Lego GBC Ball Batch Module

[sawyer klegr]

This great ball contraption module uses I mechanism that holds the balls until there are 13 in it, then the mechanism gets triggered and it started lifting the balls and dumps them into the next module. It is quite a complex mechanism, it works well, as long as it runs at the same speed you set it up for. As far as reliability, it is quite reliable when it is set up to get triggered by 13 balls, and even more reliable when you are ok with 12 or 13. (if you have not guessed by now, this was built for the Great Ball Pit challenge to build a module that only outputs 13 balls at a time) I don't know how log it can run, I have ran it for about 45 minutes and it has not had any problems, but I would not be surprised if it stopped working after a few hours. 

 

Hope you like it, there are more photos on flickr here.

[JintaiZ]

Just wow

[doug72]

Very ingenious, watched it several times now to understand the mechanics.

What is the purpose of the coupling (4 wedge wheels and 3x8T gears) mid way that drives and causes the lift to rotate on the banana gear racks ?

Like the 13 ball measuring device.  I tried to find a way but couldn’t, I could get 15 balls OK but not 13.

A definite winner of the GBP contest.

Given me some ideas for a train GBC module i am working on.

[sawyer klegr]

16 hours ago, JintaiZ said:

Just wow

Thanks!

8 hours ago, Doug72 said:

Very ingenious, watched it several times now to understand the mechanics.

What is the purpose of the coupling (4 wedge wheels and 3x8T gears) mid way that drives and causes the lift to rotate on the banana gear racks ?

Like the 13 ball measuring device.  I tried to find a way but couldn’t, I could get 15 balls OK but not 13.

A definite winner of the GBP contest.

Given me some ideas for a train GBC module i am working on.

Thanks! The purpose of that is basically a clutch. The one 8t gear in the side that the power is coming from is attached to a friction pin. I made it this way instead of using a "normal" clutch or one of the 24t clutch gears because this way it completely releases pressure for a short amount of time. It is normally not really used, but it stops the module from jamming which occasionally can happen with the 12t gears that mesh with the start of the banana gears. This only happens when it is running at really low speeds. Would still be cool to see your module if it is working :)

[doug72]

Thanks for the explanation, thought was what it was for, safer than the Lego ones.

I,ve been looking at your video at 1/4 speed to figure out how each part functions.

I have built several new gbc train modules during lockdown, they are posted on the GBC train forum.

Finally got the swing loader working with EV3, Its also posted on the Great Ball Pit site. See week 24.

Developing a simple standard “in box” for train GBC that releases a batch of 15 balls & holds back any excess balls until  next cycle.

Busy improving some older modules and have a new one currently is under construction, using the new large sprocket wheel.

Edited November 3, 2020 by Doug72

[howitzer]

Am I correct that the lifter gets triggered by weight of the balls? If that's the case, I assume only genuine Lego balls can be used, because various third party balls are probably too light or too heavy.

[Bartybum]

3 hours ago, howitzer said:

Am I correct that the lifter gets triggered by weight of the balls? If that's the case, I assume only genuine Lego balls can be used, because various third party balls are probably too light or too heavy.

It doesn't matter if they're too heavy, as you'll just have fewer balls to be loaded before it triggers. If they're too light then there'll be issues.

[howitzer]

6 hours ago, Bartybum said:

It doesn't matter if they're too heavy, as you'll just have fewer balls to be loaded before it triggers. If they're too light then there'll be issues.

Well, for too heavy balls it matters in that it reduces the throughput, so if you include this in a chain of GBC modules, it's important that every module can handle enough balls. Though from the video it seems that it's anyway slower than the usual 1 ball per second throughput required for GBC chains in events and such.

[Horologist]

18 hours ago, howitzer said:

Am I correct that the lifter gets triggered by weight of the balls? If that's the case, I assume only genuine Lego balls can be used, because various third party balls are probably too light or too heavy.

You could probably adjust the counterweight of the blue weight-sensing arm to change what weight the lifting is triggered at and allow for balls of different weights.

[doug72]

8 hours ago, howitzer said:

.Though from the video it seems that it's anyway slower than the usual 1 ball per second throughput required for GBC chains in events and such.

Timed the throughput shown on the video and its 3 batches of 13 balls = 39 balls in just over 1 min. so meets GBC regs.

[sawyer klegr]

1 hour ago, Horologist said:

You could probably adjust the counterweight of the blue weight-sensing arm to change what weight the lifting is triggered at and allow for balls of different weights.

Yes, the weight can easily be adjusted. I added some 2x2 round plates to the back of the module for this very purpose. The module can also run faster, as I was running it on only 5V as my rechargeable batteries finally died.

[Captainowie]

15 hours ago, Doug72 said:

Timed the throughput shown on the video and its 3 batches of 13 balls = 39 balls in just over 1 min. so meets GBC regs.

... wouldn't one need more than 60 balls in "just over 1 min" to meet the 1 ball per second spec?

Not that it'd be a huge problem, most shows I've taken stats at average 0.4 - 0.6 balls per second.

