The first layer wasn’t adhered sufficiently to the bed. The print head was merrily depositing further PLA, but the gear was no longer fixed to the bed and was fixed to the print head instead.
Back to Cura, load the model, add a raft, re-slice, and save as g3Drem, then import back into Dremel3D and upload to the printer. After a few minutes, I noticed that the raft wasn’t adhering to the bed. I tried to correct the problem by pulling the non-suck threads out the way .. but they just got entangled in the head, and I ended up with a mess.
“Stop fiddling with it”! I said to myself, and started it again.
The not-quite-stuck filament that you can see on the right was OK, and the raft printed adequately, and after a few minutes, the gears started to emerge.
The final thing looks like this:
There’s a bit of stringy-ness as the print-head moved back to “home”, but I’m satisfied that the raft was a good idea.
The gears separated from the raft cleanly. I mounted them in a frame to try them out, and they work. Play the video below to see them in action.