Daniel-99

Great model! I love the shapes and technical part of the car. These time I have nothing to add or remove from your words! Totally agreed! I am planning such a project as well. 1:10 scale is great for RC models, since you can use Land Rover rims and make a realistic steering (which is very important for fast Lego car)!

Yes, there was an RCBricks in the older days and many Lego technic builders in Russia use RC units and controllers to power their cars, since they are cheaper and more affordable in Russia, especially nowadays. The major problem is that their developers can not afford to make a real business of their products yet. All the amazing units and controllers we have for now being made by a single man with a great amount of enthusiasm... I hope we will get ourself a new company such as Buwizz in Russia in the future, but there are no plans about it yet. So there are no products available for sale in the West these days . All I know is that SBrick could be powered by 3S Lipo, if you make a custom connector.

Yes it helps indeed, but the usage of many motors in one car contradict the philosophy of real car engineering, in a way I explained in my first comment. It is impossible to control 12 km/h car with a cell phone on a rough terrain. Likely, there are bluetooth trackpads available which has a proportional control and can used with Buwizz units. Though I had no opportunity to test one of them yet . But both physical and proportional control is not enough to make 20 km RC car controllable, you need a physical feedback. Actually, you you have to seat in the car itself . Nevertheless, it is possible to control a fast RC car on a flat open areas, but it is a little bit boring for me.

Great calculations! I will try such built with: 4 Buwizz motors, slow output 95 mm RC tires "normal hubs", direct connection of motors to hubs via metal U-joint linkage (strong CV linkage). Such setup give a close ratio 95/107 * 5.4/4.5 ~ 1.07 while avoid losses in transmission (friction in planetary hubs, differential). All though such layout provides a signifiant stress on the transmission, so the CV joints will stress a lot under the load (comparing to the layout with planetary hubs). Unfortunately, I will be able to finish these model only in September. So I will report on results later. Agree! The lack of control is significant, and there are several points to consider: A high momentum of a car which drive fast (even bigger momentum of a heavy car driving fast). It provides quite some stress both on the transmission and suspension in tight cornering. A weak steering system. I tried many ways to strengthen the steering system: from increasing the steering arms on the wheel hubs, to the double suspension arms setups... Regardless all the improvements I made, it is all made of plastic, has a significant wobbling (in the connection of a steering rack to steering gear, and in the ball joints of a steering bones). The lack of physical feedback to the driver. It is impossible to control a fast Lego car even with RC proportional system since the driver can not feel the car. Real drivers can hear the noise of the motors, check various sensors in the car, feel most of the bumps and, most importantly, feel the steering wheel resistance (it is well known that of high speed it is harder to steer the wheels). Summing up, it is nearly impossible to control a Lego car which drive over 12 km/h especially of the rough terrain. To understand that clearly, just take a look at fast RC cars which has a tendency to roll over onto their roofs .

You made an interesting research, congrats! I would agree with your conclusions except the second one. Each motor has individual characteristics as well as It`s own areas of application. For example, PF XL motor has a plenty of torque but it is slow. So it is worth to using it in crawlers. But if you want to make a fast car with it you will have to multiply it`s speed with a gearbox, which always takes space, increase weight, has a plenty of friction... Buwizz (Buggy) motor is a lot faster than PF XL motor, so it can be widely used in fast cars. And it was mostly the only "reasonable" area of application for them, until planetary hubs appeared. Combining Buwizz motors with planetary hubs we get a lot of torque on wheels, a reliably working transmission (sipping fast but without big stress). These ideas are agreed with real car engineering. All this was right until you started speak about "high performance". The Weight To Ratio reasoning is very important for real sport cars, and clearly can be applied to Lego models. I am trying to lighten the car as much as I can to make a car with good performance, as well as real engineers does. But real engineers usually does not increase the number of engines in their cars. Yes, there was several two-engine rally cars, but we will ignore them . Engineers try to increase the power of the car by boosting the engine or changing it to a more powerful one. My conclusion from this is the following: If you want to radically improve the performance of the Lego car, you need a more powerful motor. For example, if my car was driven by two PF M-motors, I can upgrade them to PF L-motors. Further upgrade will require Buwizz motors, but what should I do next? I spent a lot of time on this question. My answer to it is the following: Maximal reasonable number of Buggy motors is 1motor per wheel (with minimal number of gears in the transmission, preferably without intermediate gears at all). Further improvement of performance will require a third party motor with greater characteristics, for example one from RC world. Why 4 motors is reasonable? Because real Electric Super Cars use such layout! Buggy motors seems to be the top motors with PF connectors, because PF connectors could melt under higher load (from more powerful motor). So a serious improvment of electronics is required, preferably RC electronics. Further we will need to reinforce suspension, transmission with metal parts. The final result of such upgrades is an RC car in big scale . So if you want a true high-performance car to drive you would better buy yourself a good RC car - it will be faster, stronger, more efficient and cheaper! I like lego RC car and I will stick to them, no matter which limitations they have. Buwizz units and Buwizz motors are great products for Lego cars, which allow to build top RC LEGO vehicles, but they have their own limitations as well as all Lego plastic parts. That is why it is important to understand these limitations and develop new cars very reasonably (balancing between mass and power).

