sqiddster

Thanks for the comments, guys. In regards to the balls: I could not afford to buy soccer and basketballs off bricklink, as the price has skyrocketed recently to over $1 per ball. Therefore, I started a topic here to try to find an alternative: http://www.eurobricks.com/forum/index.php?showtopic=69642 In the end, Blastem and DLuders showed me a great alternative - plastic beads that you can get on ebay - $5 for a bag of 100. They work really well except for the fact that they are a tiny bit smaller, and have bead holes which in very rare circumstances can prevent them from rolling from a stop. I was also kindly lent ten or so of the regulation balls to test with, just to make sure that it worked with them (it does). I'd definitely recommend those beads!

The standard spec is 1 ball per second. It can reach about 0.8, and this is fine as in practice the GBC loop will average little more than 0.5.

Thanks for the comments! 1. I would estimate about 20 minutes to fill it up in normal circumstances. However, considering a possible lack of orange balls and a lower throughput rate, I'd estimate over half an hour. 2. GBC modules are designed to be viewed from one side, so this shouldn't be a problem. 3. It could be used in either, I suppose. I am fairly sure we are setting it up in a loop this year, apparently we are going to be breaking the US record for most modules! In regards to taking all the balls: -It has overflow valves - i.e. only the needed balls are diverted to the array. This means that around 75% of the balls just flow through anyway. -I will fine tune the speed of the ball return so that the balls are returned at a constant rate. Are you coming? It would be amazing to see some of your cars!

Thanks for the Mention, Parda! Your blog is my main GBC fix ;)

Whoa, that's amazing! That thing must be heavy. Have you weighed it?

Thanks, fixed it ;)

Thanks! It can write anything I like, fitting in a 7x18 grid. However, I can't think of anything else to say, other than LEGO ;) In regards to the [media] tag, that does not want to work either! Any tips?

Hello everyone! This is my first real Great Ball Contraption module. It uses 2 NXT's, lots of PF motors, and is programmed with RobotC. It's main features are a unique color sorter, and a ball array (watch the video ). This model was interesting as it was equally a hardware and software challenge - the building was bigger than I have ever attempted, and negating ball clogs is a nightmare. It clocks in at just over 6 feet long. I built this because I had the chance to attend a Lego convention for the first time - Brickfair in the US. It should be great fun being part of a collaborative display. Multiplex by sqiddster, on Flickr

Now I face the decision of whether I should buy the cheaper lego standard color sensor, or the hitechnic color sensor v2. Anybody had any experience with these?

Thanks! Unfortunately the balls in the video are not GBC balls - GBC balls are in either a basketball or soccer pattern... That's what makes it tricky. the basketball has tiny black stripes which I assume won't be a problem... however the soccer ball is both black and white, and I am not sure how the color sensor will cope with that.

Could you not plug it in? "An undesired feature, from AFOLs perspective I would say, is a built-in power-off timer which actuates after 2h without any interaction with the battery (speed change command or charging)."

Hello again, Before I spend $34 on a color sensor, I have a question: Can it be used to sort GBC balls (soccer and basketballs) effectively? It seems a little trick to me as the soccer ball has two colors which are not even colors, and I have not had experience with this sensor. Does anyone have examples of it being done? Thanks!

OK, thanks. I suppose I could buy a handful of basketballs just to test the color sensor - at real GBC events I won't have to worry. Thanks again, there is a great community here!

Oh wow, found the exact ones you mentioned in your blog post! http://www.ebay.com/itm/100x-New-Round-Orange-Smooth-Plastic-Beads-14mm-110678-/220776067969?pt=LH_DefaultDomain_0&hash=item3367477381#ht_4850wt_1095 Available in many colors! I suppose I shall buy orange and white ;) Before I buy, I have a few questions about them... Does the weight difference play any part in their performance? IMPORTANT: How are the moulding tolerances? i.e. do they all fit within 2 studs and roll nicely? What about the small hole, does that impact rolling? I am color sensing, how close is the color of the orange one to the basketball? Many thanks for all your help! You saved me a large investment, that is for sure. EDIT: I just saw my profile on the left... Thank you very much, evil moderators XD That is gold.

