UPDATE AUGUST 31, 2021: Nothing changed; just the fact that I'm back.
Hello, I was away for a couple of years due to a bug. Every time I tried to log into my account I got a message "Your account is currently under moderation. If you believe this was done in error, please contact us." ... but gave no way to contact them; and there is no Contact link in the Makerbot Thingverse main page.
So I could not log-in, and did not know who to contact to get the problem resolved.
Over two years!
Yesterday I had the idea of googling "thingverse contact", and lo and behold google found a hidden contact page ... one that ONLY allowed for specific issues to be communicated, such as theft of intellectual property. So I filed a theft of IP complaint just to explain the log-in problem, and it was finally resolved.

UPDATE MAY 31, 2019: The gcode is upgraded to rev 2.2c; the other files remain at 2.2b, as all I'm updating is the gcode generated from the same geometry. This 2.2c gcode file is for PETG, which is a very different animal from PLA; --it's not just temperature differences; it's a whole bunch of settings that must change. I don't have the whole process perfectly optimized yet, and it does generate a lot of cobwebs; but it is pretty good now. Most importantly, the "wires" making up the fan guard print flawlessly. PETG is much better for this than PLA, as PLA is a material that the nozzle has to press down and spread like a spatula, whereas PETG is dropped almost fully liquid onto the model from a greater heigth (no much; in the order of 0.04 mm extra in Z. So with PETG there's no vertical, and almost no horizontal force exercised on the model. (For previous updates, see section Updates History below.)

INTRO:
This is going to be just like the Z-19, except that instead of using the stock model fan as the top fan, it will accept a 5015 or 5115 blower.
For general info what this is for, see the Z-19:
https://www.thingiverse.com/thing:2911981

Why Z-23?
Because the next prime after 19 is 23.

Needless to say, if you like it, don't forget to Like it :-)
And if you make it, don't forget to Make it. ::-))

A big shout of thanks to makkuro, who cutom-made a text customizer for us, which I use to show the name and revision number whenever the revision changes. The custom customizer I'm talking about is here:
https://www.thingiverse.com/thing:3094095