If you like yellow parts then there is no better set to buy that this awesome crane. One of the things that really put me back about this model was the price.
And let me say first that this model is huge . And yes, they are not small booklets with a few pages. All of them has around 70-80 pages and at least split building the crane in three logical steps: mobile crane truck, crane body and crane arm. The building experience is awesome but really expect a few days of building.The crane truck is really cool with two features that stand over the rest: the 10 working wheels with a steering system for such number of wheels and the stabilization system with four small linear actuators that emerges from the sides of the crane to make it stabler when operating the crane. The crane body has another complex gear box as well as two big linear actuators that operates the crane arm. As this mobile crane has 10 wheels you need to create a way of steering wheel that maintain them in the steering angle needed for each of them.
You can see it on this diagram to better understand the problem. The steering is very precise ans smooth for such big model. It is so large that it is hard to keep it straight.
Lego Technic 42009 Mobile Crane Mk Ii A Model Build & Review
Year of release: 2013. Pieces: 2606. Building time: 7 hours. Price: £149.99 / US$219.99 The B-model review available at my …
It goes from the back of the truck to the front part so that the stabilization system opens as one. First it exits from the truck body at four points: two on the front and two on the back. Then, when it is completely deployed you can switch the clutch and it will start working on the linear actuators to actually land the system feet so it keep the crane completely stable when working. It is a pleasure watching it working, but unfortunately the second part of the system works very very slow. In my model the feet don’t really take the crane weight. Unfortunately it isn’t enough when you are rising something that weight over 200g and it makes the crane body to bend forward.
You can rotate the crane body 360º over itself with no problem. The four functions are operating the lower part of the truck, moving up or down the crane arm, extend it and operate the wrench.
I suppose that they had to use them to make the arm as small as possible. The arm is raised and lowered using two big linear actuators on the crane body. When it is fully extended it measures well over 60cm but unfortunately it isn’t able to raise a noticeable weight without bending ( you can’t use this crane to repair your house, sorry. The arm can be extended using the gearbox on the crane body, but as well as the stabilization system, it is a slow operation. It can take around 40-50 seconds to fully extend the arm. If you can afford the money, it is a great model. It is huge, it is fun to build, it is a challenge and the best part of it is that it works. So everyone is curious to see how it performs as we have already seen some of the largest sets struggling to have its functions moving seamlessly. Thus, the comparation is more than expectable and inevitable … Once opened the flip-up cover reveals in deeper detail the electrical functions of the model, with emphasis on the functions switch box and a numeric association with several illustrations showing the main functions of the model. Also other characteristics are shown, like manual functions and the dimensions of the model. This is something expected as the box has the same size as from the 2012 flagship (9398 ) and almost twice the parts included. As any other recent sets above a certain size, this one comes with the building instructions books and stickers sheet, protected with a cardboard inside a plastic back, so that they won’t get damaged during transport as it often happened in the past. There are 6 books included, 3 for the truck, 2 for the superstructure with cabin and 1 for the crane boom. Unlike previous sets that use to include the parts list in the end of the last book, this time this comes in the first pages of book 1, what seems to me a sensible measure . This is the case of new parts (1×5 thin liftarm with axle holes in the ends – 11418 ), or existing parts in never before released colors as seen from the picture on the left.
In the picture on the right side we can also see a couple of parts which are now released with this set, in new colors for the first time. This part got extra pin holes for improved connectivity and sturdier constructions. And finally a new element which has been generating some hype – the 8 teeth sliding gear. If you notice the details on the close-up photo, you should realize there are only two inner contact points instead of four in the regular 8 tooth gear. This alone with eventually a slightly larger inner radius, should allow for the gears to slide easily over an axle. This sliding capability will offer new functional possibilities as we will see ahead in this review. Specially if you can wait and look for better deals or for the prices to start falling as the set gets closer to its retirement in a couple of years. Additionally to the partlist print above, you can also see the full assortment listed here .
