T-55A


The T-72 that a made a couple of years ago is still the most popular MOC I have made; at least in terms of internet analytics. This year, I committed to making another tank, so I figured keeping in line with old Soviet armor would be rather apropos.

The main gallery may be found on Brickshelf or at Flickr.

T-55

The T-54/T-55 line of tanks have been produced in greater numbers than any other tank. The MOC represented here is a T-55A, representing types that were assembled starting in 1970. This series included an updated NBC and antiradiation system, an upgraded engine, and also added back in the 12.7mm anti-aircraft DShK on the loader’s hatch that was part of the original T-54 spec.

As with most of my MOCs, I starting scaling the tank before any building took place. I knew I wanted to use the newer, larger track links, and I knew I wanted to use the old mid-sized wheels. This set my scale, so I got to work. Starting with the chassis and the hull I worked first on the driveline and suspension. I used simple 2×4 liftarms to connect the road wheels to a suspension axle which activated a shock absorber inside the hull. Each road wheel has its own shock absorber. Fitting them all in took some creativity, but they are all mounted inside on the left and right sides of the hull. In the end, each wheel has about 3 studs of vertical travel.

T-55 Chassis

In between each suspension bank are the remaining mechanics.  After the suspension was set, I worked on the turret functions. Right from the beginning, I knew the tank would have a rotating turret and an elevating gun. It was clear having the elevation mechanics for the gun in the turret would be tight, so I decided instead to have the functions placed in the hull rather than in the turret. Using a vertically mounted mLA, connected directly to the breach of the gun, I was able to develop a method that would elevate the gun throughout the full turret rotation. The turret rotation was driven by a 8z gear connected to the turntable, and reduced by a worm gear. Both motors for the elevation and rotation are placed directly in front of the turret.

T-55 MechBehind the turret are two PF L motors mounted transversely side by side. They drive a 1:1 gearbox which connect directly to each rear drive sprocket. The IR receivers are placed above the gearbox. For those keeping score at home, the internals are (f to r) the battery box, the turret motors, the turret mechanics, the drive motors, and finally the IR receivers.

Working on the exterior of the MOC is what took the most time. The hull came together pretty quickly, with the exception of the details over each track. Most of the finishing time came with the turret exterior. Most Soviet tanks have the distinctive mushroom turret, which considering LEGO’s cube orientation presented some challenges. The turret of the T-55 also has a slight triangle orientation when viewed from the top. Like the T-72, I designed the turret with four side orientations (left, right, front, and rear), and one top orientation. Starting from the rear, I added a basic curved structure. The sides each had a couple levels of slopes, each tapering in toward the gun. The front was a little more complex. There are two “slope blocks” made of 4 curved slope bricks, and a supporting structure. One slope block is mounted on each side of the gun. The support structure is a mess of bricks with a stud on one side, headlight bricks, and plates. The top of the turret is plates on the front, and two sloped plate sections under each hatch. The two hatches are mounted to the turret support under the sloped plate sections. The AA machine gun is placed on the top, and various external mountings are placed in various ways around the turret.

T-55 Turret Detail

After making a lot of non-powered MOCs, it was nice to get back into Power Functions. I was pleased that everything worked flawlessly. The drive had adequate traction and power. The suspension worked well, and provided good floatation and travel. The turret rotation was smooth and allowed for precise directions changes. The gun elevation worked great, though I had to limit turret rotations to under four before the clutch on the mLA would snap. After a number of smaller builds, and frustratingly long builds, I was nice to finish something that worked well, provided constant entertainment throughout the build, and turned out quite nice.

Happy building.

Audi allroad


There are not many projects I start that I do not finish. I can count a couple. But, sometimes there are projects that take a long time to complete. I either loose motivation, lack parts (read budget), or find something else to do. If I were wise, I would toss the project, and move on to something better. But there is value to trudging through the slog and completing something difficult. The Spitfire is a great example of this. The Audi Allroad has been on The Queue for about 16 months, and it’s finally done.

The full gallery may be seen on Brickshelf or on Flickr.

