has anyone expirimented with drones for long range transport?
I'm thinking of replacing my rail network completely with drones, but I'm not sure if it will be able to handle the throughput.
also how much is the fuel consumption of drones vs. trains?

I'm fiddling around with drones and it looks pretty good - for long range transport you would need to set up a lot of buffer depots with ton of drones to handle long range throughput. Insta-load is pretty great as it saves a lot of time, but drones need a lot of research to increase their speed and still would be slower than nuclear-powered trains at around 20 levels of drone speed tech. The fuel consumption isn't anything to write to home about, it's much worse than regular trains. They eat a lot of fuel and produce ton of pollution, which could trigger potential attacks of biters, if that would be a concern. But, as I said, with big enough buffer depot area to bring closer resources, this would be much flexible than trains, especially inside base, where you can transport few stacks of materials at once. I guess few hundreds of drones cruising for long distance tours for stuff could be better than trains, but to be safe, they should be in different road networks to prevent drones from main road from venturing into wildeness and choking your base.

As for throughput of drones versus trains, I would think that trains would surely win when distance is greater than ~50 chunks, as it would be much, much faster for nuclear fuel trains to travel and load/unload. I'm currently mixing transport drones with Krastorio2, so drones are even better, since trains are slower.

update: so i replaced all my train lines with drones... works very well, even for quite long distances.
if you use buffer depots you dont even need to split the road network, as the buffer depots will be prefered by drones which get stuff.
but for VERY long distances I think I will use trains

What is very long distances?

like 20 times the range of a normal radar

just for info :
vanilla radar is plus/minus 3 chunks, total 7x7 chunks, 7x32 tiles = 224 meters, 20 radars = 4.48 km
... and ...
fuel of normal drones = 0-10000 (default 50) petrol, 0-xx (default 0.025) petrol per meter, thus range by default would be 50/0.025 = 2000 meter before being out of fuel (VERY easy to modify all values in mod settings).

with the additional mod for steam as fuel it is a range of 100/0.1 = 1 km (these mod settings are hidden).

with the additional mod to use drone-fuel all values are hardcoded in the mod and mod settings for fuel are ignored. thus values are not easy to see and would have to be changed by looking closely at the sourcecode and changing them there.

Want me to expose stuff as settings?

Hmm my drones never run out of fuel... but i Have multiple supply stations.
and most of the drones have very short paths.
Ok so here is my map:
https://pasteboard.co/J6HkHz1.png

seems like i overestimated the distances, seems like more of 5x normal radar range. (the squares in the screenshot are advanced radars, I think they have 13x13 chunks range)
but the drones only move half of that at most, so more like 2,5 radar ranges for longest drone trip
but these distances are not a problem at all

2000 meter before being out of fuel

Just wondering as I haven't looked, is that 2000 meters round trip? I would assume if it's a vehicle it would be using fuel both ways so that would be a 1000 range if 2k is the distance for total fuel.

@tubs: "expose as settings?"
it is a bit confusing if i can see (and change) this mod's settings while different settings from another mod are used. this makes it also impossible to easily change values (without editing that other mod itself, possibly quite often after every single update that it gets). if mod settings from this mod are visible, please allow to modify them (for my map, probably the fuel capacity would be most important when using drones instead of trains), and hide (or better yet disable, if that is possible) those values that users are not supposed to modify.

if possible, a mod that changes values probably should either announce that somewhere (on "info" or "faq" tabs, or by changing the ingame tooltips of the orignal mod), and/or then have its own settings with tooltips along the lines "overwrite main mod's value with this value". since i am no modder, i don't know what other modders and authors think about this situation when one mod (silently/secretly) modifies values of another mod, and thus i answered here. but details about which values you should expose and allow to be changed should probably better be discussed in that other mod's discussions.

@OhMods: "roundtrip or range?"
hehe, i was thinking about this already but didn't finish testing after i got problems. for my first test look at https://mods.factorio.com/mod/Transport_Drones/discussion/5ebc66730f1be8000be27ee7 and
https://mods.factorio.com/mod/magic-lamp/discussion/5ebc61520f1be8000ef8e716 shows my problems when i tried to rebuild the test track with cut&paste :-)

my guess is that fuel is subtracted from the tank while driving (using a little even while overshooting corners, being stuck while pathfinding, etc), thus roundtrip along the taken path or pathes including all detours and derpiness ...
since the drones get items as soon as they reach the destination (provider), i would also assume that they just magically dissolve together with their cargo when running out of fuel on their way back to their base (requester), and then respawn, try again, and again, and again ... until the provider is empty

Hey everyone.

About the drones fuel consumption, Klonan talked about it in discord.

So, the drones never actually run out of fuel.
The way it works with fuel is that, when leaving the requester depot, the drone gets a full tank worth of fuel from the depot. After the trip is done and it is back to the requester depot, it refunds any remaining fuel to the depot.
That refund can also be negative, so, say a drone makes a really long trip and "runs out of fuel". Instead of stopping or anything, it continues going and continues counting consumption. Then, when it arrives back at the requester depot, it consumes that extra fuel it needed from the requester depot.

It might not be very realistic, but having it stop in the middle of the way would probably cause some not fun problems for the player, and since it is a game, fun comes first ;)

yeah that makes sense. them running out of fuel would be quite annoying

in the meantime (since my last post), i did some tests myself and found out what gcascaes described, even with two interesting additional details :

.1. when the requester depot has less fuel than should be subtracted, it is only reduced to zero. the only negative consequence for the user is that we have to wait for new fuel being delivered since new fuel in this case is only ordered after the drone came back, and not as soon as its tank was filled when leaving (to already fill up the depot again while the cargo drone still was underway)
if this happens often (eg on a requester that replaces a longdistance train) a solution might be to place another fuel depot and fuel requester (to supply that fuel depot) nearby so that refueling the cargo requester doesn't take too long before the next drone can be sent to do the long haul.

.2. when a road is interrupted between the location of the drone and its destination, the drone teleports back to the requester. if that gap is between the drone and the requester, it will first continue going to the supplier and grab cargo, then think for a second or two and then immediately teleport including the cargo. thus this transport saves half the distance and also half the time to travel and half the fuel, and you still get the cargo.
but alsthough this might be seen to be a bit cheaty, it still is not really usable as a cheat since you manually have to interrupt and rebuild the road at the right time for only very little gain.