Inserter oddities

[Mr. Tact]

This is totally a matter of curiosity, not a problem.

I know you can get uneven loading from inserters due to things like arm swing time next to curved belt and other variables. Could someone explain to me what the factor is in the setup below. Both sides of the station are using a smart loader setup, I have verified the settings are the same. The eight lanes are feed by an eight lane balancer which has never shown indication of providing uneven distribution and the distance from the balancer to the shot you see are equal on both sides. However, the right side loads faster the the left side. In going from empty to the right side being full, the left side is 1,000 items behind. What is going on?

plastic station.jpg (262.1 KiB) Viewed 2501 times

[Bilka]

Inserters prefer to take from the right lane, so they will try to do that, and then switch to the left lane when the right lane gets emptied. This switching takes time and means that they are slower than when you force them to pick up from only one lane.



I would guess that this has an influence on your setup, but there are probably also other factors.

[Mr. Tact]

Hmm, I can't visualize why that means the right side would load faster. Aren't items being provided in the same fashion to the preferred location on both sides of the rail? And shouldn't the smart loader clamp down on these issues?

[5thHorseman]

I've not loaded this to test or anything and it's not the way I normally do trains so don't know by instinct, but my guess is that the turns in the belts are screwing it up. Sometimes on a turn arms grab from what I personally consider the "wrong" side of the belt. I'm not saying it needs changed or anything, but it does currently require you to pay attention to where the inserters are grabbing from and adjust accordingly.

[Mr. Tact]

But again, those belt turns are identical on both sides of the rail -- so why would there be such a noticeable difference?

[5thHorseman]

But again, those belt turns are identical on both sides of the rail -- so why would there be such a noticeable difference?

They're not identical. They're mirrored.

[Zavian]

But again, those belt turns are identical on both sides of the rail -- so why would there be such a noticeable difference?

I'm far from an expert on inserter mechanics, but I think you are missing the point. When a belt is moving towards the inserter, the inserters prefer picking up from the right hand side of the belt, (from the inserters' perspective).

So your loading station is essentially multiple blocks of

Loader.jpg (631.21 KiB) Viewed 2422 times

(As I understand things), inserters A, C, D, F prefer to pick up from the right hand side of the belt. B, and E prefer the near side of the belt. (For E the near side of the belt is also the right hand side of the belt). So 5 out of 6 inserters in your design prefer the right hand side of the belt. Note that this doesn't change when you rotate the design. (They also won't change if you mirror the design, because that doesn't change the geometry of the belts the inserters are interacting with, from the inserters' perspective).

To achieve what you want, you need to remove all inserter interactions with belts running towards or away from the inserter. eg

loader2.jpg (867.68 KiB) Viewed 2422 times

Note that no inserters are picking up from belts running towards the inserter. Averaging the top and the bottom through a balancer, and you should get a balanced pickup from both sides of the belt.

I'm not sure which lane inserters prefer when picking up from the entrance to an underground belt, but something like the image below might also work.

loader3.jpg (824.09 KiB) Viewed 2422 times

[5thHorseman]

If a picture is worth a thousand words, perhaps an animated gif will be worth a million. Just watch how the different arms grab from different places, both because the setup is mirrored, and because the belt is running backwards. Compare the upper left of one setup with both the upper right - where it's mirrored - and the upper left - where the belt is running the other way in the other setup. BOTH things cause the arms to behave differently.

Also note how on the left, one side of the belt *never* moves. The setup on the right, one side moves more, but both sides move.

[Zavian]

Another solution is to replace the fast inserters with stack inserters. That will probably result in you picking up everything from both lanes, even though one lane is still preferred.