General Part Discussion

[Ngoc Nguyen]

These are all printed parts from TLG so far. They were all released in limited quantities.

[Zerobricks]

And they all use some kind of a mechanism that would be otherwise impossible to manufacture in one go.

Edited Tuesday at 08:00 PM by Zerobricks

[Bartybum]

1 hour ago, HorcikDesigns said:

Do we have more information about the material and technology that was used for printing the small locomotive? It looks like SLS (sintered powder) which would allow for large quantity of pieces. 

Seems to be SLS printed, yeah. It's such an aberration for Lego to use 3D printing imo. The whole point of Lego is to use standard parts in creative ways. SLS parts are a leap beyond that, and they're so damn ugly and don't fit within the dimensions of the building system. Like if I saw those parts I'd never guess that they're supposed to be Lego

[Ngoc Nguyen]

Forget the 3D printed part, this is a video from RacingBrick 

 

[JGW3000]

SLS parts - I am curious how much of a commitment LEGO has to making these. Since I am not familiar with the technology, can anyone estimate how long it would take to print the small train in the new Winter Train set? Multiply this by the number of WT sets they may sell - maybe 50,000?, then divide by the length of the production run, maybe 2 or 4 weeks?, then you have the number of SLS machines, plus engineering and prototypes. How much does each machine cost? If this effort is less than say $1-2MM, then its a fad. If this effort to make SLS parts is more than, maybe $10MM, we are going to see more of these parts if we like or or not.

[tseary]

For some very coarse napkin math, the Formlabs Fuse 1+ SLS printer (for example) can print a full job in 14 hours. The build volume is 16.5 x 16.5 x 30 cm. Assuming the little train is 2 x 2 x 4 Lego units, plus some margin, you could fit about 500-700 of them in a job. Running around the clock and ignoring scrap factor, they could print a run of 50,000 parts in a month on just two of these printers. The cost would be well under $1M. That points towards this being a gimmick.

 

[HorcikDesigns]

I doubt they use Formlabs Fuse for this task. There are many more industry-focused machines out there. Do not forget the cleaning of the parts that would take some time and cost too.

[tseary]

1 hour ago, HorcikDesigns said:

I doubt they use Formlabs Fuse for this task.

I agree, but my point is that it wouldn't take an army of printers for a production run like this. Presumably print times don't vary by a huge amount between SLS printers.

Personally, I hope that TLG isn't investing too much in 3D-printed production parts. In my opinion they only appeal to the collector market, and don't add play value.

[Bartybum]

2 hours ago, HorcikDesigns said:

Do not forget the cleaning of the parts that would take some time and cost too.

Is industrial SLS tech at the stage that cleanup is automated yet?

[RussianGuy]

On 9/11/2025 at 4:17 AM, Ngoc Nguyen said:

Forget the 3D printed part, this is a video from RacingBrick 

All 3 parts are now available here in the UK ¯\_(ツ)_/¯

[Ngoc Nguyen]

Is there any resource that provide the exact torques produced by various motors?

[m2fel]

17 minutes ago, Ngoc Nguyen said:

Is there any resource that provide the exact torques produced by various motors?

Maybe https://www.philohome.com/motors/motorcomp.htm ?

[Ngoc Nguyen]

4 minutes ago, m2fel said:

Maybe https://www.philohome.com/motors/motorcomp.htm ?

That's what Im looking for, thanks a lot!

On another note, can it be proven that two hard coupled identical motors provide more torque, preferable twice, than one motor?

[gyenesvi]

13 minutes ago, Ngoc Nguyen said:

On another note, can it be proven that two hard coupled identical motors provide more torque, preferable twice, than one motor?

Isn't that just implied by the basic laws of physics?

[m2fel]

4 minutes ago, gyenesvi said:

Isn't that just implied by the basic laws of physics?

Yes. Mechanic, physics and math :) But you will loose some power to friction thus it won't double the torque but will be close enough 

and you have to make sure the energy source (battery) will be able to deliver enough energy 

Edited Wednesday at 08:35 AM by m2fel

[Ngoc Nguyen]

3 minutes ago, gyenesvi said:

Isn't that just implied by the basic laws of physics?

I think so too but when I hard coupled two L PU motors for the 42215 they perform barely better than one motor, so Idk

[Zerobricks]

Indeed, as long as they are coupled with an identical gear ratio, they will multiply torque, not speed.