Audi allroad

After completing the OCTAN F1, I thought I could use the suspension for an all-wheel drive car. I was sure I could make the front suspension with steering work at this scale.

allroad Suspension

I wanted it to have another fun feature, so using a bunch of differentials, I developed a simple three speed transmission. Three power functions motors are connected via two differentials which connect to the drive axles. Each differential acts as a subtractor between each motor. When one motor is running, the power moves through two differentials, and the car moves slowly. When two motors are running, the power moves through one differential, and it’s a little faster, and when all three motors are running the car is running the fastest as no differentials are splitting the power. I got it to work, and within a day, I had a working chassis.

allroad Driveline

Once this was done, the MOC sat on my desk for a long time. This past fall, Thirdwiggville welcomed another citizen to the village, and this gave me lots of time late at night to get back to working on this project. I spent a couple of weeks working on the body work with the perspective of “finish this.” So the body work could use a little more polishing; doors, mirrors, better lines, maybe an interior. But I was happy to finally get this done.

The MOC worked well. The suspension functions quite well at this scale, and the transmission was simple and effective. It could be a little quicker, but I was not going to make a substantial gearing change after the MOC was built.

Two final thoughts. I need to stop building supercars because they take a lot of time and effort for me, and I find little motivation for the body work; I do not think the body work looks good, and I lack motivation to work on it. Second, I needed to test the driveline earlier in the build process. I spend too much time fiddling with gear ratios after everything was build. But this project is done, and I am happy it is.

Happy building.

Kenworth T47


The Kenworth T55 is my favorite Trial Truck I have built. It’s not the best looking, or the most capable, or the most reliable, or even the most popular but it’s the one I keep coming back to. My latest truck is a continuation of the Kenworth series of trial trucks. The T55 would pull a stump, the T47 is quicker, has better steering, and more compliant suspension.

T47

Right from the beginning I knew the truck would have a similar cabin at the T55. It would continue with the four wheel steering, and I added an independent suspension. The dimensions would stay close to the same. From there anything else was fair game. I started with the axles. The new suspensions arms made it a little bit easier to make a good independent design. A CV joint was used at the steering knuckle, which allowed for the steering pivot to be near the wheel. Each wheel had about three studs of travel.

The XL motor was placed on the left of the center line and the rechargeable battery box was placed on the right. A newly acquired Servo Motor was placed rear on the centerline directly in front of the rear axle. I had a little more space left, so I added a simple two speed gearbox. A little more space remained so I added a flat six engine.

T47 Engine

Part of my attraction of the T55 has been it’s coloring, and it’s shape. I wanted to keep the attraction similar, but in a way that would differentiate the trucks. I have been acquiring some green lately, so I thought would be a great color. The cab is basically the same, but now it can tilt so you can work on the engine.

The off road performance was not great on the T55, and the T47 was similar. The independent suspension had too much play at the wheels to be great at steering, and the articulation was not very supple. The truck was great to drive around my house, but when I took it outside it did poorly. The suspension design is better than my last independent set up. There was no slipping of the gears. I think my next design will use the same knuckle, but design a different steering connection. This truck again proves the use of knob wheels rather than a differential for a trial truck. Feel free to make your own, and let me know what improvements you developed.

Happy Building.

Iveco XTR


After a couple of more complex projects it is nice to take a break to do two simpler projects. When I need a little bit of a design rest, I do a trial truck, and usually a fictional one, so I can build as I please.

The full gallery can be found here, and free instructions can be found here.

Iveco XTR

After building a number of trial trucks, I have found some features I like to have on my trucks. Note, these features may be prioritized differently if I was participating in a Truck Trial race. These features I like are linked suspension, PF XL motor for drive, tall clearance, and a center mounted battery box. As I was making this truck for my own pleasure, I forced myself to include all of these features.

I usually start a truck with the axles, and the Iveco was no different. I created the axle with a portal axle build around my favorite piece for both the front and the rear. I also added the space to fit both a differential, or knob wheels for the final drive (though the pictures only show the latter). This would allow me to switch the traction of the truck, and allow for a minor gearing change. While the changeover takes a little bit of time, it’s a nice feature and the gives the truck some versatility. I placed the steering motor directly on the front axle with allowed the middle of the truck to be simplified vastly. In the center of the truck is the battery box mounted longitudinally, and a Power Functions XL motor in the rear. This keeps the heaviest components of the truck in the center and low.

The linked suspension is a setup developed by other that connect two pendualar axles together. Each left side has a linkage that connects the two left wheels together, and the right wheels have the same. This keeps the wheels planted as the pressure from the terrain is balanced across all four wheels. When one wheel has to go up to follow the terrain, the rest of the wheels adjust. It is simple, effective, and keeps the truck a little more planted than a suspension utilizing shock absorbers. Otherwise the truck bounces a little during an obstical.

