This is the progression of fan ducts I’ve been designing for #IGentUS . The first one (far left) was made by sighting along a metal ruler and thinking “I’ve got this much space to work with”, then making a first print. Which failed miserably…there was no space for air to flow, and the support was un-removable.
The second print was made using a little more care for making a hollow print, but I forgot I had an extruder(1)…3rd, I forgot it had a shroud, and I carved it up a little to measure for clearance. 4th fit pretty well, only it was lower than the nozzle…obviously a non-starter.
The after a night’s sleep, I realized that…dummy…you HAVE the files for the carriage. Throw in some shapes to account for the hot end and shroud, then make something that’ll work around it.
Which resulted in V6…lord only knows it it’ll actually work as desired, but at least it fits.
The big downside to printing propellant is if your hot end goes over temperature, you’re out a hot end. And a printer. And a house. And maybe a portion of your neighborhood.