Didumos69

I hope you are using this LXF-file. It has groups resembling reverse engineering steps. If you delete all (sub)groups from top to bottom (depth first) up until the last subgroup, and then restore them one by one with Undo (Shift-Ctrl-Z), then you will be able to follow the steps I used to build it. However, some steps are quite big, for example the front axles and the rear swing arms. The Servo's center position should be flat center. It can happen that your Servo is not centered, you will have to use it to make sure it centers correctly. The whole steering setup allows for perfectly centered steering. The Servo output axle should have a zero degree orientation when the gearrack is perfectly centered. The steering setup does not allow for a complete 90-degree Servo-rotation, so it does not use the last steps of the Servo. Building the rear swing arms without stressing parts is possible by using some rotational steps. I will show this in my photo instructions later.

A real LSD is open by default and only 'closes' when one output axle starts consuming practically all power. Both attempts in this thread show differentials that are not open by default. In fact they are closed by default and only 'open' with enough torque difference. This will never work in real life: Assume one wheel on a surface with full grip and the other wheel on ice. Now imagine the level of friction the rubber bands would have to induce to avoid slipping of the wheel on ice. The level of friction would need to be so high that the engine won't be able to overcome that friction. You would need so much friction that you can hardly speak of an open differential at all. The result will be that in turns, with both wheels having grip, you get wind-up etc. Not good.

? Okay, I fully agree. And in that case I think 'aircraft competition' is a better term than 'flying machine competition'.

I'm a bit confused though. What do we mean with flying machine competition? Build a model which resembles an aircraft, or build something that can actually fly?

+1 for something flying I have a pre-study already ;-)

Completely agree. I can imagine for really small models chassis's can be built from connectors only. In that case the offset problem isn't a real issue and relying on friction locking isn't much of a problem either. But in bigger builds beams are essential to form-locking structures and also essential in providing exact spacings. Both are important in reducing slack and friction, and in preventing slipping in case of structures that support moving parts or gears. To me, it all starts with a good structure and thus with beams and frames.

I would like to see an invention contest. Build a model of whatever system with a completely new and authentic approach to one of the essential features of that system. For instance a completely different approach to a gear box. Or a revolutionary approach to makng a robot walk. Anything. I would like to see what the iinventors of this forum are capable of. Who knows we'll change the world with a real invention.

Yes. I'm slowly waking up from my Summer break and this will be the first thing I will start working on. It's here. Thanks! Btw, Stud.io 2.0 makes very nice photorealistic renders .

I didn't like the idea that the belt wheel tires played a role in the overall suspension hardness. So eventually this is what I did to avoid the unintended negative camber. I once again updated the digital files (LXF, LDR) to reflect the changes.

This is the main leftover of what I built when I was a kid. It must be over 35 years old. It has rear wheel drive, independent suspension (reinforced with torsion bars), Ackermann steering and a fake V4 engine. My first builds after my dark age are about 4 years old and my kids still play with them (the red model is a heavily modded version of 8845). Both models have torsion bar suspension and Ackermann steering.

After two month without LEGO I took my Greyhound for an indoor drive and had a lot of fun again. But there were also a few things that bothered me. First of all, the rear suspension feels a little too soft and while driving, the rear suspension arms show quite some unintended negative camber. Secondly, although I did not have much trouble with the front suspension, it is clear that the front wheel hubs remain to be the weakest point of the whole build. The problem is that the vertical thin levers from which the hubs are built, are not form-locked, they are only (heavily) friction locked. So I took a look at what I could do about this, without making any consession to suspension travel and steering angle. Eventually, I managed to solve the issues by adding some silicon bands and belt wheel tires. Not very elegant, but it works. I also reinforced the front suspension arms a little. After making the adjustments, I made an indoor endurance test drive, during which I drove over all kinds of obstacles, like shoes and branches at high speed and low speed, over and over again. No problems occurred, nothing fall off or got displaced and the rear wheels don't show much camber anymore while driving. This is what I did: The changes also lift the tail a little, which looks better imo. I updated the digital files (LXF, LDR) to reflect the changes.

