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Hi there, I've developed a very annoying habit in the last few years. I randomly build pickups and other 4x4's. Even bought a real one. Anyway, the latest one is quite a biggy (sizewise) thanks to the planetary hubs. I've found a trick build them into solid axles with a practical ground clearance. This trick is going to be conroversial here. But start up with the video instead: All pics to be found here: https://bricksafe.com/pages/Attika77/ultimate-pickup In the comments under the video, noble members of our community noted, that there are parts which could solve the 1/4 stud misery. (if you don't know what is that, off you go, and whatch the video to the end! ) One of these is the 14t gear from the old diffs: I've made the attempt, but due to that collar on the bottom (top on the pic) it is too wide and puts srain on the drivline, making it hard to turn it by hand, so it is off the table unfortunatelly. So I speak for myself when I say, cuting those axles worth it. Not a rare piece, and costs 1 cent on bricklink, but only because there is no smaller value in the currency itself. In return the design prooved itself very reliable. Another "weakness" of the axle is the inperfect geometry. The wheelhubs aren't completelly vertical. There is about 1 degree tilting inside on the top. /---\ Before overdramatising this atribute, think, if you've noticed it in the video? Apart from the axles, the rest of the truck is the product of those years I've mentioned above. The essence of it is a simplest possible drivetrain: And a steering solution refined for non-rack steering: (The render is made of an older version, hence the different connector) If you don't belive your eyes, yes I choose to use 4x2 beams to form steering arms. It looks savage, but it is doing the job very well, brings ackerman geometry in the game. It does not hold the wheels rock solid of course, but in practicality it isn't noticable on the field. I've got a rack steering solution as well, but that brings the servo down A, onto the front axle (I don't do that. Ever ) B, into the mid chassis, where I don't have room for that. So we keep that for another build. Also has a working steering wheel using the rear output from the servo. ame old bevel system I've been using in most of my builds. Check the 1st episode of the pickup saga for more on that. Suspension Solid axles on a 3 link setup. It is kinda made up design, slightly inspired by the rear suspension of my Isuzu Trooper. Changing the shocks, or their hinge point on the top, gives 3 different ride height and suspension stiffness. The black, soft springs give a softer, relaxed, lower stance to it, while the dark grey shocks (known from the set 8880) are lifting the truck to a practical maximum, but still can reach full articulation. Not in all situations good to have your truck up in the sky. Like the climbing in the video. With low shock setting it made 52 degrees, but 47 "only" on big wheels and lifted shocks. The center of gravity moves with your ground clearance. That's about it, the rest is smoke-screen, like the body, and fancy doors. Oh, here is a fun fact: When it came to the seats, I realised I have 2 adjustable seats salvaged from a lorry build from about 5 years ago. Luckily they fit perfect so just made a rear bench in the same style. A non adjustable lazy style. Please feel free to ask about it, or just say something about cutting axles. I hope you find something useful here to take home with you.
Good people of Eurobricks, let me give you my first take on the planetary hubs: Please excuse me for the lenght of the video, it's meant to show the developement stage by stage. I had big expectations towards the new hubs, since they've been announced. I realised, these hubs will solve the problem of the stress on drivetrains, yet will raise a new challenge. Due to the increased torque on the wheels, the frame (chassis) and the bracing of the suspension will be the new weak link. A wanted to have a finalized rig to the date of the release of the hubs. The backbone of the design came from a five years old chassis concept, it was a non motorized chassis: To mimic the geometry of the new hub, I've used the old ones with some extension, so it can be easily swapped, when time comes: The concept of the chassis came together quite well, thanks to using techniques well practiced in my early years. But there was still a long time till the release of the new hubs. Driven by curiosity, I've planted two PF XL motors in the middle of the chassis, making them drive two axles each. One for the front axles, one for the rear ones. No additional gearing has been added, the motors were connected straight to the differentials. Of course it had to be tested, hat's the part around one minute into the video: https://youtu.be/PGQpUrOS-NQ?t=59 Came with a surprisingly satisfying result, despite the usage of the old cv's and hubs, yet it was understandably far from being a "crawler" it meant to be. Also at this point I was short of claas tyres, so I've used some similar size rc tyres on the front 4. Got the tyres eventually, still a lot of time till the hubs coming though. As the final design was gonna use 4 buggy motors, time came to make the change: Same principals, like with the XL motors: No gearing added (slow output used), 2 motors drive the front, other 2 for the rear axles. Now feeding that much buggy motors would require 4 buwizzes. Or one well sized rc lipo that can comfortably supply 2 sbricks. 4 buwizzes cost about 400-450 pounds, while the lipo comes for 30 pounds. Any question? At this stage (still no new hubs) it was an obvious, yet pretty crazy idea to hit the tarmac. So I did. That's what you see at 2:16 in the video: https://youtu.be/PGQpUrOS-NQ?t=136 I had a lot of trouble that day with the bluetooth connection, brought a head on crash int o a container. It was heart-, but no plastic breaking. Finally the hubs came by the post and the picture got full. I've also planted another servo for steering (2 in total now) Indoor durability test at 3:27 https://youtu.be/PGQpUrOS-NQ?t=207 Climbing test (60 degrees) at 4:18 https://youtu.be/PGQpUrOS-NQ?t=257 Hereby I apologize for the dark enviroment at this recording Peek on the suspension at 3:12 https://youtu.be/PGQpUrOS-NQ?t=191 Lego should not be used outdoors... ahm, okay... Outdoor test from 4:55 in the video. https://youtu.be/PGQpUrOS-NQ?t=295 I came to the verdict, that the new hubs worth their money. In a usage that abusive, you see in the video the hub-cv connection definitelly require some lubrication. I've been using silicone oil and no downside appeared so far. Here is the difference it makes: That's it so far, a little spoiler at the end of the video. Hope it's gonna catch some expert eyes...