Inserters pick up LOTS faster on a curved belt

[wobbycarly]

I wasn't sure where to post this one... It's merely an observation that I've finally made after too many hours playing (plus the countless hours watching others play!) Forgive me if it's one of those things that EVERYONE knows

I was setting up a train station and due to it being a little cramped, I turned one of the belts, so that it was curved immediately in front of the inserter. I then happened to notice that that particular inserter was swinging so much quicker than the others. This was interesting to me, so I set up this little test.

2022-02-26 17_10_08-Factorio 1.1.55.png (696.11 KiB) Viewed 6223 times

I ran it for about 20 seconds and the counts in the boxes from top to bottom were 297, 342 and 407 respectively. That's a 25% speed boost when comparing the straight belt with that curved to the right (in relation to the inserter). No doubt this is due to the additional item compression that is required to keep the inner curve going, and it also appears to the naked eye that the inserter doesn't need to swing as far.

Discuss.

[ssilk]

And what do you suggest? This board is suggestions about balancing; Should this buffed or nerved?

I think this is a good observation and one of the tricks factorio provides even for advanced players. I would not change it.

Ah yes, what your above measurement is missing is how does that behave if only one side of the belt is full.

[Tertius]

This behavior is well known and well investigated:

https://wiki.factorio.com/Inserters#Bel ... nserter.29

With the pick up from a turning left belt, it seems you actually found the fastest pick up method.
Use it and exploit it.

[disentius]

hewre are a few test results from a while ago:

[Tertius]

This is like quantum physics. The smallest parts of matter have all the same tiny fixed rules how they work, but if put together in different combinations, they result in a large variety of different, sometimes surprising behavior.

[FuryoftheStars]

Well, this makes sense. The outer lane of a belt actually "increases" in speed when going round a corner. I mean, if you have a plate that you're pushing straight forward, both left and right sides of it will be traveling at the same speed. But if you then turn left or right, one side of the plate is actually going to increase in speed to stay matched with the other side. If it didn't, it'd tear itself apart. And that's all a belt is... moving plates with items on them.

[wobbycarly]

Feel a bit stupid now knowing that's on the Wiki. I did try searching the forum, but my terms mustn't have been accurate. I love how this game still has so much to reveal...

@disentius, thanks for the cool image - I can't see the difference in construction between the 2 setups in the bottom right, and yet they have different results. Can you please explain?

[Silari]

@disentius, thanks for the cool image - I can't see the difference in construction between the 2 setups in the bottom right, and yet they have different results. Can you please explain?

looking closely, it appears the bottom one is using a yellow belt for the part the inserter is grabbing from.

[disentius]

Correct.
Original thread here:
https://www.reddit.com/r/factorio/comme ... s/f01z85m/



Here is another small difference in throughput between splitters with and without priority set.
viewtopic.php?p=456948#p456948

[NotRexButCaesar]

This will have changed now that Boskid switched the inserter pickup behavior for curved belts.
109241

Fixed inserter could take items from wrong side of a belt when the belt shape was changed.

108046

My fix here was to ignore the transport belt shape and always follow the correct logic of selecting left or right side. That means that regardless of the current shape of that transport belt, in your specific case it will be always taking items from the right lane. That means there will be an observable behavior change when inserters take from the incoming curved belt that turns left as the inserter will now prefer the outer radius which is closer. I am considering this to be the correct fix since the outer curve is closer to the inserter so it should be taking from this lane instead to begin with.

[Bilka]

This did not change, see

This was fixed with the fix for 108046. The original change mentioned in that thread was adjusted so that the pickup lane without build order weirdness is the same as always, but changing the belt from curved to straight now updates the pickup lane. Moving to resolved for next release.