Recently I’ve been trying to print some replacement cups for the anemometer on my 1-wire weather station. The existing ones have started to decay quite badly so I thought I’d try to print some replacements using PLA, with a view to using something more robust later on if it goes well.
Well, so far it hasn’t gone well. In the main the cups look great, but the tops of the cups become a real mess because they’re so small that the PLA hasn’t had time to solidify sufficiently by the time the next layer starts.
I tried printing more than one at once, but that didn’t help. I also tried raising the minimum time per layer in Slic3r, but that didn’t help either, I believe because the minimum time is overridden by the minimum print speed. I didn’t particularly want to lower that.
After dithering some time I have decided that what I really need is a cooling fan for the extruded material. There are tapped holes on the hot end carriage that would be suitable and I’m sure I have a fan lying around that would do the job, but unfortunately the controller board for my printer does not have a PWM-controlled fan output and I’d prefer not to have the fan on all the time (especially for the first few layers).
It was suggested that I could just use a fan on a separate PSU and turn it on after the lower layers are complete, but that’s quite a faff and I’d need somewhere suitable to mount a switch. So I decided to bite the bullet and upgrade the controller to an Arduino Mega 2560 and RAMPS. That has now arrived and is sitting on my desk awaiting fitting, which I think will be a holiday job.