[TC23] Wave motion GBC [Complete]

[howitzer]

Edited to add a video of the finished machine here in the first post:

 

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So, after fiddling around for a while with GBC ideas that are nice but really hard (if not impossible) to make actually work, I settled for this thing. It's superficially similar to @Berthil's Rainbow Wave GBC, but with completely different mechanics to make it work. As in Berthils machine, the basic idea is to make the balls move by applying wave-like motion on a track to pushes them forward. I'm using track tread to make it work, in such a way that the tread won't move forward but only up and down. The up motion is achieved by tread sprockets which are rolled underneath, with gravity bringing the tread back down.

I needed to make my own chain (from liftarms and frictionless pins) to move the sprockets, with rubber wheels moving the chain forward. It's currently in prototyping phase where I will attempt to make it work well enough and then do a complete rebuild for final showpiece. Here's photos of the current progress:

The wheels around which the chain go are freely spinning (size dictated by tread sprockets and parts availability), and to actually drive the chains I intend to use another wheel on the outside, with friction only pushing the chain. I'm still unsure if this will actually work out, or if I will have to invent some sort of sprocket to drive the liftarm-chain. A the current prototype is on a very short track, I also ordered more pins and liftarms to elongate the chains. I believe this contraption could also be lengthened quite a bit with enough parts and also angled so that it would run the balls uphill slightly. It should easily reach the 1 ball per second requirement as multiple balls can be pushed with each wave.

Edited November 16, 2022 by howitzer

[Heppu]

Promising start! I did a similar GBC back in 2016 and can attest that a wave-type module is a pretty reliable mechanism with little maintenance. Always a great quality to have for a GBC :)

Looking forward to seeing where this goes!

 

[Berthil]

Great start and looking forward to the progress reports. Are you planning on using the tracks as carrier or may be a carrier of own design?

[howitzer]

17 hours ago, Heppu said:

Promising start! I did a similar GBC back in 2016 and can attest that a wave-type module is a pretty reliable mechanism with little maintenance. Always a great quality to have for a GBC :)

Looking forward to seeing where this goes!

 

Thanks! I'm going to attempt to make it somewhat more flashy than just a dull-coloured wave moving balls forward. Good to hear that it's a reliable mechanism, that's indeed also my observation so far.

17 hours ago, Berthil said:

Great start and looking forward to the progress reports. Are you planning on using the tracks as carrier or may be a carrier of own design?

At the moment I think I'll use the track as it is, as it's convenient and doesn't consume too many parts but if there's time and I find enough parts I might attempt to build a custom chain for it. At the moment even the carrier chains are too short due to me running out of pins and liftarms, and while I already ordered more, there's no way they'll be enough for another custom chain...

[howitzer]

So, between working, moving and renovating my new home I have had too little time to build. However, since I got my building area finished a few weeks ago, I have taken all the time I could spare to finish my entry for the contest, and while I'm entirely not satisfied with it, I managed to finish it and it performs the thing I intended it to perform. It's highly unpolished and spills a ball occasionally, but doesn't jam and moves the balls fast enough to qualify for the rules.

I just finished the final touches less than half an hour ago, and took some photos, but I didn't manage to get a video yet, so I hope I can add one later (when I'm able to shoot the video in daylight).

Anyway, here's some photos of the process. Explanations will follow later.

 

 

Bigger photos at http://www.jousimo.fi/lego/TC23/

[DrJB]

Looks very promising. Love our work/play space as well.. :)

[howitzer]

Now I have also a video.

 

[howitzer]

And here's some cleaner photos.

The entry box on the left comes with an agitator to make the balls move to the conveyor belt, which raises them to the top. From there they fall down on the waving belt, which in itself moves only up and down while the motion pushes balls forward towards the exit.

The exit shows how the sprockets go around the ends, attached to the custom chain made of 1x3 liftarms.

Here's the area where most action happens. The motor is connected directly to the axle of the wheels driving the belts, which connect by chain to the ball lifting conveyor belt. There's also a pair of sprung wheels pushing against the belts, to ensure that the driving wheels won't slip too easily. If the mechanism gets jammed however, it will slip, protecting the motor.

A photo from the other side, showing the chain drive. Sorry about the glare from my lights.

A closer photo of the drive motor.

A closer photo of the chains and sprockets which move the belt.

The ball lift conveyor belt connects to the entry box agitator by 8T gears. This was the best thing I could come up with as I didn't have time to think of anything more efficient. This works too, even if it lacks elegance.

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All in all, this has been a learning project for me, as I don't really have much experience in this kind of things. One thing I learned was the appreciation of the skill and effort that must be put into making a complex GBC work - even with my relatively simple machine there was a lot of trial and error, building, taking apart and rebuilding.

There could've been a lot of more polishing and fine-tuning but I simply didn't have time for that, as I barely was able to make it work within the time constraint of the contest. I hope this inspires someone to build and experiment with their own GBC's!