[m2fel]

25 minutes ago, Ngoc Nguyen said:

I think so too but when I hard coupled two L PU motors for the 42215 they perform barely better than one motor, so Idk

Once again Philo did it     https://www.philohome.com/pfrec/coupling.htm

Looking at the graphs it is not even close to doubling. More like 1.5 to 1.8 times the torque of one motor.. 

[gyenesvi]

1 hour ago, Ngoc Nguyen said:

I think so too but when I hard coupled two L PU motors for the 42215 they perform barely better than one motor, so Idk

What do you expect to see? How do you measure the improvement? The speed won't change probably. One thing you could see is that it is not struggling with a weight that it was struggling before. But if it wasn't visibly struggling to begin with, then you won't see an improvement. The only thing I'd expect is more smooth boom lift if it wasn't smooth with 1 motor.

[Ngoc Nguyen]

 

8 minutes ago, gyenesvi said:

How do you measure the improvement?

I added a linear clutch on the transmission to the base LAs. If the clutch clicks, the torque to lift the base LAs is inadequate. Left side is original transmission, right side is the transmission with a linear clutch. The linear clutch must be moved to the middle to avoid collision with the arm. 

 

 

41 minutes ago, gyenesvi said:

What do you expect to see?

My expectation was that the hard coupled motors should not struggle to lift the boom, which means no clicking when lifting the arm. The result is that the hardcoupled motors resulted in less clicking than a single motor, but they still resulted in clicking. 

[gyenesvi]

5 minutes ago, Ngoc Nguyen said:

If the clutch clicks, the torque to lift the base LAs is inadequate.

I don't think this is true. Imagine you have very strong motor, and a very heavy boom. What will happen? The clutch will click. But it's not because the motor torque is not enough. It's because the boom is too heavy, and you introduced a weak link in the drivetrain, the clutch, so it's natural that it 'breaks' there. So clicking / not clicking depends on the boom's weight, so with this technique you cannot measure motor power.

5 minutes ago, Ngoc Nguyen said:

My expectation was that the hard coupled motors should not struggle to lift the boom, which means no clicking when lifting the arm. The result is that the hardcoupled motors resulted in less clicking than a single motor, but they still resulted in clicking. 

This may be explained by the two motors having more momentum and hence more continuous power delivery, so the clicking decreases somewhat, but would not disappear, which is what I would expect as explained.

[m2fel]

@Ngoc Nguyen if it was clicking before adding the linear clutch, the internal clutch of the LAs were already skipping / clicking with one motor? If that was case, two motors won't make it any better as the LAs were not able to handle the weight of the arm proper with one motor, they won't be able to do it with two.

Edited Wednesday at 11:55 AM by m2fel

[Ngoc Nguyen]

7 minutes ago, m2fel said:

@Ngoc Nguyen if it was clicking before adding the linear clutch, the internal clutch of the LAs were already skipping / clicking with one motor?

Not really, for some reasons the internal clutch of XL LAs didn't click at all. In the set up with one motor and no linear clutch, there is not enough torque so the gears would skip instead. I don't know if the XL LAs dont have internal clutch or not.

[2GodBDGlory]

21 minutes ago, Ngoc Nguyen said:

Not really, for some reasons the internal clutch of XL LAs didn't click at all. In the set up with one motor and no linear clutch, there is not enough torque so the gears would skip instead. I don't know if the XL LAs dont have internal clutch or not.

To me that sounds like the gear bracing wasn't sufficient, making it a weaker link than the LA clutch. I'd expect that if those gears were prevented from skipping, you'd have enough torque to skip the LA clutch, but it'll always skip at the weakest link first. The only way to avoid skipping with this given gear bracing would be to decrease the motor torque to a low enough point where it can't skip either the gears or the clutch, but that's probably too little torque for your purposes.

[Ngoc Nguyen]

2 hours ago, gyenesvi said:

Imagine you have very strong motor, and a very heavy boom. What will happen? The clutch will click. But it's not because the motor torque is not enough. It's because the boom is too heavy, and you introduced a weak link in the drivetrain, the clutch, so it's natural that it 'breaks' there. So clicking / not clicking depends on the boom's weight, so with this technique you cannot measure motor power

That sounds reasonable. I'll try the hard coupled motors with no linear clutch to see how they perform then.