AMA with Element Designers (Ask me Anything)

[langko]

I have a question as it’s annoying me in my current builds. Why are the 2l worm gears not exactly 2 studs in length? It means the gear can slide up and down the axle slightly which isn’t desirable because of the backlash it can create. If paired with an 8 tooth gear the backlash can be quite a bit. It’s seems to be more of a problem when mounting the worm gear vertically, when horizontal its not as bad as you aren’t fighting gravity.

[Zerobricks]

17 minutes ago, langko said:

I have a question as it’s annoying me in my current builds. Why are the 2l worm gears not exactly 2 studs in length? It means the gear can slide up and down the axle slightly which isn’t desirable because of the backlash it can create. If paired with an 8 tooth gear the backlash can be quite a bit. It’s seems to be more of a problem when mounting the worm gear vertically, when horizontal its not as bad as you aren’t fighting gravity.

That's an easy one. Because a longer one wouldn't give a full number of worm revolutions, it would end at like 45° offset and than you wouldn't be able to stack them together.

[langko]

1 hour ago, Zerobricks said:

That's an easy one. Because a longer one wouldn't give a full number of worm revolutions, it would end at like 45° offset and than you wouldn't be able to stack them together.

Makes perfect sense. (I never thought of stacking them together) But wouldn’t stacking them make the length difference even worse? 

Would it be possible to have a stackable version and a non stackable version? Maybe a new 3l one that is a perfect 3 studs long? 

[Zerobricks]

31 minutes ago, langko said:

Makes perfect sense. (I never thought of stacking them together) But wouldn’t stacking them make the length difference even worse? 

Would it be possible to have a stackable version and a non stackable version? Maybe a new 3l one that is a perfect 3 studs long? 

They already tried and failed:

 

[Maaboo the Witch]

Quite the memorable article, if only for the fact that it featured the phrase "WORM SCREW" in all caps. 

I still have my 3L worm bush thingy; it's loose as I converted my 42023 loader to the 2L worm setup a while back. TLG's reasoning on that part was correct - the ends on mine are stressed.

[langko]

Thankyou for that link. What about one without bush ends? Just like the normal one that an axle can pass through? (Sorry if I’m asking to many questions)

[Fluwoeb]

For the CV joints… is TLG going to make them more like the real joints? Maybe make them a stud and a half in diameter so that they can fit a tube around it somewhat like the rigid 7mm ribbed hoses. That would be very useful for dirt:) But then if something like that was made, then TLG would have to make a steering bracket to fit around the joint… I like the new hubs with these CV joints but I think there need to be some new suspension forks to go with them, but for the CV joints I would love it if they had two versions with one not having a loose connection for axles and the other having more friction. What do you think about making a sliding piece for use in-between the CV joints when going from transmission to a rear axle for example? I have seen box-trucks with some kind of these parts. It would help us Lego fans when making live axles and such so we can use shock absorbers and some suspension forks to support the axle instead of having to base the suspension arms around the drive shaft because it is not flexible in lengthwise motion.

I also am dissapointed in the strength of the Ducati shocks, if they were stronger they would be perfect to replicate hydraulic shock absorbers.

And the clutch, I just want to know what it was made for. Is it to transfer drive from the transmission to the drivetrain or from the engine (or motors) to the transmission (or drivetrain)?

Thank you for answering our questions! And I really love seeing companies reaching out to get feedback from customers and even people who have a hobby off of their products (like us)!

 

[Zerobricks]

34 minutes ago, langko said:

Thankyou for that link. What about one without bush ends? Just like the normal one that an axle can pass through? (Sorry if I’m asking to many questions)

Won't work unless you can somehow round Pi to exactly 3.

[langko]

7 minutes ago, Zerobricks said:

Won't work unless you can somehow round Pi to exactly 3.

Can you please explain why that is?

[Zerobricks]

Just now, langko said:

Can you please explain why that is?

Please read the topic I posted, it's all written there.

[amorti]

41 minutes ago, Zerobricks said:

Won't work unless you can somehow round Pi to exactly 3.

Well that's Bloody Stupid.

