[MOD] 42129 Mods and Improvements

[vladoniki]

6 minutes ago, gyenesvi said:

While it's true that in 42099 the steering rack itself is one stud closer to the center of the wheel, there is a limiter on the other side of the axle, which is one stud further (so exactly the same geometry as the Zetros), which limits the movement to 1 stud laterally, so the result is exactly the same angle as in the Zetros. It simply has a smaller turning radius because it has a shorter wheel base.

Yes, you are right. I have just seen it. It was built a long time ago... :)

[Ngoc Nguyen]

 

[metared]

Hello! My version of the chassis modification.

 

[Legopapa1]

On 9/2/2021 at 11:10 AM, gyenesvi said:

@efferman If I understand correctly, this increases the movement range of the steering rack by half a stud. According to my own tests, this is already too much for the CV joints, at that angle there is already considerable amount of friction on them (the wider part of the neck of the male part pushing against the edge of the female part, there's a 'hump' on every turn); sure they will turn with force, since the motor is strong enough to drive it, but I believe that they would get a lot of wear over time, especially at higher speeds. To check this, you should try to disconnect it from the drive motor so that you can spin it freely, and spin the hub from the wheel side to feel the friction. What I found is that roughly 1/4 stud more space for the movement of the steering rack is still ok, but 1/2 is just too much unfortunately. Let me know what you think.

 I also increased the steering range by half a stud. Now my truck slows down into a halt when turning.

Edited October 7, 2021 by Legopapa1
Spelling mistake

[Legopapa1]

22 hours ago, metared said:

Hello! My version of the chassis modification.

 

Nice build! Can it climb steeper than the Original with the cab on? 

[metared]

4 minutes ago, Legopapa1 said:

Хорошая сборка! Может ли он подниматься круче оригинала с кабиной? 

Hey! When I collect the final version, I will test it and unsubscribe.

[gyenesvi]

32 minutes ago, Legopapa1 said:

 I also increased the steering range by half a stud. Now my truck slows down into a halt when turning.

In the meantime, I have realized that the Control+ app is limiting the angle further, so it might not be as bad as I thought, it might just stop before it becomes too much for the CV joint. But that's only true if you use the Control+ app, with other apps, it might oversteer. Which app are you using?

Furthermore, I noticed considerable slowdown when turning even at lower angles when the batteries were getting down. Have you tried it with fresh batteries?

[Legopapa1]

4 hours ago, gyenesvi said:

In the meantime, I have realized that the Control+ app is limiting the angle further, so it might not be as bad as I thought, it might just stop before it becomes too much for the CV joint. But that's only true if you use the Control+ app, with other apps, it might oversteer. Which app are you using?

Furthermore, I noticed considerable slowdown when turning even at lower angles when the batteries were getting down. Have you tried it with fresh batteries?

I use the control+ app. With fresh batteries it's not so bad. Only with locked diffs it doesn't turn well. (Finally a reason to unlock the diffs!) 

Also, I made it a littlebit Faster than Standard with a gearbox that switches gears with the difflock button. 

[gyenesvi]

 

1 hour ago, Legopapa1 said:

Only with locked diffs it doesn't turn well. (Finally a reason to unlock the diffs!) 

Well, that's the purpose of the diff, so not too surprising :)

1 hour ago, Legopapa1 said:

Also, I made it a littlebit Faster than Standard with a gearbox that switches gears with the difflock button. 

Did you keep the difflock at the same time, or repurposed the motor/switch to a gearbox? I have also built faster gearing and a gearbox in my Unimog alternate.

[Legopapa1]

6 hours ago, gyenesvi said:

 

Well, that's the purpose of the diff, so not too surprising :)

Did you keep the difflock at the same time, or repurposed the motor/switch to a gearbox? I have also built faster gearing and a gearbox in my Unimog alternate.

Yes, I kept the difflock at the same time. I removed the motors and put them in the truckbed with a 2 speed gearbox. I'm not very happy with it because it can't handle obstacles very Well. Your Unimog looks much more Fun to drive.

[Legopapa1]

On 8/6/2021 at 9:16 AM, 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.

Hello Zerobricks, did you end up Building your mod? The zetros could certainly use some speed.

Edited October 8, 2021 by Legopapa1

[Zerobricks]

4 hours ago, Legopapa1 said:

Hello Zerobricks, did you end up Building your mod? The zetros could certainly use some speed.

I did increase the ground clearance, increase the gear ratio a bit and installed BuWizz 3.0 to power it. Next upgrade would be replacing the original motors with BuWizz motors, but that's much harder than a simple axle mod.

