has a removable axle that allows control for which way the bed tiles. But in the past the control for this tipping function was in a tricky place to reach, so I wanted to route the control to the top of the cab. I managed to add this right next to steering light. I used a top pivot design on the bed sides and rear, locked by a 3/4 pin on the bottom.

Finally, I added a crane, and since I had a little space left over, two stabilizing outriggers. The outriggers are a simple two link design that are controlled with a worm gear mechanism. The crane is a little more complicated. It is mounted on a small turntable with a rotation control on the left side of the truck. The first lift mini linear actuator is controlled by the third HOG on the top of the cab. The second lift stage is controlled by another mini linear actuator. Finally, the third stage has an extending boom that allows the reach of the crane to extend a little more. The crane can lift some; not a lot, particularly when the boom is fully extended. By removing the three HOG knobs, the cab tips to show the engine. Also, both doors open.

I loved the way this trucks looks. The beefy tires, and the cabover design give the truck presence and look of toughness. The crane was a lot of fun to play with even if it could be a little stiffer. However, this may be the last time I use this three way tipper design. I am happy I moved the control to the top of the cab, but the linkage does not have the power it needs at the start of the tip. I will have to come up with something better for the next truck.

Stay tuned, and happy building until then.

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John Deere Axron


What started out as a little tractor and trailer has grown into the Thirdwigg Farm! And it needed a bigger tractor.

Free instructions are available at Rebrickable.com.

I started with a simple, small, row tractor that I called the Atmos. This tractor was mid scale and in addition to steering and a fake engine like most of my builds, it featured a front implement mount, rear three point hitch, rear PTO, and rear Pneumatic PTO. Little did I know how the tractor would grow into a lot of other tractores, trailers, impliments, and farming support vehicles. At some point, I found myself interested in making a larger tractor, and I have always loved the Claas Xerion. The Claas been done in Lego Technic before, so I went the John Deere styling route for my build.

The tractor had to integrate into the other builds, so the front and rear mount and PTO placement dictated a couple of the hard points. I built the tractor with four wheel drive, and four wheel steering. A four cylinder fake engine is placed under the frond hood above the front axle. The rear most cylinder does not move as the crankshaft would have run into the steering unit, and any change I tried to fix it made for an ugly hood. A worm gear actuated rear three point hitch allows for implements to be mounted to the tractor.

The steering is controlled by a HOG light at the top of the cab, which caused some headaches for placement as I wanted the cab to be able to rotate. There is a small gear on the right of the tractor that controls the rotation through and internally mounted worm gear. Getting the cab to rotate in the right spot, without hitting anything, and while still having the pneumatic pump, required endless test rotations.

Since this is a Thirdwigg Farm tractor, there are many options to pair with this tractor, all with free instructions. My favorite is the Hookloadr trailer, but the Tandem Disc looks great too. Free instructions are available for all the options, so feel free to make your own farm.

It is always fun to make another tractor and this one was no exception. I wish the drivetrain was a little more smooth, but the rest of the tractor worked flawlessly. And it looks fantastic. Coupled with a trailer, makes it look strong and purposeful. And the rotating cab is so much fun to play with. We’ll see what gets added to the Thirdwigg Farm next!

Happy building!

Skid Excavator


Another little contest build, complete with Free Instructions.

I participate in a number of LEGO Technic contests, and Eurobricks hosts a number of them. The requirements for the TC22 Contest was to build a Technic construction vehicle that could fit in a 10,000 stud bounding box. It had been a while since I built an excavator, and they allow for a lot of functions in a little bit of space. I have always been intrigued with the machines built by the French company Mecalac, and after looking at their cute little Skid Steer Excavators, I had my subject. Setting the scale was important as I only had so much space. I decided on the large tracks as I think they look a little better. Setting the width with the tracks at 17 studs, would give the stability needed, and would give me some working space. Calculating the rest of the excavator would allow for 28 studs in length, and 21 studs in height for a total of 9,996 total cubic studs.

I stared with the boom, which is a little complicated. The boom is a 3 section design, and should reach far, and tuck in close to the front plow, and be able to dig deep. I planned the movements with mini linear actuators, and wanted to keep the controls easily accessible. This resulted in a design where two actuators had controls on the boom, and two actuators had controls on the back of the superstructure.

I thought I had the hardest part done one the arm was finalized, but I quickly discovered that the rest of the superstructure was going to cause some problems. First, I was not sure on the shape I wanted. It took a couple of drafts to get the rear shape right. Once I did I realized I had some space for a little engine, so I added this, and connected it to one of the boom lifts. Now a little engine turns when the arm moves. Once these features were done, it took another four drafts to make sure the tractor would not fall apart.

