BrickBear

This one would be pretty damn close if it weren’t for the awkward bar https://www.bricklink.com/v2/catalog/catalogitem.page?P=44810&name=Bionicle Matoran Torso, Gear 9 Tooth with 3 Axle Holes and 2 Pin Holes&category=[BIONICLE]#T=C edit: Now i look at it i’m not sure it’s a quarter?…

It might not have reached the state you wanted it to but it’s still very much alive and exciting to look at. Every attempt is also a page in our book of experiments.

I’ve seen a video where someone tried it with ev3 (or whatever the latest incarnation of mindstorms was) but I can’t find that video anymore and it walked in the same way as the official motorised AT-AT’s anyway. I think it could be done though. If you used smaller motors actually in the legs to bend them at the right timing which takes you to 4 connections (I think the limit is five or six per hub). Then you’d only need something to lift them up like a cam and move them forward and back like a piston which could probably be done with one motor. Maybe…I’m a powerfunctions guy myself and only ever made one walker with ev3

I remember mine was taking my technic arctic truck and making that walk with the mechanism from the official lego motorised AT-AT. It kinda worked but it wasn’t very attractive and I don’t think my m-motor was torquey enough to move it. Hopefully an xl will be enough for the current iteration.

Makes sense. Thankyou, very interesting. I’m very excited to get working on my version again eventually with all this inspiring talk. I probably need to order a few pieces first…

Mmm, I used a plate with rail to offset some of the lean. I’ve considered the inner rod as a point of support too, adjusting where the pins go too. If I may how exactly does yours work?

Mmm, I might redesign the main chassis. It’s beautifully compact but yes, it probably needs an adjustment to account for the weight.

Interestingly I learnt about tightrope walking through a novel which as part of the story explained how the physics of it works. Basically you can stay relatively stable if you place the weight further down which makes sense as a low centre of gravity is also what keeps double decker buses stable but it’s fascinating that it helps even on a thin wire. I figure if I experiment with boat weights towards the middle and slightly below the hips then it might help maintain the balance, it should provide a big help to the spindly legs.

I’m still here, life and educational has temporarily got in the way. I should be able to get back to it in a few weeks, in the meantime i’ve been having ideas. Believe me, I won’t stop working on this. As it stands right now my main concern is actually fragility, the 5L half beams that connect the legs to the cams are too fragile so i’m going to have to replace them with an alternative. Please also feel free to use this topic to discuss your own project and what got in the way and such. There may be designs that can come from the discussion.

This is exactly the video I’ve been referencing for the entire project it’s been a massive help.

I have succeeded in reducing the balancing issues by simply placing a 2x1 plate with rail underneath the innermost toe of each leg, this offsets the legs lean somewhat but it’s still precarious. Of course this means that the feet aren’t completely flat on the ground, it’s a cheap and easy fix, might have to place rubber pieces in the feet too as they tend to slip on smooth ground. I’ve also been working on the neck bending so it bends in two places, this is nearly finished and has significantly increased the rigidity of the head and assists with the balance. All that remains is to install the motors and place on the bodywork then hopefully it will work. The springs appear to be able to support the weight, let’s hope they can support some more.

I’ll order one (or a few) and see, if it turns out not to work I may just consider it an acceptable “loss” for the project. After all it still stands up and likely walks (once motors are in place) it just leans.

Ok so having worked on it some more I am being defeated by balance. Naturally it’s a little wobbly and when a leg lifts up it has a tendency to lean towards that direction. I’ve attempted to counteract that by experimenting with the head placement and so far landed on this angle as the way to support a lifted front leg. I was hoping to add a head movement mechanism which alternates the way the head is facing to shift the weight when one side has a leg lifted, unfortunately this angle is not ideal nor realistic. Note this problem is only a problem with either one of the front legs raised. A less extreme angle is enough for the back legs. the head The feet position.