Hello everyone! Finally I made a video:

Thank you! I am trying to get to the "perfection" in the definition your have on your Eurobricks page ;-) Speaking about GeekServo, it is strong enough to steer this 85 mm wheels both in stationary position and on a bumpy road on full speed. Though It is not that fast, comparing to C+ L-motor, and nearly not as powerful (I will present you another car next week with wider and bigger wheels there Geek Servo is not enough... ). So it`s usage in fast car is quite arguable, but after many tests I could say, that It really works for Phantom. On high speed RWD car needs a smooth control without fast oversteering (otherwise it is easy to loose the control!). Also I tested GeekServos in my trial truck (which I am going to present a few weeks later), I increased the steering arm so GeekServo had enough power to steer 105 mm fat RC tires. Such solution reduced the speed of the steering process, but it could be overplayed with two steering axles, as I did. Fast and big Lego cars requires coupled GeekServos per steering axle... Probably I will build such project a autumn. P.S. I see you have an interest to Wixy setup... I will try to make a presentation next week, so do not miss it!

Thank you! Speaking about control hubs... Well, after my Buwizz units drowned I bought myself TWO different Lego-compatible systems from Russian AFOLs. "Leshy 2" - the one you can see installed in the car. It is an analog of Buwizz 2.0 with inverter power supply from two 18650 sells. If one installs high power cells in it, it could convert them into high voltage output. "Wixy" - the one is not widely presented in my cars yet. It is a custom RC controller for PF motors (analog of a controller for RC models), so it can be powered by any RC power supply, in particular with 3S Lipo. With 3S Lipo the whole system became an analog of Buwizz 3.0 but way more powerful (it can supply up to 10 Buggy motors if you get enough controllers). Both systems has it`s strong and weak sides. Speaking about "Leshy 2", strong sides: electronics is hidden inside; you can change the voltage of output from 8 to 12 volts; easy change of batteries and easy to find new one (18650 cells); It has more power comparing to Buwizz 2.0; Precise physical control with RC transmitter; Low price ("Leshy 2" + batteries + RC transmitter (cheap) ~ buwizz 2.0). Great control range (over 50 m); On-off switch; PF outputs and RC outputs in one unit; special controller for lights (see the video with my Phantom); "Leshy 2", weak sides: Big size, comparing to Buwizz units (the size of big PF battery box); It is not as powerfull as 3S Lipo, and get overheated after 5-10 mins of heavy load; Batteries are heavy and can not be 100% fixed inside the unit, so it is not appropriate for fast driving on bumpy roads... Speaking about "Wixy"... It is a small white piece which has PF contacts both on top and bottom and an RC connector on one side. You need to connect the unit to a PF power source (to the bottom connector), plug motors to the top connector and connect RC output to the receiver (to the channel which is going to control connected motors). "Wixy" allows to transmit power from a power source to connected motors form a signal of receiver. It provides a proportional control as well as "Leshy 2". "Wixy", strong sides: All the wirings could be distributed in various pars of the car, so you do not need a big amount of space incide; you can power the car with any RC power source (a special cable from RC battery output to PF connectors included); easy change of batteries and easy to find new one; NO LIMITATIONS IN POWER (for each Buggy motor you need one "Wixy" controller which could be connected to one channel); Precise physical control with RC transmitter; Low price (2 x "Wixy" + battery box + all necessarily cables + mid-price RC transmitter ~ Buwizz 3.0). Great control range (over 50 m); You can use both PF and RC outputs. "Wixy", weak sides: A "slight" mess with wires; nothing else... Hope my comment was helpful to you! P.S. Next week I will snow you my new car with "Wixy" controllers!

