Krzychups

Hi! Here is a film: Here you go. They have holes for RC shocks. Unfortunately, I have noticed that holes for ball joints on 3D-printed wishbones wear out over time. At the moment, they are still working. Well, I use the ESC without the FC. It's not needed for driving. I only use the FC to program the ESC. Please direct such questions to @janssnet; he has lots of experience with iWD cars. An iWD RC car is a good idea when it comes to you, I think. Unfortunately, I've somehow broken my Geekservo... Thanks!

Hi everyone! I've finally menaged to make an in-wheel-drive Lego RC car! I use the Hobbywing Xrotor G2 45A 4-in-1 ESC and 4108 drone motors. The start-up is very smooth, it has outstanding acceleretion. It's silent, you can only hear spinning tyres. The car is very stable itself. I use soft tyres as @Aurorasaurus has suggested and they absorb some of the overload. Suspension has a super damping, it works great! The car has a tendency to brake suddenly, so I cannot quickly slow down the throttle. When it comes to the suspension, I use 80 mm Injora shocks, 3D-printed wishbones and motor hubs. I designed the beadlock rims so that they have two parts that screw together. It's not the best rim design, but I didn't want to glue the tyres. Regarding the front hubs, I use HSP 02038 ball head screws. Other photos: I'm really pleased with the car. There's a mess with those cables, not going to lie. Maybe I'll tidy it up sometime. Unfortunately, I don't have a video. I'll upload one in the near future. Really nice gearbox! Why one of the gears has such a non-standart hole? @gyenesvi, good job with your motors! @vergogneless, I really like your car with 3D-printed parts. I'm sure that this will help with the car's durability. Isn't it a bit too much of 3D printing for a Lego car?

@keepbricking, I'm afraid it won't be as you want to. I'm not sure if you want to 3D print them or CNC them. If you need CNC parts, they need to be specially designed. I don't have such .stl files myself. Unless you want my amateur technical drawings of the U-joint that I made once. I guess you have 6s battery because you use it for your drone(s). In my opinion its better to have 2s or 3s. You will destroy your bricks. @janssnet, regarding your 1/10 scale chassis, what tires and motors do you use? On my side I have 4108 bl motors and they're too big for 1/10 scale tires... I'll get back when I'll have my iWD car ready to show.

Really nice RC car. Curious to see what will come of it.

Nice! I wonder if the problem is that the motor casing can become hot and melt, as well as restrict motor cooling.

Hey, these wheel hubs have a 0.5 stud offset, which makes setting up the suspension more difficult. It's almost impossible to build a four-wheel-drive vehicle. You can only build a rear-wheel-drive vehicle, and you would need to cut drive shafts which go to the U-joint. These snips are enough to cut them. Personally, I prefer something different wihout this offset. I once worked on a project involving hubs without offset, but I abandoned it because I need steel U-joints. To clarify, there are two types of U-joints available on Aliexpress: steel (which I need) and aluminium joints (the ones in the photo). They are sent randomly. I don't want to buy more. Steel joints can be threaded, aluminium ones cannot. PS. Thanks @Aurorasaurus for your reply, I'll use non-TPU rims.

@vergogneless, good work! One note for @gyenesvi: If you want to use thicker wires, I suggest buying the AM32 ESC without cables. I haven't been able to unsolder them from my ESC. Im my opinion what you should buy is: the AM32 ESC (like this one) a small connector for connecting the ESC to the PC; a capacitor (470 µF 25 V is soldered in the ready-to-use AM32 ESC); another random ESC from which you can take cables to solder to the AM32 ESC.

Hello. I've bought parts for my new iWD RC car (motors in wheels, exactly what @janssnet has done) and they're currently being shipped. Can't wait to test it out. Since each motor is in each wheel, I have an idea how to transfer part od the load, for example during jumps - TPU rims. I have no experience with this material so I'd like to ask @Aurorasaurus. Do you think that this is a good idea? What TPU hardness have you used for your rims? What do you recommend? I think something about 95A - 98A. How the car behaves while driving? Or it's better to do something different? Thanks in advance. @Tup4n, could you show us closer this metal gear? Interesting how you can connect it to the shaft. I've modeled my transmission on this one you have. Unfortunately your transmission isn't covered. Why the designer doesn't use smaller 11 tooth pinion instead of 12 tooth one? This way, a smaller spur gear can be used without significantly changing the gear ratio.

