[MOC] Ultra 4 Crawler Buggy - Tested, final release!

[agrof]

Hello All!

It is winter time, so I am bit more busy on Legoing. After seeing, that @Didumos69 started his 4x4 buggy project, I looked into a bit deeper the Ultra 4 racing, and the rigs been driven in this extreme events. 

Finally the video, what I linked to his topic, triggered the work on another MOC: the Ultra 4 buggy. Here is another video to see the interesting bits of independent suspension system on this beast:

 

Still, I might end up with IFS (independent front suspension) and solid axle with torque bar for the rear, but the body is heavily inspired by the Lasernut buggy.

Parameters:

• 2x L motors
• 1x servo motor
• AAA battery box - in order to be replace ability with BuWizz in case
• IR control

Let's look at into the progress a bit, maybe it is interesting to read. I started on 28. november with LDD model. To set the proportions, and the body ideas, I usually place the essential parts free in space first.

Check the real inspiration thing and the very first sketch:

After that I added the electronic parts, to check the necessary minimum space. (Unfortunately Stud.io has corrupt models, so some cover parts of the motors are just not present.)

At this stage, I built the front axle, to see how can I integrate the steering. The answer is: massive fail. 

So back to drawing table, I deleted the 5x7 frame, and started to figure out, how to connect the needed fixation points for swingarms, servo. Due to this, the model gets more complex than I thought, but buildability is always first! I recommend to check meanwhile IRL building too, or at least stop by and thinking about how to add the related parts. I was hopeing for a simple MOC, but I ended up already a pretty complex assembly, so I made each step with double check. Later on, I will try to add groups in LDD to represent the buildability order too.

So far the front module with steering and IFS is ready, the middle module is almost done, I am wondering about interchangable solid axle or independent solution for the rear - not sure yet. Also the color is to be decided yet, as the springs type as well (soft or hard). I think if soft ones will be OK, than I go for white body, as it presents the "rollcage" better. In case the yellow hard shock absorbers will be needed, of course the only choice is: full MEAN black body.  

This picture shows the advantage of the white body, and also a comparison for tyre types: 3740 on the left, 45982 on the right, both on 56908 wheels.

So far 407 parts, and I guess it is about 70-75% ready. I need to figure out how to fix the roof, and create a solid, but easily disconnectable rear module. Necessary parts are ordered, so real build pics might come in couple weeks first.

And how is the road presence? I guess it will be pretty much like a punch in the face. 

p.s.: Yet another WIP, I hope for long winter nights, to finish at least some of my unfinished projects... 

Edited December 23, 2017 by agrof

[1gor]

Buggy looks cool with 24 x 43 tires 

[offroadcreations]

Very cool. I'm impressed by the use of panels.

Are you going to keep those A-pillars? The look a bit out of place sticking up. And I think you should add more "meat" to the back, with more panels/roll cage and a spare tire. These are just suggestions, do what you want with them.

I'm excited to see how this will turn out.

[BrickbyBrickTechnic]

I'm quite impressed. Looks very good so far.

5 minutes ago, Offroadcreat1ons said:

Are you going to keep those A-pillars?

I would like to know this as well, because I do not like those pillars.

Also, what about the Tigercat Skidder?

[kbalage]

Wow, very impressive progress in such a short time! I'm envious to see a whole model born in 3d, I always needed to fiddle around with real bricks... I really like the scale and especially the menacing look :) I think the A pillars are OK, adding a light bar between those 2L liftarms would make the front of the roof more unified. Can't wait to see the next steps, definitely following the build!

[Didumos69]

Very cool looking and nicely put together! I prefer.the solid axle in the back.

One critical note: The front wheel drive won't allow more steering angle than 20 degrees, otherwise the motor will eat up the CV-joints.

[agrof]

Thanks for the remarks and ideas, I store them for later tests!

For the A pillar I have some other ideas too, just like using black pneumatic hose, something like this (purple shows where it would be fitted in), simulated a bit with flex axle. This will be formed during IRL building, with LDD it is just impossible to bend the flexible parts correctly. Still, I am not fully sold on the very smooth lines here, the overall picture should be bit rugged, harsh, mean, dare to say: ugly. Like lovechild of an insect and a hammer.

@kbalage Luckily it is not much different than my daily job, also my wallet and my back are happy about 3D design.

@Didumos69 Thanks for the note, I am aware of that (spare parts stocked ), looks like this will be the compromise, I need to make here. The turning radius will be probably terrible... After watching  some Axial Yeti videos, I lean also more for the solid axle - which is more less only placeholder yet in the model.

p.s.: the Tigercat is doing well, just resting.

Edited December 2, 2017 by agrof

[Leonardo da Bricki]

I like the way this is looking. Black/white is definitely better.

