GBC General Discussion

[shadow_elenter]

So I started my first GBC, and I'm looking for some info I cant find...

I just saw a GBC video and they talk about a first time builder using LEGO chain, and that that's a very bad idea in terms of reliability and it got me thinking
Is there a list of parts that should be avoided in GBC's to make sure they survive long term operation?
And if there's not can someone tell me what parts to avoid?

 

[Ankoku]

I am curious about this one.

Is it a chain wear and tear issue? Or an issue in regards to their weakness if something gets jammed?

I think the main rule is to only design things which can't jam due to ball randomness. I am currently fighting with how a ball enters a lift wheel. Every now and then, if a ball hits it at just the right time, it jams. I don't think I can avoid it. It does fix itself, but it does so by firing said ball out of it. So you end up with random balls ejected from the system, which is less than ideal.

[dr_spock]

On 3/29/2018 at 3:59 AM, Berthil said:

I haven't used them in a GBC yet, just tried them right out of the received package. I will try to flex them up, I suspect they got compressed until the point where no balls pass through.

You could push a 14mm wood dowel or rod through to try to expand the insides if flexing them doesn't do the trick.

5 hours ago, shadow_elenter said:

So I started my first GBC, and I'm looking for some info I cant find...

I just saw a GBC video and they talk about a first time builder using LEGO chain, and that that's a very bad idea in terms of reliability and it got me thinking
Is there a list of parts that should be avoided in GBC's to make sure they survive long term operation?
And if there's not can someone tell me what parts to avoid?

 

My first GBC using the LEGO chains have been running fine since 2016 for many non-stop hours at many LUG events.   The chain hasn't jammed or snapped yet while running.  (I probably jinxed it now...)

I can't think of any parts to avoid.  The fun part of GBC is getting what crazy idea and parts you have to work.  If you plan to display it at public events, make sure it works reliably.  Unlike a video, you can't edit out the failures in front of a live audience. Sometimes that involves a lot of hard work and testing and more testing to put on a good live show.

 

 

[RohanBeckett]

My truck Dumper module has been in existence for over 2 years now... it has done 4 large exhibitions (running 2-3 days each)

No idea how many loops that 1.5mtr length of chain has done! a lot!   No breakages... although occasionally it does come apart

I have a few other modules that use a lot of chain.. no issues at all

 

in terms of parts I wouldn't use...?

Not a lot I can think of... but it comes down to the design of your module, and how a part is used, and how much stress it is under, if the design/mechanism isn't good.

Eg: Universal joints can snap apart, under extreme load, or too tight a turn.

small gears, under high load/strain can shear teeth, or twist axles

And then, you get the general wear and tear, and ABS dust, from mechanisms that run for 6+ hours.

Clutch gears, when boxed in tightly do tend to produce a lot of dust, when running at high speed!

Your biggest concern with building a GBC is: Reliable, reliable, reliable.

Round Balls jam a LOT, and even an uneven table can produce wildly different behaviour, compared to your workbench at home!

[Ankoku]

Not LEGO, but nice video for inspiration. Have spotted many techniques seen in LEGO GBC.

The video contains many machines, many of which are modular, which is quite cool.

[Great Ball Pit]

On 2018-03-31 at 1:51 PM, Ankoku said:

I am currently fighting with how a ball enters a lift wheel. Every now and then, if a ball hits it at just the right time, it jams. I don't think I can avoid it. It does fix itself, but it does so by firing said ball out of it. So you end up with random balls ejected from the system, which is less than ideal.

Lasse Deleuran has instructions and videos showing his anti-jamming mechanism.  He uses this mechanism on a few different lifts including a circular wheel.

Check out the wheel with these instructions he provided: http://c-mt.dk/instructions/models_gbc-GBCStarterWheel.htm

 

[Ankoku]

This feels more like a treating the symptom rather than the cause. e.g. you see the wheels jamming in the video.

For the mini wheel I am working with, I seemed to have prevented any jamming as the ball exits, but not quite sorted out the loading yet. I feel like a timing mechanism is the best bet.

It is purely a personal thing, I just don't like seeing things get stuck, so I want to try and avoid it in the first place.

 

One thing I wish they would move towards at GBC events, is the most unique modules, rather than just the most modules. Having 50 of the same module seems to be against the spirit of it in a way. (Apart from when they do the "make your own GBC module" at the event.)

@Great Ball Pit I loved your LEGO separator tool wheel. Ingenious and aesthetically pleasing!

[Paperballpark]

I've really got into GBCs over the past four or five months, and whilst I haven't actually displayed any modules yet, Huw (of Brickset fame) and I are going to do collaborative displays at both Bricktastic in Manchester (June/July), and at The Great Western Brick Show in Swindon (October).