I see. I use a superglue from time to time as well ;-) I made my own 4x4 off-roader with 4 PF L-motors powering each wheel. But it has one very weak place - a plastic CV joints at the front axle. I wish Lego would sell metal once! Also It would be so cool to drive both of our cars together ;-) I suppose yours will be a bit faster!

Hello everyone. This is a story of my mid-scale RC baja truck called “Phantom”. The beginning. I always had a strong desire to go fast. For that reason I made my Red Roadster powered by Buwizz motors (See my Profile for dedicated post). But this sport car has one significant disadvantage - it requires a very smooth road! So I decided to build a trophy truck. I learned a lot about trophy trucks made with Lego. Best of them had 2 Buggy motors for propulsion with a direct connection to the rear wheels. So I decided to build myself a similar setup. First trophy truck I designed in big scale (~1:10) but Buwizz motors were struggling with a load from big wheels (and that is not a problem of motors, but a problem of construction). So I made a portal reduction and the problem was solved. After that I build an ultimate dune Buggy “Dragonfly” with independent suspension driven by couple of Buwizz motors. The result was great, Buwizz motors allowed to drive it very fast on 85 mm wheels. So I decided to build a trophy truck with them. Such wheel size is the smallest one which could be used outdoors. Smaller wheels does not provide enough of ground clearance to go full speed on bumpy terrain. Photos. Front axle. I started the build with the front suspension. A technical task was the following: - to use big Lego wheel hubs - double steering rack - positive caster angle - ridged suspension arms I took many ideas from the front suspension of my Dune buggy and tried to make it smaller. Dune buggy used 9,5 L shocks so I decided to change them to 7 L shocks. Also I was able to avoid ball connections, since they struggle a lot at bumpy roads. Here is the result. The steering motors should get connected to the vertical black axe (on the first picture). The key idea was to place steering arms horizontally and in a slight diagonal way. Such placement caused some friction in the steering system, but from the other hand it reduced the wobbling to ZERO! Also there is a 3 studs distance from the connection of steering arms to the wheel hub and the pivot point of the hub (see picture 2). It reduces the maximal steering angle, but strengthen the steering system and make the control smoother! Rear axle. A technical task was the following: - direct mounting of Buwizz motors to the rear axle - Long suspension arms and long travel - Suspension with progressive hardness I decided to make it simple without any articulation, though there was some provided by bending of plastic parts. There are two sets of springs used. Small vibrations of the rear axle get absorbed by a soft 9.5 springs, while hard bumps compress the rear axle stronger, so the set of 7 L springs does their job. Finally, there is a couple of Lego rubber elements which play a role of fenders. So there are three stages of compression. First stage. Soft settings. Second stage. Hard settings. Third stage. Rear axle touches the frame. Frame of the car and bodywork. A technical task was the following: - two layers of frame - use the roof of the car as structural element - minimalistic bodywork The space frame of the car consist of two layers. Roof of the car tighten the upper layer in order to bear the load from the rear springs. The middle compartment is dedicated to power sources. The "new" cross-beams (15L and 11L) were very helped a lot. The bodywork is made with several panels which can be easily detached for servicing the electronics. Electronics. On photos above you can see a custom Lego-compatible RC unit equipped with two high power cells 18650. It provides more power comparing to Buwizz 2.0, but it is not enough for two Buwizz motors. It get overheated quite fast (5-10 mins). One may ask me, why I use it. Actually, the first version of the Phantom was powered by two Buwizz 3.0 units, which provided a plenty of power to the car. But I managed to drown the car at first outdoor driving test! So I bought replacement for them since there was no possibility to purchase new Buwizz units in Russia. Here is the video of an accident: This month I bought a different Lego-compatible RC electronics from a Russian AFOL, it is called "Wixy". It plays a role of the controller for RC motors and allows to power my cars with 3S Lipos! WIth 3S Lipo I forgot about lack of power and was able to ride the Phantom for miles and miles... Conclusion. The car Is made for outdoor driving. It has a decent speed and a good control. Though there are several weak places of Phantom which can not be fixed with plastic Lego parts. The dust is very annoying, especially on county roads! It fills all holes of the car, most importantly plastic wheel hubs. I destroyed all the wheel hubs I own and there is no way of fixing the problem... Also the car has slight problems with ground clearance - it is acceptable for city roads but too small for stony surfaces. Finally, the Truck can not go trough the tall grass with such small wheels and RWD.