[metared]

Hi. My final modification version LEGO 42129

 

[Legopapa1]

@metared Very Nice! 

[curakar]

Here are my MOD-s

 

 

 

 

 

[Daniel-99]

Hello everyone, at the beginning of September I bought myself a Zetros set... The main reason for this expensive purchase was the exclusive list of transmission parts. I would like to share with you my opinion on the set as of "RC trial truck".

Speaking in two words: total waste!

Sorry, for that, I was not going to be rude, but it was hard to find another words that could describe all my regrets on this set! Here I want to criticize the marketing provided by Lego. I would not even argue on the set, if there was no "RC TRIAL TRUCK" in the name of the set. The main reason of my complains is that it can not really drive, especially making the trial! I will try to explain my opinion in details.

 

1 It is too heavy

I do not understand people that say: "the new Zetros can climb steep hills because it has a center of gravity close to the front axle!". Let me not, that such center of gravity is obtained not by a clever placement of motors or battery box, but by the over-detailed, unacceptable heavy body, especially the hood bonnet, that opens each time you go not up the hill but down the hill (which is always a part of trial competition to see, how your car can go down the hill and not fall of it!). Also the battery box sits too high! The car can climb 47 degrees ONLY because it has too small wheels with 2 studs ground cleaners! (i will speak of it later in details). You can see a good examples of clever mass distribution in the following RC trial cars:

 

The Set have a brilliant details, BUT they add too much weight. The body very close to the original, BUT it is build of too small pieces and bricks, so it is too heavy! One can easilly fing other Zetros projects in a bigger scale which has a lighter bodywork! That is really important! For an RC car weight is more important that the overall proportions! The solution is simple: use more light panels! For example: 

 

2 Too many gears in transmission and remote Lockings

The possibility to get the remote control differential lock is great! But it add a lot of weight, and take the space. This space could be taken by the battery box, for example! Also, the rear axle diff-lock... It blows the rear axle in size (and weight) like crazy, bring the potential weak-point of the transmission. But the most importantly, that it brings too many gearings with 1:1 ratio - ridiculous! The funniest thing about all this mess with diff-lock, that is does not help with turning radius at all... And since the car has planetary hubs, the locked differential does not provide mush stress to the transmission! So WHY we need it, especially for trial (there it will be permanently locked). I saw some previous posts on this topic and noticed the 6x6 version of the truck - Very nice! The best solution here, from my point of view, is to have a permanently locked differential with a classical live-axle scheme (you can see it in 6x6 version or in Toyota FJ 40, link above).

It is worth to get rid of remote Lockings! But if Lego wants to sell customers more of its overpriced "new" C+ motors, it would be better to have 3 L-motors for propulsion! - this could have helped with overcoming the extra weight of the body. Also, with 3 motors one could build the following momentum distribution scheme: one L-motor for the front axle, one L-motor for each wheel of a rear axle with a dual drive-shaft. This is not the best configuration for trial, but this way you can make the imitation of an electronic differential in the app...

 

3 geometric passability

The original Lego car can not do real trial. Here is the list of problems:

• too small wheels - 85 mm tires are needed for this rims
• 2 studs of ground clearance - again, could be solved with a bigger tires.
• too long bonnet - this is a problem of the original car, i suppose (Unimog is 1000 better on this parameter)
• no suspension travel - need 9.5L shocks, better mounting, longer suspension arms.

Again, i would not argue on all of this points if the car was not called "trial truck" - it has no properties of trial trucks except 4x4. The tires are the source of my pain! This tires are too wide! I would not complain even on their diameter if they were as thin as Buggy tires! This tires only works for building tractors!... but not the trial tricks! Also they are too "unsoft" - even old 85 mm tires are better! Do not call the car a "trial truck" if it has a tractor tires!

Also, the suspension is too hard on both axles... And has 0 travel... I suppose an original car has a better articulation, an the TRIAL version should have even better one! Even my sport car have a better articulation! The articulation of the suspension is more important for "TRIAL TRUCK" than the snorkel ! There are plenty of clever suspension ides, tips and tricks on Youtube.. See each of the videos linked above for example. But the best way here. i suppose, is to use 9.5 L shocks (and the soft one at the back)!

The suspension arms are too short, that prevents live axles form proper articulation. Okay, i can understand, that on the front the designer wanted to keep the original suspension type with suspension arms coming from the front and to keep the proportions he decided to make them short. But what was the reason for the REAR AXLE?

