Just a comment about your setup; with the two 5015 blowers, you’re delivering an awful lot of air, definitely more than you need and I fear that you’re going to have to do a lot of experimentation to understand what is the right power (PWM) level for your fans to get a good quality print and I wouldn’t be surprised if you had to set them at 20% or less.
Unfortunately, there aren’t a lot of good (or even poor) references on toolhead cooling design.
After quite a bit of experimentation, I can say there are two important things that make a successful toolhead cooling design:
Have a good seal between the heat sink and the heater block with, ideally, no air being directed downward onto the print. If you have air passing down from the heat sink you’ll have adhesion problems for your first layers, regardless of the material. I’ve found that with essentially no air coming downward from the heat sink, you can print on PEI very reliably without any kind of glue with the model lifting easily once the print bed cools.
Have your part cooling come from at least two directions to eliminate any stringing. You’ve definitely have that going for you.
When you follow these two rules (the first one especially), you’ll find that you will get reliably good print quality over a wide range of materials and temperatures even with supplying a surprisingly modest amount of air.
You have a gorgeous looking toolhead design, but I would suggest that you first look at the seal between the heatsink and heater block first (I’m not sure, but it doesn’t look like there’s any prevention from heatsink cooling air from going downwards onto the print) and then look at part cooling to ensure that you get the best possible quality prints.
I just connect like you said. This second fan has been connected to PC6, M106 S255 in terminal, and… nothing happend, but why ?
I just checked again with 4.2V battery, + to +, - to -, and working…
I checked wiring with original (1st) fan, already in use for part cooling, AND… wiring needed to be reversed… I dont know why, but with this configuration:
Good video, thanx for the link. I don’t know if I totally agree with how he came about his conclusion as he didn’t investigate all the variables, with the big one being that they didn’t work with the Slic3r profile.
I want to reiterate that I found the most important advantage (and reason) for making sure that no air passes from the heatsink fan downwards is for adhesion. Having air flow downwards from the heatsink to the print surface will cause problems with higher temperature filaments.
That doesn’t seem to be a discussion point at all in the video.
Yep, they are both the same polarity, long time ago just changing fan duct and maybe then i just reversed for this one fan, and forgot about this, thats why one fan worked, but this secod just not.
This second needed to be reversed too, and working like a charm! Thanks a lot for help !