We start with the first book of course, and with the chassis of the truck supporting the superstructure and crane. At the end of the first book and after 75 steps, we are like this. The five axles and respective steering racks (4) are in place along with the basic switching box mechanism in the center, that will allow the selection of the two outrigger functions (extension/retraction and feet lower/raise).
Lego 42009 Build Time
We proceed into the second book until we get the basic chassis structure finished few steps ahead, before getting into the construction of the outriggers modules. Interestingly the outrigger extension arms, are built with a double gear rack stacked setup. This allows for the exact height required to let it run perfectly tight inside the studless chassis structure. Also it provides a convenient top slot that provides a guiding line for an half pin which this way locks each outrigger arm in place and prevents it from getting out of the respective casing. In these photos you should finally see the red sliding 8 tooth gears in use. Moving forward we also build the front outriggers module and attach it into the chassis. The next step consists in guarantee that the front axle is well aligned with all the four rear axles. For that we are going to build an auxiliary beam structure to align the axles in place.
Lego Technic 42009 Mobile Crane Mk II Time Lapse Build Fast Version
This is the second time we use such procedure in the building of this model and the auxiliary structure is disassembled just after. With this, we have now reached the end of book 2. The model proceeds with some fairing, the fake engine behind the driver cabin and the construction of the cabin itself. These constitute all the building steps from book 3, and let us with an almost 60cm length giant truck.
We are now diving into the second part and start building the mobile crane superstructure. The next two books cover the most complex part of the superstructure, with all the gearing from the model main switch box and the driving of the pair of large linear actuators that will sustain the crane boom. Doing some calculations we can determine a total lag of about 250º or 7/10 of a turn. At the end off book 5, is when we get this structure ready, with the crane operator’s cabin and battery box at counterweight place, attached to the truck chassis by fixing the large turntable on it.
You should realize on a small detail – the 8 tooth gear on a friction axle/pin, next to the large turntable, preventing the whole structure to freely rotate with minimum friction. Getting into book 6, we start building the last element of this model – the telescopic boom and crane. Below the inner boom assembly, with crane’s second and third section, at retracted and extended positions.This one goes inside the first and external section, which also provides the final look as it is seen from the outside. Only possible if building at a larger scale, as it is the case of this model. Once assembled together, this is the final look of the three section telescopic boom, seen in different positions (fully retracted, half extended and fully extended). The last steps consist in attaching the telescopic boom to the cabin structure providing the necessary gearing is put in place, passing the winch cable over the boom and around the winch wheel, and fixing the end. There are situations where the friction doesn’t seem to be needed at all, and it just drains power from the overall function, which is a waste specially when this is motorized. It seems to be the case again with the feet on the 42009 outriggers.
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The feet were not moving at all, and the corresponding gears seemed to be stuck somewhere. Again, we must remember this is a function where the motor is in the upper structure, and driving a quad outrigger setup in the chassis of the truck, through the turntable connecting both structures. This requires him to have big visibility on whats going on all the time, and often such cabins can be adjusted (raise and tilt) to facilitate such visibility. Specially after having the possibility to tilt the cabin in the former 8053 , but it is not the case here, where it is absolutely fixed. Although we got opening doors and adjustable seats in the cabins. The hook used for the winch itself deserves some remarks. The only drawback is that such hooks are likely not much heavy as the original was, thus causing less tension on the winch cable, when the crane is not lifting any payload. Another aspect related with the winch movement is that it does not move in synch with the telescopic boom when it is extending or retracting. The opposite happens when retracting the boom, eventually leading the winch to hit the ground. To avoid such effects one should shift between the boom and the winch operation. Although this is not a big problem as a full extension or retraction from the boom, just displaces the winch about 11cm vertically, whereas the whole model it is 77cm high. One can perfectly plan the movements in advance if really concerned with this missing feature. Hence the problem persists there and 42009 does not stay behind in this aspect!Some have also mentioned about the manual slew of the superstructure, claiming for some motorization regarding this function. It would have been great to see something in this direction, done with this large model too!
