Hmm I can't replicate it here it seems. Can you clone your world, delete everything else except that station+ship, and send it?

Also can you try with vanilla merge blocks too to see if they have the same issue?

I ended up finding the problem, but only by accident. I first tested vanilla merge blocks, which behaved little differently. The lower, static, part still jumped up to join the dynamic part. However, instead of causing general destruction and mayhem, the game then promptly crashed. Perhaps a testament to your modding skill? The weld pads were much more stable than the vanilla blocks lol.

I then began prepping my save for transfer, and cleaning up all the unrelated grids, when I noticed that the large anchor I added to the problematic static grid was separate, since it had a different grid number. After some investigation, I found some grated stairs that weren't properly joined together, but looked and behaved so because they were stuck in voxels.

After I properly joined the anchor to the static grid, I decided to try the merge again, and it finally behaved as expected. Both with vanilla blocks and the weld pads.

I can't be certain, but it definitely seems like the problem was that the dynamic grid had more blocks than the static grid, so it was chosen as the 'main grid' when merging. Thanks for your prompt reply!

while this is good to know (smaller grid moves to larger grid) it would still be better IMHO if static grids would always be chosen as the anchor point, no matter the part count. this feels more intuitive and allows a more controlled gameplay.

so far i cant think of any scenario where i would like the static grind to move instead of the dynamic.

The game code does actually make rooted grids as the parent to receive blocks from a merge, it only goes by block count if neither are rooted.

Rooted meaning any physically connected grid being static or landing gear'd to something static.

Originally posted by Digi:

The game code does actually make rooted grids as the parent to receive blocks from a merge, it only goes by block count if neither are rooted.

Rooted meaning any physically connected grid being static or landing gear'd to something static.

I wonder if this is what's causing my issue.... I'm using a mag plate on a sub-grid crane to move a building... the crane is mounted to the static grid that I'm trying to connect too but when it welds both grids explode. I wonder if I split the grids whether it'd work a bit better... food for thought...

The boom could be the game thinking BOTH grids are grounded and freaking out.

Could be extreme weight imbalances, like if you have a grid that's so light and attached masses that are so heavy that in order to hold them up it has to apply immerse forces to that lightweight grid, and any small error sends it flying instead - into anything nearby hence the explosion =)

I'd say experiment in creative to replicate it reliably and see if adding more mass to the in-between grids helps... and also report it on keen's site with the blueprint or world, maybe they can do something about it.