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Showing results for tags '42099'.
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Rocky - 4WD Rock crawler buggy I would like to present to you 'Rocky', a rock crawler buggy with a body tilting angle that averages the angles made by the front and rear axles. My shot at a 42099 B-model. Instructions are available on Rebrickable. When I saw the first images of 42099, I noticed that the amount the body tilts sideways, is mostly defined by the rear axles angle, because that axle's suspension is the hardest - it carries the battery/control unit - and it's not pendular. That got me thinking; wouldn't it be nice to make a setup in which the body tilting angle averages the angles made by the front and rear axles? Just like how a Mars Rover averages it's body angle between it's rocker bogies - with a differential - but now sideways, not lengthwise. That way it should be possible to mimic the character of 4-link suspension, which is often seen in rock crawlers. So that was my objective with this B-model and the nice thing is that this model contains exactly the parts needed to build something like that. Axle articulation Here is the setup that interconnects front and rear axles. Like in rocker bogie suspension, you should regard the body as the differential house. The body tilting angle is defined by the two axles that point sideways. I used 4 gears in the differential itself to minimize slack in the system. There is some rotational slack of course, but this is even further reduced by 1:3 given the 20:60 gear ratio with the turntables. Center of gravity Besides the differential, the center module also houses the battery/control unit, because that unit includes the tilting sensor and I wanted the tilting sensor to show the tilting angle of the body. I also wanted to keep the center of gravity low and centered. However, putting the unit in this central spot did cause issues later on... The battery/control unit - not depicted here - plays an essential role in form-locking the whole center module. The battery/control unit can be slided out sideways after removing a few pins and parts. Spring suspension Besides axle articulation, I of course also wanted to include actual spring suspension, so I attached two main suspension arms to the turntables, one for the front axles and one for the rear axles. I suspended the main suspension arms with springs placed between the turntables and suspension arms. The springs are mounted differently to the front and rear suspension arms, giving the car a little more lift in the back, which adds to a nice inclination, or rake angle, of the whole model. The whole model nicely sinks into the spring suspension under its own weight up to about 40% percent of the overall spring travel. Drivetrain I wanted to have the most simple drive train possible, so the motors are directly attached to the frames holding the differentials. This is a crawler and with the new portal hubs, there is no need for any up or down gearing. The motors add to the stiffness of the main suspension arms. I also wanted to have a track width that is two studs wider than the stock 42099 build. After some playing around I found out I could use the new CV-joints the other way around to make that possible. Steering For steering I wanted minimal slack and double sided steering rods like in the stock 42099. I limited the steering angle to make sure the maximum angle the CV-joints make, does not cause any damage. I noticed the CV-joints start wobbling when the angle they make is too big. The steering rack assembly - as well as its back side counterpart - use a trick to minimize unintended movement (slack): The assemblies are 3 studs deep and incorporate 3L axles with end-stop. The end-stops are sticking out of the assemblies and make them slightly deeper than 3 studs. For this to work the end-stops need to slide along a smooth surface. This trick makes for a very nice fit with little play and still allows the assemblies to move very smoothly. Ground clearance To increase ground clearance I used a double wishbone setup, not suspended, to take advantage of the extra lift provided by the inclined wishbones. The rear wishbones are inclined more than the front wishbones, because there the CV-joints don't need to deal with the steering angle. At this stage I also added a set of minimalistic fenders ;-). Bodywork Finally, bodywork. This was the most challenging part for me. It needed to be removable, to provide access to the battery/control unit and I wanted it to live up to my foolproof standards. The whole model can be lifted by the roof or by the A(?)-pillars. At this stage I practically used all the pins that came with the set, so I had to do a lot of backtracking to get some pins available. I ended up using all pins, including the ones that came as spare parts. Interior RC don't have interior . When I wanted to test drive with a first bodywork attempt, I found out the hard way that I could not reach the on/off button of the battery/control unit. I had not taken that into account. Eventually I found a solution in making the roof openable, as if it were a hood, just by releasing two pins. The red 10L axle in the back can then be used to turn the controller on. After opening the roof, it can be removed easily, after which the sides of the body can be removed separately to access the battery/control unit. All together this has been a great experience. Especially the limited and pre-defined set of parts made it a real challenge. It forced me to revisit all constructions over and over again, and leave in only what is essential, without making concessions to my self-imposed building standards. I ended up using 828 of the 958 parts.
Hi To whom it may concern. My one month old 4x4 extreme 42099 lost power at the rear wheels. I then took it apart to see if something might be stuck in the gears etc. No, everything mechanical including hubs were fine. Ran the rear powered up XL motor outside the truck and found that it made a grinding noise vibrating excessively and started to sieze when rotating anti-clockwise (truck moves forward) , but reverse works fine. What to do? Is there such an replacement motor available? Think the motor overheated because of resistance when not being able to make a climb etc. overload. Or just a bad motor? Why does the motor vibrate excessively and struggle to rotate ONLY anti-clockwise? Have anyone had this issue? Please advice.
shugo posted a topic in LEGO Technic and Model TeamHi All! Since last tuesday I own all new sets and I've recorded many videos (speedbuild, functionality reviews, detail views...). Thank you for watching! 42099 4x4 X-treme Off-roader Functionality review: https://www.youtube.com/watch?v=6ZfIpFKcUME Speed-build: http://youtube.com/watch?v=jgss_ZFzWEA First Look at App release: https://www.youtube.com/watch?v=pIb-Al_3o5g Control+ packiging: https://www.youtube.com/watch?v=oas_z6tcJA0 42098 Car Transporter Functionality review: https://www.youtube.com/watch?v=sHOuPBHtDtg Speed-build: https://www.youtube.com/watch?v=kY9N-2lezZI 42097 Compact Crawler Crane Functionality review: https://www.youtube.com/watch?v=Z4oRcbnZMBU Speed-build: https://www.youtube.com/watch?v=bvelE1MXuaA
shugo posted a topic in LEGO Technic and Model TeamMy own speed build video of LEGO Technic 42099 4x4 X-treme Off-Roader. Funcionality review video will be later in august. Currently the control+ app is not available for download :D Speed-build video: https://www.youtube.com/watch?v=jgss_ZFzWEA