Fan ducts and “home”

Hi all,
Printing lots of stuff now and feeling reasonably past “total beginner” at this point, due in no small part to help from folks here. So I printed the Feb 2019 “Snapmaker cooling fan duct” by Luke, at Thingiverse with an eye toward seeing if print quality might be improved, etc. Very neat design, I thought. Well, my problem though is that it seems my x and y “home” positions are in pretty violent interference with the duct (I.e., the homed print head comes closer to the front-left corner of the bed plate, than it should, and the duct crashes into the plate). I think if they were adjusted appropriately, then my z “home” position wouldn’t be a problem (which is good, as I’ve had my share of issues with z, previously…). Can anyone direct me to a good tutorial on how to adjust this Home condition?

On the mill, I modified the duct to, um, remove the interference, and I’m actually printing a 2nd duct now, with this modified duct installed. But that seems pretty unsatisfying, for sure. A lot of the ducting is necessarily missing where it probably counts, near the nozzle…

While on the basic topic of these sorts of fan ducts, what do folks think about this in general? Think they’re highly worth it, not so much, somewhere in between? What exactly is felt to be the print improvement if any? Thanks—

By the way, I’m still just using Snapmakerjs control software, if that matters with regard to how to modify the x/y homing condition with respect to the front-left corner of the bed.

Personally I haven’t found the need for one. My prints come out just fine in both PLA and PET-G without any modifications.

I’ve had a few situations where some extra air flow would help. Usually small objects that are growing wider as they get taller. They’re small enough that it can print a new layer before the previous layer has cooled. It’s usually a temporary problem, so I just blow on it.

For the home position, are you using the enclosure? Some people have reported problems with positioning if the enclosure is open.


No, or at least I’m not using the SM-built enclosure (I’ve got a larger enclosed ‘clean hood bench’ type unit I bought at an auction some time back, that is pretty perfect for housing the SM in; so no drafts inside, quiet, etc.). But I think I’ve read about what you’re referring to, re: the front door switch interacting with the unit ‘non-ideally’ in some instances, and such. Your notes about when such a fan duct might help or not is useful, thanks. My 2nd duct that I printed, with the ‘modified’ duct installed, didn’t appear to me to be any better or worse than the 1st one. So, I may take it off in the end.