Sacks coming open

We are having problems in New Zealand with the sewing on sacks ‘unzipping’ with intakes that are quite gentle. Just catch a thread and pull - presto open sack. Most intakes seem capable of doing this but some are worse than others. A frendly sewing machine fixes them but watch out and have a machine at any major events. About 3% of our sacks have come open.
Has this been see by anyone else?

Yes, this has happened to quite a few of ours as well.

The main issue is when force is applied to areas near the outer perimeter of the sacks. So for example, a claw (which would pick up a sack by the edges most of the time) has the capacity to do some damage. Even gentler intakes can do this too, though, if the force is applied in the “hot spots.” For instance, roller intakes, due to their tugging action, can cause this issue as well. It seems like a sewing machine is the only way to deal with this problem…but do take notice of one minor thing. This original sewing on the sacks is in a small “groove” on the side. This is extremely difficult to replicate if it is not done from scratch, so repairs will probably have the patched sewing on the outside, i.e. more of a ridge. This shouldn’t affect gameplay, but just keep in mind that the sacks will not be restored to “mint condition.”

Does anyone have pictures showing the failure? The sacks we have in-house have not shown any damage, but we don’t spend as much time beating them up as teams do.


We ran a 2 week summer camp, used two boxes of sacks and had 7 robots. We had two or three come open in that time. I don’t have a photo, but they all came undone on the edge with the outside seam rather than the internal. By open, I mean just enough that the white beads were able to fall out. We did not have any have more than an inch of stitching undone before we removed them from use.

We also have had one sack have a similar issue. We fixed it so unfortunately we do not have a photo of an open sack. It is just the seam in the sack that opens up.

Like Jeff said.
I had an old vacuum cleaner on standby at 3 days of events this summer.

did you have any of the sacks near any sharp objects?