Still a noob and needing some veteran advice. I have built a single rail mine-cart system planning to have the carts stop for a minute to load/unload/transfer before returning to pickup more. My problem is the time at each stop is too short. I did build one repeater setup using 97 repeaters to get me about 40 seconds. To get a 1.5 minutes would mean around 150-160 repeaters at each location requiring a lot of crafting and redstone.
I did figure out a way to use one repeater setup for each junction by interconnecting the detector rails and outputs as rarely will more than one cart arrive at a time. Still with 4 separate rails I would need 5 timers equaling 750-800 repeaters. Putting a switch at each starting point would work too and I will do that if there is no easier way to do this.
Don't use a clock. It will always be too long or too short.
Instead, use a comparator to see when the minecart has finished unloading:
When the minecart hits the powered rail, the hopper will pull an item out of the minecart, turning on the comparator, turning off the powered rail so the minecart stops. When the hopper has finished pulling all items out, the powered rail will turn back on sending the minecart back.
Thank you very much for these tips guys. I did some experimenting last night with both designs and found good and bad with both.
I liked the hopper timer as it would give plenty of time between each toggle. This worked great if the cart arrived as the off circuit toggle just started. I to figure out a way to trigger the timer only once the cart arrived because running 1.5 on to 1.5 off caused the cart to leave sometimes while still full. Will play some more tonight after work.
The dump till empty ran into an issue of the lower chest being full and stopping the system completely. I was able to resolve this by adding a couple double chests from the dump. Then using a "send when full" would hold the final cart until it was full sending that on it's way. I ran into another issue here when using only partial stacks. If the cart chest had only 50 granite blocks then it wasn't full and broke the system.
Another suggestion on chat last night was just build a double rail system. The idea was when a second cart returns from depositing everything at base it will trigger the first cart to leave loading. A delayed piston then would push the empty cart onto the loading rail but I am concerned about the amount of rail I need to make. I guess tonight I will see what happens.
…I liked the hopper timer as it would give plenty of time between each toggle. This worked great if the cart arrived as the off circuit toggle just started. I to figure out a way to trigger the timer only once the cart arrived …
Consider replacing one of the sticky pistons with a regular piston and use a detector rail to power the sticky piston. This turns the hopper clock into a hopper-clock pulse extender (when the detector rail triggers the hopper clock, it will run only one cycle, then wait until triggered again).
Thank again. Last night I actually figured out how to use a mine-cart and tripwire trigger to activate the hopper. If the track was flat a mine-cart wouldn't activate the tripwire but sloping the track triggered it and helped give the cart momentum once power was applied to the track.
Another issue I found actually resolves one of my concerns. I was building a skeleton farm that would kill and collect everything into a chest. A cart would retrieve the items from the chest and bring them to the main rail system. However I didn't know the dungeon spawner wouldn't spawn skeletons if a person was too far away.