As you can see in the video, the battery box is getting a little tired, and the snow as a little mushy, but the setup worked well. The truck stayed planted, and it was nice to have two final axle options. It is a simple design that does not require too many hard to find parts, so if you need a good little afternoon project, give the Iveco XTR a build, and tell me what you think.

OK, off to some more complicated builds. Check The Queue. There is some fun stuff coming. Until then, happy building.

T-72 Instructions


It’s going to be a busy week in thirdwiggville. Before everything goes live, I thought it would be fun to let everyone know I have completed instructions for my T-72. I don’t know what took me so long. If you want to make a copy for yourself, you can for $5.   Buy Now Button

T-72

Otherwise, stay tuned.

Bedford MWD


I have said it before, but my favorite things to build are Trial Trucks.  The combination of the driveline construction, forces on the truck, diversity of body style, and various propulsion systems offered by LEGO combine for a great building experience.  Because of this, I usually am building a Trial Truck, or have one built at all times.  But for some reason, this truck seemed to sit for a long time unfinished.  I struggle with deciding if a truck will be a model of something, or something fictional.  This decision is often made too late in the construction process.  After toying with a Daimler Scout body, I decided I needed to finish this project and the Bedford MWD body was chosen.

The full gallery may be seen here.

01

After some some experience with various designs, I decided to construct a truck around a simple locking differential idea I had recently designed.  Because I would need an extra IR Receiver for the locking function, I decided a simple two speed gearbox (1:6 and 1:10) could use the other IR channel.  I placed all the controls in the middle of the chassis.  The driveline and the steering axle would run through the middle.  On the left side was the Battery Box and the motor for the gear change, and on the right side was the XL drive motor, the gear box, and the motor for the locking differential mechanism.  The steering motor would hang out the back of the chassis over the rear pendular suspension unit.  Both axle were connected by my favorite linked suspension system.

zbedford

Each axle took a little bit of work.  I selected a simple design for the locking differential.  Basically, it is a 24 tooth differential placed directly next to a 24 tooth gear.  A pair of sliding 12 tooth double bevel gears slide back and forth one stud to connect only with the differential, or with both the differential and the neighboring gear locking out the differential.  After toying with some old flex cable, and some pneumatics, I figured I was making it too complicated.  I added a small pivot with a Small Technic Steering Arm, and connected it to a 9L link.  This way both axles could be connected, the suspension and lock could keep operating unaffected by each other, and it all could be controlled by a mini Linear Actuator.

Initial tests were positive, so I then decided to figure out a body for the design.  I worked for too long on a Daimler Scout body.  I had the structure made, but the paneling was just not happening.  After sitting on the project for 5 months, I decided it was time to make something new.  The Bedford design worked well, and helped my get excited again in the project.

Now, once I got outside to drive the truck a glaring problem occurred.  The bevel connection in each axle that transmits the longitudinal drive forces to transversal drive forces kept slipping.  You can hear it in the video.  Because of this, it did not matter if it had locking differentials, or if it had a two speed gearbox, or if it had working suspension.  Anything could stop it.  I though about reworking the axles, but then, I have been working on this for 11 months, it was time to be done.  I’ll use the locking mechanism again.  That worked great.

Thanks for reading.

CAT 573C Feller


LEGO takes up space.  We all know this, and yet we still seem to try to cram as many working functions into a MOC as we can.  Sometimes it works out well.  Sometimes we have to scrap a few functions.  Other times, the functions are so dense you really cannot believe you got it to work.  This is the story of my wheeled feller.

The full Gallery may be found here. Instructions may be purchased for $5 USD.  Buy Now Button

CAT 573c Feller

I have been thinking about making a feller for about two years now.  It is a project I have never seen done before, with the exception of two tracked fellers (OK, and my other one).  Over this time, I have been planning, acquiring parts, and making plans, and over the last four months I have been building.  Nothing I have made has been so complicated or so dense.  There is no space left.

As I always do, I stared with the dimensions of the vehicle.  The schematics for the CAT 573C were easily available, so I stared with the chassis.  I knew space would be an issues, so the driveline had to be simple and compact.  The Power Functions XL motor would be geared down 3:1 and mounted just behind the rear axle.  A drive shaft would move through the steering pivot to the front axle.  The rear axle would have simple pendular suspension.  The steering would be completed by two linear actuators placed on either side of the pivot with a PF M motor on top.  Simple enough.

