[HELP] Generic Building Help Topic

[Aurorasaurus]

3 hours ago, Milan said:

Technic Pub is for...anything but Lego :)

Oh, just one of english's many tricks, I thought it meant anything but still lego.. my bad :)

35 minutes ago, Carsten Svendsen said:

I should be able to drop it on the ground from standing height, and only have minimal cosmetic repairable damages.

Wow, thats very solid indeed.

5 minutes ago, 1gor said:

To make realistic model as much as possible with minimal parts as possible no matter propulsion, functions,  looks or construction (I usually use as much frames as possible).

How would you say the strength of your models is in a bit of rough play? Light weight = less forces under its own propulsion, arguably more sturdy than big strong builds sometimes.

[1gor]

31 minutes ago, Aurorasaurus said:

 

How would you say the strength of your models is in a bit of rough play? Light weight = less forces under its own propulsion, arguably more sturdy than big strong builds sometimes.

Something like that; currently I'm rebuilding onw my model and hope to finish it untill end of February and post some pictures of it. Basically I use frames 5 x 7, 5 x 11 H shape or 7 x 11 as much as I can. Propulsion is also very simple; mostly I use XL motors (Powerfunctions) and then upgear them (using spur gears because they are have less friction than bevel gears), then daytona or gray differentials (both tun smoother than red differntial introduced in 42109 set) and hub reduction at end... when trying to replicate shape I use mostly pannels because they are sturdier than bricks...

[pekka111]

Beginner question: all the beams have odd number of holes? Half beams have 6 hole version but not one with 4 round holes? So do you cut custom lengths if something else is needed?

Edited January 7 by pekka111

[allanp]

2 hours ago, pekka111 said:

Beginner question: all the beams have odd number of holes? Half beams have 6 hole version but not one with 4 round holes? So do you cut custom lengths if something else is needed?

If you want to, it's your Lego. Your question is essentially a question of Lego purism. Some members like to stick strictly to what comes in a Lego box unmodified. Others allow themselves to go crazy with modified parts, 3D printed parts, third party parts (such as buwizz or aluminium beams and steel axles), clone brand parts, brushless motors, metal bearings and so on. But when posting your model in the forum it's usually customary (though not required) to state what parts stray from pure, unmodified Lego. Enjoy the hobby how you please, there's no judgement here. And besides, don't Lego designers themselves create new parts for themselves to use?

[gyenesvi]

3 hours ago, pekka111 said:

Beginner question: all the beams have odd number of holes? Half beams have 6 hole version but not one with 4 round holes? So do you cut custom lengths if something else is needed?

I guess most people just try to work around that problem with some other parts that are available, but resulting in more bulky builds. Do as you find suitable, but also make sure to complain about it in public forums, so that TLG realizes that we all need some beams of even lengths, such as 4 and 6 :) The more of us spell that out, the more chance that we'll see those appear in the future!

[pekka111]

Thanks :) I guess 3D printing is difficult, since you would like the tolerances to be quite small. Is there a reliable (Chinese) brand that makes original looking and durable parts in those missing sizes?

Edited January 7 by pekka111

[Aurorasaurus]

2 minutes ago, pekka111 said:

Thanks :) I guess 3D printing is difficult, since you would like the tolerances to be quite small.

5mm for pin holes, 6.2mm for the little counterbore or whatever it is, 1mm depth for that too. 8mm spacing between holes. Theres even a site for it: https://marian42.de/partdesigner/

That said, you should make a simple test piece to dial it in even more for your machine.

[pekka111]

3 minutes ago, Aurorasaurus said:

5mm for pin holes, 6.2mm for the little counterbore or whatever it is, 1mm depth for that too. 8mm spacing between holes. Theres even a site for it: https://marian42.de/partdesigner/

That said, you should make a simple test piece to dial it in even more for your machine.

Thanks! We have cheap printing here in public libraries so maybe I'll do a test.