Yes (see the post below), and it has been included in @jb70's Pimp-up-my-Bugatti MOD.

I abandoned the IOS BuWizz app, because it disconnects all the time. For me it works fine with Android BuWizz app on my phone, but only on first connection. On a second connection it takes many attempts to connect to both BuWizz's, so I power off the BuWizz's instead to setup a 'first' connection again. If this doesn't help you, you could try asking in the dedicated BuWizz thread. Thanks! I was hoping to find time for making photo instructions before the holiday season, but I didn't. During the summer I'm too much occupied with other things, like camping with my family and cycling in the mountains. I sure will be making instructions, but probably not before the 1st of October.

Lego is all about making 'models'. And to me 'model' means: Simplification of a system (or thing) that brings about one or more aspects of that system's (or thing's) nature. Models allow us to zoom in on certain aspects while leaving other aspects out. So it's all about what exactly do you want to tell with your model. That being said, to me 1.) reliability and 2.) recognizability are key. 1.) Both static stuctures and technical functions need to be reliable. No parts falling off, no functions that only work under specific conditions, no displacements caused by normal use. 2.) A model does not need to be a replica of a real vehicle or machine, but I do want a model to be recognizable as a specific kind of system, for example a supercar, a telehandler, etc.

It has only one speed and uses only 4 gears for the entire transmission.

I read about the original concept coming from Lego Technic Mastery, but having a concept is one thing, making it reliable and incorporating it in a model in a way that makes sense is also a big challenge. And in this case the incorporation has been executed excellently. So to be more precise: I love the shifter concept and the way it comes to life in this build.

Very intriguing bike and I love the shifter!

Yeh, the marriage process does not cause lag, but it can introduce friction like @Scot-e-dog assumes. @kbalage is right about the lag. If you take into account the number of gear meshes (engine to diffs) directly involved in each gear: R::4, 1st: 11, 2nd: 15, 3rd: 11, 4th: 15, 5th: 13, 6th: 17, 7th: 13, 8th: 17, you see why. Earlier in this thread we have shown that the gearbox could do with 2 less meshes, which reduces lag. This mod is part of @jb70's pimped up version.

Thanks @BrickbyBrickTechnic! I agree with @Jeroen Ottens. I will try to fit the liftarm version in the rest of the chassis.

This is so cool! I'm proud to have provided the platform for this postapocalyptic monster. Could you share the details of the planetary gear reduction?

Superb bodywork and great functions! Chassis-stiffness comparable with 42056 makes me less enthousiastic, but I guess you had to make some consessions to live up to all other objectives, like versatility and modularity. And a center console of only 5 studs is a great achievement too (actually, a must-have in a 1:8 scale car imo).

I don't and I can hardly imagine this has anything to do with the way these parts are used in the limiter (I assume you use (oo)-pieces and not (xo)-pieces). The axle-holes of these cross-blocks are designed slightly too tight, to keep a firm hold on the axles inserted. It might be that having an axle inserted for a long time causes enough strain to cause this kind of injury.

Thank you very much! It's on rebrickable now. I have been thinking about putting a more advanced gearbox (using the new parts) in my rugged supercar too, but I fear I will only start working on a serious project somewhere in October or November. I find it hard to grasp what is going on here. I will study it later. Do you have a digital design?

In step 5 a blue 3L pin is installed, but I think it's not needed. I don't think it was in my LXF-file. Would be nice if you could remove, but if it's too much hassle than we leave it like this.

Great! If you're okay with it, I will use these instructions to put this one on Rebrickable, giving you credits for the instructions of course. I followed the instruction steps and everything seems clear to me. Only the way the silicon bands are wrapped (with a cross) is not completely clear. Perhaps an inset with a real photo would help? This is the best shot I have. Could you show us a screen-shot of the unfinished work. You're making me curious. Could you make a photo or video. Would love to see it. In your video it appears you need slightly more than 45 degrees to disengage, which would mean there is a small chance of having double engaged gears. However, my experience from playing with 4-speed gearboxes is that this really doesn't happen.