Then off to the cab and the attachments. The can was simple enough, with a simple chair and the HOG mounted to turn the superstructure. I created four different attachments, including two excavator buckets, a skid bucket, and a set of forks. In what is becoming a standard feature of my builds, each can be changed over by pulling a couple of axles on the boom.

I was pleased with how this build turned out, and it was good enough for a third place in the Eurobricks contests. All the attachment options made for a fun, playable model, and the movement of the boom was perfect. Feel free to build one of your own.

Happy building.

End Loader


Time for another Eurobricks contest! Free Instructions are available at Rebrickable.com.

Another Eurobricks contest was made available, and this one was right up my alley. In fact, I was so excited about the contest, I made two MOCs. The contest was to create a small, less than 10,000 cubic stud, construction vehicle. I figured an end loader is perfect for the contest theme, and it was a while since I created one. I build a quick draft of the shape including where the steering, engine, and bucket would go.

At this scale I decided quickly that adding an engine would be a great feature, but four wheel drive would only distract from the look and the function of the bucket. The engine is a little 3 cylinder unit that is mounted transversally behind, and powered by, the rear axle. This placement allowed for steering and bucket tilting to be placed in a HOG placement.

Drive Mech

I next worked on the linkage for the bucket. It took a couple of tries, but I finally got a linkage with full movement. Two mini linear actuators are placed on the side of the loader for bucket lift, and are linked together. The manual control is a small gear on the left side. The bucket tilt uses a Z-linkage design that allows for the bucket to move correctly through the lift movement and not dump any load. This is controlled by a single mini linear actuator, with a controlling gear on the top of the engine cover. The head of the bucket allows for quick change between a bucket and forks. Finally, steering is controlled by the HOG on the top of the cabin, and keep my high standards for steering feel with low slop.

I was pleased with this little creation, but it was not as interesting as the other MOC that I designed. So while everything worked well, and looked great, I submitted the other MOC for the contest. I hope you enjoy the MOC, and feel free to build one of your own.

Happy Building!

John Deere Scout


Another addition to the vastly growing Thirdwigg Farm.

I built the Atmos Tractor a couple of years ago as a small little project. Soon I had created a number of attachments and trailers to work with the tractor, and soon I was more tractors and other machines were added. But the balance needed some additional tractors, so I decided to make a little partner.

The John Deere Scout specifically so I could use the new Tractor tires that came from Lego 42122 and Lego 42129. But I wanted to it to be a smaller tractor with many of the features needed for full Thirdwigg Farm integration. Thus, the tractor had to have the common front and rear attachment points, a rear PTO, and steering because I put that it everything. Soon it was clear that the size of the tractor was going to make a fake engine poorly done, so I left it out. But I wanted some other feature to make this tractor unique.

The front bucket uses a worm gear function to lift the front arms. It is driven by a mechanism that drives rear, and then up to the top of the cab. There is a little gear for the HOG function that is just behind the steering HOG. A small worm gear mechanism is used to tilt the bucket. The arm can be easily removed if the desire is for the tractor to mount something on the front attachment point. The rear PTO is connected directly to the rear differential, and the common three point hitch is installed as well. Finally a trailer hitch is attached.

I also made a couple of attachments specifically for this tractor including a snow plow and scrapper, and a little trailer. Both may be found for free at Rebrickable.

With each additional tractor I add, I think it will be the last, but I keep having more ideas, and each one has been fun to design. I was pleased with how this tractor turned out, and how well it functioned. The tires look great at this scale. Most importantly, it matched well with each of the other tractors. The instructions are freely available at Rebrickable along with all the other Thirdwigg Farm builds, so feel free to make one of your own.

Happy building.

Lego 8440 Update


I am on a little bit of a old set update kick right now, so here is another one.

Free instructions are available here.

When I do an update, I like to add features, but keep the look and feel of the original in a way that you see the build and know what it is referencing. It’s is easy to see the old studded design and have the impulse to recreate the set with studless beams. But there are a lot of new parts that have been released since those old sets were released and many of the new parts allow for a lot of new functions.

For this set, I started first with the bodywork. Once the bodywork was where I wanted, I would fit in as many new functions as I could. It turned out that not many functions were added. But at least the bodywork was a nice update to the original.

Updated 8440 (red) over original 8440 (light trans-blue)

I kept the V6 that 8440 had, and devised a new rear transmission to the rear wheels. It is single speed, but it is geared up in a way that the engine spins faster than it does in the original. I then started adding details to the engine that would fit under the engine cover. I had to keep some exhaust pipes, and cooling radiators, but it took a little time to get those to look the way I wanted. I finally found a solution that was a step up from the old pneumatic tubes.

