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.

Hawker Typhoon MkIb


Two years ago I built the Spitfire MkIIa. It remains one of my more popular builds, and one of which I am still quite proud. It was not my first large plane, though when I completed it, I said it would be my last.

As my father would say, “never say never.”

Typhoon

The full gallery may be seen here.

I learned a lot of great things from the Spitfire. Large scale building is exciting, and challenging in that you have to think about significant structural considerations, placement, and shaping before and while your build.

With this in mind, I wanted to develop what I have learned, but allow myself the ability to take a large scale aircraft to the next level. I wanted to improve the function of the control surfaces, design my own propellor, use four Power Function channels, and use the boatload of Dark Green parts that I had recently acquired. I considered a number of airplanes, including doing the FW-190 again, but I finally settled on the Typhoon. Time to get building.

After some planning, I had my scale. 1/13 was an appropriate size for me to replicate the plane and its functions, while still keeping the plane from getting too large. This scale would also allow for LEGO wheels for the landing gear, and a worker able propellor spinner design. As I learned from the Spitfire, placement of large components needed to be done early, and placed in the MOC to its exact final location. As the structure of the fuselage and wings would be stressed heavily, large components could not get in the way. Once I placed the engine block, the landing gear, the power functions, and the control surfaces, I was able to start putting together the robust structures that would support the final plane. One of the major challenges of this plane was the outset landing gear on the wings. Because they were located 42 studs apart, the wings needed to be strong. But due the the space taken for the control surfaces, and the massive 24 cylinder power pack, the wings still sag a little under load.

The control surfaces were activated with strings with studs on each end. I found this to be a better system than the axle controls for the Spitfire. It kept the controls more smooth, and reduced the amount of play in the controls. The elevator and ailerons were controlled with the joystick, and the rudder was controlled by two foot pedals in the cockpit. The remaining functions were controlled via Power Functions. An XL motor powered the massive 38 stud diameter propellor, as well at the 24 cylinder Napier Sabre engine. A M motor controlled the pitch of the propellor. Another M motor powered the landing gear, and still another  adjusted the flaps. All four motor were mounted in the chin of the aircraft; I had to use that huge chin for something. The two IR receivers were mounted in under the windscreen, and the rechargeable battery was mounted behind the cockpit.

Finally, I had to make sure all the markings were accurate. Again, due the limits of dark green parts, it was not an easy task. I started with wings, and made sure to add invasion stripes, and work my way out to the tips. The roundels were a little different than the Spitfire, but were a little larger. The fuselage took a little work to make sure the panels could be easily removed, but I eventually got there. The fuselage roundel should have a yellow ring around the outside, but the strip is so small, I could not figure out a good way to do it.

The plane worked almost perfectly. The ailerons were a little sticky, but other wise everything else managed to work for an 8 hour shift at Brickworld. The plane was liked enough to be nominated for Best Air Ship. While it did not win, it was validation that the the model was a success.

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.

Spitfire Mk IIa


I am not a very ambitious person.  Sure I made it through college and graduate school, and have managed to work well in job for a while now, but for me to do something challenging, takes a lot of convincing.  It doesn’t happen often.  This project was a little bigger than it should have been, and I got in over my head.  This is not the first time this has happened (1, 2).  The project was interesting enough for me to keep moving forward, even after six months.  I present my 1:12 scale Spitfire Mk IIa.  I hope you enjoy the work.

View the full gallery here, and the work in progress gallery here.  Flickr set is here.

Spitfire 3/4

First, the whole reason I did this project was because of the excellent Baby Twin Otter of Cpt. Postma completed two years ago.  If you have not yet seen this creation, take a look at the above link.  When I first saw this model, I went home a made his variable pitch propeller   This was the first step to my Spitfire, though at the time I did not know it.

I chose to do the Mk IIa version Spitfire for a couple of reasons.  First, the model had to have a three blade prop, because I wanted to use Cpt. Postma’s design.  Spitfires stopped using a three blade prop somewhere in the middle of the MkV series.  Second, I wanted to model a eight gun variant, rather than the cannon variant because I think it has a cleaner look, and I love the red and yellow leading edges on the eight gun variants.  Finally, while it would have been great to do a early model Spitfire with the dark tan camouflage  adding both the dark green and dark tan would have been too expensive, and even more ambitious.  I found a number of pictures of a certain MkIIa with all the features I wanted.  I chose a Spitfire flown by Lt. Tomas Vybiral, who was a Czech pilot with the French Air Force.  The plane was Spitfire P8081 when he flew for the British in Squadron No. 312.  It had simple markings for me to recreate, a camouflage pattern I would be able to do (read afford), and I found some good documents to help my modeling.

Next came the internal planning.  The Spitfire would have working ailerons  flaps, rudder, and elevators (with correlating pilot controls), prop, prop pitch, V-12 engine, and retracting landing gear, all within the 1:12 scale.  Once I had the dimensions calculated, I started placing things in a simple “placeholder” model on my floor.  I constructed the engine, the propeller spinner, pedal/joystick assembly and placed them in the placeholder.  Then I made the placeholder 3D.

It took two months to get the rest of the internals all set.  The required moving various parts of the 3D placeholder, and adding additional parts.  The joystick is connected through various liftarms to the rear elevator, and by axles to the ailerons   The pedals connected though a shaft to the rear rudder.  You can see the gears on the rudder.  The flaps have a simple lever in bottom left side of the cockpit.

The rest of the functions are controlled via Power Functions.  The small 8878 battery box is placed behind the cockpit, as is the IR receiver.  A PF M is housed under the V-12 and drives four mini linear actuators for the landing gear.  It is strong and simple, and works well.  It does not have the correct Spitfire landing gear geometry, but if someone can figure out a way to do it at this scale…well, I can’t figure it out.  A second PF M is used to power the propeller   It is placed directly behind the V-12.  Finally, a third PF M is placed behind the V-12, and works through a system of gears to power two mini linear actuators to move the pitch of the prop.  It’s messy inside, but it has everything I wanted.

After the internals, I had no idea how hard the rest of the Spitfire would be.  LEGO, you need to make more parts in Dark Green.  I know how selfish that sounds, but it would have been more helpful.  Thank to some newer sets, like the 10226 Sopwith Camel, and the  21016 Sungnyemun, it made it much more possible, but still limited me in many places.  I spent the next four months acquiring parts, and placing small plates over the rest of the plane.  With some help on the roundels from Dieterr89, it eventually came together.   The bodywork took a long time.  Too long.  And the lack of some parts in Dark Green forced me to make some concessions.  The canopy frame should be all Dark Green, but it was not going to happen with what is available.  The camouflage is not as clean as I would have liked, and there are some abrupt steps where some plate limitations made the transition for one part to another not smooth enough, such as on the rear fuselage.  Also, try as I might, I could not get the leading edge of the wing to be perfect.  The dihedral did not help either, nor did the yellow leading edge.  Also, the gaps between the control surfaces and the fixed part of the wing and stabilizer was more than I would have liked.  But this has happened before.

I am please with how it turned out, but there are some parts that I wish would be better.  I never seem to remember this when I start a project in this scale, but free moving functions just do not operate well as you hope when you keep adding parts.  The control surfaces work, but they could be smoother and lighter.  The powered functions worked flawlessly. I was very please with the way the markings turned out.  They are not as flush with the plane as painting would cause you to believe, but they make the Spitfire clearly identifiable.

My father would always tell me “never say never,” but it may be a long time before I do another large plane.  But I guess I said that back in 2008.

I hope you enjoy.  Thanks for reading.

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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