All the others take about 45” to 60” for the full movement amplitude (with rechargeable batteries), which is quite a lot of time. Although better to have these functions running slow then faulty!
For instance the telescopic boom extension works flawlessly and without the “hiccups ” we can observe on 8421. This is definitely achieved with the contribution of a great bracing done for the gear plus worm gear setup, at the top of the the boom, which guarantees that the mechanism never slips back. In fact we notice the biggest advantage not exactly when it lifts but when it is lowered. The gearing is already available at the outriggers level, and with a small switch box we can also control the feet. It was also the right excuse to get the new 8 tooth red sliding gears. A special note also goes for the easiness to replace the batteries. The battery box detaches really easily and you don’t have to disassemble any surrounding parts to access the batteries compartment. Now about the steering and turning radius. Hence the observations are quite within the expected. The center axle does not steer and the next ones immediately after and before turn 13º. These differences seem very adequate for a natural and effortless steering. All the steering axles turn with the same gearing ration combination, hence the differentiated steering angles are achieved through different length steering arms on each axle. In the video below you can see a demonstration with most of the functions above mentioned. And also my first serious timelapse experiment, with a few missing fragments. Hope you enjoy the videos despite a bit tedious (eventually)…
LEGO Technic 42009 Mobile Crane MKII Review
I just need to switch between functions using the lever on the switch box. It is not even need to disassemble anything to fix this. It is enough to lower the winch till the end and let it continue winding in the opposite direction, till the winch reaches the tip of the boom. Love them all, but 42009 is definitely the best looking, most functional and most realistic one!
I feel something should have been done differently on the stacker car to make it look nicer. On the the other end, the then wheels used in the main model, are the exact number required to build a stacker with double wheels in the front axle (like the real ones) plus the truck.
I feel that virtually nothing was sacrificed in this model, that would fit into its already large size. Although it was a great pleasure to build this model and finally to have the privilege of playing with it!
Although the still high ranks regarding innovation, these were the among the lowest ones as we always expect for more new parts specially in a vary large set such as this one. Although since it is not in the main scope of this review, a better rating for this category was also hindered. For all the rest it is something really worth to buy, but those living with budget restrictions will likely need to pass this one. The gears to the pair of actuators should be on the same side not the opposite!
I was waiting for a review from you one this one. In their case, probably also with more common and thinner batteries. Thanks for the review, lots of lovely gear trains but this model is still not for me. What stops the telescoping boom from going farther?
On the 8421, there were a couple of 1/2 pins that acted as stops. If you removed or moved these pins, you could get another 6-8 studs of extension without compromising strength. To be able to have the gears on the same side, instead of opposite sides you _do_ need an additional part to accomplish this. The outriggers extend and retract just fine with the main gear. It seems as if there is a lot of tension on the gears throughout the entire assembly. Was this an issue for you on initial assembly?
Thank you very much for the excellent review and any help you may be able to provide me with.
I just reverse the set up for one of the gear mounts?
Is this normal or any idea where we’ve done something wrong?
I was looking back at my instructions for 8880 (super car) and 8480 (space shuttle), and both needed only about 40 instructions for the whole model.They then told me that it attaches to part in step 38.
I think they could easily have moved the outrigger control to the other side.
I double checked the instructions yet still they do the same.
I remember having some issues with the outriggers working the opposite way they were expected to on one side of the crane. Australia, and the anticipation was killing me!
Although with over 1000 pins, some might call that cheating!
This set also has 162 gears, 290 axles, 591 beams. See the inventory page for the full breakdown. The back of the box has a couple of perforated sections which you can tear to open it a bit easier than the old way of ripping the backing off. There are 15 bags with #1, 5 bags with #2, and 4 bags with #3. A quick look at the instructions revealed why. The cabin which uses the 5 x #2 bags and books 4 to 5.
