[Tutorial WIP] Cooldown Juggling Rapid Fire Dart Trap Engines (Animated Guide) (2024)

[Edit 2021-01-12: url links to each gif added because embedded playback stopped working. Full gfycat album here.]

The principle with all of these designs is to stagger the firing times of a series of traps using a track of pressure plates (activated by some mob or player) and then lock in that staggered firing sequence by rapidly reactivating all the traps continuously thereafter, using a high speed 'engine'. Each trap will only fire a second time after their initial firing cooldown has ended. This means that they will repeat the initial firing sequence again and again, provided the repeater engine keeps firing steady and fast.

Hoik engines are great for this since they can ensure a perfectly locked-in sequence, never letting the pattern slip by even a single tick (at up to 60 activations pr second). Dummy powered hoik engines are ideal, since they are invulnerable to friendly or hostile attacks and will continue running while you are anywhere on the map. However, any steadily firing engine will generally do a fair job too (e.g. bird engine, minecart, etc) depending on your requirements. (See examples in my old Fastest Engines Guide.)

This type of dart battery design was first shown by @DicemanX here in this thread and the repeater concept was first proposed by @Unftf.

The approach has benefits over the previous designs that used a 1 second timer for each trap (or column of traps):

1. You don't need to make a whole load of timers, each requiring a whole load of metal bars.
2. Since Terraria 1.3 dart trap firing cool-downs were increased to 3.33 seconds, so would only fire a maximum of once every 4 seconds on a 1s timer. The newer method always fires them at full rate, a 20% improvement in damage output per trap.

My previous rapid fire dart trap guide shows a selection of designs for Terraria 1.2 which should still be valid for all platforms other than PC. But console and mobile uses should be able to craft most of these designs too, simply shortening their tracks by ~11% (rounded up/down) to save on wasted simultaneous firings. That old video guide shows a couple of usage scenarios for these machines: mob or invasion grinders, boss arena.

Also see Diceman's guides with several of his builds using rapid darts: rotten chunk/vertebrae farm, efficient dungeon guardian farm, Wall of Flesh auto-farm, ultimate chain auto-farm (all biomes mobs), (old) Truffle Worm farm, Surface autofarm (mobs, events and invasions, including pirates), etc, etc.

I've enumerated a series of different designs, below, that you might pick from depending upon how many dart traps (or super dart traps) you have available, how rapidly you want them firing, what statues you've found and what stage of the game you are at (post Mech boss for teleporters, etc). For each I've shown the exact layouts for firing darts in either direction. However, it is recommended to only fire the traps in the opposite direction to the direction of travel of the firing sequence priming agent (that is, fire to the left, the lower row of dart traps). That allows for perfectly looped firing pattern, due to the helpful offset between first and last trap. In the opposite direction the offset opens up a gap in the pattern instead. The faster the battery fires, the longer it is, the bigger the offset between first and last traps and the bigger the gap in firing.

Note that a stand alone dummy (or skeleton, etc) hoik engine can be added to any of these designs for convenient operation, but I've tried to show how you can use the priming agent in each case for the repeater engine too. For elegance and for fun.

In each design, the exact spacing and positioning of traps, plates, engine, etc, is important. However, traps can be placed above or below the plate run, staggered horizontally and have as many additional rows are you like. Don't forget to actuate your dart traps so they can fire through each other too (then remove the actuators)!

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The "Soggy Flapper" - Water slows birds down to half their normal speed, allowing a compressed plate run, perfectly spaced for near optimal number of traps. Submerged birds always tack towards player, so when activating this you must stand at the far end, opposite the statue. The water level is deliberately low like that, so the bird can exit the water quickly at the end, to transition into the repeater engine.

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The "Wet-foot" - Players basic move speed is the same as a bird, and water slows player movement down to half too, so this design produces the same firing pattern as the bird in water (above). Remember to take any speed boosting boots off first.

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Minecart Dummy Hybrid - Each booster track adds 15 tiles per second to the minecart speed. But the iron minecart is capped at a max speed of 48.4 tiles/s, so after slowing down with 3 reverse booster tracks: 48.4 - 45 = 3.4 tiles/s. A leisurely pace for a fairly compact battery. The last pressure plate starts a dummy ghost hoik engine, leaving the player free to go anywhere in the world with the darts still running (can be added to any other design here).

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"Rail Repeater" - Same priming mechanism as above, tweaked slightly at the end to launch onto a minecart engine (in place of the hoik engine). "Boing, boing, boing!...". This can be built post Mechanic (pre-hardmode).

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The "Bone Shaker" - Good old skeleton tech. A near perfect 5.5 tile/s walk speed and play-like dimensions makes these statue mobs great for this application. Able to step straight into a hoik engine at the end of a run. Be aware of Skeleton idiosyncrasies: they will try to attack the player first at night, but will always start off walking to the right during daytime, also they despawn instantly when off-screen during day at surface level.

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The "Bunny Button Basher" - A gentler pace than the skeleton track, but just as workable in a carefully designed hoik engine. Be aware that bunnies are easily distracted, running away from nearby monsters (while priming the engine but ok when being hoiked).

There are many more viable designs possible. Piranha have the same move speed at skeletons and there's no reason you couldn't use goldfish or even sharks, perhaps immersed in honey, to compact the track (a "sticky fin"?). So I'd love to see any other workable design, below! Or post if there's a flaw in one of my designs above, or they can be improved in some way!

In the next post (media embedding limit): a couple of spear and flame trap engines that use the same design concept...