Blakbird

What counts as up-to-date? There is a Brickstore file posted on my Bricksafe account which is the version I used to buy the parts to build the model, but it doesn't include any changes I made while building. It should be 99% accurate.

Hmmm, I didn't think the changes were that subtle. Take a look at the history pages for each year and you should see the difference.

I also noticed the change in finish on the engine connecting rods some time ago. I didn't think too much about it, but they are definately different. For the angle connectors, I agree with the others that the 2L has always been matte and the 3L has always been gloss. Why? Good question. With Technic parts in particular, you'll find there are quite a few different kinds of plastics used, not just the same old ABS. For example, a 1x8 Technic brick is not the same material as a regular 1x8 brick. It is a more rigid and brittle formulation to compensate for the material lost to holes. This is really noticeable in the half width liftarms which are the stiffest kind of plastic used in LEGO. They make a much different sound when dropped on the floor! The differences in formulation can also be seen easily in pins. For example, the new 11214 pin is very soft to make it deformable and easy to use the axle end. In general, any pin connector with an axle end is softer than a regular pin because the axle must compress a bit when inserted into a slot. Pins can be more rigid because they have slots to help them deform. The brand new 15100 connector pin is particularly stiff and quite difficult to put into a hole. All of this is my way of saying that I wouldn't be surprised if the 2L and 3L connectors are actually a different material and that accounts for the different finish. My LEGO muscle memory tells me that the 3L is stiffer. In fact my LEGO muscle memory also tells me that the old shiny engine connecting rods were hard and the new ones are soft. Try dropping each on a table and see if they sound different.

Next come the outriggers. The following image shows the two outrigger functions integrated together (and they do overlap considerably). Outrigger deployment is shown in teal and lowering is shown in brown. The general mechanical arrangement is nearly identical to that in the official 42009 set. The difference is that instead of being driven by a motor in the superstructure through the turntable, these outriggers are driven by a pair of vertically mounted L motors. We'll look at the deployment function first. The L motor uses some bevel gears in a vertically mounted gearbox to drive a longitudinal axle which keeps the front and rear outriggers in sync. There is only a single stage of 20:12 reduction before a set of 12 tooth gears drive the racks which deploy the outriggers. This means that, unlike 42009 which deployed the outriggers painfully slowly, these go out really fast. It could be argued that they are actually too fast for scale, but it is not a problem. This function requires very little power and therefore probably could have used an M motor, but the L motor is much easier to attach to a studless chassis, especially in this orientation. Now we'll look at the outrigger lowering. Again, the L motor uses some bevel gears in a vertically mounted gearbox to drive a longitudinal axle which keeps the front and rear outriggers in sync. After a 12:20 reduction and a bevel gearbox to convert the rotation to a perpendicular direction, a long 16L axle goes to each outrigger. Like 42009, the key to this whole thing is the red 8 tooth gear through which the 16L axle can slide freely. This allows the system to drive at any outrigger position, including stowed. As the final drive axles turn, each drives a small linear actuator at each corner. Whether or not the actuators have the power to lift the model is a trivial technicality, because they bottom out internally before they extend far enough to do so. Still, they provide enough support to stabilize the suspension while the boom is slewing to the side of the model. Lowering speed is acceptable and reasonably scale. All in all, the outriggers work very well and I have no complaints. The only minor thing to watch out for is to make sure the vertical linear actuators are stopped before they hit their end stops. If you drive them all the way to the stops, it adds a lot of strain the gear train which in turn makes it difficult for the other motor to slide the axles through the red gears. If you run into the stops, just back off for a fraction of a second before stowing and everything will move much more smoothly.

Well, I spent all last week working on some changes to Technicopedia which I uploaded last weekend. I was waiting to see if anyone would notice (I was betting on nychase or allanp), but no one has!

