[HELP] Generic Building Help Topic

[Zerobricks]

Also current pneumatics don't suck air, they always use positive pressure. First LEGO version is a different story though. 

Edited August 4, 2024 by Zerobricks

[Krxlion]

Hi everyone!
I have a question regarding usual drivetrain angle. So I am currently upgrading my recent MOC and I noticed that the angle of the drivetrain makes it that between universal joint and steering CV joint is not one stud space (just enough for red bush), but stud and something (picture).

It is probably due to further layout of the chassis, but I don't have any half stud offsets (except the one in the shock absorber). My question is it normal thing that I have this like a 1/4 stud space in axle left? I am trying to make a precise model, so I can receive good geometry, etc. By this situation I cannot put 6 stud link (in a Studio, because program detects collision), that should be connected to ball joint pins (visible on the picture), because the length is 6 and around 1/4 stud. Thanks in advance, and If you don't understand what am I trying to say, just let me know.

Edited August 10, 2024 by Krxlion

[Stereo]

It's the vertical offset, you go down 1.5 studs and back 5 so the total length between ball joints is 5.22 studs.  Usually with solid axle designs it's allowed for on the springs by letting them rotate front to back as well as side to side.

[Krxlion]

5 minutes ago, Stereo said:

It's the vertical offset, you go down 1.5 studs and back 5 so the total length between ball joints is 5.22 studs.  Usually with solid axle designs it's allowed for on the springs by letting them rotate front to back as well as side to side.

Thank you so much for this informative and quick reply. It is indeed a solid axle, and it is able to rotate from side to side, but I need to work on front and back movement.

[CrazyMichael2]

I have a question about the Lego control + hub 88012.

While designing a moc, I used 2 L motors coupled together for the driving. And 1 L motor for the steering. I connected steering to port A on the hub and the 2 drive motors on C and D. This worked fine with the code I had in the powered up app. Later I decided to change the ports the motors are connected to. Steering went from A to B and the drive motors went from C and D to D and A respectively. I also change the code appropriately so that the toggles were driving the right motor. However, when the steering motor calibrated, it was unable to rotate past the middle to the left, but was able to turn right still(could turn left back to the middle but not keep going). It seemed like the steering motor had less power when plugged into this different port(B). This issue was solved by reverting the change in which port the motors were plugged into. I did not notice any change in the 2 driving motors.

Does anyone know why changing the port a motor is plugged into would affect the power of the motor.

The set the hub and motors came from was 42160 in case it is related.

[NV Lego technic]

Not sure if this is the right place to ask, but what is kingpin inclination? Is it related to caster? And what is the difference?

[2GodBDGlory]

3 minutes ago, NV Lego technic said:

Not sure if this is the right place to ask, but what is kingpin inclination? Is it related to caster? And what is the difference?

It's been a while since I thought about that! If I remember correctly, kingpin inclination is similar to caster in that it relates to the angle of the steering axis, but instead of being tilted in the front-back plane, it's a tilt in the left-right plane:

So in this picture, the red line would be the kingpin inclination, while the blue line would be vertical. Note that the wheel is tilted at a different angle than the steering axis, because the camber of the wheel is different than the kingpin inclination.

Is that helpful?

[NV Lego technic]

Yes, think you very much.

[NathanR]

I have two concentric octagons formed from liftarms and the 44224/44225 technic rotation joints. The inner and outer octagon have side lengths of 13 and 18 modules, respectively, from corner to corner. Each side of the outer octagon is 6.0355 modules away from the corresponding side of the inner octagon. If I link them with a 7L liftarm, would the 0.0355 stud offset (about 0.284mm) put too much stress on the pins?

The octagons will mounted on their edge, with 6 copies forming a barrel on its side, and this frame will be supporting ~5kg of lego. So I am reluctant of replacing the 7L liftarm with an axle and 32013 to allow a gap to open up.

[mahjqa]

What I'm looking for is a variation on a differential drive.
Typical diff drive has two inputs, two outputs.
1- Powering input one means both outputs rotate the same direction
2- Powering input two means both outputs rotate different directions

What I'm looking for is again a mechanism with two inputs and two outputs.
1- Powering input one means output 1 and output 2 rotate at the same speed
2- Powering input two means output 1 rotates, while output 2 remains stationary.

Does anyone know of such a mechanism?

 

Edit; nevermind. Powering one output of a differential with one motor and powering the differential itself with the other seems to do what I want. Now to fix the speed of the outputs.

Edited September 12, 2024 by mahjqa

[schraubedrin]

On 9/12/2024 at 3:44 PM, mahjqa said:

Powering one output of a differential with one motor and powering the differential itself 

Sounds like you invented the Toyota Prius Gearbox (e-CVT)

 

[ColletArrow]

Dusting off my account to post this question here - I think it's the best place, but I haven't been on these forums for a long time!

A couple of months ago I bought a used copy of 42053, the Volvo pneumatic excavator from 8 years ago. This is my largest set to date, and it was a lot of fun to assemble and play with operate. However, as the largest set amongst my collection of mini- and midi-sized builds it feels a bit lonely, which got me wondering what other sets it might scale well with.

Is there any online catalouge/archive/database where I can sort and browse Technic sets by scale - be it 1:15, 1:20, 1:30 etc.? My usual go-tos of Bricklink, Brickset or Rebrickable don't seem to have anything helpful here.

