Stamper Desynchronizes with Non-Synchronized Machines

Bug: Stamper Desynchronizes with Non-Synchronized Machines

This issue is a duplicate of #223 Using a splitter followed by a cutter was having strange behaviours. I was fe....

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Stamper Desynchronizes with Non-Synchronized Machines

Status:	Duplicate
Added by:	ionnizer on April 29, '26
Reported for:	0.8.5 Auto

Steps to Reproduce

No steps to reproduce

Explanation

When a stamper running at 60/min is connected to two machines that run at 30/min, sometimes the stamper will run at 60/min instead of 30/min.

This happens when the two connected machines are not synchronized. If both child machines tick on the same second it runs fine, but if they are offset the stamper gets confused and runs twice as fast. Watching the animations I can see the two connected machines alternating on the 60 line, but on the 30 one both run at the same time.

My guess is the stamper has a 1 item buffer for each output, so when an item is taken from an output it forces the machine to consume a cube, but since the other output is full that product is lost. So it grabs another cube the next tick to replace that one.

I determined this occurred when I added a tunnel to the bottom line. By deleting and replacing segments of that section of belt I can reliably reproduce the desync.

Screenshot details: Blue cubes are split and fed into the 2 factory lines. You can see the top stamper is consuming 30 and the bottom 60, but both lines output 60. The bottom right shows two stampers connected, with the first green and the second yellow which should not be possible.