minecraft-java-edition
I am trying to create a wheat farm using a minecart that goes back and forth below dirt blocks that have planted seeds.
How do I solve those issues?
Minecarts will favour travelling south or west (known as the South-West rule) when they reach an intersection. Also, placed tracks will favour curving south or west. Additionally, when two minecarts are adjacent to each other, they will speed up extremely quickly,. This is commonly called a booster. The South-West rule is used when making self-resetting boosters:
As far as I understand your question, you have trouble with the track going trough the door...
Here is a screenshot of my setup, first you switch over to the new track, then you go trough the 'door', but by going down under the door block the track doesnt break and just creates a slope whenever the door is open, this would work in both directions.
Also as often happens with these timed things, the doors or track switcher might not stay open long enough, here is a way to lengthen that. (This is my own design, not all that compact, but the only thing that makes sense and works for me)
Best Answer
Just quick info on powered rails for the next two points.: Any motion at all causes the powered rail to have an effect on the minecart.
Bouncing is done by putting a powered rail at the end of the track, followed by a block. The slight bit of backward momentum "activates" the powered rail, causing it to go to full speed in the other direction.
By pushing the minecart slightly with your body while on a powered rail, the minecart's movement "activates" the powered rail, causing it to go to full speed in that direction.