[MOD] 42129 Mods and Improvements

[Ngoc Nguyen]

Hood lock mod:

Replace this part

 

 

with these

 

 

To preserve the appearance, the half bush can be removed, and the axle can be pushed in further, at the expense of your nail the next time your want to unlock the hood.  

Edited July 21, 2021 by Ngoc Nguyen

[whitepen]

Nice MOD! Could you share the bricklink studio file with me so I can try nodding this with PF?

Edited July 18, 2021 by whitepen

[992bricks]

List of improvements that I will give mine: 

• Multi-speed gearbox
• Buwizz 3.0
• @Ngoc Nguyen's hood lock
• Front Diff lock
• RC Tires
• Maybe Buggy Motors or extra L motors
• Maybe softer shocks at the rear
• And of course, the obligatory shoebox on the back! 

Edited July 18, 2021 by 992bricks

[Johnny1360]

I will definitely be looking to see your results, that is some heavy modding.

[Ngoc Nguyen]

The name is Zetros, and it is associated with mobile homes, so upon this base, I'll build my expedition truck 

 

 

This mod is a low budget version. I removed all the motors, removed the differential lock structures, simplified the axles design, and gave it a good ole HOG. As a result it has no need for the new 11L alternating beams.

I tried to put a fake engine under the hood, but there is simply no space, and I bumped into constraints everywhere. It was not until I started trying to put the engine did I realize it needs a vertical space of 6 studs (3 for the 2L liftarm rotation, 3 for the 3L axles). If I put it in the lowest possible position, it will interfere with the front suspension. So I scrapped that idea. The model still has a 4x4 drive train with a center differential, but that's it.

I'll put this thing on rebrickable as soon as 42129 is listed.

In this state it has 1755 parts, and the preliminary price Studio gives me is 255 USD already.

Edited July 21, 2021 by Ngoc Nguyen

[2GodBDGlory]

That first sentence is a rather stretched Biblical allusion, is it not?

Also, do you think it is possible to build the original set without the 11L alternating pinhole beams? I'd like to try building it from online instructions once they are available, but I won't have those parts for quite a while. I've got no problem making some mods, but do you think they would be prohibitively complicated?

[Ngoc Nguyen]

3 hours ago, 2GodBDGlory said:

do you think they would be prohibitively complicated?

I do think it'll be complicated. The set has 9 11L alternating hole beams. 1 is used in the front axle, 2 are used on the sides, and 6 are used in the rear axle. The first three are easily replaceable, but the last one will need a major redesign of the rear axle.

[2GodBDGlory]

18 hours ago, Ngoc Nguyen said:

I do think it'll be complicated. The set has 9 11L alternating hole beams. 1 is used in the front axle, 2 are used on the sides, and 6 are used in the rear axle. The first three are easily replaceable, but the last one will need a major redesign of the rear axle.

Ok, thanks!

[Seasider]

I’m still undecided on this set, to me the length of it just looks odd with the size of wheels. Does anyone know if it’s possible to shorten the whole model reducing the rear bed length and shortening the wheelbase by the same amount? Or is all the space between the axles limited by mechanisms, motors etc

[kbalage]

No any complicated mods, rather some variations with wheels, shock absorbers, and a few things to remove that come off easily:

 

[1gor]

@kbalage thanks for informing video; IMHO tumblers look the best and climbing ability is not so bad at all 

[992bricks]

Ok, Thanks @kbalage, I can now cross off the suspension mod on my list!

[Zerobricks]

Found a way to redesign the axles for following improvements:

• Increased ground clearance under both axles
• Increased steering angle (by a few degrees)
• Improved gear meshing on the rear axle with the use of 7x11 frames, so it shouldn't be able to slip out anymore
• Reduced number of gears on the rear axle drive.

I already build the sketches of the axles, only waiting for the set now.

And of course I will add a BuWizz 3.0 on top for more power 

[Igor1]

3 hours ago, Zerobricks said:

And of course I will add a BuWizz 3.0 on top for more power 

How much?