2 x Buwizz 3.0 units - is a serious improvement ;-) I used them together in some of my cars until they get drowned... Does axes hold such big wheels while cornering? High speed + tight corner = extremal load on an outer front wheel which could pull it off the axe. (again, tested with my cars).

Cool! Though I would change the transmission. I would connect the front and rear wheels with double friction gear and connect brakes to the rear axe! It would prevent the car from making 180 degree turn while the emergency breaking

Here is another MOD of Dragonfly. Now with Mindstorm 51515 block as a power source. The new version has 2 C+ XL motors for propulsion which are connected directly to the rear wheels. Rear axe has a free articulation, but it does not do much, since the car is not powerful enough to go off-road. For steering a 51515 medium angular motor is used. To be able to control this buggy I installed the Mindstorm app on my tablet. But there is no easy way to make it go without programming... I spent several hours trying to make a proportional control. It is easy to understand that I need, but it is hard to program it in the Mindstorm environment, since there is a very limited choice of commands. So I decided to use some cheats. This buggy uses the proportional control module from M.V.P. (51515 model). But M.P.V. code requires two angular motors (one for steering and another one for propulsion), so I placed another angular motor in the cockpit and add a "fake" front-back joystick to the control (purple one). I am totally disappointed with the 51515 set. It is very weak. Steering motor has not enough power for calibration (with the front wheels lifted from the ground) without any load... You need to restart calibration to get some kind of "working steering system". For comparison, C+ L-motor powered by a Buwizz unit at 50% do this job easily! Further, car is very slow, again due to the weakness of 51515 unit. To see the difference, watch a video below: In this video both buggys are powered by Buwizz 3.0 units. The red one has 2 C+ XL motors for propulsion while the black one has 2 Buwizz motors. The difference with 51515 unit is dramatic! Finally, the mindstorm software is very unfriendly for driving the car. It takes a lot of time to connect a tablet to 51515 unit, and to calibrate the steering system. But the most annoying thing is the delay of the control! Here are few photos of my Buggy: Which version of Dragonfly you like the most?

Both the front and the back of your car looks good! And the perpendicular placement of the motor is cool.

That is so cool! My fav. are additions. Can`t wait for the next creation in this series! One thing I do not like is the gigantic scrab radius. But I understand, that there is not way to make it more realistic in this scale. (this is one of the reasons I am building bigger cars). P.S. I am very impressed by the driving of this car with only one L-motor!

I love the ground clearance, but this buggy is not that fast... How often you need to change the gears in portal hubs?

Thank you! Honestly, I was waiting for your reply! I agree, that the whole car can be lowered down (see the very end of my summary). I am working on it right now.

