Another guide on how to get a near nontiltable plank
ALL TIMES ARE APPROXIMATE
Note: the step surrounded in blue marbles is only needed if you want an exact angle. Skipping it also turns the 'over night' into just 4-9 hours (I don't have time to calculate the exact numbers).
The effectiveness increases with size. It is not at the angle it is displayed at. The first plank can only rotate in 1/2 radian increments; the next one, twice that.
Those 1st few hours produce a plank good enough to stabilize an aircraft but why bother when you can get something that I am STILL trying to rotate for just a few more hours.