Well, I certainly have more of an open mind about using other ball alternatives. However, I didn't see in your blog any link to where I can buy some. Any link? I supported the cuusoo project, but as I said before, I have serious doubts about the feasibility of it succeeding, especially when you look at what lego is looking for - set ideas, not parts pack. A better bet would be a 'GBC starter module' or something like that.

Wow, an honor to hear from the creator of the standard! Making my module process zamor spheres as well would be a nightmare, seeing that it is already processing a stream of orange/white balls! I am afraid the lack of these balls are going to be a pressing problem in the coming years... Bricklink is even running out of them! I have heard complaints from organizers stating that they have an ever-present lack of balls. Something is going to have to be done. I wonder what we could do. It is really tough, considering all of the existing modules, as you said.

Parda, you are very fortunate to have access to so many balls! Too bad I don't live in Europe... Hmm. It really is a shame. In all honesty, I have doubts about that Cuusoo project. It is a great idea, and I wish it would work, but the way it is going it seems the only projects getting through are those with references to popular culture, like the minecraft set.

Thanks, I hadn't seen that topic. It really is a pity though. The GBC standard was created in 2005... I wonder how hard it would be to change that standard? If not, beads would be a somewhat suitable replacement. I worry about weight differences, however! @dhc6twinotter, there is a link to the youtube vid in the flickr description. The reason I am conforming to real GBC standards is because I can come to BrickFair this year! I am very excited, have a number of module ideas, but my main problem is the insane prices for the balls! The organizer for the event was nice enough to mail me a handful, but the module I am working on is huge, and will be able to lay out a grid of balls in a color pattern! This requires a huge amount of balls (hee hee). Hmm....

Hello everyone, The GBC (Great Ball Contraption) is one of the main reasons I get into Technic. I just love the whole concept of it. I have built my own using zamor spheres, which are a dime a dozen. Recently I moved to the US, which means I have the oppurtunity this year to participate in a real GBC display. To my dismay, however, the prices of the soccer and basketballs have dramatically increased, and I can't find any for less than $1 a ball! This is insane! Is there anything I can do? How do you guys get your GBC balls? Thanks, sqiddster

How about when you realize all 10 of your pneumatic cylinders have simultaneously stopped working... Also, I wonder if any of you guys get this, but that time when you are working on a really complex part which is somewhat fragile... trying to squeeze in a bushing or something... and then, like magic, it all falls apart in your hands.

It is all about the kids. If the main function of the model is just to make the engine spin faster when the car is driven by hand, kids will feel ripped off as they do not understand the mechanical complexities.

OK, I am going to give it a try. I have access to a workshop, perhaps they will have some silicon based grease. What do you mean by 'sometimes it does, sometimes it doesn't'? Have you had experience with trying this method? Yeah, my newer cylinders from the Unimog don't leak, but who knows what will happen in 10 years...

The actuator problem is very interesting ;) I gave it a bit of thought, this should work: Let me know if you don't understand ;)

I don't see how lubricant would stop the air from leaking out of the seal. I would be delighted to be wrong about this, however. I wonder how long it would last...

Hello everyone, I am one of the ones fortunate enough to have purchased the amazing lego pneumatic backhoe all those years ago. Recently I have set about building a pneumatic MOC. However I am distraught to find that the rubber seals in my old pneumatic cylinders have partially failed, and air is leaking out the top whenever the cylinder contraction encounters a small force. I certainly do not want to pay the huge price for new cylinders, especially when I have perfectly good ones (apart from the seals). I contacted Lego customer service, but they are not being very helpful. Does anyone have any experience on repairs, modifications, or replacements I could make to stop this air leakage? I am prepared to dismantle the cylinders and/or purchase replacement rubber seals. Many thanks, sqiddster