1980SomethingSpaceGuy

It looks nice ! Especially with the roof on, IMO. NPU of the side panels around the cockpit! Maybe you could find a way to get the headlights a bit smoother (lower)? I would have some ideas but I don't know if you have those parts in orange or if they even exist in that color..

I reckon Jim is getting more and more tired about tires. Next TC will be boats..

Lovely little one! Congrats!

That steering wheel needed more grip. The size of the seats was a bit off. Because of the size of the gearbox, those still are a bit to high and spread apart, but there's not much I can do. Also, since I let my kid play with it, the front needed to be a bit stronger. That brought me to this: Full independent suspension, steering, gearbox, fake engine, check. We've seen a lot of mini fake engines lately. I think it makes sense if the objective is replicating an existing model, but when building freestyle, I prefer the classic one. I rather have a crankshaft and rods than lots of over-simplified cylinders. The number of cylinders then becomes the measure of size of the engine block, rather than matching the count of cylinders in a typical engine of a similar real life vehicle. I'm old school Technic maybe.. With that large differential, wide tires and no specific suspension parts, I'm not sure I could put the seats a lot lower without expending the wheelbase. These constraints and the result they produced are somewhat comparable to a 1920s car, so I think it's telling me it wants to be a hot rod. Now I can move to body design!

I was not satisfied by this rear axle and the pullback motor solution. I figured I needed more Technic: independent suspensions and a gearbox. So I reconsidered using longitudinal swingarms and a fake engine. This is was I have now: It's sturdy and everything works fine.

I'm sure this counts. I love the challenge!

One more white rubber band to center the direction, correct rear suspension setting, a couple of seats, a steering wheel, I think I have a chassis! Just for fun, I've cast a few panels on it. I don't think it's going to look like this in the end, but I like the simplicity of it.

Smooth! I like it.

Way not enough torque for that! But I guess it's called "up" indeed, since usually we care about the motor and start counting from that. You're right. I meant I geared down the back wheels to the spring to get a long push instead of a kick. But it's not working well, it barely moves. I'll try other ratios, cheers! Edit: I tried different ratios and the best is.. 1:1. A bit of anticlimax, but well... I assembled both axles and this is current state: I now have to decide where I'm going with this. My idea was an electric race car.

Notice how I geared down the motor? It's not going to jump like a rocket. It's more pacing. But indeed, I'll probably need the steering to return to straight on its own (rubber, spring..) No problem. Only challenges!

Thanks! I seize the opportunity to tell you I love your work. Especially the P38. One of my favourite prop planes IRL, and you really nailed it. So it seems. But that's what I like building Lego: trying new stuff. I find it more frustrating to copy existing solutions than seeing my experiments fail and having to restart. Yes! Thanks! The only ball link arms I have at hand just don't fit, so I have to be creative. It works surprisingly well! Yesterday, I lowered the rubber bands' top attachment point one stud lower because the suspension was a bit stiff. It's even better now. The vertical 3 studs pins (the ones with their middle part exposed) play an important role in the stiffness. Yesterday, I started working on the rear axle. The only differentials I have at hand are old school 4 studs wide. They just won't fit between two wide tires and still allow the usual double universal joint axle solution. I could offset the diff and use longitudinal axles, but it made no sense in my mind. So I gave up independent suspension and will suspend the whole rear axle. In order to keep something fun about it, I figured I could use a pullback motor (rules ban electric motors ). I very seldom use them, so why not? This is what I got: It's quite compact. I love when moving parts have so little clearance but still are perfectly safe. As usual, the way the shocks are setup and the rear axle connected to the chassis is only for demonstration purposes. Cheers!

Thanks again Jim for this new TC! I want suspension in my build. So I started with the front axle, seems the biggest challenge to start with. This is what I have yet: The steering wheel is for demonstration purposes, it will most likely be moved, as will be a lot of other surrounding parts. I'll probably the steering on the other side of the axle, gearing it down and taking advantage of this to put some offset. Suspension uses 2 white rubber bands (true Lego), and are fully independent. Since the wide tires are the only ones I have at hand, this whole has to be quite compact, but I'm happy with how it started. Cheers!

Thanks for the organization of this new TC, Jim, that's great! Thanks also to have widened the choice of tires a bit. I happen to only have two 43.2 x 22 ZR, at the moment, but I think I might get 2 more. I really don't want to be annoying, but... I have six of these 43.2 x 22 H. Are these considered balloon? Would they be acceptable?