The boom arm which uses the 4 x #3 bags and book 6. The first page of book #1 has a new cartoon describing how to sort out the parts. The stickers are also now numbered which will help avoid mistakes.
I can’t help but wonder how long until they break, and what possible need could there be for them that multiple smaller axles couldn’t achieve. These are used to allow the horizontal stabiliser arms to extend while maintaining a gear train with the vertical stabilisers. The 5 axles all have different turning angles, to allow a truck of this size to be drivable. This is achieved by varying the distance between the gear rack and the wheel axle. The third axle does not turn at all and is the mid-point around which the other axles pivot. It is also the only axle with a differential gear to allow for this as the outer wheel needs to travel a lot further when turning than the inner wheel does. The added complexity to do this would have also been quite a challenge!
The panels that sit on top of the truck body are a nice touch. They are purposefully not locked into place as securely as other parts so that they can be lifted up for inspecting the gear trains underneath. This was a relaxed building schedule with time out for eating, photos, etc. The completed truck without the cabin/crane attachments doesn’t look very pretty to me, compared to say the 8258 body.
I would love to see some rendered images of just the gear trains included in the instructions.
I find that stuff very interesting and it would also help with diagnosing problems or modding the set for improvements. It felt similar to the 8043 build, in large part because of the double linear actuator setup. The instructions indicate to thread it through the pulley wheels, but then the axle does not turn easily as it rubs against the neighbouring axle’s gear (with or without a knot in it). The instructions at the end of book 5 tell you to test the power function connectivity after mounting the cabin. Mounting the cabin onto the truck wasn’t hard, but getting it off was another matter entirely.I opened the handy flaps on top of the truck to view the gear trains and was able to move the horizontal stabilisers quite freely.
I placed the cabin back on and tried again and the horizontal stabilisers worked fine this time.
I put the clutch gear in neutral and turned the gears manually. The drive shaft connecting to the cabin’s motor moved easily.
I could move them with enough force but there was a lot of friction somewhere. Visually inspecting all the gears showed that none of them were wedged in too tight, they all had a bit of give in them.
I then disengaged all four linear actuators to see what difference that made and the gears could turn quite freely after that.I put them back on one by one to test the motor. Of course once all four were back on it worked perfectly!
Solving these kinds of problems is half the fun of building a large complex model like this, and forces you to better understand how everything works!
Unfortunately, some of that length is lost in order to maintain strength of the overall arm when it is extended. This usually confused me and made me wonder how it was going to work like that.
I think the boom arm was my favourite section to build even though it was the simplest and quickest.
I have to skip ahead to see it in context to figure it out. Maybe it’s just my girly hands, but putting this set together hurt. My finger tips were quite red and sore afterwards. Unfortunately, they are not strong enough to lift the weight of the truck. Fully dropping the vertical stabilisers will see them grind to a halt eventually, if you lift the truck up they will continue for a tiny bit more. However if you try to push the truck with them fully deployed, you will see that they do have some grip and will start to bend sideways. The varying wheel angles and differential make it very smooth and easy to turn. Plus, the turning radius isn’t bad for a vehicle of this size. The whole top can also swivel around 360 degrees while the motor is on.
I didn’t do something quite right in the build.
I was very curious as to how much weight it could lift.
I eventually settled on something a bit lighter as you can see in the video . The issue of “jerky motion” when retracting the boom is due to the worm gear, (located on top of the boom), that drives the extension/retraction function. It can slip forward / backward a bit on it’s axel.
When retracting, the worm gear moves reaward as far as it can, then begins to turn the gears that move the rack gears. But then gravity causes the boom section to slip down, forcing the worm gear forward. A delay occurs while the worm gear moves rearward again.
I solved this by making a thin shim from plastic sheet, (the type some products are packaged in). Just finished building this set – 12 hrs total and enjoyed every minute!
A crane at that scale would be a monster!
It would cost a fortune, and not sell in large amountsbr2.