From here, things got complicated quickly.  The MOC would have four remaining functions.  The feller saw, the grapple arms, the feller tilt, and the feller lift.  Since trees are rather heavy, fellers are designed with as many of the system mechanics behind the rear axle.  As such, all of the functions I would add would need to be in the rear, as the front would not have any space.  I quickly learned this would not work.

Eventually, I found what would fit.  The IR Receivers would make up the rear bumper, and the battery box would be directly over them, off to the left.  Two PF Ms would be on the right and would drive two mini Linear Actuators.  These would move two pneumatic valves. These pneumatics would move the lift function and the grapple arms function.  An air tank would supply the pressure from a pneumatic pump placed on the driveline.  Another PF M would be placed over the front axle to give the feller head the tilt functions (it should be noted, 7 designs, and five weeks were spent on this feature alone).  The final PF M was in the feller head, and would drive the feller saw.

After packing, repacking, and packing again, all the features we set.  Then all the cabling and hosing were placed.  No easy task, as I was running out of space, and 25 or so hoses, and 10 cables take up a lot of room.  I added some comfort features to the cable, including a (half) chair and a roll cage.  And so Mr. Technic could get in, a little step.  Then a lot of paneling for the rear, including some access doors on the rear, and the model was done.  Here it is in action.

As you can see in the video, the MOC worked well, but some of the functions did not work as clean as I would have liked.  The drive and steering were fine, with an easy drivability.  There was a lot of mass in the back, so sometimes the torque from the drive motor would cause the back to tip.  The saw worked well enough, and for the most part so did the tilt, but the pneumatic lift struggled.  It was a little overloaded because the saw unit was too heavy.  The grapple arm worked well, but for both pneumatic rams were hard to control.  As always with LEGO pneumatics, they too often are off or on.

Until the next MOC, happy building.

Talon Track


Every once and a while I see something so creative I have to build something like it.  I happened with my HH-65.  It happened with my Zil 132.  And to some extent it happened with my Spitfire.  But when I saw the Urban Buggy from Chrismo, I though I have to make something like it.  It was such a fresh and creative design.  It had such great lines, a perfect stance, and a unique driveline setup.  But while imitation and outright plagiarism are the most sincere forms of flattery, I thought something of my own design would be a better contribution to the LEGO community.  I present my Talon Track Car.

You may find the full gallery here, and the instructions here.

I designed this car to be fast and stable, just like a track car.  I started with a drivetrain that would be reliable and effective.  A PF XL for drive, and a PF M for the steering.  I placed the PF M in the front mounted directly on the suspension unit, with a return to center spring in the middle of the mount.  The system is set up differently than in my Rumble Bee, but uses the same return part.  Each suspension arm would have a single shock absorber.  Directly behind the steering motor was the XL for the drive.  It was geared up with a 20z/12z ratio, with the driveshaft connecting directly to the 20z gear that turned the differential.  The rear suspension used an independent setup that was developed a long time ago for my Red Car Bigger (great name, huh).  If it’s not broke, don’t fix it.  The suspension was planted.  I placed the rechargeable battery box and the IR receiver behind the rear axle.

The car was quick, and didn’t have any problems, but faster would have been cool.  The return to center system worked well, especially for the quickness of the car, and the quickness of the steering.  It was easy to control.  The car was robust, and crashed well.  So go ahead and build your own.  Enjoy.

3 Speed Sequential Transmission with Changeover


A couple of years ago, I was building a MAN LE with the sole intention of creating a new gearbox.  The tried and true changeover with clutch gears is a great system, and works well in a lot of situations, but I had been disappointed with how it functioned in trucks.  Particularly with the neutral.  I could not have my trucks roll backward.  There had to be a better system.  There were four things I wanted to address:

First, each gear-change had to move seamlessly from one gear to the next.  No neutral.

Second, it had to be easily controllable with power functions.

Third, it had to be sequential.  No first to third gear shifts.

Fourth, it had to work.  Every time.  With no slipping.

The first goal was easy to address.  I came up with a simple sequential gear box, that would move between three ratios all spaced one stud apart.  In order to get to gear three, you had to go through gear two.  To make sure the gears would slip into sync every time, I chose the double bevel gears as the change over gears.  You can see in the video how they slide into gears pretty easily.