[Zerobricks]

8 hours ago, Igor1 said:

How much?

I don't understand the question? 

[Igor1]

@Zerobricks It was an unsuccessful attempt to joke, sorry. I just saw your other mods with BuWizzes and there were a lot of them. Therefore, I decided to clarify how many BuWizzes will be on the Mercedes?

[Zerobricks]

40 minutes ago, Igor1 said:

@Zerobricks It was an unsuccessful attempt to joke, sorry. I just saw your other mods with BuWizzes and there were a lot of them. Therefore, I decided to clarify how many BuWizzes will be on the Mercedes?

I think just one, still thinking if I should replace original drive motors too.

[2GodBDGlory]

I've completed building a Zetros from my collection, and as a first mod (there will be more), I'd like to show my solution to the grinding gears in the rear axle others have pointed out. My solution is to replace the black 3l pin with pinhole being added on this step of the instructions 

With the assembly on the bottom of this picture

such that the black 12t gear meshes with the differential, and the 16t gear meshes with the other three 16t gears shown in this step 

This setup results in the differential being driven by two different 12t gears simultaneously, reducing the likelihood of skipping.

In my testing, I was unable to cause a skip. Driving it into a wall on a wood floor resulted in all four wheels spinning, while carpet caused the drive motors to stall.

I should mention, though, that my model is using older balloon tires and PF, and I had to replace all the alternating pinhole beams with other stuff. Thus, I am unsure how my mod would perform in an otherwise stock set. If anyone tries it, please let me know how it works!

Edit:

I've continued modding the set, and my current setup had 3x higher torque at the rear diff. This setup is giving me skipping, so the mod isn't invincible. I still don't know if it would show up in a normal truck, though.

Edited August 6, 2021 by 2GodBDGlory

[Zerobricks]

Good idea driving the diff from both sides. Does the fact both 12 tooth gears are not totally aligned cause any issues? 

I meanwhile managed to add 2x BuWizz motors which drive the new, stronger central diff instead of 4 studded long one.

I also managed to squeeze in a half pin based online 6 engine driven by the motors under the hood. 

The mod should increase speed by some 3x times at simillar torque.

[2GodBDGlory]

5 hours ago, Zerobricks said:

Good idea driving the diff from both sides. Does the fact both 12 tooth gears are not totally aligned cause any issues? 

I meanwhile managed to add 2x BuWizz motors which drive the new, stronger central diff instead of 4 studded long one.

I also managed to squeeze in a half pin based online 6 engine driven by the motors under the hood. 

The mod should increase speed by some 3x times at simillar torque.

No, everything seems to be within Lego tolerances.

That sounds like a pretty fun mod you've got there!

[whitepen]

12 hours ago, Zerobricks said:

Good idea driving the diff from both sides. Does the fact both 12 tooth gears are not totally aligned cause any issues? 

I meanwhile managed to add 2x BuWizz motors which drive the new, stronger central diff instead of 4 studded long one.

I also managed to squeeze in a half pin based online 6 engine driven by the motors under the hood. 

The mod should increase speed by some 3x times at simillar torque.

Awesome!

[efferman]

On 8/6/2021 at 2:31 AM, 2GodBDGlory said:

 

Spoiler

 

Is it only me or have i built my axle fix mirrored?

Edited August 7, 2021 by efferman

[2GodBDGlory]

4 hours ago, efferman said:

Is it only me or have i built my axle fix mirrored?

 

It does look that way...

[Touc4nx]

I just found this mod on Rebrickable :

(Image from time-hh on rebrickable)
This should allow to lock the bonnet only using spare parts.
I don't have 42129, so I can't test, but this seems promising…

[efferman]

Now i have my own Zetros, and when the suspension is fully compressed my Axle fix collides a little bit with the Slide CV-Joint. A new instruction: https://bricksafe.com/files/efferman/vehicle-axles/42129 rearaxle fix.pdf

Compared to the Lego Axle is my axle much less huge.

Because iam using different tires, i had to move the dbg 15L liftarms to the inner side of the frame.

Edited August 18, 2021 by efferman