Now we'll look at the steering. This model steers 5 axles (1,2,4,5,6) making the model rotate roughly around the 3rd axle. By way of comparison, the rear Grove GMK6400 steers all 6 axles, although axles 3 and 4 disconnect at high speed. The real crane also has an additional crab steer mode. Looking at the picture below, you can see that the steering is driven by an L motor. As I was building I was thinking that an L was overkill, but having finished the model and experienced the weight, I can see that it was a good choice. The L motor drives through a bevel gearbox into a worm gear giving 8:1 reduction. The use of a worm gear also means that steering backdriving loads won't make it to the motor. Like the drive system, the steering uses a longitudinal axle which runs the length of the carrier. This single axle is important to keep the steering in sync. It is also important while building to make sure that the steering is centered while joining each module. You can see that axles 1 and 6 use a 12 tooth gear on the steering rack, and axles 2, 4, and 5 use an 8 tooth gear. This results in two different steering angle ratios. Ideally, every axle would have a different steering ratio based on its distance from axle 3 (the pivot point), but in practice this is difficult to achieve. The result is that there is considerable strain on the tires and suspension when driving with the steering turned. The steering power is adequate, but the gearing results in steering which is a bit fast making it tricky to find the straight ahead position. An additional complication to driving straight ahead is the fact that the steering links are installed at a considerable angle. This results in quite a bit of free-play or wobble meaning that the wheels on a given axle are not necessarily parallel depending on the driving forces being applied to them. This is especially apparent on carpet when you can see quite a bit of toe out on several axles while driving forward. Still, the steering works very well given the stiffness constraints of the parts we are working with and the tremendous weight of the model. I am using all V1 receivers on my model and I find that the drive motors slow considerably when I am steering at the same time. I'm not sure whether this is a limitation of the receiver or the current limit of the battery box, but it would be a good experiment to try a V2 receiver at least at this position. I think all the others could be V1. Alternatively, the steering and drive could be on separate receivers as long as you set up your transmitters to accommodate it.

I assume you mean 12 tooth bevel gears. The gears in the differential are not a problem. They cannot fall out because the 4L axles with middle stop are used, and they are not breaking. Adding an extra spider gear to the differential does nothing structurally unless it is guided by a pin on the housing. I suspect that "final" instructions will still take a while, but my draft 3 instructions are already available and are sufficient to build the model, however they don't include any of the improvements we are making to solve specific issues. I like the submodel callouts you used. I had actually thought of those exact same things but decided to skip them in favor of getting usable instructions as quickly as possible. I'm glad to see that we are thinking of the same types of instruction improvements! Two things: you need to use a PLI substitution to get a complete shock absorber in the parts list instead of a separate cylinder and piston. The belt is also missing from the parts list. Alex, I highly recommend that you wait a bit before doing any more work because you are working with an old version of the file. The version I am using is different and incorporates some changes I made while building the model to solve problems. I'll give you a copy of the file as soon as I am finished with the changes. This is one of the things I intend to bring up in the review. The superstructure needs more counterweight.

It is unlikely LEGO is ever going to produce a $1000 Technic model, but we can dream. I think this would fall into the same bucket as the Land Rover Defender 110 Cuusoo project. It would have to be so simplified to meet their quality and marketing standards that it would bear no resemblance to this model. In fact, this has already happened and it is called 42009! Yes, I have built it. I'll be providing my impression of each function as I go along in the review. I'll also provide some build photos.

Let's start by looking at the drive system. This model drives all 6 axles (12 wheels) via a pair of XL motors. By way of comparison, the real Grove GMK6400 is a bit different. Only the first 2 axles are driven by the engine through a conventional transmission, axles 3 and 6 are not driven at all, and axles 4 and 5 are hydrostatically driven only at low speed. So our model is superior to the real thing in some respects! The image below shows the drive system. We start with a pair of XL motors in parallel at the front of the vehicle under the cab. The first thing that might surprise you is that these two motors are torque summed through a bevel gearbox. Bevel gears are known for their weakness, so you might expect them to break. However, the bracket used to support them seems to solve this problem by supporting them securely enough to avoid skipping teeth. After a single stage 12:20 gear reduction, a longitudinal axle then runs the entire length of the vehicle taking the torque to each axle. The next thing that might surprise you is that each axle is powered by an 8 tooth gear. These gears are also known for being weak, so make sure to use the new reinforced style gears. Each 8 tooth gear drives the ring gear of a differential. You'll notice that the diffs are not oriented laterally like a typical vehicle because there was no room. Gerger has provided a clever solution to orient the diffs longitudinally. The output of the diff is a pair of 20 tooth double bevel gears which drive a 16 tooth gear on an axle on either side. Each drive axle has a gearbox which can pivot on the suspension axis. Here is a close-up view of a single driven axle mechanism. You can see the 8 tooth gear driving the diff and the tan output gears in the front and back. CV joints are used as output to the hubs which are from 42000. Steered axles use one hub (10ea) and non-steered axles use the other (2ea). The XL motors provide adequate power to drive the vehicle. It is not fast, but a crane like this should be slow. The bevel gears and the 8 tooth gears survive the torque well, even when negotiating small obstacles (like the end of my finger). There is one problem, however. As you can see in the above picture, the final tan 12 tooth bevel gear is supported in its gearbox by a red 2L axle. This red axle then rests inside a CV joint. The problem is that the recess inside the CV joint is 1.5L deep. This means that the red axle can back into the recess allowing the tan bevel gear to fall out. This has happened to me repeatedly. As the crane drives along, it occasionally deposits a bevel gear on the ground behind it. Thankfully, it keeps right on driving and even more thankfully, it is not hard to replace the gear by removing the wheel. Unfortunately, this cannot be solved by using a longer axle because 3L is too long. We really need a 2.5L axle. You can also see the V-8 engine in the first image which is belt driven by a shaft connected to the ring gear of the first axle differential. This shaft has the same drive speed as the main longitudinal drive axle. The belt reduces the speed a further ~3:1 which means that the motor turns very slowly. Ideally, the upper and lower pulleys would be reversed which would speed up the engine by 9x which would be perfect! Unfortunately, there is no room for the larger pulley on the lower axle. Alternately, the engine could use a small pulley (same size and the lower pulley) which would increase the speed by 3x.

