QIDI rear mounted dual blower for active print cooling

thingiverse

FIRST THING FIRST, this requires a crucial adjustment on the Y-axis to ensure clearance for the blowers and assembly behind the print head. This is vital because when both the build plate is raised all the way up, and the Y-axis is fully extended, there's no clearance between this blower and Z-axis bearings as the X-axis jogs past. The Z-axis bearings are wider than the Z-axis rods, so once the Z-axis bearings are lower than the blower assembly, clearance issues disappear. You can do without the shim if you modify your start script and build plan accordingly, but I strongly recommend the shim personally. Now that's taken care of: This achieves three things I really wanted. Firstly, both print heads have cooling systems in place, so I don't need to constantly switch spools based on cooling needs anymore. Secondly, each print head has its own blower. I found that simply using the stock blower to cool both heads at once was resulting in sub-par cooling and warping issues. Thirdly, REAR MOUNTED. To me, this is way better than obstructing the view of the print via a front-mounted assembly. Bonus features - I opted to use blowers rather than fans because these printers simply don't have enough space to smoothly transition from the large diameter of a fan down to the small diameter cooling ducts. All the cooling assemblies I see that use fans sharply transition to a small set of ducts directly in front of the fan, reducing their capability. Blowers, due to their design, higher static pressure, smaller exit, are better suited for this application of forcing air into these smaller cooling assemblies. That's my take on the situation and I don't have test data to back it up - so take it with a grain of salt. I purchased blowers here: http://www.ebay.com/itm/262351228368?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT They are the same manufacturer and dimensions as the stock QIDI blower. They have slightly higher current draw and probably higher CFM. Also, searching for "24v 5015s blower" will point you in the right direction: The main criteria are: - 50x50x15mm - some are wider than 15mm so be careful - 24v I chose .14 amp blowers while the stock was .11 or .12 from memory. Blowers are simply wired in parallel; plugged into the original QIDI harness. Another note - the two blowers are isolated from each other, so you could use this with only one blower while waiting for another in the mail, or if you simply want a rear-mounted blower. Mounting: tabs interface with the top of the X-axis carriage, but allow translation left & right (along the X-axis). I left it this way as this is my beta product if you will, and in case there were clearance issues. There aren't, and I simply affixed a small piece of double stick foam tape to the same surface as the tabs. This snugs everything up nicely and I didn't even remove the backing to expose the adhesive to the print head carriage. Print Settings Printer: QIDI Rafts: No Supports: Yes Infill: 30% Notes: Supports are important for the overhang at the top of the part. Nothing else needs supports. I used the stock QIDI turbo fan. Infill did not prove to be significant throughout my prototype prints; 30% works fine.