Quote

Johnson used in the sorter various gears and other rotating components which for tidiness he constructed with the value for pi of exactly three (rather than the customary "three and a bit") as the ratio between their circumference and their diameter. The Sorter itself came to be known as the New Pie, and eventually caused the downfall of the Ankh-Morpork postal service as the machine started sorting mail that hadn't been written yet.

(Sorry, couldn't help myself, reminded me of something from my favourite books).

Edited February 9, 2021 by amorti
For context

[langko]

4 hours ago, Zerobricks said:

Please read the topic I posted, it's all written there.

I’m sorry, I have read through it multiple times and I still don’t understand. 
 

Your answer to my original question was so that the worms are stackable (which I understand) But if you did not care about them being stackable could you not make them whatever length you’d like? A perfect 2l 3l or even 4l? For clarity I only mentioned making a 3l one so it would be easily distinguishable from the current 2l one. I would actually rather a perfect 2l one as it’s more compact, but understand that would be a nightmare telling it apart from the current one. 
 

I’m not sure what Pi has to do with it.

[Zerobricks]

1 minute ago, langko said:

I’m sorry, I have read through it multiple times and I still don’t understand. 
 

Your answer to my original question was so that the worms are stackable (which I understand) But if you did not care about them being stackable could you not make them whatever length you’d like? A perfect 2l 3l or even 4l? For clarity I only mentioned making a 3l one so it would be easily distinguishable from the current 2l one. I would actually rather a perfect 2l one as it’s more compact, but understand that would be a nightmare telling it apart from the current one. 
 

I’m not sure what Pi has to do with it.

Sorry, but I don't think this topic is a good place to teach about geometry of 3D objects, we are far from the original theme. I suggest you ask your questions in approprioate topics.

Now back on AMA...

[anyUser]

On 2/6/2021 at 8:45 AM, Jim said:

There will be a final round of answers!

It's been a month since the first/only answer. Do you expect there will be more information?

[Jim]

Yes, I got the answers last week. Will try to post them today.

[Parazels]

So no more questions?

I have a very important question:

why do we not have a medium-sized rotating table for cranes and excavators?

[Jim]

4 minutes ago, Parazels said:

So no more questions?

Nope. The session has ended.

5 minutes ago, Parazels said:

why do we not have a medium-sized rotating table for cranes and excavators?

Possible answer; because they haven't been necessary (enough) to warrant creating two new molds?!

[Seasider]

Don’t keep us in suspense for too long @Jim 

[Jim]

Oops...

Response to Seasider
We need a plug to lock the spring inside the suspension. To make an inline connector it would need to be part of the plug. This was not possible to make with enough strength to withstand our demands for twisting force.  
For the Ducati bike, as short a length as possible was also a big wish. 

Response to Bartybum
My way into TLG was through their Job database where I applied for a job as a Technical elements design, in the FrontEnd department. My job is to make the design organization ideas into the safest elements with the most building interfaces and best LEGO quality, while keeping it mass producible. And I love it! 
My background went through an apprenticeship as a machinist and onto a bachelor’s in mechanical engineering. Followed by 15 years working in other parts of the mechanical industries. My department consists of different engineers with different level of work experience. So just apply if you find an interesting job at the job database.   

Response to Even-Eleven the Engineer
The size of the CV was the best compromise we had at that time. 
Testing elements in dirt is not part of our quality check, and seen from an engineer point of view, it would cause a big change to all function elements.  
The Ducati suspension force was chosen so that it would work as good as possibly as a motorbike front suspension.
The clutch was developed to protect weaker LEGO elements in large transmissions systems, of course it needs to be at the right place in the systems, or it will not do its job.

Answers by:
Anders Merrild Kristensen, 
Mechanical Engineer Manager

 

This concludes the AMA. Thanks to TLG for providing us with this possibility!

[JGW3000]

Jim - Great questions and answers. More information can be gleaned by "reading between the lines". Make sure you let TLG know how much their time is appreciated! 

 

 

[allanp]

Thanks Jim (and TLG). It's always cool to get these kind of behind the scenes insights.

[Seasider]

Thanks @Jim hope we can continue this series of Q&A