I’ve seen a number of fan shrouds available currently for the snapmaker, but my question is would you think they are necessary and what purpose would they serve, as the printer seems to be functioning well withing its set parameters with the stock fan/cooler.
Technically there is no part cooler on SnapMaker. The fan on the side is for cooling the extruder so heat from the hotend does not creep up into the extruder and melt the plastic early. The fan on the bottom is cooling the stepper motor which makes it run more reliably. Yes some of the air from these two fans exhausts down onto the part, but that is not the same thing.
A part cooling fan is useful for a few things. One is to cool the plastic while the hotend is “bridging” plastic from one spot on a print to another through the air. This allows the plastic to solidify quickly and not droop as much.
Another is certain types of plastics like PLA have a large “Glass Transition Temperature Range.” I am not an expert on this, but as I understand it there is a range of temperatures where PLA behaves more like taffy than solid plastic. This means that it can get pulled around by the nozzle after it is put down. If the print head goes back over this area before it has cooled out of this temperature range the plastic can warp. This is especially true for smaller prints and layers with small cross sections. (Think the smoke stack on Benchy https://www.thingiverse.com/thing:763622). These layers are so small the layer below it has not solidified yet and the movement of the print head moves the lower layer around.
There are other reasons but these two are the main ones. Knowing when to use a part cooling fan and when not to takes time to learn.
It would be interesting to see one of the “overhang” type benchy parts run with and without the cooling shroud to highlight the usefulness of the shroud.
I wonder if we can get a 40 or 50mm fan to run in sync with the snapmaker by connecting it to the RJ45 module port, as I recall port nº4 is free when 3D printing. Anyone tried that?
That port has 4 stepper motor wires and 2 wires for an end stop. There is nothing for a fan.
what about trying to power it via the usb port?
That would probably imply having the printer hooked up to a pc, as I don’t believe the printer has any cash to store the gcode
You wouldn’t necessarily need a PC hooked up to the printer. The USB port for the memory stick does have power; enough to power a RasPi running Octoprint.