Really nice RC car, I like the whole look of it. I appreciate that you have built a chassis with a 2-speed gearbox and how you have dealed with locking diffs, even if they don't work properly. I have also tried, but the gearbox haven't worked well, there have been a lot of friction. Regarding the diff locking system, I've tried with small SG90 servos, but it hasn't worked as I've wanted. Finally, I don't have these functions. It's better for me to drive without the thought in the back of my mind that something might not work and break down. The weight of your vehicle is similar to real trial RCs (RC rock crawlers). In extreme cases, they can weigh up to 4 kilograms. I wonder how these little springs can lift the whole chassis. Your front and rear axles are massive. I don't say that they're bad, but how about @HorcikDesigns's 3D printed live axles parts? And this is where we reach the limits of LEGO bricks and 3D-printed parts. Not everything can be done with them. But on the other hand, this starts to be a departure from LEGO bricks and a bit of improvisation. At this point it's better to go into normal RCs, I think. What do you mean by this? Could you show us how you have done it? I generally usually use M3 screws. I wouldn't put a lot of metal parts, because it will stress on other parts and potencially break. Could you show us how the chassis looks wihout the bodywork? I wish we could meet someday and drive our models together :D

I agree that the suspenion is too stiff. So far these are the softest springs I have. Maybe with a bodywork this problem will be less noticeable. And yes, it is not always easy to see how hard is the terrain to drive. I'd say that the chassis is finished and the bodywork is in progress. It's all about 3D printing a few panels as I don't want to buy them. Yep, they're the with ball bearings and for diff lock, but I don't have diff lock since my idea with the SG90 servo to lock them haven't worked. Gears were skipping and it's plastic so it can break and you drive it with a thought in mind that it will soon break. I've showed my idea on this forum in this topic before.

Today I was in a forest with my crawler. Here are some photos and films. It has live axle suspension with the Panhard rod at the rear and 98 mm diameter tires The final reduction is about 1:48,5. I use my custom reduction for the A2212 motor (this one is 1400 kv) and a transfer case. It has no diffs. The RC servo is used for the steering instead of the geekservo. I decided to use this one because I had had some problems as skipping gear on the gear rack and the whole steering was placed low so the ground clearance wasn't good. I've modified one of HorcikDesigns' live axle part to mount it. For the hardware parts I use a 3S battery and the AM32 40A ESC. I really like how it performs, it does serious offroad. Unfortunately, I've melted one axle by trying to climb that steep hill in the photo above :/ In conclusion, a lot of 3D printed parts and fun! PS. I'm sorry that I haven't finished the differential case yet.

What a nice RC car! I really like it. How about making brushless vehicles in bigger scale? Does toe out cause any problems with maintaining a straight line while driving? From my experience toe out causes that problem with RWD cars. Or in this scale the problem doesn't exist?

Well, I have some problems with extrusion in my 3D printer. Sorry for that.

I'll upload some photos in few days' time, as I'll have a new filament. What exactly do you mean by new shapes/sizes? I can make other parts, but I use parts that are from sets made by someone who is mentioned in the description. These LEGO sets are quite old, though. I would treat these parts as panels to be printed when someone is missing them or they don't come in a particular colour or are not very available. You can also experiment with TPU. This is a flexible material. As I have no knowledge of this material, there is little I can say.

Hey! I've made 3D models of the panels for 3D printing if anyone wants to: https://www.thingiverse.com/thing:7043525/files. I also recommend things made by this person: https://www.thingiverse.com/ionnight/designs.

M3 DIN 7991/ISO 10642 - hexagon socket countersunk head cap screws. I don't know the lenght. You can also use DIN 965/ISO 7046.