[doug72]

28 minutes ago, Captainowie said:

... wouldn't one need more than 60 balls in "just over 1 min" to meet the 1 ball per second spec?

You are correct, my mistake, brain fog due to CV-19 Full Lockdown again.

Edited November 5, 2020 by Doug72

[howitzer]

16 hours ago, Horologist said:

You could probably adjust the counterweight of the blue weight-sensing arm to change what weight the lifting is triggered at and allow for balls of different weights.

That would work if the balls are all the same weight, but if you mix Lego and third-party balls, you're still screwed.

[Horologist]

5 hours ago, howitzer said:

That would work if the balls are all the same weight, but if you mix Lego and third-party balls, you're still screwed.

Yeah, in that case you'd probably be best off running the module slightly fast of one ball per second and tune the counterweight so that even if the weight of the balls varies, there will always be enough weight to trigger the lift. Sometimes it might lift when it's not full, but if it runs fast it wouldn't fall behind one ball per second.

[Thierry-GearsManiac]

Original idea ! And rather advanced mechanism for sequencing the successive states.

On my side, although I already thought about such principle (but only in a theoretical way), I couldn't manage to find a mechanical solution, given that I gave me an extra design constraint : powering down the motor while the platform is waiting to be fully loaded, i.e. turning it off when it returns to its starting position, and turning it on again when fully loaded.

 

[sawyer klegr]

On 11/6/2020 at 3:31 AM, Horologist said:

Yeah, in that case you'd probably be best off running the module slightly fast of one ball per second and tune the counterweight so that even if the weight of the balls varies, there will always be enough weight to trigger the lift. Sometimes it might lift when it's not full, but if it runs fast it wouldn't fall behind one ball per second.

You could also just set the weight to trigger at 12 balls to account for any differences between real and "fake" balls.

22 hours ago, Thierry-GearsManiac said:

Original idea ! And rather advanced mechanism for sequencing the successive states.

On my side, although I already thought about such principle (but only in a theoretical way), I couldn't manage to find a mechanical solution, given that I gave me an extra design constraint : powering down the motor while the platform is waiting to be fully loaded, i.e. turning it off when it returns to its starting position, and turning it on again when fully loaded.

 

Thanks! Your idea of having the motor turn of while it is waiting is a great idea! I think it could be quite challenging, it might be necessary to have a more complicated mechanism, maybe having the last ball roll off into another part of the mechanism to give it more leverage of the electric switch the motor is attached to?

[Thierry-GearsManiac]

20 hours ago, sawyer klegr said:

Thanks! Your idea of having the motor turn of while it is waiting is a great idea! I think it could be quite challenging, it might be necessary to have a more complicated mechanism, maybe having the last ball roll off into another part of the mechanism to give it more leverage of the electric switch the motor is attached to?

Challenging, I totally agree ! That's why I failed, even in pure theory. And real building would be even tougher, as I experienced in an advanced mechanism from the beginning of this year (a bell-meter which required a lot of redesign and fine-tuning... but was eventually still not enough reliable).

For actuating the switch off and on with enough force, the mechanism made for lifting the ball receptacle would have to simultaneously rewind some kind of energy storage device (a counterweight or a spring/rubber band), then trigger it when the ball receptacle reaches its down position (without falling), making it turn the switch off and stop mid-race, locked. Then, the last ball (either by following another path as you suggest, or because of the total weight of the ball receptacle) would unlock the energy storage device, which would, thanks to its remaining potential energy, turn the switch on again.

Some kind of clock escapement anchor would be mounted on the switch in order to move it back-end-forth during the discharge of the stored energy, but the rewinding phase should not act on this anchor.

 

With my current LEGO skills, I would be only barely able to build some prototype of the core of such a mechanism in a reasonable time, but not a complete and highly reliable GBC module.

Another difficulty I see is that the ball input should be able to work with no stirring or delivery mechanism, which seems hard to achieve, otherwise the motor should stay permanently on for driving it, ruining the purpose of the core mechanism.

 

[sawyer klegr]

3 hours ago, Thierry-GearsManiac said:

For actuating the switch off and on with enough force, the mechanism made for lifting the ball receptacle would have to simultaneously rewind some kind of energy storage device (a counterweight or a spring/rubber band), then trigger it when the ball receptacle reaches its down position (without falling), making it turn the switch off and stop mid-race, locked. Then, the last ball (either by following another path as you suggest, or because of the total weight of the ball receptacle) would unlock the energy storage device, which would, thanks to its remaining potential energy, turn the switch on again.

Some kind of clock escapement anchor would be mounted on the switch in order to move it back-end-forth during the discharge of the stored energy, but the rewinding phase should not act on this anchor.

^ That is a great idea! Did not think of using the motor to lift a heavy weight for something like that, maybe could start with a clockwork module so you don't need to worry about waiting for 13 balls? 

[kieran]

Very clever how that movement is achieved, I like the way once activated it stays running

[sawyer klegr]

On 11/8/2020 at 10:13 AM, kieran said:

Very clever how that movement is achieved, I like the way once activated it stays running

Thanks! It was partly inspired by vending machines and a old clock :)