[agrof]

Update: 477 pcs, rear axle is finished, roof is attached. The only thing is missing, the pneumatic hose (black) to form the A pillars- roof side tubes - roof back, I plan to use one piece of hose going through. As you might notice, the rear shocks don't fit properly in the model, I don't have the mood to adjust everything in correct angle for now, first I want to see the characteristic of the suspension. I would be surprised if it would match for the first try...

Now, waiting for parts, and first build test can begin. I will maybe add a bit rollcage on the rear yet (no spare wheels planned, no need for extra dead weight), but not much, I kinda satisfied with the ugliness of it - even if some don't agree.   

Also I need to test the gearing, I would like to see it climb rather than speeding, and secretly hope for good trial performance... except the turning radius as mentinod before.

Scale comparison, a bit longer wheelbase, same track width, a bit lower than the 42037.

Edited December 12, 2017 by agrof

[kbalage]

Can't wait to see it being built IRL... will not win a beauty contest but still cool :) That front view pic looks like some kind of "Ford A model got a nose job and goes to Baja" stuff :)

[agrof]

Yepp, that is the goal, I think You nailed the description.  Take a rat rod, put an Ultra 4 chassis underneath, and rock it!

I played around a bit with panels for the rear segment, now it feels more complete (damn, I lack 2 white panels from my order now).

[BrickbyBrickTechnic]

2 minutes ago, agrof said:

I played around a bit with panels for the rear segment, now it feels more complete (damn, I lack 2 white panels from my order now).

Wow! It looks awesome! But what will those white panels do?

[agrof]

They help to look awesome - that is the only purpose. 

[agrof]

Just to have it as plan-B for hardcore crawling, I prepared a "locked differential" version too.

Edited December 5, 2017 by agrof

[BrickbyBrickTechnic]

44 minutes ago, agrof said:

Just to have it as plan-B for hardcore crawling, I prepared a "locked differential" version too.

Can we see a topside image of that lime version? I'd say from what I can see that it looks better than the white.

[agrof]

Sure, virtual reality is our friend, but meanwhile makes our heart sour not to having parts in wished colors... 

[agrof]

I added real rollcage, for sake of stability, the main parts are made of liftarms. The magenta colored  12M axle should prove, that everything aligned - which is actually 99% true, but as LDD approved it, I consider it legal.  It extends the roof line well, so I might keep it. Can't wait for parts arrival, fingers crossed that not much must be redesigned, and I considered all directional structural stability.

Edited December 6, 2017 by agrof

[Boulderer]

Looks great. I look forward to an opportunity to produce a copy myself. 

[agrof]

Update: all the parts arrived! 

Just made a quick test, the 24x43 tires sit pretty well on 56908 wheels, they have maybe sligtly lower friction, than the 81,6 tires - if not the same. It differs a bit for each, as the old tires are... well, old.

I don't believe, that during normal LEGO crawling conditions they will fall off or rotate critically. And the main thing: they do look badass.

https://bricksafe.com/files/agrof/ultra-4-buggy/24x43 tyre 56908 wheel.jpg/1280x672.jpg

p.s.: Tomorrow I am on holiday, so some progress is planned!

Edited December 15, 2017 by Milan
Converted oversized image into the link.

[1gor]

24 x 43 tires look cool with black rim. The whole moc looks very ballanced in design with panels (rat-rod style bodywork and 4 x 4 buggy chassis) and it has minimalistic approach as it is desirable for such vehicle 

[agrof]

Front axle modul is almost finished. So far so good, as planned, but pretty dense, buildable, but tiny fingers needed. 

[Didumos69]

Looking good sofar! Nice to see some real life building .

[1gor]

15 minutes ago, agrof said:

Front axle modul is almost finished. So far so good, as planned, but pretty dense, buildable, but tiny fingers needed. 

 

 

But it is robust, I know because I use similar setup with "H" frames on central chassis part for my Unimog 

[agrof]

And still not robust enough, I made bracket for the steering rack in every direction (I tought), still it can click over by 1 tooth... I assume, the gear rack itself can bend a bit and let the servo gear slip. As I am building the "locked diff" version, I figured out a way to support from underneath, unfortunately it does not work with the normal diffs so I might not publish that version.

As it should be a hardcore crawler at the end of the day, I don't mind it.

[Didumos69]

1 hour ago, agrof said:

And still not robust enough, I made bracket for the steering rack in every direction (I tought), still it can click over by 1 tooth... I assume, the gear rack itself can bend a bit and let the servo gear slip. As I am building the "locked diff" version, I figured out a way to support from underneath, unfortunately it does not work with the normal diffs so I might not publish that version.

As it should be a hardcore crawler at the end of the day, I don't mind it.

Isn't a 3L liftarm enough, instead of the T-shape? Or maybe you can make something that is two studs wide, then it would fit with a normal diff.

Something like this:

Edited December 15, 2017 by Didumos69