8440 Update Chassis

Keeping the front steering was simple, but fitting it into the narrow nose was a little bit of a trick. The final result is not too interesting but works well, and allows for a removable nose. A simple rear wing was added as well, and can be easily removed.

The remake did not add as many new functions as I originally wanted to add. True, the design stayed faithful to the original, but a wanted a little more than that. Everything worked well, and looked great, but it was a little too simple. Maybe the next update I do will have a little more opportunity to make some updates. Until then, happy building.

Synthe Combine


It was time to build a combine harvester for the Thirdwigg farm.

You may find instructions for this model at Rebrickable.com.

I was putting off building a combine for a while because they are pretty complicated. It took me a while before I felt like I understood enough about them to translate them to a LEGO MOC. After some time learning about them, I was ready to begin something. The scale was set based on the Atmos Tractor, so then it was a matter of deciding how many features I could add into the model. The models started with the thrashing mechnism, and then everthing fit in around it. I settled on a rotating thresher rather than a set of shuffling screens. In the center of the combine is a rotating auger that separates the grain from the staukes. As the auger spins it move the crop rearward separating the grain as it travels rearward. In the MOC, the auger is connected to the front wheels as the combine moves. Under the auger is a reciprocating screen that further separates the grain. Likewise this is also connected to the front wheels. At the rear of the auger are two spreaders that spread the chaft out the back of the combine.

Also connected to the front wheels is a takeoff that operates one of two cutting heads. The cutting head uses two augers on each side to move the corn to the center so it may be driven into the combine. A cutting edge is right behind the cones, and its movement is driven by a link below the combine, so it may cut back and forth. The full corn head is removable, and can be easily replace with a grain head. Each head is mounted on a moveable mounting plate, which can be moved up and down for harvesting and transportation.

In addition to the harvesting functions, the combine also has an opening right side so you may see the internal functions of the tractor. Here you may also see the mechanism that opens the top hopper. Additionally, the grain extractor on the left of the combine can be extended. Steering for the rear axle is operated by the air intake on the rear of the body.

This MOC took more time than usual for me, and there were a couple of times that I thought about scrapping the build, but I am happy I stuck with it. In addition to having another vehicle to populate the Thirdwigg Farm, the functions of the Combine were fun to implement in this build. Each worked well, and were fun to play with. The interchangeable head was an addition that changed the look of the combine depending on my mood, and each functioned well.

I guess it’s time to plan another tractor. Until then, happy building!

Ionos Sport Sedan


Sometimes I cannot make a decision. This is the LEGO result of that problem.

You may find free instructions for the AWD and the RWD (my favorite).

At the end of 2020, I decided to make a sport sedan. I find the sport sedan to be my favorite kind of car (see here and here), and it was time to do another one. I acquired a couple of the Defender wheels, which look more sporty than the other 56mm wheels. These would be the center of the build. The car would be long hood, short deck, with faired fenders. Then more questions happened, and I could not make up my mind.

What transmission did I want? What engine would be best? Could I fit all wheel drive? Was that appropriate? As I found myself asking these questions, I began answering “well why not that too?” It was here, the project took a dramatic turn. The car would be fully modular and interchangeable. After playing around with some dimensions and simple structures, I decided on the following setup: Two different transmission and rear suspension modules, one floorplan, one body (in two colors), two engine tubs for all wheel drive and rear wheel drive, and three engines. Demensions were set with a width of 27 studs at the rear tires, and 25 studs at the front tires, and a wheelbase of 33 studs.

Each of the 9 modules were build in constant flux with each other as I managed attachment points, size, and interchangeability. I settled on a 4 speed manual transmission module, and a 4 speed sequential transmission module. The manual is shifted in the cabin, and the sequential has a shift lever on the rear bumper. While four speeds is basic for a LEGO car these days, it kept space inside for four seats. Once the transmission modules were basically set, I was off to another module.

The engine tubs were a lot of fun and took less time than I thought they would. There are two tubs. The first, is built to support the front independent suspension and two different engine designs. The Straight Six is my favorite engine, so I wanted to make this options possible. The steering race for this module is placed far forward to allow for the I-6 to fit. In fact, the front of the engine is two studs from the front of the car. The V-8 fits well, and is placed behind the front axle centerline. The second engine tub features a fixed Flat 6 engine, and two fake electric motors; one for each side of the front axle. This unit is the hybrid and All Wheel Drive engine tub. Each tub attaches to either transmission module with six pins and one axle for steering. Drive connects by a 8 tooth gear off the engine.

Then I built the floorpan. This simple build provides the floor to both the cabin and the underside of the car. It is connected at six points, four to the chassis, and two to the center of the body. These points stiffen the car, and connect it all together. The body took the most time as this is what most people would see. Early, I committed to the sides panels including the doors and the part just behind the front wheels, and the roofline. Otherwise everything else was fair game. The front bumper took some time in order of the two studs of space, but I was pleased with the design. Next I managed to get the A, B, and C pillars to look the way I wanted. The C pillar took some trial and error but finally got a shape that was fast looking without the coupelike lines that seems to be permitting sedan design these days.

The rear took the longest. It was at this point where my focus on the MOC was starting to wain. Over months I tinkered with different trunks, different lights, and different rear bumpers. Eventually, I got to where I am now which could be improved, but I was pleased enough to call it complete. I added a little spoiler, and the body was done.

Ionos Sequential Rear

After everthing was built set, I rebuilt the whole car. As I did, I checked fit and built a Bricklink Studio file. With each step I found improvements along the way, and learned how to make better instructions. The result was a car system that fit together well, and gave for an interesting build. Again, if you are interested in the detail, or building your own you may find the instructions here and here.

This was my most favorite build in a long time. If you are interested, the Dark Azure, Manual, AWD version is my preference. The integration of all the parts was fun to do, and the build, test, rebuild process that went through every stage was a case study in continuous improvement. Both transmission work flawlessly. The suspension is stiff and functions as they should for a car of roughly 2500 parts. The varied engines were a fun inclusion. The design of the car is sporty and keeps the lines and proportions of a traditional Rear Wheel Drive Executive Sedan: long hood, short deck, short front overhang. I hope you enjoyed the car, and if you build it, I hope you enjoy the build. I definitely did, and will do something similar in the future.

Until then, happy building.

Unimog U400/U430


I frequently build another Unimog after it has been a couple of months since the last one, so here is another TWO!

You may find building instructions for both the U400 and the U430.

I generally find myself building a Unimog about every year, and this year, I built three. Kindof. Early in 2021, I built a Short Wheelbase U500 in blue, and I loved it. So, I wanted to see if I could take the build a little further. I’m partial to the U500, but the U400 seems to be a little more popular, and the current U430 was another challenge I wanted to try.

Instructions available for both.

The chassis for both is a modification of the U500. The wheelbase is 2 studs shorter, so I removed the winch and the PTO on/off switch, and modified the bed tipping mechanism. The rest is the same, including the front and rear PTO, the four wheel drive, and the I4 engine. Both the U400 and the U430 have a manual pneumatic pump with a front/rear switch for attachments.

The tipping bed is the same for both, and can tip in three directions. The three sides drop as well. And the cab for both is generally the same, with a slight change to the front to address the styling differences for both. You can see the similarities between both in the videos below.

I’m pleased with these MOCs, and how they worked. The U400 is the most beautiful MOC I have made in a long time. It currently adorns my desk at work, and will continue to do so for some time. While I wish both would have portal axles, the stability of the drivetrain, and the flawless reliability is worth tradeoff. The U430 looks great as well, especially with the tires, the orange is my favorite. Hopefully I am able to make some attachments for the front and rear. Stay tuned.

Until then, happy building!

Compact Telehandler


Sometimes I plan out a build, and other times, a build just kind of happens. This was the latter.

You may find free instructions for this MOC at Rebrickable.com.

After building the Atmos Tractor, and then a gazillon implements, attachments, and trailers, I started branching out to other machines that could be used at the Thirdwigg Farm. The Compact Loader was a result of this. I was playing with the new LEGO 42122 tires, and quickly came up with a little four wheel steering idea. I added a fork boom, and decided to see where the project would go.

I am quite fond of LEGO 8283, and the rest of the design was influenced by this little set. I tried a couple of boom extension designs, but each looked a little too “overweight” for the little tractor. So I came back to the extension design that was used on 8283. A mini linear actuator is used to lift the boom. Both functions are controlled by two separate gears on the back of the telehandler.

The cab came together pretty quickly, though I had to make sure the new tires had a clear range of motion. I added some lights, and front fenders which brought a little visual weight to the front. I had a tricky time finding rear fenders that I liked, but I eventually found a solution I liked. In my move towards increasing the readability of my instructions, I have published a PDF with step-by-step instructions that list required parts for each step. I hope they are clear for you, and they bring value to your own build.

The Compact Telehandler worked just as I hoped. The steering is great; it’s fun to drive this little tractor around on a small desk. The boom lift works well, and has a great range of motion. The extension works smoothly, though since it is driven by a worm gear, if the extension is in the wrong position while trying to lift the boom, the boom will bind. The fork tilt mechanism is smooth, and is easily accessible in all boom positions. We will see what next build come from just playing with a couple of parts.

Happy building.