For Christmas I got my wife a WeCreat laser cutter/engraver and soon discovered the 3inch vent line is not the best choice. I desined a 4inch adapter which I hooker up to an additional inline fan. This improves the airflow out of the laser dramatically and results is virtually no smoke smell when ventig the air outside.

I printed this in white PLA and its seems sturdy enough. If PLA doesn't work in the long run I will print the adpater in white PC instead. The adapter is a very tight fit and you will have to adjust the nuts which are under the currnet 3inch exhaust a little to get it ti fit, but once fitted it is totally tight.

Happy lasering.