2GodBDGlory

1. I decided to go with one independent motor per (rear) wheel because I wasn't using any differential, and having no mechanical connection between the wheels allows the inner wheel to be forced to rotate slower when steering. It's kind of a low-tech alternative to a differential that saves efficiency. I guess which drivetrain you go with will depend on your priorities for the car. If you just want it to go fast on level ground, I would probably suggest RWD with one motor per rear wheel. If you want to be able to do mild off-roading but still have lots of speed, I would go with RWD with the two rear motors hard-coupled on the axle. If you are willing to sacrifice more speed for off-road ability, then you could go with the 4WD, though if you're actually hoping to do more crawling, you might want to find a way to hard-couple both axles together, so that even if only the rear wheels have traction, they still get the torque of both motors. 2. That sounds like an interesting electric setup! Do I understand correctly that you're running a lower-voltage battery into the IR receiver, and then using relays attached to the receiver's output to control the motors from a higher-voltage battery? That's cool! My setup is very custom and hacked-together. I've got: Custom 3D-printed housing with 3 18650 cells wired in series Controller board from an RC car (bought cheap from a place that sells replacement parts). It's not really a standard RC controller; it's just what came with this one car my brother had that was somewhere in between a cheap toy and an expensive hobby-grade car. Two buggy motors wired through heavy-duty plugs I pulled from some old hoverboard parts Controlled by the controller matching this circuit board Then, my steering stuff is on a completely different circuit, because the 11-12V of my batteries seem to fry the servo control stuff on the control board! It has: ~6V battery pack from this RC car system (Formerly 9.6V, but one of the three cells is dead) Second, identical, controller board from this RC car system PF L-motor connected to the positive and negative wires of the steering system Position sensor from original RC car servo motor in 3D-printed case attached to steering system and the other three wires of the steering system. (This RC car had a non-standard servo system that would just read positions from a sensor and use that with a controller in the main board to tell a basic DC motor which direction to rotate) Controlled by a second, identical controller, making this a two-handed job!

That's a tricky one. Do I understand that your parameters are: 1. No PF-style Servo motors 2. No continuous stalling of motors and 3. Return-to-center steering? If so, there's not much I can suggest... One option (that requires spending money!) would be to buy a GeekServo, which is pretty cheap and offers nice, more reliable control, but requires a hobby RC-style controller. Here's a link to a place to buy one: If my inferred parameter #3 isn't actually crucial, which seems doubtful given how fast your car sounds, you could always try just putting a good 1:8 or 1:9 ratio between the motor and the steering rack and just forget the return-to-center steering, but I doubt that'll work well.

Yeah, I think two buggy motors in an axle could work well! Nice battery pack! I recently built myself one that's essentially the same, a 3S 18650 pack, which I've been using with two buggy motors, one on each rear wheel. One tip: Don't stack the buggy motor plugs, or the high current will likely melt out the plastic around the contacts!

1: 10 3: 6 5: 4 4: 3 6: 2 2: 1

Nice MOC! It looks well thought-out, with all the functions you'd expect, and good looks, despite being an alternate model! My favorite parts are the use of the gear bracket for the joystick and the large 2x2 pistons in the spirit of the original!

Only in the 9V range, though, right? I wish there was a way to get the full 11+ voltage output Lego motors can handle with physical, proportional control. It seems like you can't really get all three of those together as an integrated system, so Buwizz + BC2 is really the best it gets. Buwizz is too expensive for me, so I'm still waiting for China to come up with something!

Nice little tank! I love seeing the applications of those compact CADA electronics, and the torsion bar system is impressively compact! I'm a fan of the way you use non-Lego parts in unique colors to make your cars look better, but my one critique here would be the use of non-Lego parts where there are exposed studs, because I have a hard time not associating those bare, flat, logo-less studs with the lousy knock-offs of my youth... Though on the other hand, I probably wouldn't worry about it if I were in your position, because I too like saving money!

