Search the Community
Showing results for tags 'portal hub'.
Found 4 results
I think anyone who ever used the portal hubs came to this issue. The hubs simply have the steering pivot point so far from the center of the wheel, that you need to either reduce the steering angle, or have a model with large fenders. Today I came up with this simple mechanism to compensate for that by simply turning the whole front axle in the opposite direction. The two tilted 6L links are usually used to keep the axle from moving forwards/backwards. In my case they are attached to the steering rack at a high angle. Moving the steering rack will cause the geometry of the axle to change - rotating it to (mostly) compensate for the large pivot point: Of course this is just an idea for now, but it should be easy to implement on a real model. The wider the axle, the better the compensation. Of course the axle has to be designed in such way, that suspension, drive and steering system will be able to work with this degree of movement.
Here's a creation I put together in a couple of evenings after Wall-E to enter in a trial contest at a LUG meeting: The contest had a few rules: - Use the 62.4 Lego tires (which do look a little small for the height on this model) - Make it 17-20 studs wide - Use 1 IR reciever - Use 1 or 2 motors for drive - 1 motor for steering Everything else was pretty much free game. It features quite a load of "stolen" ideas: - Zblj's little portal hubs (thanks for that nice idea, though I should brace them more since they can get seperated a little under force as I found out at the trial) - Snipe's limited slip diffs with rubber bands (though obviously more people used this idea, I am not sure who used it "first", I only know I saw Snipe's post first. Either way: thanks) - TLG's 9398 steering setup (which I only made a little smaller) While I know diffs aren't a good idea on trial trucks, I refused to have no diffs in my model. So I looked at other options, came across something called "torsen diffs" but I couldn't fit them in a 20 stud wide vehicle with portal hubs (21 is the best I got). Then I came across this idea for a sort of limited slip diff, which worked pretty well at the trial. You can also see the steering axle has some free play (and 2 bevel gears) so the steering would still work when the suspension is at an angle. On a rare occassion, under force the bevel gears would skip on the gear rack since on the other end are 2 universal joints, so bracing isn't the best at it could be. Also given the fact that due to the suspension the steering axle's range of motion isn't even fully utilized I could have probably braced it in the given space, but I didn't find out until the trial that this actually needed some better bracing Trying to keep the weight low and balanced I learned that a battery loaded AAA battery box is about equal in weight to a XL motor and servo motor. So having the 2 motors on one side and the battery box on the other seemed like a good idea.The XL motor ended up with a gear reduction of 1:7. Which means it certainly isn't the fastest, but it runs up a steep hill until it would simply fall on his back before gears would grind. Gears did grind however at the trial, but that was partially due to lack of skill from the driver and especailly one very annoying (yet awesome, because it proved to be the most challenging) obstacle After I had a functional chassis, I pretty much slammed a body on top of that with a little interior. I didn't have much time left before the meeting to make it really fancy. In hindsight I would have probably made it a little bit lower and cover more of the chassis, but I still think it turned out all right The guy who organized the trial at the meeting said we had to keep a space open on the model for a 2x4 tile. He made these nice 2x4 tiles with a custom print. Of course you would like a video, but at home I don't have much obstacles suited for "trial". However at the meeting, the guy who organized it made a video, but he hasn't released it yet. I hope to see it soon so I can link it here
Some people say it is the best offroader of the world, other people call em the big brother of the U400. Mercedes call it..... Unimog UHN Well, i have taken my priority on the look of the Unimog UHN and not on the offroad abilitys, for this i would need 3 lockable diffs and a shiftable bearbox with many gears. one thing is adequate to the UHN series what tlg could not made, because this would be to expensive to produce. I Talking about the portal hubs which are in the lego version very large and having a pivot point far away of the wheel, so i made my own. But this was not enough for me to replicate a proper unimog, so i have made a rim with a deep offset and a realistic look This all makes a wide and flexible frame in a realistic shape possible. and like the real frame it is highly flexible The Gearbox is simple and offers no shifting, what is not really a good decission because a gear reduction of 4,2 to one is not suitable for every situation. For heavy offroad under good grip conditions the torque is not enough. designing the cab and details is hard to describe so i let the pictures tell the story. and finally the actual available videos. A longer vid will come and the ldd file I hope you like it