The second goal was the most difficult.  I have stuggeled with finding a solution that would allow a motor to move from one great to the next without “overshifting.”  To many designs require you to stop the motor so the gears are perfectly meshed.  After looking at a design from ATRX, I had an idea.  I needed to use the pulley wheels to move the gearbox in three steps.  So, how could I get the pulley wheels to stop at three spots around a half a rotation.  The pulley wheels would be connected via a 24z gear to a differential.  Each side would have M motor, with stops for half a rotation.  One motor would move a half a rotation, transmit the rotation through the differential which would turn it into a quarter rotation, moving the pulley wheels a quarter rotation as well.  One motor would shift from gear 1 to gear 2, then the other motor would shift from gear 2 to gear 3.  It was sequential, and it would only allow you to shift to the adjacent gear.

Finally, it worked.  Every time.  No missed shifts.  I have made a couple of modifications to the gearing and structure to make it a little more compact and with better ratios, but if your looking for a new gear box to use for your next MOC, this might be the ticket.

See the full gallery here.

Used in my Freightliner M2, MAN LE, and ZIL 132.

Mack Marble 5T


I confess.  I took the bait, and started on the 2012 You Design It, We Build It before the final rules had been confirmed.  I should know better.  After all my schooling, you would think I have a good idea about how to follow directions.  The first direction is, wait for directions.  But, with all LEGO building, I enjoy what I am creating, and so even after the rules and directions have been given, I still want to contribute to the LEGO community.  So, my next MOC is another Trial Truck, built with the intention of being easy to play with, easy to build, and tough enough to handle child play.  All with instructions, so you can build one.

See Instruction Page

I built this model based on what I thought could be improved on set 9398.  While this new set was a great step forward for the LEGO company, I felt there where a couple of changes that should be made to make the model a better off-roader.  Because I was working with the assumption that this would be something LEGO would produce, I gave myself a couple of constraints.  First, the model had to be less than, or equal to, the cost of 9398.  Second, the model had to have improved off-roading skills.  Third, the model had to have easy playablity, so the drivetrain had to be reliable, the battery should be easy removable, and it should be easy to drive.

I started the frame before the axles.  I placed the battery box directly over the driveshaft.  An XL motor was place behind the BB and three 16z gears above the driveshaft.  One 16z gear went up to the fake motor shaft.  The driveshaft would connect front and rear to the two axles through the new ball joints from 8110.

I then built the two axles, starting with the rear.  To keep the speed of the Mack similar to the 9398, I would gear down the XL motor to about 1:4.  The driveshaft came out of the ball joints and connected to the differential.  I chose two 12z/20z gear sets as the final reduction.  This would keep the driveline a little stronger, and help keep various axles from working their way out of the gears, much like the design of the 9398.  The final gearing was 1:3.89.  It’s not a stump puller, but it could still move up most hills.

The front axle was a little more tricky.  Basically, it had a similar setup, with a PF M motor placed on in it to work the steering.  This was by design.  To keep the driveline reliable, and limit the failure of steering, I kept the steering part of the axle, rather then having components placed in the chassis, and then connected via a shaft to the front axle.  The steering is a little quick for my liking, but it works flawlessly.  To understand more about the axles, check out the instructions.

Through a little trial and error, I connected the suspension, and tweaked it so it would function in a way that was robust, and allow for great movement.  I am still not pleased with how it turned out aesthetically  but it functioned without problems, it supported the model well, and allowed for sufficient articulation, so I left it.

I then added a simple body, a basic rear bed, and added some engine components such as exhaust,  intake, and a simple turbocharger behind the fake motor.  When I was done, I noticed the cab looked a little like an old Unimog.  This seems to be a theme with me, as I love the look of the Unimog.  On the other hand, I do not like the look of too many cabover truck designs, as such, many of my trucks have the slight setback cabover design that is very similar to the Unimog.  My T55 is like this, and this is why I have built so many Unimogs.

The model worked well.  the suspension and stability was perfect.  The truck was stable, and did not roll over, all while being able to handle various terrains.  The gearing was sufficient and would be great for a playing child.  It was easy to change out the 12z/20z gears in the portal axles to a 8z/24z setup which made the truck a little more strong.

It would be a great model for many LEGO fans due to cost, reliability  stability, and playability.  So I have posted instructions for people to enjoy the model as well.  I think it would have been a great LEGO set, then the rules were released.

Next time I’ll wait for the rules.  Thanks for reading.

Full gallery is here.

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