I've created a new topic for the Grove GMK6400, so please continue the discussion over there. This topic can still be used to collect the various other changes to 42009.

In another active topic on Eurobricks, modifications to the LEGO 42009 Mobile Crane MKII have been discussed. Many of these modifications have been rolled into a single "ultimate" model which has been under discussion for several months with a full instruction project well underway. I felt that it was time that this magnificent model had its own topic. In this topic I will present the history of the model, detail how all the individual functions work one by one, then go through my review of the build process and thoughts on each function. I expect this writing process will take at least several days, so watch this topic for updates, and please feel free to add to the discussion. By the time the review is done, I'm hoping the "final" instructions will also be available for download. Drafts are already available. It all started with Technic set 42009, "Mobile Crane MKII", by far the biggest crane LEGO has ever released and also the largest Technic set ever by part count. You might think this would be enough to satisfy anyone, but you would be wrong. From nearly the day that the set was released, fans around the world were already modifying the set to make it even bigger and better. The first major modification came from Jurgen Krooshoop. His "Ultimate 42009" looks nearly identical to the official set, but instead of having a single motor and a gearbox to switch between them, Jurgen's model featured 8 motors to control all the original motorized functions as well as driving and steering. Any of these could be operated simultaneously. Jurgen was kind enough to produce a full set of professional instructions for his model. The original model features a 3 stage telescoping boom, but the full extension of this boom is not very impressive because there is so much overlap of each section at the stops. Cristophe Moittie solved this problem by creating an extended boom which was nearly the same length as the original when retracted, but was much longer when extended. Instructions for the extended boom were then created by afol1969 here at Eurobricks. Finally, Eurobricks member Gerger decided to extend the cranes 5 axles to 6. While he was at it, he added full independent suspension to every axle. At this time the model no longer resembled 42009 very closely, so Gerger changed the appearance to loosely match the Grove GMK6400 mobile crane. He was kind enough to provide an LDD file of the completed model, and from there (and a couple of design iterations later) various EB members such as myself took over to make an LDraw file, a parts list, and full instructions. Finally, we arrived at this brilliant model: From the outside, you might be tempted to miss how complex this thing is, but from inside you can see the 9 motors and copious mechanical functions. In this color coded image I've produced, you can see the interweaving of all the functions: Red = Drive: 2 XL motors, all 6 axles driven Blue = Steering: L motor, 5 axles steered Yellow = Suspension: all 12 wheels independently suspended Teal = Outrigger Extension: L motor Brown = Outrigger Lift: L motor Pink = Slew: M motor, 360 degree rotation Tan = Boom Luff: L motor, parallel linear actuators White = Boom Telescope: L motor, 3 stage telescope using cable return Green = Winch: M motor At current count, this model features 3504 parts and 199 pages of instructions.

I never posted it. It has been superseded by draft3. Now that I have built the model (just finished it), I will be making more changes to the instructions and will upload draft4. They go at the top of the windshield. The black bushes go to either side of the cab. I eliminated both of them from my build by just using black 3L and 2L axles. Looks fine and you will never notice the difference. I also changed the color of the 4ea dark bluish gray 32184 connectors which are quite rare. I used light bluish gray since you can't see them anyway.

Draft 3 of the instructions is now posted. I did the superstructure in a big hurry so I'm sure it is not up to my usual standards, but I also think it is good enough for any experienced builder to build the model.