I think in general I'd agree with you that PF has more versatility, and it's definitely the system I prefer all-around; I just think that your model in particular could really have benefited from some of its unique features. Though, now that I think about it, with seven motors and two sensors, you'd need nine ports, which puts you into three-hub territory, which would be seriously annoying. Though, on the other hand, I suppose you could get rid of the servo for controlling forward/reverse, (since you could probably do that in the code) getting you down to eight ports and only two hubs, which sounds reasonable. I'm definitely not suggesting that you change it, though! I think using PF must have made for some extra work without major practical advantages, but does make it a significantly cooler model from a complexity standpoint! I love seeing those WeDo sensors actually being used in an RC MOC!

Looks to me like it would have to be a 23L to go all the way through. 1 on the far end, 6*3=18 for the stuff inside the screws, and 4 on the near end would make that. I think it's more likely that there are multiple axles inside the screws (Perhaps they've only got holes 1 stud deep, and are just connected by 2L axles), and the blue on the end of the screw is just a standard friction axle-pin going into the red part, with (presumably) one of the black pin+2L axle parts going from the red part, through the brick, and one stud deep into the screw. They do look like very interesting parts, though! It would be nice if the sliding part that meshes with it were a bit more Technic-compatible, but it shouldn't be a big deal.

Very nice MOC! I love that you managed to build a Tesla MOC that is actually innovative (In the spirit of the originals) while maintaining the direct drive. I also like the way you accomplished all the functions within the PF ecosystem, using the WeDo sensors and 8878 batteries instead of PU, which I imagine would have made it easier. The torque vectoring is very cool too! Overengineered, yes, but that's the point! The aesthetic is nice and clean, and the trailer is massive! Good work!

Very nice job! That lifting roof and the motorcycle lift are both very interesting functions, the look is great, and it's got to have about the most detailed interior of any Technic model I've seen!

Space sounds fun, but I'm not particularly interested in the modular car one. I guess I'm just sick of building cars at this point!

I guess this is a problem Lego already solved back in the day with wheel covers for their Racers sets, like this one: https://www.bricklink.com/v2/catalog/catalogitem.page?P=85969&idColor=11#T=S&C=11&O={"color":11,"iconly":0}

Ok, sounds good! I missed the fact that you'd already built and tested it, so I'll assume it's good!

Nice work, that looks like a very fun model! I do worry about that gearbox though, especially the new differentials being used. I'd imagine they'd wobble a lot because they don't allow for the axle to pass all the way through them, but hopefully it works fine!

It would honestly be really interesting to have an active cooling fan do anything on a Lego model! I'm not sure if it could be made effective enough to work well with high-current plugs, but it'd be cool to try. I just upgraded to heavy-duty plugs ripped out of old hoverboard parts I had lying around, which is a reliable but boring solution...

Nice work! That's a nice recreation of a classic set, with some nice usage of specialized large parts for the engines and hatch.

That is a pretty cool outrigger system!

Maybe we should switch to some other thread or PM after this, but I've never found the wires to be the weak link, always the plugs. The PF plugs just have one small contact, but if I remember correctly the 9V plugs have two contacts per side, so you'd think maybe they could get close to double the current. (Though they're also close enough that they might share the heat a fair bit anyways.

Oh, interesting! I wonder if the old original 9V plugs would hold up to higher current any better than the PF-style ones on my Chinese motors.

Yeah, they are running at 12V peak, but I don't think that would increase current. Though I suppose it might increase heat for other reasons? It would be interesting to directly measure the amp pull with my multimeter; maybe I will soon. It is likely, though, that the 2.8 was just too much for the connector...

Yeah, I was wondering about that too. In my case, the problem might have been that I was running two buggy motors off of the same plug, which would double the current there, but in general I'm not sure. According to E = IR, given a fixed voltage no higher than Buwizz outputs, and an equal resistance from the motor, the current ought to be the same, shouldn't it?

It would definitely be possible, but at some point you might have to worry about having high current melt down the wimpy Lego plug. I ran into that recently running two buggy motors off of one plug off of an RC car controller on a 3S lithium battery, so I had to solder a beefier plug in in parallel with the Lego one.

Or maybe have a short piece of integrated rubber hose attached to the check valve would help, since that way it would be impossible to put in backwards if the rest of the instructions were followed.

Phew, it's getting hard to keep track of all the new panels! It'll be interesting to see a small-scale "W16" engine. Interesting that they have such prominent Lego stickers on it!