Active Cooling Fan Duct for Replicator 1 / Duplicator 4 / FlashForge

Author: thruit00, published on 2014-04-10

Click this button to get the 3D model


There is a new version of this duct available at thing 537918

Anyways in case you decide to print this version here please carefully read the following information completely:

This active cooling duct is designed to work on the following MK7/MK8/MK9 Dual Extruders:

  • MakerBot Replicator 1
  • FF3DP FlashForge
  • CTC Creator Dual
  • WanHao Duplicator 4 and Duplicator 4X
    (please read the bottom note if you have one of the last 3 listed printers)
    A version for Replicator 2X is a work in progress at thing:298733
    It is based on the great rolling air flow idea and design of SSW :

    Because I had trouble to import his model, I had to draw it from scratch with the following main differences:
  • redirected air outlets to the tip of the nozzles and to the printed model instead to the nozzle body.
  • 2mm less deep (rod to fan front) to allow closed print chamber doors (if they are attached to the outside of the printer) on ABS prints.
  • improved usage of the MK7/8 middle trapezoid rod window for higher air rates
  • target of the outer air ducts redirected more to the back of the nozzle to almost cover 360 degree of cooling.
    Besides the printed duct and the two distance bolts you need a 24V 40x40x10mm fan and two M3x60 hexagon socket screws (or one of the clips mentioned in UPDATE2 later on) to attach it to your extruder block. In addition you need two normal M3 nuts and two M3x15 countersunk head screws. If you have no front door you can use any screw head you want, and you don’t have to read the next sentence. Depending on that and your chosen fan you might need to counterbore the two upper fan holes for a flat finish of the screw heads and your fan front. If your front door is installed inside the window frame (like on Duplicator 4X) and not infront of the frame (like on my modded WanHao Duplicator 4 and CTC printers), you have to modify it to be instaled infront of the frame to gain space for the active cooling.
    UPDATE: low_detail version replaces original stl. Its stl resoltion is rendered to 0.05mm and 5 degree. This should result in a comparable print but requires much less memory to slice.
    UPDATE: Added an additional version _ActiveDuctD4_V1nohole.STL of the duct with removed air way holes which are not required if you install this duct with a clip like the one for Duplictor 4 or CTC/FlashForge
    Important Duplicator 4/FlashForge/CTC note:
    Your installed mighty board is unable to control this fan by default! If you are a soldering expert and aware of the risk of killing your mighty board and losing your warranty, you can solder the missing part Q6 which is a MOS-FET named PSMN7R0-30YL (bought mine on the most famous online auctions platform) and an additional power connector to your mighty board. One of the pictures above show my modified board. Don’t blame me, if you fail on doing that!
    Update: Currently ignore ActiveDuctD4_UN.STL, it is a work in progress and was requested by a 3rd party developer to improve the way the cooling duct is attached to the carriage.
    Disclaimer: All trademarks mentioned belong to their respective owners. Modification of your device might result in a full loss of warranty.


I sliced my duct with Makerware 2.4.1 custom profile and printed it on a Duplicator 4 with Sailfish 7.6 firmware. Normally I prefer to use Simplify3D for slicing but with this model the printed bottom duct shifted layer by layer to the right side. With Makerware I have not had an Issue like this.
Update1: Simplify3D 2.0.1is slicing the latest design/stl now without any issues!
Update2: Simplify3D 2.1.0 crashes when slicing with a layer height of 0.1mm and a random layer start pont enabled. As a workaround you can use a layer height of 0.11mm!
Update3: Simplify3D 2.1.1 slices flawless!
The filament material I suggest to use is ABS if you want to do ABS prints in future because it can stand higher temperatures of the ceramic tape coated hot extrusion heads.
This slicer profile settings I used for my ABS print:

  • Layer height: 0.1mm
  • Shells: 1
  • Infill: 100%
  • Extrusion temp.: 230 degree
  • Heat bed temp.: 90 degree
  • Disabled bridging (will be used anyways)
  • Disabled raft
  • Disabled support
    If you have any kind of active filament cooling which cools the nozzle output without strongly cooling the whole object try to turn it on – even if its ABS! This helps on the bridging details a lot. I’m printing on a special carbon style plate without further adhesion improvements (like glue, abs juice, hair spray, kapton tape, blue tape,…) and haven’t had detaching problems on one of my countless test prints while developing this duct.
    I have not tried, but printing at a layer height of 0.2mm might also help if you have bridging problems you are not able to fix in your custom profile.
    The above pictures of my print were created directly after printing without any reworking and I mounted it as it is to the printer. Except for the color I’m really happy with it 🙂
    Some notes on the modification I did to enable cooling fan control on WanHao MightyBoard:
    First of all – you have to be aware of the risk to destroy your printer and you will lose the warranty for it!
    Because soldering the small SMD chip pins with a soldering iron and risking a short in between I decided to use hot air soldering instead. I heated up the Q6 region carefully to ~280C with the hot air soldering gun, applied no clean flux (tin-solder was already applied at production time, so no additional tin-solder is required), placed the MOS-FET with a backing pump (you could also use a a pair of needle tweezers) and carefully soldered it with hot air at 390C (never directly point the hot air gun on the chip or any other surrounding parts – point it to the MOS-FET ground side and the pins without staying to long at one position). This main soldering step should be finished after a few seconds to not overheat the chip but long enough to get a good soldered connection. At the end the fan power connector can be soldered with a normal soldering iron without any big effort.
    Good luck!

License: Creative Commons – Attribution – Share Alike

Tags: ABS, Active_Cooling, Air, Air_Duct, Blower, Cooling, CTC, Dual_Extruder, Duplicator, Duplicator_4, Extruder, Fan, Fan_Duct, FF3DP, Fillament_Cooling, FlashForge, Flash_Forge, PLA, Rep1, Replicator, Replicator_1, WanHao