Speaking of Unimogs... This car has a better base for trial.. I was surfing trough youtube couple of days ago and found a nice trial competition. Can you recognize the trucks? Was there any Zetros? Lego tell me, WHY did you make a "trial" version of a Zetros truck? 

 

 

4 Driving experience is awful!

Sorry about you guys, but I get sick from hearing from another review on Zetros set that "it is awesome trial truck, it can climd 47 degrees". Also it is so stupid to see the following avatar on youtube video: a lucky face of a man with a Zetros on the back that is staining on a steep hill. 

 

"честно про Zetros" from Russian means "truth about Zetros". Now iti is my turn to tell you the truth! The only thing that Zetros can do is to climb flat hills! It is awfully slow, has a weird turning radius and will stuck in the first grassy place with a transmission full of fresh greenery! It is totally unplayable on the street due to its small wheels. And you will get tired of it after a first home-drive (do not believe videos on youtube! they are made to get views and likes (i mean vides on Zetros)). Even old 9398 is two times better as a crawler and can be played outdoors! To prove my words i will link the following video:

After a big disappointment with Zetros i build my own trial car. (green one) I will make a post on it later, but a few things you need to know about it are the following:

• Live axles with 9.5 L shocks
• open differentials
• 2L PF motors pover EACH axle separately (not the best setup for trial)
• planetary hubs, 5L ground clearance!
• 1,5 kg (Zetros has >2 kg of mass)
• Buwizz 3.0 for power (In my video Zetros has a Buwizz 3.0 unit as well)

Then i made a journey with 9398 and my new car - they were very close, like tow brothers! 

 

5 Price

The licensed model is WAY OVERPRICED! Even if you want some parts from these set it is worth to buy several other set which together with provide all needed parts. Together with a license, unfair Lego company also sold you a new electric that is also overpriced! And for this enormous amount of money you get a "trial tuck" that can not do REAL TRIAL!

 

 

Summary

The Lego company plays its cunning game! 

Zetros is unplayable. It can only stand on a shelf.

Do not buy Zetros set if you have any limits with money - there are plenty of other "good" sets.

 

 

Positive section

If you is the one who have bought Zetros and got disappointed from it, DO NOT TRY TO IMPROVE IT! - it is impossible due to the wrong philosophy of the car...

But i will tell toy the good news: Zetros Set has enough pieces to build many cars that can really do trial. For example, there are two for now:

And yes, the bottom one is the Unimog! 

If yo have extra parts you can build even better trucks! Because all the parts for the transmission this set already have! For example this car has 3L C+ motors for propulsion and one L-motor for drive (you can replace it with M-motor and a worm gear).

 

And the last question to Lego company: could your Zetros set perform like this:

 

Feel free to comment on my review and have a real TRIAL with Zetros mods (f it is even possible  ).

 

 

 

 

[whitepen]

@Daniel-99 Nice points about the set! It also could have been made smaller and used the jeep tires so that it could be lighter and faster with better overall performace. Maybe i will try to build this mod myself.

[Lukes_Brick_Studio]

16 hours ago, Daniel-99 said:

Hello everyone, ....

Sorry, but I don´t think that a topic, which is about improving this set is the right place to share your opinion on this set. I can partially understand your intention behind this post, but I don´t think it is at the right place... 

Edited November 23, 2021 by Lukes_Brick_Studio

[Igor1]

@Lukes_Brick_Studio Agree

[metared]

23 hours ago, Daniel-99 said:

Hello everyone, at the beginning of September I bought myself a Zetros set... The main reason for this expensive purchase was the exclusive list of transmission parts. I would like to share with you my opinion on the set as of "RC trial truck".

Speaking in two words: total waste!

Sorry, for that, I was not going to be rude, but it was hard to find another words that could describe all my regrets on this set! Here I want to criticize the marketing provided by Lego. I would not even argue on the set, if there was no "RC TRIAL TRUCK" in the name of the set. The main reason of my complains is that it can not really drive, especially making the trial! I will try to explain my opinion in details.