[Aurorasaurus]

5 minutes ago, pekka111 said:

Thanks! We have cheap printing here in public libraries so maybe I'll do a test.

https://bricksafe.com/files/Aurorasaurus/miscellaneous/3d-print-tolerance-tester/tolerance tester.stl
Here's a simple test piece I use for checking how different filaments tolerances are, this should be perfect for you. 0,9, 1, and 1,1 on the side are how deep the counterbore is. And the other numbers are the diameter of the pin hole.

[1gor]

13 hours ago, pekka111 said:

Beginner question: all the beams have odd number of holes? Half beams have 6 hole version but not one with 4 round holes? So do you cut custom lengths if something else is needed?

Personally I don't cut anything (that is why I have lots of trial and error). Lots of time I needeed 8 studs long liftarm...but I can only hope for it. Generally I use only Lego parts, but I'm very limited with Lego tire dimensions...

BTW, there is also very usefull 9 studs long liftarm ½ stud thin...

Edited January 7 by 1gor

[2GodBDGlory]

9 hours ago, pekka111 said:

So do you cut custom lengths if something else is needed?

Generally no. Some people go all-out with modification, and many will use specialist third-party parts if they fill a gap Lego can't really fill, and others use only official Lego. It's uncommon to use modified parts for basic structure. You're free to do as you wish, though!

[Stereo]

Odd numbers make more sense on their own - you can combine them to get even numbers, but you can't combine even beams to get an odd length.  Inconvenient if you need the span to be a single beam, but usually Technic sets just design for those sizes to be odd numbers I guess.

[gyenesvi]

8 hours ago, pekka111 said:

Is there a reliable (Chinese) brand that makes original looking and durable parts in those missing sizes?

Weirdly enough, no, Chinese brands don't really get creative and produce all the missing sizes, they mainly copy the existing parts. Though Cada makes some unique parts, but those are rather new designs than missing sizes in an existing concept. I find that quite weird an sad (would be a low hanging fruit for them).

7 hours ago, 1gor said:

BTW, there is also very usefull 9 studs long liftarm ½ stud thin...

Which part is that? I have never seen a thin liftarm longer than 7L.

1 minute ago, Stereo said:

Odd numbers make more sense on their own - you can combine them to get even numbers, but you can't combine even beams to get an odd length.  Inconvenient if you need the span to be a single beam, but usually Technic sets just design for those sizes to be odd numbers I guess.

I don't buy that logic :) Odd numbers simply come from the fact that original Technic bricks have even studs (for even width builds), and they had odd number of holes shifted half a stud relative to the studs, such that there's a hole that falls to the middle, and also so that other bricks connected perpendicularly with pins would have enough clearance. Later the studs where shaved off, the ends were rounded off, and there was the birth of the studless liftarm, made around the pinholes themselves, and hence technic models became odd width because of that. But for the other two dimensions (length, height), there is no natural center, so even liftarms would also make perfect sense there, and would be just as useful.

[Fabulous Fox]

So I have a question that’s always bothered me and I’m hoping some of you on here can give your thoughts since many of you are pretty experienced MOC builders.

I’m horrible at designing Technic MOCs. 

 

I’m totally fine with designing system MOCs. I’ve been building Lego and Lego Technic sets and others’ MOCs for years and years, from the simplest to the most complex. I’ve watched countless videos and read countless topics on Technic. I have and have read Sariel’s book. I understand all the basic mechanical principles and part types. I understand how to brace gears and build strong.
 

But for some reason, when I sit down to start a MOC, my brain just doesn’t seem to work. I can’t really think more than two steps ahead, which I know you need to with Technic. It’s not like this with system.

Now, I can design super small MOCs, like micro scale, and even small mechanisms (I made a custom differential once), but as soon as I need to design a full vehicle it’s over.

Recently, I built 42131 and some alternate builds, and I was motivated to make a wheel loader out of its parts (adding tires and one more differential ofc). I sat down to start and my brain just couldn’t, beyond putting the differentials in and connecting them by a few beams and a turntable in the middle. It’s been like this every time I’ve tried to design a vehicle in Technic.