And if not, then I'm hoping the combined brainpower of this forum might help my specific instance - 42053 has a width of 120mm compared to the real thing's 2520mm, and a wheelbase of 134mm compared to 2600mm, so I'd say it has a scale of 1:20. What other sets (mainly construction/ agriculture/ commercial) would fit this scale?

[howitzer]

57 minutes ago, ColletArrow said:

Dusting off my account to post this question here - I think it's the best place, but I haven't been on these forums for a long time!

A couple of months ago I bought a used copy of 42053, the Volvo pneumatic excavator from 8 years ago. This is my largest set to date, and it was a lot of fun to assemble and play with operate. However, as the largest set amongst my collection of mini- and midi-sized builds it feels a bit lonely, which got me wondering what other sets it might scale well with.

Is there any online catalouge/archive/database where I can sort and browse Technic sets by scale - be it 1:15, 1:20, 1:30 etc.? My usual go-tos of Bricklink, Brickset or Rebrickable don't seem to have anything helpful here.

And if not, then I'm hoping the combined brainpower of this forum might help my specific instance - 42053 has a width of 120mm compared to the real thing's 2520mm, and a wheelbase of 134mm compared to 2600mm, so I'd say it has a scale of 1:20. What other sets (mainly construction/ agriculture/ commercial) would fit this scale?

Vast majority of Technic sets don't have a scale in relation to real life vehicles, as they are not based on real things - just inspired by them. The obvious exceptions are licensed sets, but I don't think there's a comprehensive catalogue of them by scale. Cars are pretty easy, most are 1:8 or 1:10 and the small ones are I think somewhere around 1:15? But for other machinery the scaling varies quite a bit.

[ukbajadave]

I'm placing a bricks and pieces order and I thought I'd grab some new diffs. Apart from 65414 diff housing and 65413 diff gear 28z what else should I get? (I've got plenty of the little gears)

Also any other recent parts I should throw in the basket?

[pleegwat]

15 stud wide body vehicles comes up pretty regularly. This includes 42175 from this year (which you probably won't be interested in), as well as 42144 from 2022, 42128 from 2021, 42112 and 42108 from 2020, and 42098 (the car transporter) from 2019. Many small cars denoted in reviews as 'fits on the car transporter' also fit this scale; those are 13 studs wide.

Length can be completely off for these, particularly trucks tend to be too short for their width, but they look reasonably in scale as long as the widths line up.

[bruh]

Ok, so I’m not sure if this even exists yet, but does anybody know of a MOC of a gearbox with 1 input and 4 outputs that the input can be switched to? I basically want 1 motor with the option of powering 4 functions via 2 clutch rings. However, I need to have only 1 output axle rotate at a time.

Edited October 26, 2024 by bruh

[Zerobricks]

Just look at sets like 42114, 42145, 42009, 8258, 42082, etc...

[bruh]

Ok, thanks. 

[Saruzeufel]

42131 has exactly that if you want an RC version or 42055 has a manual version similar to what you are looking for.

A very  basic version of such a gearbox would look like this:
The blue gears and the long grey axles are outputs. Shift outputs by rotating the orange selector 90° either via a PU motor set to stepper mode or using a stepper mechanism (or add friction pins and turn by hand)
 

 

 

Edited October 28, 2024 by Saruzeufel
faulty link removed

[bruh]

Ok. I’ll look into that!

Edited October 28, 2024 by bruh

[bruh]

Ok, so i built it, but it isn’t quite what im looking for. When i rotate the input, at least 3 of the outputs spin. Did i make it incorrectly, or is that what it is supposed to do? 

[Saruzeufel]

Do they spin if you add some resistance to them (because they are free spinning together with the axles)?

[dantheman12]

What are people's experiences with making responsive steering? Currently trying to find some solutions. I'm working on connecting the steering wheel to the front wheels of my 1:8 silvia, currently the axles follows like this: steering wheel > universal joint > worm gear driving a 16 tooth gear > 24:8 gear ratio > 2 more universal joints > 7L steering rack driven by a 12 tooth gear. I need to do some work strengthening the worm gear, but happy with the overall design, although it seems way too fancy. But the steering wheel can turn about 270 degrees when changing direction without moving anything. I know the u - joints have a bit of slack, so stacking them can cause this issue, but the way I've built the front end theres a bit of a lengthy path the steering drive has to take to get to the rack. Has to go about 6-7 studs to the left, and then a couple studs down. Has anyone dealt with this before? 

Thanks

[bruh]

On 10/29/2024 at 1:11 AM, Saruzeufel said:

Do they spin if you add some resistance to them (because they are free spinning together with the axles)?

Ah yes thank you! i just tried adding some friction to them, and it does work. I am in the process of strengthening it, but I might not use it. I want the crane to be fully motorized, and having a motor switch between the outputs still uses two motors: one to drive it and one to switch it. Good new is, I completely forgot that I had more motors! I was trying to use only the Control+ motors with the Mindstorms HUB, and I neglected to remember the Mindstorms motors. Goes to show how idiotic a person can be when immersed in a project lol.

[m00se]

Not really a building question, but also not worth opening separate topic: Is there a (most likely not Lego) device capable of controlling two (or more) Control+ hubs? Something like a Playstation controller. I really hate having to use my phone to use the Control+ hubs for multiple reasons: building Lego is for me a way to NOT be on computer or phone for a few hours, I might need the phone to take pictures, I hate configuring these apps, but most of all: I want physical buttons to feel like I'm controlling my MOC. I know you can use the BrickController2 App with a Playstation controller, but I'm really looking for a standalone solution.

So something like this, but on steroids: