A couple years ago I paid a manufacturing company to build a mold for a product I sell. I'm still paying off the small business loan I took out for it, so I can't yet take on anything too expensive and I assume having a mold re-machined is expensive. But rather than assuming, let me ask. Here's the situation:

When having the item designed, we used 3d printing for the prototype, which worked well. The test units from the injection mold were quite a bit thinner. I saw that the difference was that 3d printing makes item "walls" that are fairly thick (depending on the setup, of course), while molding makes the walls exactly the thickness specified in the design. So my molded items are a bit too thin. At the time I felt that it made them feel a little cheap, but still usable/sellable so I didn't ask the manufacturing company to change it. But I do have a few customers reporting that the items are breaking in use. I'm considering whether to approach my manufacturer to have the mold re-machined a little to make the items come out thicker. I know nobody here can give specifics, but would that be a moderate cost or would it cost nearly as much as having a whole new mold machined?

The last couple of runs I requested the parts be made with Nylon 6 plastic, if that helps address the question. Could I solve the issue with a different type of plastic (non-toxic) instead?

Edited to add:. I've read the replies so far and want to thank you guys. I mostly wanted a sanity check before I reached out to the manufacturer, but I know they are the ones to give me the real, detailed answer I need. The replies so far tell me that it is doable, and maybe not too expensive and maybe I can work with them to try different materials instead, first. I'll contact them with my issue and questions.