42128 - Heavy-Duty Tow Truck

[Aleh]

I'm dissapointed because this Tow truck has old differentials. Why did TLG invent new diff and continue putting the old ones into the sets?

[AVCampos]

Probably because it's cheaper and, since it's not part of a motorised drivetrain, doesn't need to be as strong.

[Void_S]

2 hours ago, AVCampos said:

Probably because it's cheaper and, since it's not part of a motorised drivetrain, doesn't need to be as strong.

The same reason why only 42099 and 42129 (yet) get planetary reduction hubs indeed 

[Aleh]

16 hours ago, AVCampos said:

Probably because it's cheaper and, since it's not part of a motorised drivetrain, doesn't need to be as strong.

Is the new diff stronger and more robust than the regular one?

[Repkovsky]

7 minutes ago, Aleh said:

Is the new diff stronger and more robust than the regular one?

Yes, this is because there are 5 gears inside instead of just 3, so the risk of slipping or damaging 8-tooth gear is much lower as the forces are spread to more elements.

[allanp]

6 hours ago, Aleh said:

Is the new diff stronger and more robust than the regular one?

Yes, much stronger. It also gives a better gear reduction (both for motorised and non motorised models, because I want my fake engines to spin FAST!). Only flaw with the new one is that the output shafts are still driven by a 12t bevel right on the end of the shafts. But still much stronger than the previous ones.

[Aleh]

I meant actually not about 12t gears inside, but about the diff as a part. I don't remebmer any broken differentials since 2012 :)

[Ngoc Nguyen]

I think this is the first time (or at least to me) that the part list in the official instruction has wrong information. I was disassembling my A model to test build the C model I designed. When I checked the number of tubes in the official instruction, both the online one and the book one, apparently there are 10 black tubes and 12 grey tubes in the set. However, there are way less tubes than that in the boxes. I freaked out for a minute. Then I checked Bricklink, Rebrickable, and Sariel's review, and found out that there are only 5 black tubs and 6 grey tubes in the set.

[AVCampos]

The Cat's inventory in the instructions book also mentions both Gen2 and Gen3 black pins, but the set itself only has Gen3.

[thekoRngear]

Noob question here regarding building. Since this is my very first pneumatic set I am a bit tensed.
The lower blue+LBG pipe conjunction seems a bit out? Is it normal? I roughly know a re-enforcement will be assembled and mounted pretty soon. Will this "out" interfere? Kindly enlighten me

 

Edited December 7, 2021 by thekoRngear

[Jundis]

39 minutes ago, thekoRngear said:

Will this "out" interfere? Kindly enlighten me

The hoses in pneumatic sets are usually longer then they need to be, just to rule out any tensions stress and a resulting disconnection from the valves. As they are very flexible, no need to worry here. This bulge you referring to will just flex inwards when you assemble the cabin :-)

[thekoRngear]

7 hours ago, Jundis said:

The hoses in pneumatic sets are usually longer then they need to be, just to rule out any tensions stress and a resulting disconnection from the valves. As they are very flexible, no need to worry here. This bulge you referring to will just flex inwards when you assemble the cabin :-)

Thanks a lot man! 

A bit different thing that I wanna tell. My package came with a paper envelope for the sticker and the more-than-necessarily-huge manual book. Well done, it infact was needed long time ago. Howevr, my black pins don't produce the satisficing click sound when clutched. They used to produce that even in the last year's sets like the Sian. Also, the black of the black pins looks a bit dull or lets say less black. Must be something to do with the newer materials? The pins otherwise feel very sturdy though....

Edited December 7, 2021 by thekoRngear

[AVCampos]

48 minutes ago, thekoRngear said:

Howevr, my black pins don't produce the satisfactory click sound when clutched.

Most likely they're Gen3 pins, which were introduced this year.

[thekoRngear]

Yep! Those are the ones packed with my unit. I immediately recognized by the left most one which looks glossy. However, they all are not glossy, some of them are matte-ish. Come one Lego! After making instructions so obviously fool proof (like sets like 42138 will someday have as thicc books as a 42128 ones) you are also tryin' to bury that satisfying click sound. Pity

Also, I have observed when a beam is about to be braced on another beam/thick lift-arm where multiple pins/cross-pins are clutched, it is a bit hard to brace them. Could not say that is not a placebo though

[thekoRngear]

Guys, I have this strange (or embarrassing) problem that I found just after I had built the Tow Truck.

The tow bar does not go up when pumped. Well, it does go up, just a little. A gentle push by hand and it goes upward.

Today I disconnected the tow bar structure by removing the yellow 5L axle only to find it just goes down and up smoothly! Connect the structure and it apparently struggles to up the tow

From my observation:

1. takes the same amount of pumping to make it go down and go up

2. Going up just a (literally) little slower than going down

Has anyone faced this problem? Is a significant strip down required?

Below picture is after I have pumped the pressure pump to make it (the yellow thin cylinder) go up. You see it just went up smoothly.

 

Edited January 2, 2022 by thekoRngear

[allanp]

@thekoRngear I had this issue and it was caused by the black hose needing to slide through the blue beam with the yellow triangle by a small amount as the rear tow arm moves through its range of motion. You can see if yours is the same by reconnecting the black hose without routing it through the blue beam.

[anyUser]

I observed similar behaviour of the tow 'bar':

- it can easily be moved up and down, e.g. for testing several times in a row

- I put on some weight (truick) to find about the lifting capability. After that it took a couple of pumping 'sequences' to raise the bar (I did not use my hand to push it up directly)

- I kept the bar for a day in the lower position, again after some weight had been put onto it. It was even more reluctant to change position.

