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I don't see why it is struggling as the red beam is turn at 90°. BTW, very clever idea because it's very compact and don't need any gear !

Thanks Jurgen ! Ramacco, as you mentionned, small pneumatic cylinders prevent driving ring from falling out of the 16t gear. If you mount chang over catch on a friction pin, then I guess that you won't have any problem with this ! Ps : for your project, you had better to choose Volvo brand because Hydrema uses boggy suspension not 3 pivoting points one.

Torque is influenced by the number of teeth. So knob gear changes nothing to torque, bevel gears can change something (if it's 12t/20t for instance) and differential will change torque only if there is a 3:1 reduction. When locked, it acts as if it was an axle, not a differential, so no, you don't lose any power. Also, knob gear aren't very efficient at high speed due to its only 4 teeth ( the less teeth a gear has, the less efficiency it has). But I guess you already know everything of that, so I probably don't understand what you exactly mean.

Hello everybody ! Once I saw Han's articulated hauler, I find that it's really nice BUT not built for good performances on climbing. Why? Because Han did not make the right choices. Indeed, his 3 points suspension system is nice but involve lot of weak parts. Moreover, there is no portal hub, which means that all the drive train is under high stress. Han says that he reaches lego limits but I only thing that he reaches limits not cause to lego parts but cause to his choices. I decided to build a hydrema dump truck because this firm is not well known but make excellent construction equipment. First of all, I wanted to build a 6x6 but finally I switched for a 4x4 for three reasons : -No central differential -I have only four big wheels of the same type -Multi-tip ( principal reason for my choice) Here is the model which inspired me : And here is my lego MOC : It owns : -Integral propulsion powered by Xl motor ( 6:1 reduction ) -Front and rear lockable differential ( simultaneously)thanks to small pneumatic cylinders -Front live axle -Rotating hitch -Articulation with two mini-las -multi-tip ( rotating and dumping bed) Let's take a closer look at the front axle : I use portal axle from 8110 to good support wheels. All the reductions are on the axle to reduce stress on drive train. Everything is built strong, motor struggles and stops before one gear ( or one cv-joint) skips or breaks. Front-axle is maintained by four points (V-link, Panhard rod and two schock absorbers) On the photo above, you also can see the mechanicsm for the articulation ( two mini-las).From the first prototype, a better look at this function : No reduction, La are "directly" connected to M motor). Left switch is used to lock or unlock both differentials differentials unlocked differentials locked To rotate the bed, I use the same system as the 8868 one ( pneumatic cylinder pushes or pulles rack which turns a 12T gear directly attached at the superior turn-table part. (picture from very first prototype). Two pneumatics cylinders are used to tip the bed. Very powerfull. As I didn't see how to built its characteristic look with studless, I switched to studfull. I have not a lot of studfull parts so I have do my best with my inventory. Reproduce bed form was very hard. I'm satisfied by its look, same if its shape differs from the original. About its offroad capacites I'm happy because it performs well BUT Xl-motor suffers quickly due to lack of reduction. The problem is that I could only put more reduction before weak parts and I don't want to break them. I'm currently building a new hydrema dump truck but this time a 6*6 with rear boggy suspensions and 9:1 reduction after differentials to have a truck which performs still better. Finally, here are the video and my brickshelf galery for additional pictures : My brickshelf galery My video :

jacobkristensen, I have nothing wrong without, I simply have a hard time to understand what you want to say to me :)

Rather of high speed I would say. Knob gear is not made to turn so fast and due to its 4 teeth, its performance is worse at this emplacement.

Here they are : some pictures during disassembly process : And you can see all of them here : Mygallery

Thanks.Alasdair, I will take some pictures of the balanced system, so you can understand how it works !

Not a lot of things to say about this one : This was the last MOC I built for fana'briques exhibition. Most of my parts was taken in others creations, which limits me during this building. Two M motors are used for arm movements. One of them is directly attached to the linear actuor. Indeed, I hadn't no more 12t sb gear and cv-joint. Xl motors are used for propulsion ( one Xl for each track), both with a 12/20 reduction. As you can see on the above picture, there are two mini turn-table. These one are usefull to increase rigidity in the balance system. It works thanks to the track "flexibility" because rear gypsies are fixed ( meaning there are two fixed points). In action : Most difficulties during building came from exterior aspect itself where I needed to use some plats ( a technic that I'm not used to build with) Finally, after some trials, it turned quite well Here, some pictures during building process : And finnaly, the video. Sorry, I dind't take a video with both loader and skip truck :/ Next, I will present my hydrema dump truck, recently finished. I'm open to any comments as usual( begin to be boring to say always that :p)

Thanks. No way to reduce weight I think because I have tried to optimise a maximum the construction.My hydrema dump truck is finished, I will prensent it soon.

No, it's too heavy, it weights 2kg200 and only one Xl drives it. With less reduction, it won't be able to drive over some obstacles.

