We have 4 inch wheels and 200rpm 6 green motors, how can we make a robot that drifts and has a drivetrain of 350-450 rpm?
450 rpm 4in? Are you sure (94 in/sec is awfully fast…)
Even 350 rpm (72 in/sec) is on the faster side.
For 350 rpm from 200 rpm motors, do 84:48. Anything geared above this I would not recommend.
However, be warned of using 84 tooth gears on drivetrains. They are almost the same size as 4’’ omni wheels, so any slight tipping will result in them scratching the tiles. Not to mention the fact that making a bottom crossbrace with them is hard since they’re so big.
4’’ wheels are also not exactly the best for drivetrains due to the lack of viable ratios. I would suggest you use 3.25’’ wheels.
Might I recommend 300 rpm (62 in/sec), which is 200 rpm geared up 72:48?
Use all omni wheels
I recommend checking out Catalogue of Drive Gearings. You can find different gear ratios here. You can make a robot drift by using only omni wheels on your drivetrain.
https://m.youtube.com/watch?v=VbLf8aXQSpg
This video talks about any different kind of wheel size and gear ratio you could want. Recommend checking it out.