Could it be some grease that locks the piston in its extended position?

[thekoRngear]

@allanp
What the!!! It does lift up just fine as if there was no resistance or such.

So what should I do now? As I slid it again through the blue beam it gets stuck again 

@anyUser great observation. I will definitely check if that same happens to me

Edited January 2, 2022 by thekoRngear

[anyUser]

On 1/2/2022 at 9:46 AM, allanp said:

You can see if yours is the same by reconnecting the black hose without routing it through the blue beam.

I can confirm that the pnematic cylinder is moving a bit when the bar is retracted.
The proposed solution works much better but the tube gets squezed by the tow bar in its upper position - respectively prevents from being fully upright.

To me it already made a difference when I removed the blue 3L liftarm and kept the tube inside the grey connector.

I made another observation: When I push the truck in forward direction the 'cylinders' in the fake engine often block the rotation of the crankshaft.
This does not happen if the truck is moved backwards. I have bulid the motor accroding to instructions:

(Step 334)

End of brown axle is levelled with the 1/2 bushing.
This appears to be a similar issue as with the first version of the 42112 cement mixer.

Raising the brown axles by (almost) 1/2 L will remove the issue.

[amorti]

I did some minor mods, no parts required. Nothing to aesthetics, because to me this already looks plenty good enough for a technic set. It's all about the functions!
The 5.5L axles on the 2nd axle stick out too far compared to those on axles 3&4. So at step 8 swap them for 4L axles with stop from bag 4, which are for the winch ratchet levers. You can then use the 5.5L axles on the ratchet handles in steps 623 and 630. There are two red 1L axle bushes in the spare parts to put on those so they look more like function parts.
Swap the 16:20 gear pair on the crane rotation input so you can actually use that function without getting out of breath. They go on at steps 60 and 74. The 20t gear is close to hitting the 2*4 liftarm that raises the 2nd axle, but there's no actual collision.
Same goes for the rear lifter input. At step 100 put the 20t not the 16t, then at step 104 put that 20t in, instead of the 16t. Again, it'll make the function actually usable.
 

27 minutes ago, anyUser said:

 Raising the brown axles by (almost) 1/2 L will remove the issue.

Yep, I found the same.

[thekoRngear]

16 hours ago, anyUser said:

I can confirm that the pnematic cylinder is moving a bit when the bar is retracted.
The proposed solution works much better but the tube gets squezed by the tow bar in its upper position - respectively prevents from being fully upright.

To me it already made a difference when I removed the blue 3L liftarm and kept the tube inside the grey connector.

I made another observation: When I push the truck in forward direction the 'cylinders' in the fake engine often block the rotation of the crankshaft.
This does not happen if the truck is moved backwards. I have bulid the motor accroding to instructions:

(Step 334)

End of brown axle is levelled with the 1/2 bushing.
This appears to be a similar issue as with the first version of the 42112 cement mixer.

Raising the brown axles by (almost) 1/2 L will remove the issue.

I did not get as lucky as you. Even after removing the 3L Beam with yellow warning sign the black tube refused to get raised. So I had to remove the LBG connector hub too and ensured the rigidity stays as firm by adding some extra parts. Since the black tube is not in the centre it gets a bit stuck by the left blue 7L beam, a slight push towards centre and it's all good. The tow bar problem is now gone. I actually did not understand what AllanP already told was the solution.
As for the Engine, well, I did what is more than a solution. I made a 3 cylinder piston engine with the good ol' engine blocks right when I was building it as I knew some folks here and there had problems with the crappy stock engine.

@amorti's tweaks are great. The crane now rotate slightly faster. I also (accidentally) made the gear swap to the 2nd axle lol. The axle is now raised and lowered a bit faster with no collisions or such.

Edited January 4, 2022 by thekoRngear

[amorti]

15 minutes ago, thekoRngear said:

I did I also (accidentally) made the gear swap to the 2nd axle lol. The axle is now raised and lowered a bit faster with no collisions or such.

I've been meaning to try this. I think it wouldn't hurt to reduce the torque on that, as it's more than it needs and feels like you bend parts too easily from the input knob.

BTW - who noticed how incredibly solid the steering is? You can twist that HOG input a long way winding tension into the axles, but no gears will slip - or if they do, it's way past my comfort level of torturing the bricks.

 

Edit: yep, I'm happier with the 2nd axle function being regeared, too.

Edited January 3, 2022 by amorti

[thekoRngear]

25 minutes ago, amorti said:

BTW - who noticed how incredibly solid the steering is? You can twist that HOG input a long way winding tension into the axles, but no gears will slip - or if they do, it's way past my comfort level of torturing the bricks.

You can count me in. The steering is superb! I played with it a lot yesterday. Sariel complained (lightly) the top steering requiring a bit more rotation but that's fine with me

Edited January 3, 2022 by thekoRngear

[mpj]

I don't know if it has been already pointed out, the price of this set has been increased from 149 to 169 euro in Europe. 

It is a very good set and it had a very good price compared to other sets... but it was too good to be true.

[XTN]

1 hour ago, mpj said:

I don't know if it has been already pointed out, the price of this set has been increased from 149 to 169 euro in Europe. 

It is a very good set and it had a very good price compared to other sets... but it was too good to be true.

There's been very emotional debates about that in other forums in the end of 2021.

What they say is, they raise the retail price shown in the catalog. 
There was no verified information if they also change the dealer purchase price, because that one is a big secret.

Time will tell how much discount we will see here in Europe now, maybe the discounted prices in the online shops wont change that much during 2022.