 

1 It is too heavy

I do not understand people that say: "the new Zetros can climb steep hills because it has a center of gravity close to the front axle!". Let me not, that such center of gravity is obtained not by a clever placement of motors or battery box, but by the over-detailed, unacceptable heavy body, especially the hood bonnet, that opens each time you go not up the hill but down the hill (which is always a part of trial competition to see, how your car can go down the hill and not fall of it!). Also the battery box sits too high! The car can climb 47 degrees ONLY because it has too small wheels with 2 studs ground cleaners! (i will speak of it later in details). You can see a good examples of clever mass distribution in the following RC trial cars:

 

The Set have a brilliant details, BUT they add too much weight. The body very close to the original, BUT it is build of too small pieces and bricks, so it is too heavy! One can easilly fing other Zetros projects in a bigger scale which has a lighter bodywork! That is really important! For an RC car weight is more important that the overall proportions! The solution is simple: use more light panels! For example: 

 

2 Too many gears in transmission and remote Lockings

The possibility to get the remote control differential lock is great! But it add a lot of weight, and take the space. This space could be taken by the battery box, for example! Also, the rear axle diff-lock... It blows the rear axle in size (and weight) like crazy, bring the potential weak-point of the transmission. But the most importantly, that it brings too many gearings with 1:1 ratio - ridiculous! The funniest thing about all this mess with diff-lock, that is does not help with turning radius at all... And since the car has planetary hubs, the locked differential does not provide mush stress to the transmission! So WHY we need it, especially for trial (there it will be permanently locked). I saw some previous posts on this topic and noticed the 6x6 version of the truck - Very nice! The best solution here, from my point of view, is to have a permanently locked differential with a classical live-axle scheme (you can see it in 6x6 version or in Toyota FJ 40, link above).

It is worth to get rid of remote Lockings! But if Lego wants to sell customers more of its overpriced "new" C+ motors, it would be better to have 3 L-motors for propulsion! - this could have helped with overcoming the extra weight of the body. Also, with 3 motors one could build the following momentum distribution scheme: one L-motor for the front axle, one L-motor for each wheel of a rear axle with a dual drive-shaft. This is not the best configuration for trial, but this way you can make the imitation of an electronic differential in the app...

 

3 geometric passability

The original Lego car can not do real trial. Here is the list of problems:

• too small wheels - 85 mm tires are needed for this rims
• 2 studs of ground clearance - again, could be solved with a bigger tires.
• too long bonnet - this is a problem of the original car, i suppose (Unimog is 1000 better on this parameter)
• no suspension travel - need 9.5L shocks, better mounting, longer suspension arms.

Again, i would not argue on all of this points if the car was not called "trial truck" - it has no properties of trial trucks except 4x4. The tires are the source of my pain! This tires are too wide! I would not complain even on their diameter if they were as thin as Buggy tires! This tires only works for building tractors!... but not the trial tricks! Also they are too "unsoft" - even old 85 mm tires are better! Do not call the car a "trial truck" if it has a tractor tires!

Also, the suspension is too hard on both axles... And has 0 travel... I suppose an original car has a better articulation, an the TRIAL version should have even better one! Even my sport car have a better articulation! The articulation of the suspension is more important for "TRIAL TRUCK" than the snorkel ! There are plenty of clever suspension ides, tips and tricks on Youtube.. See each of the videos linked above for example. But the best way here. i suppose, is to use 9.5 L shocks (and the soft one at the back)!

The suspension arms are too short, that prevents live axles form proper articulation. Okay, i can understand, that on the front the designer wanted to keep the original suspension type with suspension arms coming from the front and to keep the proportions he decided to make them short. But what was the reason for the REAR AXLE?

Speaking of Unimogs... This car has a better base for trial.. I was surfing trough youtube couple of days ago and found a nice trial competition. Can you recognize the trucks? Was there any Zetros? Lego tell me, WHY did you make a "trial" version of a Zetros truck? 

 

 

4 Driving experience is awful!

Sorry about you guys, but I get sick from hearing from another review on Zetros set that "it is awesome trial truck, it can climd 47 degrees". Also it is so stupid to see the following avatar on youtube video: a lucky face of a man with a Zetros on the back that is staining on a steep hill. 

 

"честно про Zetros" from Russian means "truth about Zetros". Now iti is my turn to tell you the truth! The only thing that Zetros can do is to climb flat hills! It is awfully slow, has a weird turning radius and will stuck in the first grassy place with a transmission full of fresh greenery! It is totally unplayable on the street due to its small wheels. And you will get tired of it after a first home-drive (do not believe videos on youtube! they are made to get views and likes (i mean vides on Zetros)). Even old 9398 is two times better as a crawler and can be played outdoors! To prove my words i will link the following video:

After a big disappointment with Zetros i build my own trial car. (green one) I will make a post on it later, but a few things you need to know about it are the following:

• Live axles with 9.5 L shocks
• open differentials
• 2L PF motors pover EACH axle separately (not the best setup for trial)
• planetary hubs, 5L ground clearance!
• 1,5 kg (Zetros has >2 kg of mass)
• Buwizz 3.0 for power (In my video Zetros has a Buwizz 3.0 unit as well)

Then i made a journey with 9398 and my new car - they were very close, like tow brothers! 