For prototyping nylon doesn't make sense. It's quite a hard material to print. At the beginning I had a problem with adhesion. You need to have good adhesion, no air movement (closed enclosure is recomended), direct extruder which can reach high temperature (250-270 degrees Celsius). I'll probably print only adapters to the axles from nylon. Nylon is very durable and heat resistance itself. Polycarbonate is an alternative, but I don't have knowledge of it, it's also a hard material to print. I don't say that it's a must-have, you can use other materials.

Cool! @killerfrost, does your wheel hub for metal cv joint have any offset? If so, the pivot point won't be aligned. Anyway, good work. Well, I've printed 3 versions of the diff housing and nothing of them work properly. When I screw the housing to the 5x7 frame, the diff doesn't turn. Probably wrong tolerances. Now looks like this:

Search this and look at the photos on Ali:

Thank you. I can, but you will need a another gear. This gear comes with the differential, so it may be quite expensive. For axles, I use Lego axles with connectors and metal u-joints. I use a 3s battery. I remember breaking one of the Lego 3L axle connectors and twisting one of the axles up with this mad torque.

Sorry, that was the previous version before I've bought planetarny hubs. I've build it just to play with it. I won't use it anymore in a new RC car. Instead I'll use my special gearbox to attach the motor (similar to HorcikDesigns' A2212 gearbox, I've modelled it on this design: https://cults3d.com/en/3d-model/game/brushless-motor-for-technic-jlt ). There's no point in paying over the odds. I'm not ready to publish it yet, but in the future I'll do so. Can I ask why? What's the purpose? Looking forward to it!

Thank you @Krxlion for your reply! The 40A ESC looks very small and it's also much cheaper. I don't think I'll use stronger motors than the a2212 BL motor in crawlers, so it will be suitable, won't be? Are there any bigger differences between the 80A and 40A ESCs? Regarding my crawler, I was faced with the question of whether to buy this ESC. As I wrote earlier, I really want to be able to control the model accurately at slow speed. I only need to rebuild my crawler with planetary wheel hubs and make different transmission. Now it looks like this: Well, it's a bit dirty. It a sturdy and simple chassis. Looks much better than before. I expect to build the first prototype in no more than 3 weeks, but I'll have to wait a while before testing it in a RC car.

Hello everyone! I'd like to share the results of my work with you. I've done reverse engineering. It looks almost like Zene's differential, maybe with some small changes. Instead of metal adapters, I'll print them from nylon (the black parts). I highly recommend printing from strong material. The final cost is about 4 times cheaper than buying the differential from Zene. The needed parts are: the 3D printed adapters and housing, 4x M2x10 screws and 4x M2 nuts (you can use different types of screws, but the max head screw diameter is 4 mm), the differential, 1x M3x3 DIN 913/ISO 4026 - hexagon socket set screw with flat point, 2x 12x8x3,5 mm bearings (they comes with the diff) and 1x 15x10x4 bearing, the 4 mm diameter metal rod cut to about 11 mm with a flat surface on one side. By screwing the hex socket set screw, you lock the shaft with the attached gear. What type of grease should I use to lubricate the sprockets and is there any point in filling the diff with rc silicone oil? I'll share the stl files with you. So, what I need to do is to buy screws and other parts! What do you think about it? Cool!

Can you link these axles? Thank you. @Krxlion, I would also like to ask you about the AM32 ESC you have. Do you have the the Rhino ESC (it's expensive) or cheaper substitute? Can you see much difference between normal ESCs and this ESC? How does it compare to driving a RC model? I'm very tempted by the possibility of controlling the model precisely at low speeds.

Thank you! Is this a differential for any Wltoys RC car or a HSP part? It will make it much easier for me to search for such a part. I think I've seen differentials like the one pictured, but they often don't have the dimensions given. I also see that the gear diameter is 27mm, which is more than 3 studs (24mm). The Zene's differential is also a bit taller than 3 studs. I'll see how to do it.