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Hello Eurobricks! A few months passed since I shared with you my creations. Well, I was working hard on two RC projects and now I am proud to introduce you one of them! It is called "Hornet" and it is an Ultimate 4x4 Baja Buggy. Technical specs: 4-wheel drive, open differentials Full independed suspension Brushless motor, 3S Li-Po, GeekServo Custom wheel hubs with metal bearings Carbon-fiber axes, metal U-joints Transmission sits on the metal bearings Positive caster angle, kingpin inclination, Ackerman Anti-rowbar at the front axel 98 mm RC wheels understeering Light tubular frame A story behind the build. Half a year ago I bought myself a Brushless setup adapted to Lego. It can provide a strong and stabled stream of power to my RC Lego cars. In two days after the motor arrived I build a first project with it to test its capabilities. Of course, this was a buggy! The main goal was achieved, I was able to test the new system and it performed greatly! Though I was not happy with the car itself. It had technical problems with both front and rear suspension, steering, overview and proportions... During the winter holidays I found a great set of RC wheels on AliExpress. They looked ten times better then all the other RC wheels I had, so I bought them and at once started a new 4-wheel drive project (which will be revealed in my next post). All I will say now, it has solid axle suspension and no planetary wheel hubs. So it appeared to be quite fast and somewhat unstable due to the soft suspension and high center of gravity. I decided to postpone that project and build a fast and more stable Baja truck with the front in-depended suspension and the solid rear axle. The fist prototype can be seen of the picture below (half-way dismantled) and it looks totally weird, especially the placement of the Brushless motor! With such layout I tried to load the rear wheels, but did not succeeded. Despite a completely failed project, I get two important ideas from it. 1) My custom wheel hubs allows to build an advanced front suspension and steering with king-pin inclination, positive caster angle and Ackerman geometry. Also I learned how to use a half stud off-set for the attachment points of the lower suspension arm. 2) The placement of the Brushless motor behind the rear axle greatly load the rear wheels. I was not ready to give up, and decided go bigger next time and use my favourite 98 mm RC wheels. By widening the wheel base significantly I decided to solve the front wheel drive problem! It is well-know that steering rack is usually interact with a differential. Also the steering rack must be placed behind the front axle to achieve the Ackerman geometry. So I decided to move the front differential one stud to the front. The first sketch of the front axle looked very promising, so I decided to "copy" it for the rear axle. Well, to keep the same wheel base as at the front i needed to use the half-stud off set once again and this time on both lower and upper suspension arms. That is why the rear differential is covered with a mess of connectors and beams... Solving all problems with axles, I connected them together via central driveshaft and had to decide how I should place the Brushless motor. The problem is that the motor has a size of a PF XL motor, and so it requires a 24 to 24 tooth gear combination to connect it to the central driveshaft (and place the motor on a side or on top of the driveshaft). I was not happy with it because big gears would stick out from the flat bottom of the chassis. The brilliant idea came right in time! I decided to place the motor behind the rear axle and place the another driveshaft over the rear differential. This allowed me to use a 12 to 20 tooth gear combination! In addition it loaded the rear axle to achieve the understeering feature. It took me another day to finish up the first prototype, and I took the Buggy to an extensive driving tests. These tests took me over a month to complete, since they were interrupted with a melting of the snow. The following improvements were made (one by one): Reinforcement of the upper suspension arm. First version of the front suspension was falling apart on each big bump. Lowering of the suspension by one stud. This was made to increase the stability on the straight line and make the overview of the buggy closer to references. Also I widened the tubular frame for the same reason. Playing with gear ratios: differential swap and swap from 12:20 to 16:16 gear combination in between the driveshafts. Adding an Anti-rowbar with a carbon-fiber axe to the front axle. It was added to increase the stability on the fast corners. Making 3.5 L axes to solve the problem of the front U-joints falling off from the differential. The results. A tremendous efforts had been applied to finish this Buggy. A lot of hard work, tricky decisions and big regrets... Does the Hornet worth it? - NO! As a result I build myself a balanced RC car with a precise control, decent speed (about 15 km/h), enduring transmission and good-looking bodywork. But I would not suggest anyone to follow my way, because it will cost you a lot! If you want to get a good driving experience you would better buy an RC car! LOL.