Yes, it's the roof. I gave it a smoother haircut. It's 1 stud lower, and now tucked by the grey bar behind to flush with the A pillars. But indeed, it's subtle.

I smoothed it down a bit. I think it's better now. Needed to fix that headlights setup too. And that was for our episode "How to make a car without car parts".. Thanks for watching!

Yep ! The small details count. Yeah.. It's neither cute nor aweful Anyway, I enjoyed the journey in RC vehicle design and even if the limited amount of (especially dedicated) parts was quite a challenge, I think I might build something more consistant soon.

This quick build left a lot to be desired. I took some time this weekend to rethink this fellow a bit. First, since I want full suspension and a differential, this is probably the narrowest I can do with my pieces: a couple steering CV joints on each side of a 5 x 7 frame. The steering on the other hand, was a bit tricky. All I have as steering specific parts is 4 of those guys: And I finally figured out why I always had a hard time building something clean with these. They're meant to be used with this fellow: Which imposes the width of the drive train. So I'm using this one instead: The small one is meant to be used with an 8 tooth gear, and the big one width a 12 tooth gear, so they have different rack height to base. Thing is, a quarter rotation (like the servo does) on a 12 tooth gear causes more rack translation than the steering arm can handle. So I need to use the 8 tooth gear on the big rack. Which requires the rack to be offset by some fraction of a stud length. This is the solution I came up with: A double rack to prevent sliding, and 1/2 pins to raise the racks. Building something strong around this was not trivial. In the first iteration, the XL motor was driving the differential directly. The output speed was too slow I thought, so I geared it up. A bit of trial and error was required since the XL motor has quite some torque. Having that figured out, I was a lot happier with my simple RC platform: I then put myself to modular body design. What you see here are literally all of my red panels. I tried to make the most of them. The body wraps the chassis tightly and is held by only 3 pins and 4 axle in holes. A panel on the side lifts up to allow access to the battery switch. I'm a lot happier with it now. I don't think I could do much better with my current parts pool. Thanks for watching!

Well... The motorbike shocks were added after everything else was built because I underestimated the overall weight and the rear proved too soft. Rather than redesigning the whole thing, they were just added on top. It's just a couple hours' kid toy build ;) And indeed, the wheels are a bit exposed.. But the speed is pretty low, which helps!

Very nice! The wheels' size ratio and the engine hood with headlights work especially well.

Edit: current state photo: Long time have I looked down at electric motors in Lego. I had in mind the poor battery life, connector quality and motor usability of my first Technic motor set, 8054. All of these were miles away from the brilliant design of the bricks themselves, which could withstand years and all sort of rough play and keep all of their (friction) power. Plus the battery packs were cumbersome and the very fact that something was consumed when playing didn't match the philosophy, in my mind. I didn't want any more electric set. Years passed. NXT was introduced and I got into it. Being able to program my own contraptions' behavior added a lot to the fun of designing stuff. Then I discovered GBC and I knew I needed a few PF motors. From there, being able to remotely control them for other purposes of course adds to fun, so I why not also get a set with a remote ? Finally, I recently got my first PF servo motor. Just because remotely controlling a motorbike without one makes things a bit too hard. So here I am. With finally enough stuff to build my own RC vehicle. I first gave motorbikes a try, but they need quite a bit of speed to gain stability and there isn't much free floor surface in our apartment. I had to test the prototype outside, and was not very happy with the first iterations; I achieved stability and control, but the minimum speed was a bit high and the lean angle too small. The kids asked each day when they could try the new build. As I was explaining my 5yo daughter that designing a motorbike was not easy; she candidly asked why I was not making a car ? Of course my first thought was "because harder problems are more fun!". And then scraped my Red Buggy to add 2 more wheels and a differential. I only kept suspension on the challenge list and built my first usable Lego RC vehicle. It's dead simple, not optimal on any level, but my daughter loves it!

I finally had some time to publish it. The battery levels, the blanket, the ground clearance of these quick builds, none of these were optimal. But our fun was!

12:10 5:6 9:4 20:3 14:2 24:1

3 + 1 alternated would do the trick for the photo..

With make-do lighting and a smartphone camera, it's kinda hard to rival the digital renders. Still, it's fun to compare!

Can do.. Yes, that was part of the idea.. Put those motors as close as possible to where their torque is applied. And in the process optimize space. Also, in this prototype, the tracks are loose on the ground between the wheels, which kind of defeats the purpose of maximizing ground contact surface, but this could be addressed.