 

5 Price

The licensed model is WAY OVERPRICED! Even if you want some parts from these set it is worth to buy several other set which together with provide all needed parts. Together with a license, unfair Lego company also sold you a new electric that is also overpriced! And for this enormous amount of money you get a "trial tuck" that can not do REAL TRIAL!

 

 

Summary

The Lego company plays its cunning game! 

Zetros is unplayable. It can only stand on a shelf.

Do not buy Zetros set if you have any limits with money - there are plenty of other "good" sets.

 

 

Positive section

If you is the one who have bought Zetros and got disappointed from it, DO NOT TRY TO IMPROVE IT! - it is impossible due to the wrong philosophy of the car...

But i will tell toy the good news: Zetros Set has enough pieces to build many cars that can really do trial. For example, there are two for now:

And yes, the bottom one is the Unimog! 

If yo have extra parts you can build even better trucks! Because all the parts for the transmission this set already have! For example this car has 3L C+ motors for propulsion and one L-motor for drive (you can replace it with M-motor and a worm gear).

 

And the last question to Lego company: could your Zetros set perform like this:

 

Feel free to comment on my review and have a real TRIAL with Zetros mods (f it is even possible  ).

 

 

 

 

Forgive me.  But there is clearly a negative feeling in your opinion.  Is this necessary in the post about improving the lego set.

Edited November 24, 2021 by metared

[Daniel-99]

28 minutes ago, metared said:

Forgive me.  But there is clearly a negative feeling in your opinion.  Is this necessary in the post about improving the lego set.

Your note is an honest one, thank you! 

Of one wants to, he can take some conclusions concerning the ways of improvement of a set:

• if you want a shelf model, then there are plenty ways to go
• if you want an RC model, then there is nothing to improve in this set - impossible!

I saw several good improvements of this set to make it and RC one, all of them include:

• chassis transformation (shorter wheel base, longer suspension arms)
• new live axles (lighter, smaller, steadier)
• bodywork (to make it lighter)
• changes in the mass distribution

I would say, that after that much transformations your [MOD] becomes a [MOC] - isn`t it true?

And without this transforms you will not be able to get a good RC mod! Good luck!

 

[Legopapa1]

@Daniel-99 you are right. It's really hard to make it fun to drive

[Igor1]

Guys, maybe I missed something, there was a lot of discussion about cracking gears, doors and hood without locks, etc. But has anyone reworked the grille on the Zetros before? If so, where are your photos?

I just liked the grille from the early leaked prototype better.

Edited January 14, 2022 by Igor1

[thurd]

On 11/24/2021 at 5:00 AM, Daniel-99 said:

If one wants to, he can take some conclusions concerning the ways of improvement of a set:

• if you want a shelf model, then there are plenty ways to go

So which models should I buy to build good offroad trucks? Serious question. I need at least 3 L motors, lots of axles and gears, suspension parts etc. 

Is there a better combination of sets that give me those parts cheaper? Zetros is available now for 200e. 9398 is 300e+ and a PF set. I'd rather get PU since future models will also use it and I'd rather have 2 PU hubs for building than a 1xPU and 1xPF.

[gyenesvi]

7 hours ago, thurd said:

So which models should I buy to build good offroad trucks? Serious question. I need at least 3 L motors, lots of axles and gears, suspension parts etc. 

I'd say the Zetros is really good to get the 3 L motors, heavy duty CV joints, differentials and planetary wheel hubs and offroad wheels. You also get some suspension parts and gears and axles, though it's not a great parts pack for these. On the other hand, the Defender is a great parts pack for suspension parts (different types of joints and wheel hubs and differentials), gears and axles, but it does not have any electronics. The two together should give you all you need.

Alternatively, you could calculate the cost of getting a Defender and then buying the electronics separately, but you should also consider getting the heavy duty components (planetary hubs, CV joints, differentials), as those are much better for RC offroading.

One more alternative that I'd consider is a Defender + 42099 Extreme off-roader. With those two you get most of the goodies, but instead of 3 L motors, instead you get 1L + 2 XL motors, which is also good for offroading (plus you get larger wheels as well). Then if you really need that, you could buy 2 more L motors separately.

Here you can check what offroaders I managed to build from these 3 sets, may be useful as reference or inspiration:

https://rebrickable.com/users/gyenesvi/mocs/