INTRODUCTION This gearbox is the successor of my previous 8+N+R-gearbox. It is based on the new parts released on the Yamaya MT-10 SP #42159. Thanks to these, I could make a new and better gearbox for 1:8 manual supercars. Thanks to the 8 positions by rotation, I made a 6+N+R gearbox. The best arrangement I found was to put 2 cylinders between 2 shafts, each cylinder controlling 2 forks. Thus, I would need 2 cylinders to make the 8 positions I wanted.   VIRTUAL DESIGN I started with simulations in Excel when the parts were not available yet. The purpose was to virtually recreate the functioning of the new rotary cylinders to find out a configuration that worked. So, I reproduced the sequence of the cylinders. Then, I created an offset between the 2 cylinders. To make the best gearbox possible, it was necessary to obtain: Reverse gear on an extremity of a shaft Not 2 gears engaged at the same time on the same shaft   EXCEL TABLE The Excel table may seem hard to understand, but the main difficulty is because I made written in French! The first column represents the positions of the rotary cylinders. The second column is used to create an offset between the 2 cylinders. I tested all the configurations and keeped the ones that respected the criteria above. Then, I used the supposedly working configurations to calculate the possible gear ratios. The sub-table called “Transitions” corresponds to the ratio between the two main shafts. Then, on the sub-tables on the right, I put the gears on the primary and secondary shafts to get 3 different ratios on each shaft, placed in the correct sequence, for each remaining possible configuration. I got only 2 possible configurations (A and B). Other configurations exist, but they are symmetries of these two configurations, so they are useless. I finally came out with only one possible configuration, which is the one I realized in Stud.io and in real life.   IMPROVEMENTS             Compared to my previous gearbox, this new version features: Way better efficiency More compact, easier to integrate into a chassis More reliable gear selector More realistic and easier to understand The shifter can be less robust The input and the output are centred, and can easily be moved It is reversible, meaning that you can power both the input and the output Gears better staged   HOW IT WORKS? The way it works is close to a dual-clutch gearbox - however, the exact same operation cannot be achieved due to the way the sequence of a rotary changeover cylinder is made.   The ratios are better staged than the ones of my previous gearbox. The reverse gear is situated between the 1st and the 2nd gear, making it more realistic. R: -0.375 N: 0 1st: 0.25 2nd: 0.45 3rd: 0.50 4th: 0.75 5th: 0.90 6th: 1.50   A simple mechanism prevents from shifting from 6th to reverse gear. This mechanism can easily me moved to another place (for instance close to the shifter) though.   The centre changeover cylinder is used to create a 45° offset between the two other cylinders. However, to spare a part, you can use one of the following assemblies.   VIDEO   REBRICKABLE LINK Here is the Rebrickable link if you want to test this gearbox! https://rebrickable.com/mocs/MOC-171508/Anto/ultimate-6nr-gearbox-with-forks/#details   I’m wondering what the gearbox on this summer’s supercar will look like. It should either be pretty similar, or totally different. What do you think?