Hey, Eurobricks! In this post I want to tell you about one of my latest MOCs, called Blue Mamba. It was made for outdoor King of the Hammers competition. Unlikely I was not able to participate in the competition this year, but I am not disappointed because it is very fun to drive this car. Main features 4-wheel drive In-axe motors (one PF L-motor for each wheel) 2 x Buwizz 3.0 units for power RC tires 97 mm Bodywork The race vehicles used at the King of the Hammers are known as Ultra 4 vehicles. This Ultra4 class is unlimited 4400, and every vehicle is custom fabricated by each team. Most of the vehicle made with metal tubular frame and plastic body panels. I tried to replicate the bodywork to match the real prototypes. Black pieces imitate a tubular frame of the car. Side panels and the hood are the structural elements of the chassis. The total weight of the car is about 1,280 grams. Half of the weight (4x PF L-motors) is located in axes, this is not good for the dynamics of the car at big speeds, but helps a lot in trial. Steering motor and Buwizz units are located in the cockpit. It is possible to lower them, so there is a reason to revisit the chassis once again. Suspension The rial race combines desert racing and rock crawling. So the Lego version of the race combines high-speed and trial sections. For good performance in trial Blue Mamba has a free articulation of a rear axe. The string are placed on the middle link, so rear axe can suspend jumps. Front axe has a limited articulation for a good control at high speed. Drivetrian Ultra4 vehicles has both powerful engine and the gearbox which allows to drive fast on straight lines and slow on rock-crawling segments. But Lego gearboxes has a significant disadvantage - a huge loss of torque. So I decide to place the motors in axes. This gives nearly zero losses, but has it`s own disadvantage: an extremal load on the CV joints which connects front motors to the wheel hubs. There is no way to deal with in without widening the wheel base and adding the portal reduction.. I hope some day Lego will make a new hubs that connects to new CV joints (without planetary reduction). In-axe motor placement provides some restrictions to the size of axes. I tried to maximize the ground clearance. Big wheels partially solve the problem. The resulting ground clearance in not big as one the cars with portal hubs has, but it is comparable to the ground clearance of cars with front independent suspension (there were several competitors with such configuration). Also it is worth noting that front and rear axes does not stick out from the side profile of the wheels, so Blue Mamba has great approach and decent angles. Control and Power The car is powered by two Buwizz 3.0 units. Powerful lego cars usually have a big problem. They can not go on a full speed for a continuous time since the driving motors consume a lot of power. I build many cars powered Buwizz 3.0 units. And I noticed that 2 Buwizz motors or 4 PF L-motors consume more power then the battery can give (in continuous drive). A good example of a car with 4 L-motors and 1 Buwizz unit is my Jeep Wrangler. To deal this problem, I places two units in the Blue Mamba. This doubles the travel range of the car and allows to drive Blue Mamba on full speed during the race. But multiple tests show that 1 Buwizz unit is enough for this car, since there are no losses in the transmission (in the first video car is powered by a single Buwizz unit). For steering a C+ L-motor is used. It is placed in a cockpit in between Buwizz units. Small scrab-radius, positive caster angle and proportional steering provide a good control of a car. Summary The competition has passed, and I there is a video on youtube: This allows me to compare my car with the other competitor cars. I would not win the race but perform good. I will look for the next King of the Hammers competition and prepare Blue Mamba to it. The following changes will be made: Buwizz units will be replaced with RC electrics The cockpit will be lowered for few studs The wheel base will be lengthened for 4-6 studs (to prevent the car from flips at high stairs in trial) I made a 3D model of Blue Mamba, but I have no motivation for making PDF instructions since Rebrickable does not work for me nowadays... Hope everything will be changed soon! Now we can only wait and play Lego!

Here is a longer run of Dragonfly in the snow!

I agree, that the caster angle is too big, but I will keep it and make more driving tests. The tires I bought at Aliexpres, that is very common in Russia https://www.aliexpress.ru/item/1005003264692710.html?spm=a2g39.orderlist.0.0.280d4aa6UZj40A&_ga=2.250904326.1876355886.1648824271-1596240348.1648271540 But all tires with the following parameters will fit well on lego rims: outer diameter: 85 mm inner diameter 1,55 inches width: 28 mm.

DRAGONFLY Dune Buggy Hello everyone! For a very long time I had a dream to build a dune buggy, and finally, my dream come true! The main goal was to use a C+ electrics instead of Buwizz unit. Of course, I am not the first who attempted to build a buggy. I take an inspiration in Madoca`s Blue Lightning buggy. Technical specifications: - Light and ridged tubular bodywork - electrics form 42099 set (controlled with C+ app for 42099) - Long-travel independent suspension - positive caster angle on the front wheels - Long wheel for stability on the straigt lines - Double steering rack and steering arms reduce wobbling of the steering system - understeering feature (rear wheels get more grip) - RC tires 90 mm Buggy performed well, comparing to the 42124 set. It appears to be a car that is very comfortable to play with. The speed of the buggy allows you to walk with your normal speed in the park driving it at the same time! Here is a small video of my first tests: As I said, the main goal of this project was to use C+ electrics. But after that I decided to boost it with buggy motors! The overview of the car does not change much. Rear wheels get a positive caster angle, and wheel size was reduced from 90 mm to 85 mm (for reducing speed and increasing torque). Here is a short video with Buwizz-powered Dragonfly. I will definitely make another video about this car then the summer comes.

Looka very fresh! How much time did you spend with making all this renders? And which program did you use? I am making renders directly from Studio.io and they are not as good as yours.

Thank you for your feedback! I am waiting for the snow to melt. Really want to show this car on a full speed to you all.

I think a white stroke on rims will make it even better!

Finally, I get myself a 51515 lego set, so not I have white mudguards. Here are fresh pics!