I can lift up to one kilo on the bed ! The La is powered by a Xl motor, don't forget it ;)

This time, it's my scania skip truck that I present. You have maybe already seen it if you often check brickshelf galery. Let's start by a summary of the building process. It was the first version : When I firstly presented it on setechnic, some members told me that doors were to big and I redesigned a new cab : Its suspension system was a flex one : It owned an integral transmission, a front axle steering with ackermann effect and a gearbox to switch from driving to skipping. Unfortunately, this first version was unable to drive. See the problem : So, a long reflection process began where I sought were the problem was. I removed front driving, without any change, removed only rear axle driving (so the front one was still in place in this trial), without any change.All the trials I did to find the problem was unsucessfull. So, I decided to change from flex suspensions to classic spring one to see if there was any difference. Indeed, as you can see on previous pictures, all axles are not positionned on the same straight and the curvature on the right or left flex is not the same ( for a same axle), resulting on a truck not perpendicular to its wheels. You can also see here the fake engine, driven by front axle ( which explain also why I can not remove front drive) I also removed dual wheels on rear axles to reduce friction. With all these changes, truck drove better than previously, but it was still not perfect. So, desperated to ever find what the problem was, I removed again front wheel drive and it worked now very well ! Unfortunately, I wanted this truck to be able to drive over some obstacles as lego bricks and rear axles are not strong enough to support torque without gears skipping. Front axle is the only one where gear can no slip. I decided naturally to create a second gearbox, below the first ( remember, the one which change from driving to skipping) which allows me to change from all wheel drive to 6*4. The final version was born : Naturally, doors can be opened : With a front loader, which will be soon feature on EB : And finally, the video for the new version : This truck is already disassemblied, pictures of this process will be uploaded soon.

It's an excentric system. If you have an old motor, the one which turns at 4000rpm, connect a triangular liftarm by one of its cruciform connection and run the motor at its full speed, you will quickly understand what an excentric is :)

TechyMind is a french moderator on setechnic.com

Hello everybody ! It's long time since I have featured for the last time a MOC here. So, I'm going to present MOC I have built for fana'briques exhibition. Let's begin with a simple jeep, inspired from nico71's one, created to participate in the trial truck contest at fana'briques2012. It's AWD and AWS and owns a fake engine under the bonnet ( which turns really slow due to a 3/1 reduction). I finished second, principaly because it was hard to pass over a bridge obstacle due to its 4 wheels steered. Here is the video, done before fana'briques exhibition, it do not represents well the jeep capacities. I have still disassembled it and toke some pictures during this : There are many other pictures on my brickshelf galery :Here I'm open to any questions or comments !

Nice videos but way too long. As it's AWS, remove differential is a bad idea for turning radious ( as I already say :p )

It looks nice but mini-la are disproportionned. Longer one would be better and he coult lift much more.

Are you sure your battery were recharged? It seems less performanc from what I have seen at fanabriques. Also, when trying to pass your hand, you need to turn a wheel not to attack the obstacle with two wheels perpendicular to it. Same thing happens when you try to climb over its box. Also, to compare it with your jeep you need to climb the same obstacle ( a step of 5 cm and a staircase of 5 cm is different obstacles). But it's still clear than a trial truck with a xl motor is more performant. Designers don't put Xl motor simply because its torque can damage parts.Thanks for the vid !

Hmmm. I'm sorry, but I think that I have some Truck Trial experience, after building three of them which where performing well enough. Two of them were built without differentials and my last used them. From what I have seen, the last using differentials was the most responding, and the most playable.With a litte experience, you can pass almost the same obstacles as you will pass without differentials You probably don't see the point to use differentals because truck trial in Poland is in outdoor and turning in a small space is not the point. But we have not the same philosophy in france ( or in any case the guy which participate at the fana'briques competition has the samephilosophy as I have I think). The course showed in Anio's video is small and a good turning radious IS needed when you know that each time you drive in reverse you lost point. I hope you will see soon some videos of this competition to see that differentials were a most ( for me, naturally). Our trial truck are light and manoeuvrable where Poland's one are more heavy, more slow and it's probably for this reason we don't have the same trial truck conception. Yes blakbird, there are in real life multiple technics to block totaly or partially a differential but in lego, most of these technic or not possible. I simply say that I prefer put differentials in a truck trial rather than not use them, because the first solution has more advantages in my opinion.

Oh Allamp, it's indeed evidend why these u-joints break ! Thanks for opening my eyes :) Locking differentials would be very complicated to integrate with the parts currently avalaible. A trial truck with a central articulation could be the solution but it would be more heavy. Naturally, it depends which obstacles you want to pass with your trucks but I think differentials are the best solution.

Remove differential is the worst thing you can do at my eyes. Before, all trial trucks used NO differentials but it was a mistake for me. Turning radious is just ridiculous without differentials and you can't maneuver your vehicle proporly. Don't know if you have already participated in a trial competition and see the difference between trucks with differentials and without but it's astonishing how the differential allow a smooth drive! So, yes, differentials hamper performances but with good suspensions, tires are still always in contact with the ground. You should also see that your obstacles are just enormous, (bigger than the diameter tire) which explain why it can climb your course ! Edit : yes Raus, lego joint are too weak. You can build your own but they will be bigger or use a rond plate at the end to consolidate it. All in all, lego are just plastic parts... One thing which is strange is that, during fana'briques trial truck competition I have broken a joint where torque was the lowest... One of these :

No, we speak about new ones, the ones where you can connect round pins on both side.

Yes they are bigger. Their lenght is 7, not 6 for instance.