From what I understand the 1x4 spring missile blocks are essentially just a spring held in the middle of a block, when you insert one of the long translucent projectiles they push against the spring and the little stopper built in to the projectile holds the spring in tension past a certain point, when you push down on the projectiles “tail” the stopper is moved downward away from whatever it is caught on and the spring expands again to shoot the projectile out. The mechanism i’ve made slides along three axles, one red at the bottom and two cream at the top, when i pull on a 4x2 technic L beam which is connected to the two cream axles, the mechanism is pulled backwards and the projectile is pushed into these https://brickset.com/parts/4630114/cross-block-form-2x2x2, specifically the slopes part which causes them to press down and shoot out. An elastic band pulls the mechanism back into place afterwards ready for reload.

I did it! It took a few days but it is compact and works well while also being nice and secure. The first iteration worked similarly but this version I moved a few things around to make room for the three minifigs I wanted to have inside the cockpit. Loaded: Pulled: (tried to include video but can’t get it to work)

Apologies for the late reply That’s something I hadn’t considered, I could have a play with that concept, though I wonder as it would be on a smaller scale that the pieces would have less flexibility due to being secured closer at each end (if i’m thinking of an axle for example). Like build the head around the mechanism? That’s a possibility, it would certainly provide a more secure connection.

I’m currently working on an AT-AT project using technic for a movie accurate walking mechanism and I also want to incorporate a somewhat movie accurate missile launcher. In the movie when an AT-AT fires it’s “chin weapons” the cannons recoil backwards (you can see this here): https://m.youtube.com/watch?v=wfuRpZAcTJk I’d like to see if I could implement that motion to trigger the smaller 4x1 brick spring loaded missile launchers which came in 75054 AT-AT (the set i’m working with). However as you can see the space below the head in this model (a recreation in bricklink studio by someone else) is fairly small: https://file.bricklink.info/19/797/797807.png I’ve been through a few iterations but nothing really any good and i’ve seen some wonders in compact mechanisms here so I thought i’d ask for some help.

I am nothing if not dedicated to my goal of destroying echo base.

Progress of today, finalised the connection of the gearbox, built the rear panelling around it for a more compact length, attached the legs and began adding the stoppers in a different position. Once I attach the head mechanism for balance, the xl motor and AAA battery box it should be ready for testing next weekend or possibly the one after that. Final stretch!

Thanks, I was motivated by the tedium of reconstruction :D I should add it has made the top of the structure a little wider but this is not a worry as it only 9 beams wide and does not affect leg movement or bodywork, in fact it actually provides more attachment points, hoping it makes things easier as a result

Okay so I added/am adding a feature that enhances the mechanism somewhat, this required removal of the legs but essentially makes calibration of the lego positions much easier: As i’m sure you’re all aware, working with worm gears requires keeping them strongly held within a tough frame, unfortunately however that means it’s a pain to adjust their position if you find something isn’t quite right. Now, with this small gearbox system allowing me to unite and separate the drive from one of the pairs of legs, I can freely rotate one pair to adjust their positions slightly and perfect the movement of the legs relative to each other without taking things apart to adjust things. Perfect. Secondly it has caused me to strengthen things even further and thirdly it does not take up much more vertical space. Win win.

It breaks up the monotony of redesigning the system each time I run into an obstacle. But also as the key problems have been fixed (the feet that are not raised being flush with each other on the floor, the strength of the springs to hold up the weight) it (the mechanism) is essentially finished, in the pic below you can see it was nearly there before I had to fix the aforementioned issues. I reckon i’ll get it walking next weekend. Balance ✅ Strength ✅ Bend ✅

It is great to finally be adding bodywork where the shape and design is somewhat a good compromise between accurate and possible (what with the gears and movement being quite limiting). Admittedly I did not work very much on it this weekend as I was working on another non lego project. So this much progress in such a short time is good.

Thanks, though i’m afraid from what I can tell the gait is the same as the other lego motorised AT-AT. But I have news. So I ran into a problem where the positions of the feet were not at an angle such that all feet that were supposed to be on the ground at a point in time were not flush. I have since changed that, the mechanism remains similar otherwise. I believe I am on the last stretch though to getting a moving machine. I intend to use the head turning left and right for balance too so that mechanism will have to be made. Progress though, is happening.

So i’m using the 75054 AT-AT set. But i’m making adjustments to make it more accurate (more cockpit space for example). The goal is once i’ve finished the mechanism to isolate all the pieces that come with 75054 and then only use those for the body (i’ve made a more accurate version before just from said pieces). All the while making sure weight distribution is good