I currently have twelve modules, and here's a couple of videos of most of them. Any questions, just ask. They all seem fairly reliable, but I guess I'll only see how reliable once they've been running for a full day at a show!

 

 

 

 

 

Edited April 2, 2018 by Paperballpark

[RohanBeckett]

@Paperballpark   Love the BallDozer, and the Twin Wheel Lifts!  very original!

[Frequenzberater]

Ball dozer is very unique. Cool!

[JBrost]

On 3/31/2018 at 11:26 AM, shadow_elenter said:

So I started my first GBC, and I'm looking for some info I cant find...

I just saw a GBC video and they talk about a first time builder using LEGO chain, and that that's a very bad idea in terms of reliability and it got me thinking
Is there a list of parts that should be avoided in GBC's to make sure they survive long term operation?
And if there's not can someone tell me what parts to avoid?

 

I recall one of the Beyond the Brick GBC walk-through videos having something to that effect in it.  Making it worse, it was MY module that the comment was made about-- a module that I cannot recall every having a chain snap(and it has now been to several shows)! 

Like almost every other LEGO piece, it is all about using it in the right manner and accounting for potential problems.  In the case of chain links, they CAN separate relatively easy if they are used in a manner that stresses the links.  If that hasn't been taken into account in the design of the GBC module, reliabilty of the module can suffer because of it.  In the case of my module, the chain links don't separate because the drive train has a clutch gear in it before the chain.  So when a jamb occurred causing the chain to stop, the clutch gear became the "weak link" rather than the chain snapping (pun intended). 

It's not that you can't use certain parts because they're "not good for GBC", it's just that you have to account for any potential weaknesses in the design of the piece.  If a ball can get somewhere and jamb the drivetrain of a module you can either 1) make sure that the drivetrain won't break when the jamb occurs and can be quickly & easily fixed and returned to duty, or 2) re-design the module so that balls can no longer jamb it in the first place.  I tend to start with method 1 and work toward method 2 because method 2 requires LOTS of testing.  This way I can use a new module in a GBC display with relatively high reliability (module doesn't destroy itself--simply stop module, pick out stuck ball, restart module) while looking for ways to re-design the module to prevent jambs in the first place.          

[Ankoku]

You could actually run an NXT which keeps track of motor RPM and stops the motor and sets off and alarm if the RPM drops dramatically for more than X in time.

Press the main NXT button to reset and start the motor off again. You can also charge/run it off the mains.

[Maico]

@Paperballpark

nice videos and modules. Are these modules coming to PKH in Trontheim, Norway as well?

for those who can't get enough of following the blue ball...

https://youtu.be/DGyDJeV2Rck
https://youtu.be/ruu_zGKOWM0
https://youtu.be/fjRfMXfMfRw
https://youtu.be/B07Hz93uaGo
https://youtu.be/RX_7pt7zN1c

Edited April 4, 2018 by Maico

[Ankoku]

Hadn't come across this one before. I like the idea of it though.

 

[Berthil]

Just finished my GBC Ball Counter if you are interested:

 

[Ankoku]

Came across this one a French forum. Quite unique.

http://www.techlug.fr/Forum/viewtopic.php?f=5&t=11531

Have looked at his stuff before, but hadn't spotted this, which is his latest posting.

[Frequenzberater]

Nice one!

[Paperballpark]

On 04/04/2018 at 3:28 PM, Maico said:

@Paperballpark

nice videos and modules. Are these modules coming to PKH in Trontheim, Norway as well?

for those who can't get enough of following the blue ball...

https://youtu.be/DGyDJeV2Rck
https://youtu.be/ruu_zGKOWM0
https://youtu.be/fjRfMXfMfRw
https://youtu.be/B07Hz93uaGo
https://youtu.be/RX_7pt7zN1c

I'm afraid not, I've no plans to travel abroad with my GBCs. Sorry!

[Berthil]

This time a different approach on making a GBC video :)

At the end of the video you see me holding up my version of the Akiyuki Train Elevator and Rotary dumper put together in one module. Because of the new 'old style' base this has become a very solid and sturdy module where nothing wiggles and shakes. A video of that coming soon.

[Ankoku]

Some new GBC designs by Riku Katsumata: https://www.youtube.com/channel/UCwuHrRs5-_H56QtvCWHTghQ

 

 

 

 

I rather like this one:

 

[Berthil]

My GBC lineup at a 3 day event last Pentacost weekend.

 

[Maico]

 

[Captainowie]

On 25/05/2018 at 7:58 AM, Maico said:

<snip>

That red tower at ~3.5 minutes looks mighty familiar!

[Maico]

May be because I am using it for almost 8 years now?

 

[Ankoku]

Although not LEGO, this inspires!

 

It reminds me of the LEGO logic gates machine people do.