When you guys are designing Technic MOCs, what’s your process like? Does it really just take tons of thinking, brain power, and time, trial and error, more than I think? Or is it relatively straight forward for you guys?

I think I could if I REALLY had to, it would just take months probably.

At the end of the day it’s not a big deal, because I love building from instructions so much. 

[Aurorasaurus]

51 minutes ago, Fabulous Fox said:

When you guys are designing Technic MOCs, what’s your process like? Does it really just take tons of thinking, brain power, and time, trial and error, more than I think? Or is it relatively straight forward for you guys?

I've been making things with technic for maybe 7 years, and only started actually being "good" at it in the last year I'd say. So for one thing, it takes a lot of practice, trial and error over many models. You start to build a sort of sense for what should and should not work, like all things.

Everyone's process for designing a MOC is different. For me, I think about my goal for the finished model. Do I want it to look good, drive well, be really strong, etc. Then, focus on the most important aspects for reaching your goal. For example, recently I wanted to build an offroader that looked good. So I started building a body, and fully completed the body before moving on to the chassis. But another build, I wanted to make something fast and strong. So I started with the front suspension, because that is usually the weak point in jumps and things. Then I made the rear axle, then the rest of the chassis. Then I thoroughly tested it, then made a lazy ish body because the goal wasn't for it to look good.

Don't be afraid to take inspiration from, or outright copy other people's designs - no need to reinvent the wheel. Your models will probably be better if you use things that are already proven to work well.

I know I struggle with bodywork, I don't enjoy it and I'm not gifted with it. If you have something like that, force yourself to practice until you're happy with your abilities. I used to struggle with suspension, so I spent years tinkering and not utilising the resources available to me. Build other people's MOC's and see how they do it. It's fascinating just how different two models really can be.

Best of luck!

[Carsten Svendsen]

2 hours ago, Fabulous Fox said:

When you guys are designing Technic MOCs, what’s your process like? Does it really just take tons of thinking, brain power, and time, trial and error, more than I think? Or is it relatively straight forward for you guys?

At the end of the day it’s not a big deal, because I love building from instructions so much. 

First thing is to have a vision. Say you want to build a racecar (wow so original), well the bodywork is always going to be the last thing you make right? So everything underneath it isn't really too important, as long as it stays together. 

You need to always think in terms of functionality first. It's technic, not system, so the whole point is to not have a boring static model. 

I tend to make mock-ups of whatever core functions I want to have first and then build my way out from there. So if you want a racecar with a 6 or 8 speed gearbox, you would start with that to get it right, and not start with the frame and the wheelbase because that is going to hinder the development of the gearbox later. 

And build lots of iterations. I have probably 4-5 different versions lying around of the same thing to draw inspiration from.

It's good that you build a lot of sets from instructions, but don't just follow along mindlessly, keep your brain engaged, ask questions, why did the designer choose this solution over another solution? Play with the model as you build it, and if you can, find old instructions on the LEGO website and build those with the bricks you have as the instructions from 15-20 years ago are much harder and challenging.

I can also recommend that you watch this video: 

 

When I started building and designing my haybaler as you can see just underneath here, I started with the core function; the baling chamber, and I made a lot of mockups in brickwork to get the spacing and circle of the gears just right. Then I attached both sides together with the gears and now I had kind of a box. Then it was just a matter of putting a frame on it, and then the 2nd functionality of the other chamber had to be installed. I make it sound easy, but this took probably around 2-3 months of intensive building after work.

And then when I had a frame and the chambers all operated smoothly, it was time to put wheels on it, cylinders and bodywork which took another year of on/off building. The amount of headaches and massive walls to overcome didn't make it easy, ut where there's a will, there's a way.

I've been wanting to take it apart and make building instructions, but it seems like Stud.io never improves their technic building functionalities. It's too unreliable still. Also, I would like to redo the whole model, there is definitely room for optimizations, but given it's so long ago and most of the functions are hidden deep in the model, it'd be impossible to redo it without taking it apart, and that's why I want to do it digitally first, just in case I mess up.

Edited January 25 by Carsten Svendsen

[allanp]

Try building what's called a sketch model first. It's a properly crude multicoloured version that focuses only on one thing, usually the functions. Search Google for "8043 prototype" and you'll find the first version of it. Another thing is you can try building the outer bodywork without any regard for what's inside it. Basically, don't try to build a finished thing from the start. For a typical 1000 piece Lego set, the designer probably assembled over 50,000 pieces worth of sketch models and prototypes and exterior details and so on.

[Carsten Svendsen]

6 hours ago, Fabulous Fox said:

But for some reason, when I sit down to start a MOC, my brain just doesn’t seem to work. I can’t really think more than two steps ahead, which I know you need to with Technic. It’s not like this with system.

Could it be that you just doesn't have a memorized library of all available technic parts yet? There are thousands of combinations with connectors and the like, and to know exactly which pieces to combine can be hard, if not impossible if you never even knew it existed in the first place, or you've simply forgotten. This can only be solved with time and practice. It also helps to sort out your pieces in many different containers to draw inspiration from.

[Fabulous Fox]

7 hours ago, Carsten Svendsen said:

First thing is to have a vision. Say you want to build a racecar (wow so original), well the bodywork is always going to be the last thing you make right? So everything underneath it isn't really too important, as long as it stays together. 

You need to always think in terms of functionality first. It's technic, not system, so the whole point is to not have a boring static model. 

I tend to make mock-ups of whatever core functions I want to have first and then build my way out from there. So if you want a racecar with a 6 or 8 speed gearbox, you would start with that to get it right, and not start with the frame and the wheelbase because that is going to hinder the development of the gearbox later. 

And build lots of iterations. I have probably 4-5 different versions lying around of the same thing to draw inspiration from.

It's good that you build a lot of sets from instructions, but don't just follow along mindlessly, keep your brain engaged, ask questions, why did the designer choose this solution over another solution? Play with the model as you build it, and if you can, find old instructions on the LEGO website and build those with the bricks you have as the instructions from 15-20 years ago are much harder and challenging.

I can also recommend that you watch this video: 

 

When I started building and designing my haybaler as you can see just underneath here, I started with the core function; the baling chamber, and I made a lot of mockups in brickwork to get the spacing and circle of the gears just right. Then I attached both sides together with the gears and now I had kind of a box. Then it was just a matter of putting a frame on it, and then the 2nd functionality of the other chamber had to be installed. I make it sound easy, but this took probably around 2-3 months of intensive building after work.

And then when I had a frame and the chambers all operated smoothly, it was time to put wheels on it, cylinders and bodywork which took another year of on/off building. The amount of headaches and massive walls to overcome didn't make it easy, ut where there's a will, there's a way.

I've been wanting to take it apart and make building instructions, but it seems like Stud.io never improves their technic building functionalities. It's too unreliable still. Also, I would like to redo the whole model, there is definitely room for optimizations, but given it's so long ago and most of the functions are hidden deep in the model, it'd be impossible to redo it without taking it apart, and that's why I want to do it digitally first, just in case I mess up.

I appreciate the detailed response! I actually already do a lot of these things, especially looking at older instructions and thinking about their decisions , except I didn’t think of having different iterations of the same thing. 
 

I used to watch that video a lot when I was younger, it’s a lot of what inspired me to get into Technic. 

[Fabulous Fox]

I guess I should have clarified my question a little bit. I don’t think I have a problem with coming up with the initial idea for a model, functions, and general steps to take to design it nor not having enough knowledge of parts. I know most Technic parts off the top of my head (how they can connect to other parts too) and have all my Technic parts sorted pretty well. I’ve been building official sets and MOCs for years now. Mostly from 2005 to present.

I should say that I try making alternate models from the bigger sets way more than I ever have tried freestyle ones, I don’t really know why (maybe this is my problem).

What my problem is, is in ACTUALITY designing it, part-by-part. The part where you’re using your brain to figure out which parts to attach. You know, the part where you sit down with a part and think, “What do I need to connect to this? What should connect to this so that it makes sense to connect to this I need 10 steps down the line and also be braced properly?”

I can TELL you how to brace parts and how to make certain mechanisms. But when I have to really sit down and connect the parts, it just doesn’t click. 

For some reference, when I’m sitting down and I’m figuring out which part to connect next, I tend to think to myself all the parts that would remotely make sense to connect to it, and mentally go over each one in my head until I find one that makes sense and ALSO gives me most potential connections for future parts.

But the problem is, I don’t know which parts I will need to connect 10 steps down the line yet. Am I supposed to just guess and keep changing things as I see fit? That sounds like I would need to change parts 50 times each before finding the right combination.

An example of this is, say I want to insert an axle. If I don’t know exactly how the build will go 20 steps down the line, how am I supposed to know which length or type to use? If I decide to just use any length for a placeholder, I’d imagine I would have to change it at least five times or so before finding the right one.

Maybe this is a mindset shift I need? Maybe it just takes longer than I think? If you guys had unlimited time to build, say a 2,000 piece Technic alternate build, how many hours do you think it would take you? (Just the model not the instructions or anything else).

[allanp]

43 minutes ago, Fabulous Fox said:

But the problem is, I don’t know which parts I will need to connect 10 steps down the line yet. Am I supposed to just guess and keep changing things as I see fit?

Basically yes.

43 minutes ago, Fabulous Fox said:

Maybe this is a mindset shift I need? Maybe it just takes longer than I think? If you guys had unlimited time to build, say a 2,000 piece Technic alternate build, how many hours do you think it would take you? (Just the model not the instructions or anything else).

Depends on how good you want the results to be. To start with, to get a working sketch model like this one...

(I think it's okay to show this 16 year old image right?)

Something like that sketch model would probably take anywhere form a day to a week of solid, focused building depending on how well things come together on the first try, and if the parts are available to make the functions I want to make. If I want to make a mechanically accurate automatic gearbox, well that would obviously take much longer to get a working prototype than an excavator because more parts exist to make a working excavator than exist to make a mechanically realistic automatic gearbox. But for your idea of a wheel loader from 42131, if you are using one motor per function (as in no fancy function switching gearbox), and allowing myself to use extra parts like wheels and a bucket, you're basically making 42030, for that I'd say about a day for the jankiest of sketch model. With fancy function switching gearbox it might take a few more days. If you're aiming to have 2000 pieces for your finished wheel loader, this sketch model might have as little as half that. 

Usually, official set designers will just not change anything, and instead just move on to building version 2, then version 3 and repeat till about version 50 or more in some cases. But even if your changing and rebuilding the sketch model, the approach is the same. From this starting point you just refine and refine and refine. In the above example, The tracks could do with more detail so add some upper rollers and side beam structure. I might then build a cabin and see where that can attach to the side. I might then decide to move the battery box to the rear to use it as a counter weight. Instead of paralysis by analysis, you are making one decision at a time. You can only climb a mountain one step at a time. After several months, up to a year maybe by a professional Lego designer, the above sketch model eventually became this...

 

 

The more you build, the faster you'll get.

[Fabulous Fox]

2 hours ago, allanp said:

Basically yes.

Depends on how good you want the results to be. To start with, to get a working sketch model like this one...

(I think it's okay to show this 16 year old image right?)

Something like that sketch model would probably take anywhere form a day to a week of solid, focused building depending on how well things come together on the first try, and if the parts are available to make the functions I want to make. If I want to make a mechanically accurate automatic gearbox, well that would obviously take much longer to get a working prototype than an excavator because more parts exist to make a working excavator than exist to make a mechanically realistic automatic gearbox. But for your idea of a wheel loader from 42131, if you are using one motor per function (as in no fancy function switching gearbox), and allowing myself to use extra parts like wheels and a bucket, you're basically making 42030, for that I'd say about a day for the jankiest of sketch model. With fancy function switching gearbox it might take a few more days. If you're aiming to have 2000 pieces for your finished wheel loader, this sketch model might have as little as half that. 

