A midscale trial jeep

[Appie]

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

Edited March 6, 2015 by Appie

[MajklSpajkl]

I really like, but I think the tires should be those from 42029. Otherwise, good job!

[Appie]

Thanks :)

Yeah, those would probably be better, but those weren't allowed for the trial it was competing in.

I might tweak the model in the future and include those tires. For the next trial competition the whole thing is getting an overhaul anyway, since I learned for these rules and the obstacles present, a bit more speed is not a bad thing :)

Learned a lot for the next trial though ;)

[miguev]

I can't wait to see the video! Nice to see people doing trials with these tires, it looks like if you don't put the rule to use them everybody will go with the big, bigger, biggest tires they can. I like your limited slip diffs, saw something similar in a TC6 model and now waiting for rubber bands to give it a try

[Rishab N]

Little tall for my taste, but it looks very good

[Coola1]

Dang, I wish I had 4 of those wheels, but all I got is 2 from an old creator dragster. Awesome build though, smart how you put the battery on one side and managed to pack the motors on the other.

[Nalyd997]

Those tiles must have been what Mahj posted on Flickr a while ago

[weavil]

Nice work! I like how you did the limited slip on the diff! The color scheme reminded me of the 5580.

[Appie]

Thanks all.

Those tiles must have been what Mahj posted on Flickr a while ago

Yup, he organized it.

[DamonMM2000]

Neat, I like it!