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!

Hi, first time attempting to attending an Eurobricks competition. We shall see how this goes since my plan *might* be a bit too ambitious. The idea is to have a EV3-based 3DOF stewart platform to move the balls. I've wanted to make a stewart platform out of Lego for a while but never had a good application for it. GBC seemed like a good fit. Consept mechanism: Current status: In a three degree of freedom Stewart platform, 3 large motors working in tandem can change the platforms angle in 2 axis (roll and pitch) as well as move it up and down (heave). The current plan is to have a free moving pendulum with "ball fork" that pivots around the center of the platform. This fork would pick up balls on one side of the machine and swing to drop them off on the other side. The system will of course need an input sorter to lift the balls to required height. It will most likely be a semi standard stepper module. If I find the pendulum fork to be too unreliable or too slow to meet the 1ball/sec requirement, I might need to simplify the system. Most likely ditch the idea of the pendulum and use a fixed bucket and shute system attached to the the platform itself. There are still a lot of questionmarks with this project and wether it will finish in time. But I figured If I present it here, it might give me more motivation to work on it ;) ! Next up in line is to start on the code for controlling the platform and designing a better pendulum as well as some sort of input and output racks that mesh with it. Rules violation As is evident from the pictures my model includes non Lego elements. These are: Raspberry Pi with Brickpi3 board to control the EV3 motors. 3D printed case for the RaspBerry Custom made shorter length EV3 cables I understand that these violate the rule: "All entries are to include only real LEGO. No clone brands, 3rd party parts, or digital entries allowed." Since these are not part of the core mechanical mechanism to move the balls, I'm hoping these would be allowed. If not, I'm totally ok with that and will happily continue this project outside the scope of the TC23 competition.

Cool project! Seeing and especially hearing all the mechanisms churn away gives it a nice vibe. This would definately be a hit attraction at some smaller Lego event. I don't see the need to change the color scheme to yellow but if you like that more, then go for it! (lots of rebuilding lol) As a minor thing I would attach the pneumatic cables better to to the claw structure so as to prevent them from hanging loosely and blocking the view.

That's a lot of work for instructions on something only a few people (if any) could even consider building just because of its size and the piece count alone! Hope you enjoyed the process. I guess it will at least serve as a momento for you once its torn down and the pieces are used for other awesome projects.

I was imagining somethink brick built for the buttons like this. Thank you for the instructions for the cables! They look super cool and kinda easy to do. might consider getting the parts to do some myself!

Impressive and good luck on the event! I would make the E-stop buttons even larger (and sturdier) if you are planning to let the audience handle them. Bigger the better! Hope the power outlets at the event can handle all the wattage. I had problems once when my model ran from the same plug as the whole GBC layout. Sigh. Also, sorry if this is a stupid question, but are those white cables fully custom built? Their long lenght looks really useful.

It won't be more compact, but you could use technic links in the joint for better articulation and hide the linear actuator inside the vehicle. Also looks like you are not planning to have a drivetrain running trough the joint like the real thing?

I like where this is going so far! Super solid looking base. Using so many gears will intoduce play into the drivetrain. You'll lose some accuracy in getting exact end effector position if that is a concern to you. Also, with a larger suction surface your setup could easily lift much heavier pieces. Is this an motor/hub problem or a code problem? I assume it's code since you can move all 3 motors simutaniously no problem. Then I guess its a matter of just coding a simple trajectory generator. Do you have IK and FK equations in order? If so, for each movement between 2 points, scale each motors speed by: (angle to travel / biggest angle to travel). This way each motor will take the same time to rotate their desired angle. For longer movements instead of going from A to B, my trajectery generator generates enough "in-between points" such that for each movement between 2 points, each motor has to rotate in only 1 direction. Hope that helps.

The vacuum itself in my robot is created by actuating regular large Lego pneumatic cylinder. The suction cup is not Lego but an industrial vacuum suction cup taped to the end of a Lego pneumatic hose. For kinematics you might find this github page useful: delta kinematics

Parallel delta robots are indeed cool! Especially the kinematic equations are real funky compared to conventional serial arms. I made my own a few years back with a suction cup attatchment. Seeing you use tow balls in the joints makes me want to revisit that design and redo the joints with proper geometry.

Tracked vehicles might be hindered by part count (lots of small parts needed). Small size competition sounds intreguing.

It's a cool little car, but I would really like to see a video or at least pictures of it in real life. Rendered images are fine, but especially with creations designed for play rather than looks, I want to see them in action! Also how securely is the curved 3x13 panel in the hood attached? It looks like its only held in place at the front. Rebrickable is full of awesome models, many of the best ones available free of charge. Personally I'm interested in models that have novel building techniques and a great build experience more than whether I own all the pieces, but that's just me. Also if I'm planning on buying something, I always check what free instructions the person has available to evaluate if the paid instructions are worth the money. I can instantly spot a few deal breakers that would bar me from buying your instructions (apart from the price to part ratio). Hope these help you improve on them: Many of the guiding arrows go trough pieces and sometimes even point to the wrong spots. (for example check your "simple steering mechanism" step 4 arrows.) looks unprofessional and can hinder more than help. One of the black Bionicle tooth pieces on the left side of the blue version render appears to be floating without no apparent axle inside it. I would guess the same mistake is present in the instructions and parts list.

Thank you all for the kind words! The main rotor blades being directly connected to the swashplate is not really a thing in real helicopters so I can see why using a wheel hub would not be common in moc helicopters. In my research to see if anyone had built 8412 before, I did come across This [TC15] entry by Tomik that was inspired by 8412 as well and it uses a wheel hub. So I can't claim to be the first to come up with that idea. If anyone wants a better look at the insides, I have uploaded FREE instructions for this on Rebrickable: https://rebrickable.com/mocs/MOC-95970/Olli Mäkinen/nighthawk-helicopter-tribute/#details All Finns are welcome! Normally we focus on live events but now with covid there have been some contests to fill in the void. "Palikkatakomo" if you want to google us.

Hello! Our LUG recently hosted a competition loosely inspired by your [TC20] competition to create a studless version of an older Lego set. Our ruleset was revised heavily though, to accomodate any MOC building style - not just Technic. Main idea was to 'modernize' a set released before the year 2000. Since the idea originated from here and my entry was made with Technic, I thought it was fitting to share mine here. The Nighthawk helicopter is a studless recreation of the 8412-Nighthawk from 1995. It retains the same functions and a similar size, though being slightly wider going from 6 to 7 studs wide main body. The 8412 used flexible cables for tilting its main rotor but here the same is achieved with linkages. This is also the main reason why the modern version uses more pieces (375 vs 287). I tried to use as many older black and light bluish gray 3L pins for a more uniform colour scheme. Also, love or hate them, I used stickers to capture the originals yellow stripes. The modern Technic way of creating details! :P Manual features: Spinning main and tail rotor using the crank on the left side Adjustable main rotor pitch and roll angle using the control stick in cabin Unfortunately, I’m too young to have owned the set myself, so I have no direct side-by-side comparison available. I did try to recreate the original photo in the instructions for fun though: Thank you for inspiring our LUG with the competition. Any feedback is appreciated!

Hardest part for me is often making sure the model and especially the bodywork is built structurally rigid. It's easier to build stuff that looks cool when you build it for show and not for play. The real challenge is securing all of the panels and other exterior details so that if you grab the model from the wrong spot or shake it a bit too much everything still stays in the correct orientation. This comes especially apparent when building small scale builds with lots of detail.