[MOC] CPT Truck

[designer-han]

Hi all,

It's a while when I posted my latest MOC on this forum. Although I do not post that often, I do read many times the posts on this platform. One post that catch my attention was 'Decreasing number of MOCs' recently. Many the discussions around: we miss good MOCs, we miss the stunning Blakbird renders, are there really no MOCs around, FB versus EB, why are there just only some comments on a post, MOC-ers just use this EB forum for posting for selling BI's, etc, etc. And yes, there is many to say about all of those viewpoints. My take away - as being a MOC designer for almost 15 years around: Building MOCs is for me (and I guess the most of them) a hobby, using your creativity and technical skills to design a model that is appealing, works as designed, fix challenges of flex/bend/gearings (as it is ABS and not metal), overcome PF versus PU engineering (I do strongly believe in PU; but TLC isn't leapfrogging in this market.... unfortunately). Regarding selling of BI's; I never understood why people complain about that, most MOC models out-there do hold a part-count that easily cost above 250-400 euro's from scratch (e.g. if you did not own any part of it). I do know from experience that creating BI's take even more time compared to developing a MOC; and it just not stops with the BI's. Part-lists are required to make it easier to source missing parts. And honestly, I thought do become rich  but as Technic MOCs are just a niche market.... it's absolutely not the case at all. And, I do sell mostly 1 BI to China; knowing my MOC will show up within a couple of weeks on AliExpress.... 

But anyway, I am drifting away. Let's share my latest MOC.

This CPT-Truck uses tracks to crawl off-road; CPT stands for Cone Penetration Testing (CPT), a technical methodology to investigate soil types on a certain location. This is being done by pushing cones into the ground, measuring the resistance and friction during penetration. This truck is NOT able to push cones into the ground; I had slightly the idea to design this, but the construction to lift the truck itself was a challenge in itself. The first tries failed, as the truck wobbled on it's tracks, as the LA's are not that stiff at horizontally (they are of course vertically). So, I needed to add additional gearing racks/sliders to mitigate the wobbeling. The tracks itself are designed straight forward. But, both tracks needed to 'grip' around the truck's chassis, and as the space left between the both tracks is 3-5 studs wide... another challenge appeared. How to design a 3 studs wide chassis between the front/rear wheels, have a drive-train, and even a center-diff with PF-motors? The only way was 'up'; so the PF motors needed to go into the shelter. And, as the model is relative heavy (4kgs), the drive-train had to powered with 2 PF XL-motors.

The truck is 4WD; and uses the new hubs with planetary gearings. Why? Well, these new hubs do come with a strong CV joint. And, it appears that this hub/CV joint has a broader steering circle compared to the 'traditional' hubs being used in the Porsche, Bugatti models. The downside is that a lot of up-gearing needed to be done, as the planetary hub has significant down-gearing. Not ideal, but it works reliable. Hopefully TLC will design this new hub/CV joint WITHOUT a planetary system. I am looking forward the rebuild my Dump Truck 10x4 into a 10x8 model, RC.

Other functions are straight forward; tilting cab, working V8. And, PF LED lights at the front and rear side! Manual functions are opening doors, opening grill and rear shelter door, including a folding stair/ladder.

Hope you like the model and learned something about CPT. As far as I know this is the 1st CPT Truck I have seen in Technic on this scale, but maybe I am mistaken.

As always, more information to read on my website http://www.designer-han.nl/lego or youtube video: https://www.youtube.com/watch?v=kJi8VjvGS28&feature=youtu.be

 

I made some renders with Stud.io / Adobe Photoshop; I have to admit it's just being in the shadow of the Blakbird renders.... but okay, its not that bad I thought.

 

Edited January 13, 2021 by designer-han

[jorgeopesi]

I do not like non Lego parts but it is awesome to see a trucks and tracks together, I like how you have used the panels to reinforce everything and the short and explanatory video is rare and appreciated  .

[dhc6twinotter]

This is great!  It's always nice to see a MOC from you. I didn't know such a machine existed.  I love the complexity of everything, and I'm impressed by the fact that the LAs could lift the whole truck up. What does the PF switch do?

Great renders too!  I wish I had those skills. 

[JintaiZ]

Nice build! I'm especially impressed with the complexity of it.

[Mr Jos]

19 hours ago, jorgeopesi said:

I do not like non Lego parts but it is awesome to see a trucks and tracks together, I like how you have used the panels to reinforce everything and the short and explanatory video is rare and appreciated  .

And where exactly are these non Lego parts? I don't seem to find any.

 

@designer-han Wonderfull MOC, many gears/ techniques involved in a not so usual model. 

However, was the wormgear/clutchgear really needed for the lifting? It seemingly makes it very slow and the LA's already have clutches inside them to make them extend all 4 to the same length when maxed out.

[jorgeopesi]

2 hours ago, Mr Jos said:

And where exactly are these non Lego parts? I don't seem to find any.

 

@designer-han Wonderfull MOC, many gears/ techniques involved in a not so usual model. 

However, was the wormgear/clutchgear really needed for the lifting? It seemingly makes it very slow and the LA's already have clutches inside them to make them extend all 4 to the same length when maxed out.

Sbick.

[MajklSpajkl]

Great idea and execution. I've known about CPT tests, but didn't know about this type of truck. Well done.

[Pattspatt]

Wow, this is amazing. Very impressed by how well you’ve designed such an unusual mechanism - it works great! Amazed that it can lift all those electronics so effortlessly. The tilting cab, fake motor, and fan visible through the front are cherries on top ??

[designer-han]

It's a while ago that I visited my own post....

Thanks for the nice responses; let me turn back to you for the questions raised.

 

1) What does the PF switch do? It is used to turn on the PF LED's at the front and rear side of the truck.

2) Non LEGO-parts. Originally I design always with pure LEGO parts, and thus using PF Infra-red. But this has - as we know - major flaws; that's why I add Sbrick to the Building Instructions as well. I might switch to PU definitely, when the App User Interface is improved for programming the controls.

3) Correct that the worm-wheel makes it slow; but, keep in mind that the truck's weight is 4kg. A single LA is able to deal with ~ 1 - 1,5kg; so I really wanted the model to function reliable. The benefit of having a clutch and worm-wheel for each LA is the ability to level the truck automatically, or to synchronize LA's at the end-positions. Using only gears will led to a sort of 'bang-bang' on the end-positions.

 

[Void_S]

Wow! Initially, I had a question why the rear axle is set so rearwards. And it was answered very quickly! 

Amazingly complex model, I like it!

[designer-han]

Added the famous cut-away Blakbird render at the first post; very glad he was willing to perform the rendering task.

And knowing that some members really appreciate his renders as well!