Usually, official set designers will just not change anything, and instead just move on to building version 2, then version 3 and repeat till about version 50 or more in some cases. But even if your changing and rebuilding the sketch model, the approach is the same. From this starting point you just refine and refine and refine. In the above example, The tracks could do with more detail so add some upper rollers and side beam structure. I might then build a cabin and see where that can attach to the side. I might then decide to move the battery box to the rear to use it as a counter weight. Instead of paralysis by analysis, you are making one decision at a time. You can only climb a mountain one step at a time. After several months, up to a year maybe by a professional Lego designer, the above sketch model eventually became this...

 

 

The more you build, the faster you'll get.

I never thought of refining a sketch-like model over and over again and not worrying about being 20 steps ahead all the time, I think this may help. I remember Markus showing all the prototypes in the bulldozer video but for some reason I never thought of doing that for MOCs.

Funny you mention the 8043, it was my first flagship and one of my favorite Technic sets to this day. Best Christmas Present ever 

[Jurss]

We have had many topics about this thing

f.i. 

 

Maybe put is search "How" on topic names. 

But in general, it is not easy thing, I think. Bilding for real takes really lot of interations, where You build, disassammble etc. I have had builds, where I return to it after some few years. I have even disassambled what I have had, and after some time restart fro scratch, from some photos and memory.

Also I have had added some part, with Idea, that  will need to connect something later there, but then I need later to replace it with something simpler. With axis, I usually use something longer. 

Also I'm building often some prototype for some section, then rebuild it for use in my build.

[sondh]

NEED HELP WITH GEAR SLIPS

Hey, hope you guys can help me with this, I have been scratching my heads off all day.

My son is at the age when kids are fascinated with space and stuff, so I looked around what I have in lego and followed JKBrickworks to build an orrery, with the intention to motor it up with a powered up motor (instruction here). Due to my inventory limitation, I made a modification: instead of using LEGO PART 6539 Technic Driving Ring 2L, 4 Ridges, I used PART 18947 Technic Driving Ring 3L,  paired with 2x 18946 Technic Gear 16 Tooth with Clutch on Both Sides. To accommodate with the 3L driving ring, the orrery is 1 stud higher than the instruction.

Now here is the problem: it takes a lot of force by hand to turn the crank and move everything. I swapped some gear parts here and there but generally it stills need a lot of delicate force, as turning too fast would lead to slipping gear.

I tried to hook up with a L motor and the Technic powered up hub, the motor can turn a little bit before the hub led light flashes orange and shut itself down, likely due to overload issue. I think I can get some sensor data from the motor regarding the torque and force being used, but it's clear that there is something not right with the gears.

I read the comments on Rebrickable and it seems no one was complaining about gear issues, so it must be me only.

Video of the issue:

https://youtube.com/shorts/dvGSeqx8bJQ

Lower section

Upper section

Beam with 3 gears in the upper section. I tried a different 16 tooth gear with clutch to see if it solves the problem, but this gear made turning even more difficult.

TROUBLESHOOTING METHODS THAT I HAVE TRIED:

• Separated the upper part and lower path to test each gear sections, The lower section have no problem turning, but the upper section takes a bit of force, particularly this set of gears.

 

Appreciate any kind of help or guidance to make this work!

Edited January 28 by sondh

[Carsten Svendsen]

The easiest thing you can do is to remove sections one by one to see where the issue originates from.

I believe the problem is that you want the Earth module to rotate way faster than the base input speed. An increase in speed always leads to a increase in required torque as well.

What you can do is to rebuild the entire gear mechanism, to have the input axle connect directly to the Earth module, or as directly as possible, then reduce the gear ratio for the sun afterwards.

Also, your studs on the bottom of the sun module might also cause issues, put a round tile with center hole on it to fix this.