I'm not quite sure what you mean by your suggestion. I admit that I did this much faster than my normal instructions and did not take as much care so there are certainly things that could be improved. I wanted it to be buildable as soon as possible because it is a holiday weekend in USA and I intend to finish building it. I can release the file when I am done if people want to make improvements. I can add page numbers to the final PDF file. The suspension is quite stiff and there are 14 shock absorbers. Nevertheless, I think the outriggers will actually help to stabilize the model even though they cannot lift it. I can't answer yet. The boom is not as heavy as you might think, and this L-motor does not need to go through a big gearbox like it does on 42009 so I think it will be OK. As it turns out, no. The boom is nearly that of Cristophe except that it is 11 studs longer and there are some color changes. However, there is no reason you could not use the instructions of afol1969 except that then the parts list won't be quite right. If you want to do that, start with only the carrier parts list and use a separate parts list for the boom and/or superstructure. I wanted to use afol1969's instructions, but because of the changes I ended up having to redo the whole thing myself which also resulted in draft2 of the instructions. I built the boom last night and can confirm it works well (although the second stage was installed backward in the digital file). I have fixed a couple of things. There is no string in the instructions for the second stage, so use afol1969's instructions for that. I also added the return string as discussed in the thread about the extended boom. I was hoping to use Jurgen's instructions for the superstructure, but again it turned out there were quite a lot of changes. There are rollers underneath, cosmetic changes to the panels, and a bunch of color changes to parts inside. Because of this, I spent all day recreating all the instructions for the superstructure from scratch. I am happy to say that I am done, and the final 200 page draft3 is running now. Again, I think you could use Jurgen's superstructure with no mods if you want, it just means the parts list would be different. Yes, it has been lengthened, and yes the original would work. Yes, there is a link to the parts list several posts back. It is on my Bricksafe account with the instructions. Nice catch. I've fixed it. While I am sitting here waiting for the new instructions to render, I also did some messing around with the boom angle. I was not quite happy with the fact that the boom only raises to about 45 degrees. The real crane can go to more than 80 degrees. I found that by changing the cams which attach the linear actuators to the boom to 3x3 bent liftarms, you can get extra lift by using a different hole. This means it won't be able to retract all the way down, but you can just change which hole you use when stowed. It is not perfect, but it allows the model to be displayed in a higher position. Here is a picture after the mod:

You got the wrong species. I look like this:

Anyone who wants to make an appointment to stop by my house can get personalized instruction for a small part donation.

He looks real good for a prototype son. You should probably have a few more just to make sure you have the process perfected though.

What are days? I exist outside of time. That's because I perceive the thoughts of MOC builders from vast distances.

5571

I've completed a first draft of the instructions and posted it at my Bricksafe. For the most part I stuck with the steps that Gerger already created with a bit of re-ordering here and there, some buffer exchanges, and a lot of rotation steps. The carrier is about 600 steps over about 130 pages. I started building it last night. I've completed the first two axles and the instructions are working well. After the carrier, the instructions just do the superstructure all in one step. I'm trying to decide what to do about that. The main part of the superstructure can be built with Jurgen's Ultimate 42009 instructions which already exist. The boom can almost, but not quite, be built with afol1969's instructions. This boom is longer so those instructions really need to be modified. I'm putting off deciding what to do about the superstructure until later. Feel free to download the file and give me some feedback, but I probably won't be putting a whole lot more work into the carrier as long as everything is clear enough that it is buildable. I'm not going for perfection. By the way, I ran into an interesting LPub bug. The image below shows Page 25 which for some reason had pages 1-24 overlaid on it. A good way to save pages, but it is hard to build this way!

I don't have any problem with your posts Paul, but I did find it ironic that your response to someone complaining that you post in too many places is to spam every board you can think of with a query about whether or not people like your posts.

Wow, I didn't realize you understood me so clearly. I'm impressed! Gerger, can you give us any information or photos on how to route the extension wires for the outrigger motors?

The real Tumbler use Super Swampers. The Unimog tires are actually closer to accurate than any other LEGO tire. The proportions are about right, but the tread is wrong.

No, not unlimited so building these two models in the same year was hard. I fund most of my LEGO hobby by selling parts and instructions. I don't really earn any profit but it funds more LEGO which allows me to keep going. There are lots of different kinds of Americans, but those of us who live in big cities do tend to work too much. That's why we need diverting hobbies!

While it is true that 6AA cell batteries are capable of a MUCH higher current output than a 9V block battery (which has 6 tiny 1.5 cells inside it), in LEGO practice the current is limited to ~1A anyway. So while the 6AA batteries may be capable of much more than 1A, you will never get it out of the battery box. So as long as the 9V battery is capable of 1A, you won't see any practical drop in performance. In other applications (like R/C), the difference would be immediately noticeable and unmistakable.