[0.16.51]Inserters stuck looping with uncompressed blue belt

[golga]

It seems when I have an uncompressed blue belt both stack and fast inserters get stuck in this loop trying to pull items off of the belt. As seen in this gif. This just might be timing issue as removing and replacing the insterter fixes it temporary but then eventually it starts to loop again. Also picking up the contents of the belt resets the loop, but like replacing eventually it will get stuck back into the loop.
Note that it is not a power issue

[kitcat]

The items are perfectly spaced so that the inserters take just a bit too long to switch belt sides to reach them before they go out of range. I think the only way to prevent that is making sure that the items are spaced differently. Considering that there’s so little on the belt, the most reliable ways would be either putting all items on one side of the belt (don’t need to switch sides) or using slower belts (more compact and more time to grab).

[Klonan]

It seems when I have an uncompressed blue belt both stack and fast inserters get stuck in this loop trying to pull items off of the belt. As seen in this gif. This just might be timing issue as removing and replacing the insterter fixes it temporary but then eventually it starts to loop again. Also picking up the contents of the belt resets the loop, but like replacing eventually it will get stuck back into the loop.
Note that it is not a power issue

Can you provide the save game so we can test a solution?

[mrvn]

The items are perfectly spaced so that the inserters take just a bit too long to switch belt sides to reach them before they go out of range. I think the only way to prevent that is making sure that the items are spaced differently. Considering that there’s so little on the belt, the most reliable ways would be either putting all items on one side of the belt (don’t need to switch sides) or using slower belts (more compact and more time to grab).

A splitter that side feeds the belt onto itself can help too. Puts 3/4 of the belt on one side when it is sparse but doesn't prevent a full belt. Repeat after some inserters or to get even more of a bias.

[Rseding91]

Thanks for the report however that's simply how it is at the moment. Because "management" wants inserters to chase items on belts this is always going to be a possibility: the item out-running the inserter.

So, until I'm allowed to remove that mechanic (which I doubt I ever will be) inserters are doomed to be broken in weird setups like this.

[voddan]

Because "management" wants inserters to chase items on belts this is always going to be a possibility: the item out-running the inserter.

Thank you for a detailed and clear explanation. However are we to understand that you don't see a technical possibility of fixing this issue without changing the design of the game? Of the top of my head I can think of a couple solutions that 1) preserve belt speeds and spacing and 2) move inserters' hands in a physically-possible way:

1. Speed up the inserter arm when it grabs the items. Speed of turning around may stay the same.
2. For fast belts start collecting the items from the end of the belt section thus minimizing the inserter movement
3. Predicts the item path and move the inserter hand there rather than chaise the item from behind

Have you considered all of those and deemed them unimplementable? Why?
Sorry if that discussion has already took place internally. Still, I think it would be useful to document the major points here.

[DarkShadow44]

Not 100% sure, but with the inserter buffs from FFF 419 this might be not an issue anymore.